1/*
   2 *  linux/arch/arm/mm/dma-mapping.c
   3 *
   4 *  Copyright (C) 2000-2004 Russell King
   5 *
   6 * This program is free software; you can redistribute it and/or modify
   7 * it under the terms of the GNU General Public License version 2 as
   8 * published by the Free Software Foundation.
   9 *
  10 *  DMA uncached mapping support.
  11 */
  12#include <linux/bootmem.h>
  13#include <linux/module.h>
  14#include <linux/mm.h>
  15#include <linux/genalloc.h>
  16#include <linux/gfp.h>
  17#include <linux/errno.h>
  18#include <linux/list.h>
  19#include <linux/init.h>
  20#include <linux/device.h>
  21#include <linux/dma-mapping.h>
  22#include <linux/dma-contiguous.h>
  23#include <linux/highmem.h>
  24#include <linux/memblock.h>
  25#include <linux/slab.h>
  26#include <linux/iommu.h>
  27#include <linux/io.h>
  28#include <linux/vmalloc.h>
  29#include <linux/sizes.h>
  30#include <linux/cma.h>
  31
  32#include <asm/memory.h>
  33#include <asm/highmem.h>
  34#include <asm/cacheflush.h>
  35#include <asm/tlbflush.h>
  36#include <asm/mach/arch.h>
  37#include <asm/dma-iommu.h>
  38#include <asm/mach/map.h>
  39#include <asm/system_info.h>
  40#include <asm/dma-contiguous.h>
  41
  42#include "dma.h"
  43#include "mm.h"
  44
  45struct arm_dma_alloc_args {
  46	struct device *dev;
  47	size_t size;
  48	gfp_t gfp;
  49	pgprot_t prot;
  50	const void *caller;
  51	bool want_vaddr;
  52	int coherent_flag;
  53};
  54
  55struct arm_dma_free_args {
  56	struct device *dev;
  57	size_t size;
  58	void *cpu_addr;
  59	struct page *page;
  60	bool want_vaddr;
  61};
  62
  63#define NORMAL	    0
  64#define COHERENT    1
  65
  66struct arm_dma_allocator {
  67	void *(*alloc)(struct arm_dma_alloc_args *args,
  68		       struct page **ret_page);
  69	void (*free)(struct arm_dma_free_args *args);
  70};
  71
  72struct arm_dma_buffer {
  73	struct list_head list;
  74	void *virt;
  75	struct arm_dma_allocator *allocator;
  76};
  77
  78static LIST_HEAD(arm_dma_bufs);
  79static DEFINE_SPINLOCK(arm_dma_bufs_lock);
  80
  81static struct arm_dma_buffer *arm_dma_buffer_find(void *virt)
  82{
  83	struct arm_dma_buffer *buf, *found = NULL;
  84	unsigned long flags;
  85
  86	spin_lock_irqsave(&arm_dma_bufs_lock, flags);
  87	list_for_each_entry(buf, &arm_dma_bufs, list) {
  88		if (buf->virt == virt) {
  89			list_del(&buf->list);
  90			found = buf;
  91			break;
  92		}
  93	}
  94	spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
  95	return found;
  96}
  97
  98/*
  99 * The DMA API is built upon the notion of "buffer ownership".  A buffer
 100 * is either exclusively owned by the CPU (and therefore may be accessed
 101 * by it) or exclusively owned by the DMA device.  These helper functions
 102 * represent the transitions between these two ownership states.
 103 *
 104 * Note, however, that on later ARMs, this notion does not work due to
 105 * speculative prefetches.  We model our approach on the assumption that
 106 * the CPU does do speculative prefetches, which means we clean caches
 107 * before transfers and delay cache invalidation until transfer completion.
 108 *
 109 */
 110static void __dma_page_cpu_to_dev(struct page *, unsigned long,
 111		size_t, enum dma_data_direction);
 112static void __dma_page_dev_to_cpu(struct page *, unsigned long,
 113		size_t, enum dma_data_direction);
 114
 115/**
 116 * arm_dma_map_page - map a portion of a page for streaming DMA
 117 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 118 * @page: page that buffer resides in
 119 * @offset: offset into page for start of buffer
 120 * @size: size of buffer to map
 121 * @dir: DMA transfer direction
 122 *
 123 * Ensure that any data held in the cache is appropriately discarded
 124 * or written back.
 125 *
 126 * The device owns this memory once this call has completed.  The CPU
 127 * can regain ownership by calling dma_unmap_page().
 128 */
 129static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
 130	     unsigned long offset, size_t size, enum dma_data_direction dir,
 131	     unsigned long attrs)
 132{
 133	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 134		__dma_page_cpu_to_dev(page, offset, size, dir);
 135	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 136}
 137
 138static dma_addr_t arm_coherent_dma_map_page(struct device *dev, struct page *page,
 139	     unsigned long offset, size_t size, enum dma_data_direction dir,
 140	     unsigned long attrs)
 141{
 142	return pfn_to_dma(dev, page_to_pfn(page)) + offset;
 143}
 144
 145/**
 146 * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
 147 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 148 * @handle: DMA address of buffer
 149 * @size: size of buffer (same as passed to dma_map_page)
 150 * @dir: DMA transfer direction (same as passed to dma_map_page)
 151 *
 152 * Unmap a page streaming mode DMA translation.  The handle and size
 153 * must match what was provided in the previous dma_map_page() call.
 154 * All other usages are undefined.
 155 *
 156 * After this call, reads by the CPU to the buffer are guaranteed to see
 157 * whatever the device wrote there.
 158 */
 159static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
 160		size_t size, enum dma_data_direction dir, unsigned long attrs)
 161{
 162	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
 163		__dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
 164				      handle & ~PAGE_MASK, size, dir);
 165}
 166
 167static void arm_dma_sync_single_for_cpu(struct device *dev,
 168		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 169{
 170	unsigned int offset = handle & (PAGE_SIZE - 1);
 171	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
 172	__dma_page_dev_to_cpu(page, offset, size, dir);
 173}
 174
 175static void arm_dma_sync_single_for_device(struct device *dev,
 176		dma_addr_t handle, size_t size, enum dma_data_direction dir)
 177{
 178	unsigned int offset = handle & (PAGE_SIZE - 1);
 179	struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
 180	__dma_page_cpu_to_dev(page, offset, size, dir);
 181}
 182
 183static int arm_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 
 
 
 
 
 
 184{
 185	return dma_addr == ARM_MAPPING_ERROR;
 
 
 
 
 
 
 186}
 187
 188const struct dma_map_ops arm_dma_ops = {
 189	.alloc			= arm_dma_alloc,
 190	.free			= arm_dma_free,
 
 
 191	.mmap			= arm_dma_mmap,
 192	.get_sgtable		= arm_dma_get_sgtable,
 193	.map_page		= arm_dma_map_page,
 194	.unmap_page		= arm_dma_unmap_page,
 195	.map_sg			= arm_dma_map_sg,
 196	.unmap_sg		= arm_dma_unmap_sg,
 
 197	.sync_single_for_cpu	= arm_dma_sync_single_for_cpu,
 198	.sync_single_for_device	= arm_dma_sync_single_for_device,
 199	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
 200	.sync_sg_for_device	= arm_dma_sync_sg_for_device,
 201	.mapping_error		= arm_dma_mapping_error,
 202	.dma_supported		= arm_dma_supported,
 
 203};
 204EXPORT_SYMBOL(arm_dma_ops);
 205
 206static void *arm_coherent_dma_alloc(struct device *dev, size_t size,
 207	dma_addr_t *handle, gfp_t gfp, unsigned long attrs);
 208static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,
 209				  dma_addr_t handle, unsigned long attrs);
 210static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 211		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 212		 unsigned long attrs);
 213
 214const struct dma_map_ops arm_coherent_dma_ops = {
 215	.alloc			= arm_coherent_dma_alloc,
 216	.free			= arm_coherent_dma_free,
 
 
 217	.mmap			= arm_coherent_dma_mmap,
 218	.get_sgtable		= arm_dma_get_sgtable,
 219	.map_page		= arm_coherent_dma_map_page,
 220	.map_sg			= arm_dma_map_sg,
 221	.mapping_error		= arm_dma_mapping_error,
 222	.dma_supported		= arm_dma_supported,
 
 223};
 224EXPORT_SYMBOL(arm_coherent_dma_ops);
 225
 226static int __dma_supported(struct device *dev, u64 mask, bool warn)
 227{
 228	unsigned long max_dma_pfn;
 229
 230	/*
 231	 * If the mask allows for more memory than we can address,
 232	 * and we actually have that much memory, then we must
 233	 * indicate that DMA to this device is not supported.
 234	 */
 235	if (sizeof(mask) != sizeof(dma_addr_t) &&
 236	    mask > (dma_addr_t)~0 &&
 237	    dma_to_pfn(dev, ~0) < max_pfn - 1) {
 238		if (warn) {
 239			dev_warn(dev, "Coherent DMA mask %#llx is larger than dma_addr_t allows\n",
 240				 mask);
 241			dev_warn(dev, "Driver did not use or check the return value from dma_set_coherent_mask()?\n");
 242		}
 243		return 0;
 244	}
 245
 246	max_dma_pfn = min(max_pfn, arm_dma_pfn_limit);
 247
 248	/*
 249	 * Translate the device's DMA mask to a PFN limit.  This
 250	 * PFN number includes the page which we can DMA to.
 251	 */
 252	if (dma_to_pfn(dev, mask) < max_dma_pfn) {
 253		if (warn)
 254			dev_warn(dev, "Coherent DMA mask %#llx (pfn %#lx-%#lx) covers a smaller range of system memory than the DMA zone pfn 0x0-%#lx\n",
 255				 mask,
 256				 dma_to_pfn(dev, 0), dma_to_pfn(dev, mask) + 1,
 257				 max_dma_pfn + 1);
 258		return 0;
 259	}
 260
 261	return 1;
 262}
 263
 264static u64 get_coherent_dma_mask(struct device *dev)
 265{
 266	u64 mask = (u64)DMA_BIT_MASK(32);
 267
 268	if (dev) {
 269		mask = dev->coherent_dma_mask;
 270
 271		/*
 272		 * Sanity check the DMA mask - it must be non-zero, and
 273		 * must be able to be satisfied by a DMA allocation.
 274		 */
 275		if (mask == 0) {
 276			dev_warn(dev, "coherent DMA mask is unset\n");
 277			return 0;
 278		}
 279
 280		if (!__dma_supported(dev, mask, true))
 281			return 0;
 282	}
 283
 284	return mask;
 285}
 286
 287static void __dma_clear_buffer(struct page *page, size_t size, int coherent_flag)
 288{
 289	/*
 290	 * Ensure that the allocated pages are zeroed, and that any data
 291	 * lurking in the kernel direct-mapped region is invalidated.
 292	 */
 293	if (PageHighMem(page)) {
 294		phys_addr_t base = __pfn_to_phys(page_to_pfn(page));
 295		phys_addr_t end = base + size;
 296		while (size > 0) {
 297			void *ptr = kmap_atomic(page);
 298			memset(ptr, 0, PAGE_SIZE);
 299			if (coherent_flag != COHERENT)
 300				dmac_flush_range(ptr, ptr + PAGE_SIZE);
 301			kunmap_atomic(ptr);
 302			page++;
 303			size -= PAGE_SIZE;
 304		}
 305		if (coherent_flag != COHERENT)
 306			outer_flush_range(base, end);
 307	} else {
 308		void *ptr = page_address(page);
 309		memset(ptr, 0, size);
 310		if (coherent_flag != COHERENT) {
 311			dmac_flush_range(ptr, ptr + size);
 312			outer_flush_range(__pa(ptr), __pa(ptr) + size);
 313		}
 314	}
 315}
 316
 317/*
 318 * Allocate a DMA buffer for 'dev' of size 'size' using the
 319 * specified gfp mask.  Note that 'size' must be page aligned.
 320 */
 321static struct page *__dma_alloc_buffer(struct device *dev, size_t size,
 322				       gfp_t gfp, int coherent_flag)
 323{
 324	unsigned long order = get_order(size);
 325	struct page *page, *p, *e;
 326
 327	page = alloc_pages(gfp, order);
 328	if (!page)
 329		return NULL;
 330
 331	/*
 332	 * Now split the huge page and free the excess pages
 333	 */
 334	split_page(page, order);
 335	for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
 336		__free_page(p);
 337
 338	__dma_clear_buffer(page, size, coherent_flag);
 339
 340	return page;
 341}
 342
 343/*
 344 * Free a DMA buffer.  'size' must be page aligned.
 345 */
 346static void __dma_free_buffer(struct page *page, size_t size)
 347{
 348	struct page *e = page + (size >> PAGE_SHIFT);
 349
 350	while (page < e) {
 351		__free_page(page);
 352		page++;
 353	}
 354}
 355
 356static void *__alloc_from_contiguous(struct device *dev, size_t size,
 357				     pgprot_t prot, struct page **ret_page,
 358				     const void *caller, bool want_vaddr,
 359				     int coherent_flag, gfp_t gfp);
 360
 361static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
 362				 pgprot_t prot, struct page **ret_page,
 363				 const void *caller, bool want_vaddr);
 364
 365static void *
 366__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
 367	const void *caller)
 368{
 369	/*
 370	 * DMA allocation can be mapped to user space, so lets
 371	 * set VM_USERMAP flags too.
 372	 */
 373	return dma_common_contiguous_remap(page, size,
 374			VM_ARM_DMA_CONSISTENT | VM_USERMAP,
 375			prot, caller);
 376}
 377
 378static void __dma_free_remap(void *cpu_addr, size_t size)
 379{
 380	dma_common_free_remap(cpu_addr, size,
 381			VM_ARM_DMA_CONSISTENT | VM_USERMAP);
 382}
 383
 384#define DEFAULT_DMA_COHERENT_POOL_SIZE	SZ_256K
 385static struct gen_pool *atomic_pool __ro_after_init;
 386
 387static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE;
 388
 389static int __init early_coherent_pool(char *p)
 390{
 391	atomic_pool_size = memparse(p, &p);
 392	return 0;
 393}
 394early_param("coherent_pool", early_coherent_pool);
 395
 396/*
 397 * Initialise the coherent pool for atomic allocations.
 398 */
 399static int __init atomic_pool_init(void)
 400{
 401	pgprot_t prot = pgprot_dmacoherent(PAGE_KERNEL);
 402	gfp_t gfp = GFP_KERNEL | GFP_DMA;
 403	struct page *page;
 404	void *ptr;
 405
 406	atomic_pool = gen_pool_create(PAGE_SHIFT, -1);
 407	if (!atomic_pool)
 408		goto out;
 409	/*
 410	 * The atomic pool is only used for non-coherent allocations
 411	 * so we must pass NORMAL for coherent_flag.
 412	 */
 413	if (dev_get_cma_area(NULL))
 414		ptr = __alloc_from_contiguous(NULL, atomic_pool_size, prot,
 415				      &page, atomic_pool_init, true, NORMAL,
 416				      GFP_KERNEL);
 417	else
 418		ptr = __alloc_remap_buffer(NULL, atomic_pool_size, gfp, prot,
 419					   &page, atomic_pool_init, true);
 420	if (ptr) {
 421		int ret;
 422
 423		ret = gen_pool_add_virt(atomic_pool, (unsigned long)ptr,
 424					page_to_phys(page),
 425					atomic_pool_size, -1);
 426		if (ret)
 427			goto destroy_genpool;
 428
 429		gen_pool_set_algo(atomic_pool,
 430				gen_pool_first_fit_order_align,
 431				NULL);
 432		pr_info("DMA: preallocated %zu KiB pool for atomic coherent allocations\n",
 433		       atomic_pool_size / 1024);
 434		return 0;
 435	}
 436
 437destroy_genpool:
 438	gen_pool_destroy(atomic_pool);
 439	atomic_pool = NULL;
 440out:
 441	pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n",
 442	       atomic_pool_size / 1024);
 443	return -ENOMEM;
 444}
 445/*
 446 * CMA is activated by core_initcall, so we must be called after it.
 447 */
 448postcore_initcall(atomic_pool_init);
 449
 450struct dma_contig_early_reserve {
 451	phys_addr_t base;
 452	unsigned long size;
 453};
 454
 455static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata;
 456
 457static int dma_mmu_remap_num __initdata;
 458
 459void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
 460{
 461	dma_mmu_remap[dma_mmu_remap_num].base = base;
 462	dma_mmu_remap[dma_mmu_remap_num].size = size;
 463	dma_mmu_remap_num++;
 464}
 465
 466void __init dma_contiguous_remap(void)
 467{
 468	int i;
 469	for (i = 0; i < dma_mmu_remap_num; i++) {
 470		phys_addr_t start = dma_mmu_remap[i].base;
 471		phys_addr_t end = start + dma_mmu_remap[i].size;
 472		struct map_desc map;
 473		unsigned long addr;
 474
 475		if (end > arm_lowmem_limit)
 476			end = arm_lowmem_limit;
 477		if (start >= end)
 478			continue;
 479
 480		map.pfn = __phys_to_pfn(start);
 481		map.virtual = __phys_to_virt(start);
 482		map.length = end - start;
 483		map.type = MT_MEMORY_DMA_READY;
 484
 485		/*
 486		 * Clear previous low-memory mapping to ensure that the
 487		 * TLB does not see any conflicting entries, then flush
 488		 * the TLB of the old entries before creating new mappings.
 489		 *
 490		 * This ensures that any speculatively loaded TLB entries
 491		 * (even though they may be rare) can not cause any problems,
 492		 * and ensures that this code is architecturally compliant.
 493		 */
 494		for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
 495		     addr += PMD_SIZE)
 496			pmd_clear(pmd_off_k(addr));
 497
 498		flush_tlb_kernel_range(__phys_to_virt(start),
 499				       __phys_to_virt(end));
 500
 501		iotable_init(&map, 1);
 502	}
 503}
 504
 505static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
 506			    void *data)
 507{
 508	struct page *page = virt_to_page(addr);
 509	pgprot_t prot = *(pgprot_t *)data;
 510
 511	set_pte_ext(pte, mk_pte(page, prot), 0);
 512	return 0;
 513}
 514
 515static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
 516{
 517	unsigned long start = (unsigned long) page_address(page);
 518	unsigned end = start + size;
 519
 520	apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot);
 521	flush_tlb_kernel_range(start, end);
 522}
 523
 524static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
 525				 pgprot_t prot, struct page **ret_page,
 526				 const void *caller, bool want_vaddr)
 527{
 528	struct page *page;
 529	void *ptr = NULL;
 530	/*
 531	 * __alloc_remap_buffer is only called when the device is
 532	 * non-coherent
 533	 */
 534	page = __dma_alloc_buffer(dev, size, gfp, NORMAL);
 535	if (!page)
 536		return NULL;
 537	if (!want_vaddr)
 538		goto out;
 539
 540	ptr = __dma_alloc_remap(page, size, gfp, prot, caller);
 541	if (!ptr) {
 542		__dma_free_buffer(page, size);
 543		return NULL;
 544	}
 545
 546 out:
 547	*ret_page = page;
 548	return ptr;
 549}
 550
 551static void *__alloc_from_pool(size_t size, struct page **ret_page)
 552{
 553	unsigned long val;
 554	void *ptr = NULL;
 555
 556	if (!atomic_pool) {
 557		WARN(1, "coherent pool not initialised!\n");
 558		return NULL;
 559	}
 560
 561	val = gen_pool_alloc(atomic_pool, size);
 562	if (val) {
 563		phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val);
 564
 565		*ret_page = phys_to_page(phys);
 566		ptr = (void *)val;
 567	}
 568
 569	return ptr;
 570}
 571
 572static bool __in_atomic_pool(void *start, size_t size)
 573{
 574	return addr_in_gen_pool(atomic_pool, (unsigned long)start, size);
 575}
 576
 577static int __free_from_pool(void *start, size_t size)
 578{
 579	if (!__in_atomic_pool(start, size))
 580		return 0;
 581
 582	gen_pool_free(atomic_pool, (unsigned long)start, size);
 583
 584	return 1;
 585}
 586
 587static void *__alloc_from_contiguous(struct device *dev, size_t size,
 588				     pgprot_t prot, struct page **ret_page,
 589				     const void *caller, bool want_vaddr,
 590				     int coherent_flag, gfp_t gfp)
 591{
 592	unsigned long order = get_order(size);
 593	size_t count = size >> PAGE_SHIFT;
 594	struct page *page;
 595	void *ptr = NULL;
 596
 597	page = dma_alloc_from_contiguous(dev, count, order, gfp);
 598	if (!page)
 599		return NULL;
 600
 601	__dma_clear_buffer(page, size, coherent_flag);
 602
 603	if (!want_vaddr)
 604		goto out;
 605
 606	if (PageHighMem(page)) {
 607		ptr = __dma_alloc_remap(page, size, GFP_KERNEL, prot, caller);
 608		if (!ptr) {
 609			dma_release_from_contiguous(dev, page, count);
 610			return NULL;
 611		}
 612	} else {
 613		__dma_remap(page, size, prot);
 614		ptr = page_address(page);
 615	}
 616
 617 out:
 618	*ret_page = page;
 619	return ptr;
 620}
 621
 622static void __free_from_contiguous(struct device *dev, struct page *page,
 623				   void *cpu_addr, size_t size, bool want_vaddr)
 624{
 625	if (want_vaddr) {
 626		if (PageHighMem(page))
 627			__dma_free_remap(cpu_addr, size);
 628		else
 629			__dma_remap(page, size, PAGE_KERNEL);
 630	}
 631	dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
 632}
 633
 634static inline pgprot_t __get_dma_pgprot(unsigned long attrs, pgprot_t prot)
 635{
 636	prot = (attrs & DMA_ATTR_WRITE_COMBINE) ?
 637			pgprot_writecombine(prot) :
 638			pgprot_dmacoherent(prot);
 639	return prot;
 640}
 641
 642static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp,
 643				   struct page **ret_page)
 644{
 645	struct page *page;
 646	/* __alloc_simple_buffer is only called when the device is coherent */
 647	page = __dma_alloc_buffer(dev, size, gfp, COHERENT);
 648	if (!page)
 649		return NULL;
 650
 651	*ret_page = page;
 652	return page_address(page);
 653}
 654
 655static void *simple_allocator_alloc(struct arm_dma_alloc_args *args,
 656				    struct page **ret_page)
 657{
 658	return __alloc_simple_buffer(args->dev, args->size, args->gfp,
 659				     ret_page);
 660}
 661
 662static void simple_allocator_free(struct arm_dma_free_args *args)
 663{
 664	__dma_free_buffer(args->page, args->size);
 665}
 666
 667static struct arm_dma_allocator simple_allocator = {
 668	.alloc = simple_allocator_alloc,
 669	.free = simple_allocator_free,
 670};
 671
 672static void *cma_allocator_alloc(struct arm_dma_alloc_args *args,
 673				 struct page **ret_page)
 674{
 675	return __alloc_from_contiguous(args->dev, args->size, args->prot,
 676				       ret_page, args->caller,
 677				       args->want_vaddr, args->coherent_flag,
 678				       args->gfp);
 679}
 680
 681static void cma_allocator_free(struct arm_dma_free_args *args)
 682{
 683	__free_from_contiguous(args->dev, args->page, args->cpu_addr,
 684			       args->size, args->want_vaddr);
 685}
 686
 687static struct arm_dma_allocator cma_allocator = {
 688	.alloc = cma_allocator_alloc,
 689	.free = cma_allocator_free,
 690};
 691
 692static void *pool_allocator_alloc(struct arm_dma_alloc_args *args,
 693				  struct page **ret_page)
 694{
 695	return __alloc_from_pool(args->size, ret_page);
 696}
 697
 698static void pool_allocator_free(struct arm_dma_free_args *args)
 699{
 700	__free_from_pool(args->cpu_addr, args->size);
 701}
 702
 703static struct arm_dma_allocator pool_allocator = {
 704	.alloc = pool_allocator_alloc,
 705	.free = pool_allocator_free,
 706};
 707
 708static void *remap_allocator_alloc(struct arm_dma_alloc_args *args,
 709				   struct page **ret_page)
 710{
 711	return __alloc_remap_buffer(args->dev, args->size, args->gfp,
 712				    args->prot, ret_page, args->caller,
 713				    args->want_vaddr);
 714}
 715
 716static void remap_allocator_free(struct arm_dma_free_args *args)
 717{
 718	if (args->want_vaddr)
 719		__dma_free_remap(args->cpu_addr, args->size);
 720
 721	__dma_free_buffer(args->page, args->size);
 722}
 723
 724static struct arm_dma_allocator remap_allocator = {
 725	.alloc = remap_allocator_alloc,
 726	.free = remap_allocator_free,
 727};
 728
 729static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 730			 gfp_t gfp, pgprot_t prot, bool is_coherent,
 731			 unsigned long attrs, const void *caller)
 732{
 733	u64 mask = get_coherent_dma_mask(dev);
 734	struct page *page = NULL;
 735	void *addr;
 736	bool allowblock, cma;
 737	struct arm_dma_buffer *buf;
 738	struct arm_dma_alloc_args args = {
 739		.dev = dev,
 740		.size = PAGE_ALIGN(size),
 741		.gfp = gfp,
 742		.prot = prot,
 743		.caller = caller,
 744		.want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0),
 745		.coherent_flag = is_coherent ? COHERENT : NORMAL,
 746	};
 747
 748#ifdef CONFIG_DMA_API_DEBUG
 749	u64 limit = (mask + 1) & ~mask;
 750	if (limit && size >= limit) {
 751		dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
 752			size, mask);
 753		return NULL;
 754	}
 755#endif
 756
 757	if (!mask)
 758		return NULL;
 759
 760	buf = kzalloc(sizeof(*buf),
 761		      gfp & ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM));
 762	if (!buf)
 763		return NULL;
 764
 765	if (mask < 0xffffffffULL)
 766		gfp |= GFP_DMA;
 767
 768	/*
 769	 * Following is a work-around (a.k.a. hack) to prevent pages
 770	 * with __GFP_COMP being passed to split_page() which cannot
 771	 * handle them.  The real problem is that this flag probably
 772	 * should be 0 on ARM as it is not supported on this
 773	 * platform; see CONFIG_HUGETLBFS.
 774	 */
 775	gfp &= ~(__GFP_COMP);
 776	args.gfp = gfp;
 777
 778	*handle = ARM_MAPPING_ERROR;
 779	allowblock = gfpflags_allow_blocking(gfp);
 780	cma = allowblock ? dev_get_cma_area(dev) : false;
 781
 782	if (cma)
 783		buf->allocator = &cma_allocator;
 784	else if (is_coherent)
 785		buf->allocator = &simple_allocator;
 786	else if (allowblock)
 787		buf->allocator = &remap_allocator;
 788	else
 789		buf->allocator = &pool_allocator;
 790
 791	addr = buf->allocator->alloc(&args, &page);
 792
 793	if (page) {
 794		unsigned long flags;
 795
 796		*handle = pfn_to_dma(dev, page_to_pfn(page));
 797		buf->virt = args.want_vaddr ? addr : page;
 798
 799		spin_lock_irqsave(&arm_dma_bufs_lock, flags);
 800		list_add(&buf->list, &arm_dma_bufs);
 801		spin_unlock_irqrestore(&arm_dma_bufs_lock, flags);
 802	} else {
 803		kfree(buf);
 804	}
 805
 806	return args.want_vaddr ? addr : page;
 807}
 808
 809/*
 810 * Allocate DMA-coherent memory space and return both the kernel remapped
 811 * virtual and bus address for that space.
 812 */
 813void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 814		    gfp_t gfp, unsigned long attrs)
 815{
 816	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
 817
 818	return __dma_alloc(dev, size, handle, gfp, prot, false,
 819			   attrs, __builtin_return_address(0));
 820}
 821
 822static void *arm_coherent_dma_alloc(struct device *dev, size_t size,
 823	dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
 824{
 825	return __dma_alloc(dev, size, handle, gfp, PAGE_KERNEL, true,
 826			   attrs, __builtin_return_address(0));
 827}
 828
 829static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 830		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 831		 unsigned long attrs)
 832{
 833	int ret;
 834	unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
 835	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
 836	unsigned long pfn = dma_to_pfn(dev, dma_addr);
 837	unsigned long off = vma->vm_pgoff;
 838
 839	if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
 840		return ret;
 841
 842	if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
 843		ret = remap_pfn_range(vma, vma->vm_start,
 844				      pfn + off,
 845				      vma->vm_end - vma->vm_start,
 846				      vma->vm_page_prot);
 847	}
 848
 849	return ret;
 850}
 851
 852/*
 853 * Create userspace mapping for the DMA-coherent memory.
 854 */
 855static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 856		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 857		 unsigned long attrs)
 858{
 859	return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
 860}
 861
 862int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 863		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 864		 unsigned long attrs)
 865{
 866	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
 867	return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
 868}
 869
 870/*
 871 * Free a buffer as defined by the above mapping.
 872 */
 873static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 874			   dma_addr_t handle, unsigned long attrs,
 875			   bool is_coherent)
 876{
 877	struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
 878	struct arm_dma_buffer *buf;
 879	struct arm_dma_free_args args = {
 880		.dev = dev,
 881		.size = PAGE_ALIGN(size),
 882		.cpu_addr = cpu_addr,
 883		.page = page,
 884		.want_vaddr = ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0),
 885	};
 886
 887	buf = arm_dma_buffer_find(cpu_addr);
 888	if (WARN(!buf, "Freeing invalid buffer %p\n", cpu_addr))
 889		return;
 890
 891	buf->allocator->free(&args);
 892	kfree(buf);
 893}
 894
 895void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 896		  dma_addr_t handle, unsigned long attrs)
 897{
 898	__arm_dma_free(dev, size, cpu_addr, handle, attrs, false);
 899}
 900
 901static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr,
 902				  dma_addr_t handle, unsigned long attrs)
 903{
 904	__arm_dma_free(dev, size, cpu_addr, handle, attrs, true);
 905}
 906
 907/*
 908 * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems
 909 * that the intention is to allow exporting memory allocated via the
 910 * coherent DMA APIs through the dma_buf API, which only accepts a
 911 * scattertable.  This presents a couple of problems:
 912 * 1. Not all memory allocated via the coherent DMA APIs is backed by
 913 *    a struct page
 914 * 2. Passing coherent DMA memory into the streaming APIs is not allowed
 915 *    as we will try to flush the memory through a different alias to that
 916 *    actually being used (and the flushes are redundant.)
 917 */
 918int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
 919		 void *cpu_addr, dma_addr_t handle, size_t size,
 920		 unsigned long attrs)
 921{
 922	unsigned long pfn = dma_to_pfn(dev, handle);
 923	struct page *page;
 924	int ret;
 925
 926	/* If the PFN is not valid, we do not have a struct page */
 927	if (!pfn_valid(pfn))
 928		return -ENXIO;
 929
 930	page = pfn_to_page(pfn);
 931
 932	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
 933	if (unlikely(ret))
 934		return ret;
 935
 936	sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
 937	return 0;
 938}
 939
 940static void dma_cache_maint_page(struct page *page, unsigned long offset,
 941	size_t size, enum dma_data_direction dir,
 942	void (*op)(const void *, size_t, int))
 943{
 944	unsigned long pfn;
 945	size_t left = size;
 946
 947	pfn = page_to_pfn(page) + offset / PAGE_SIZE;
 948	offset %= PAGE_SIZE;
 949
 950	/*
 951	 * A single sg entry may refer to multiple physically contiguous
 952	 * pages.  But we still need to process highmem pages individually.
 953	 * If highmem is not configured then the bulk of this loop gets
 954	 * optimized out.
 955	 */
 956	do {
 957		size_t len = left;
 958		void *vaddr;
 959
 960		page = pfn_to_page(pfn);
 961
 962		if (PageHighMem(page)) {
 963			if (len + offset > PAGE_SIZE)
 964				len = PAGE_SIZE - offset;
 965
 966			if (cache_is_vipt_nonaliasing()) {
 967				vaddr = kmap_atomic(page);
 968				op(vaddr + offset, len, dir);
 969				kunmap_atomic(vaddr);
 970			} else {
 971				vaddr = kmap_high_get(page);
 972				if (vaddr) {
 973					op(vaddr + offset, len, dir);
 974					kunmap_high(page);
 975				}
 976			}
 977		} else {
 978			vaddr = page_address(page) + offset;
 979			op(vaddr, len, dir);
 980		}
 981		offset = 0;
 982		pfn++;
 983		left -= len;
 984	} while (left);
 985}
 986
 987/*
 988 * Make an area consistent for devices.
 989 * Note: Drivers should NOT use this function directly, as it will break
 990 * platforms with CONFIG_DMABOUNCE.
 991 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
 992 */
 993static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
 994	size_t size, enum dma_data_direction dir)
 995{
 996	phys_addr_t paddr;
 997
 998	dma_cache_maint_page(page, off, size, dir, dmac_map_area);
 999
1000	paddr = page_to_phys(page) + off;
1001	if (dir == DMA_FROM_DEVICE) {
1002		outer_inv_range(paddr, paddr + size);
1003	} else {
1004		outer_clean_range(paddr, paddr + size);
1005	}
1006	/* FIXME: non-speculating: flush on bidirectional mappings? */
1007}
1008
1009static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
1010	size_t size, enum dma_data_direction dir)
1011{
1012	phys_addr_t paddr = page_to_phys(page) + off;
1013
1014	/* FIXME: non-speculating: not required */
1015	/* in any case, don't bother invalidating if DMA to device */
1016	if (dir != DMA_TO_DEVICE) {
1017		outer_inv_range(paddr, paddr + size);
1018
1019		dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
1020	}
1021
1022	/*
1023	 * Mark the D-cache clean for these pages to avoid extra flushing.
1024	 */
1025	if (dir != DMA_TO_DEVICE && size >= PAGE_SIZE) {
1026		unsigned long pfn;
1027		size_t left = size;
1028
1029		pfn = page_to_pfn(page) + off / PAGE_SIZE;
1030		off %= PAGE_SIZE;
1031		if (off) {
1032			pfn++;
1033			left -= PAGE_SIZE - off;
1034		}
1035		while (left >= PAGE_SIZE) {
1036			page = pfn_to_page(pfn++);
1037			set_bit(PG_dcache_clean, &page->flags);
1038			left -= PAGE_SIZE;
1039		}
1040	}
1041}
1042
1043/**
1044 * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
1045 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
1046 * @sg: list of buffers
1047 * @nents: number of buffers to map
1048 * @dir: DMA transfer direction
1049 *
1050 * Map a set of buffers described by scatterlist in streaming mode for DMA.
1051 * This is the scatter-gather version of the dma_map_single interface.
1052 * Here the scatter gather list elements are each tagged with the
1053 * appropriate dma address and length.  They are obtained via
1054 * sg_dma_{address,length}.
1055 *
1056 * Device ownership issues as mentioned for dma_map_single are the same
1057 * here.
1058 */
1059int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
1060		enum dma_data_direction dir, unsigned long attrs)
1061{
1062	const struct dma_map_ops *ops = get_dma_ops(dev);
1063	struct scatterlist *s;
1064	int i, j;
1065
1066	for_each_sg(sg, s, nents, i) {
1067#ifdef CONFIG_NEED_SG_DMA_LENGTH
1068		s->dma_length = s->length;
1069#endif
1070		s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
1071						s->length, dir, attrs);
1072		if (dma_mapping_error(dev, s->dma_address))
1073			goto bad_mapping;
1074	}
1075	return nents;
1076
1077 bad_mapping:
1078	for_each_sg(sg, s, i, j)
1079		ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
1080	return 0;
1081}
1082
1083/**
1084 * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
1085 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
1086 * @sg: list of buffers
1087 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
1088 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1089 *
1090 * Unmap a set of streaming mode DMA translations.  Again, CPU access
1091 * rules concerning calls here are the same as for dma_unmap_single().
1092 */
1093void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
1094		enum dma_data_direction dir, unsigned long attrs)
1095{
1096	const struct dma_map_ops *ops = get_dma_ops(dev);
1097	struct scatterlist *s;
1098
1099	int i;
1100
1101	for_each_sg(sg, s, nents, i)
1102		ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
1103}
1104
1105/**
1106 * arm_dma_sync_sg_for_cpu
1107 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
1108 * @sg: list of buffers
1109 * @nents: number of buffers to map (returned from dma_map_sg)
1110 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1111 */
1112void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1113			int nents, enum dma_data_direction dir)
1114{
1115	const struct dma_map_ops *ops = get_dma_ops(dev);
1116	struct scatterlist *s;
1117	int i;
1118
1119	for_each_sg(sg, s, nents, i)
1120		ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length,
1121					 dir);
1122}
1123
1124/**
1125 * arm_dma_sync_sg_for_device
1126 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
1127 * @sg: list of buffers
1128 * @nents: number of buffers to map (returned from dma_map_sg)
1129 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1130 */
1131void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1132			int nents, enum dma_data_direction dir)
1133{
1134	const struct dma_map_ops *ops = get_dma_ops(dev);
1135	struct scatterlist *s;
1136	int i;
1137
1138	for_each_sg(sg, s, nents, i)
1139		ops->sync_single_for_device(dev, sg_dma_address(s), s->length,
1140					    dir);
1141}
1142
1143/*
1144 * Return whether the given device DMA address mask can be supported
1145 * properly.  For example, if your device can only drive the low 24-bits
1146 * during bus mastering, then you would pass 0x00ffffff as the mask
1147 * to this function.
1148 */
1149int arm_dma_supported(struct device *dev, u64 mask)
1150{
1151	return __dma_supported(dev, mask, false);
1152}
1153
1154#define PREALLOC_DMA_DEBUG_ENTRIES	4096
1155
1156static int __init dma_debug_do_init(void)
1157{
1158	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
1159	return 0;
 
 
 
 
 
 
 
 
1160}
1161core_initcall(dma_debug_do_init);
1162
1163#ifdef CONFIG_ARM_DMA_USE_IOMMU
1164
1165static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)
1166{
1167	int prot = 0;
1168
1169	if (attrs & DMA_ATTR_PRIVILEGED)
1170		prot |= IOMMU_PRIV;
1171
1172	switch (dir) {
1173	case DMA_BIDIRECTIONAL:
1174		return prot | IOMMU_READ | IOMMU_WRITE;
1175	case DMA_TO_DEVICE:
1176		return prot | IOMMU_READ;
1177	case DMA_FROM_DEVICE:
1178		return prot | IOMMU_WRITE;
1179	default:
1180		return prot;
1181	}
1182}
1183
1184/* IOMMU */
1185
1186static int extend_iommu_mapping(struct dma_iommu_mapping *mapping);
1187
1188static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
1189				      size_t size)
1190{
1191	unsigned int order = get_order(size);
1192	unsigned int align = 0;
1193	unsigned int count, start;
1194	size_t mapping_size = mapping->bits << PAGE_SHIFT;
1195	unsigned long flags;
1196	dma_addr_t iova;
1197	int i;
1198
1199	if (order > CONFIG_ARM_DMA_IOMMU_ALIGNMENT)
1200		order = CONFIG_ARM_DMA_IOMMU_ALIGNMENT;
1201
1202	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
1203	align = (1 << order) - 1;
1204
1205	spin_lock_irqsave(&mapping->lock, flags);
1206	for (i = 0; i < mapping->nr_bitmaps; i++) {
1207		start = bitmap_find_next_zero_area(mapping->bitmaps[i],
1208				mapping->bits, 0, count, align);
1209
1210		if (start > mapping->bits)
1211			continue;
1212
1213		bitmap_set(mapping->bitmaps[i], start, count);
1214		break;
1215	}
1216
1217	/*
1218	 * No unused range found. Try to extend the existing mapping
1219	 * and perform a second attempt to reserve an IO virtual
1220	 * address range of size bytes.
1221	 */
1222	if (i == mapping->nr_bitmaps) {
1223		if (extend_iommu_mapping(mapping)) {
1224			spin_unlock_irqrestore(&mapping->lock, flags);
1225			return ARM_MAPPING_ERROR;
1226		}
1227
1228		start = bitmap_find_next_zero_area(mapping->bitmaps[i],
1229				mapping->bits, 0, count, align);
1230
1231		if (start > mapping->bits) {
1232			spin_unlock_irqrestore(&mapping->lock, flags);
1233			return ARM_MAPPING_ERROR;
1234		}
1235
1236		bitmap_set(mapping->bitmaps[i], start, count);
1237	}
1238	spin_unlock_irqrestore(&mapping->lock, flags);
1239
1240	iova = mapping->base + (mapping_size * i);
1241	iova += start << PAGE_SHIFT;
1242
1243	return iova;
1244}
1245
1246static inline void __free_iova(struct dma_iommu_mapping *mapping,
1247			       dma_addr_t addr, size_t size)
1248{
1249	unsigned int start, count;
1250	size_t mapping_size = mapping->bits << PAGE_SHIFT;
1251	unsigned long flags;
1252	dma_addr_t bitmap_base;
1253	u32 bitmap_index;
1254
1255	if (!size)
1256		return;
1257
1258	bitmap_index = (u32) (addr - mapping->base) / (u32) mapping_size;
1259	BUG_ON(addr < mapping->base || bitmap_index > mapping->extensions);
1260
1261	bitmap_base = mapping->base + mapping_size * bitmap_index;
1262
1263	start = (addr - bitmap_base) >>	PAGE_SHIFT;
1264
1265	if (addr + size > bitmap_base + mapping_size) {
1266		/*
1267		 * The address range to be freed reaches into the iova
1268		 * range of the next bitmap. This should not happen as
1269		 * we don't allow this in __alloc_iova (at the
1270		 * moment).
1271		 */
1272		BUG();
1273	} else
1274		count = size >> PAGE_SHIFT;
1275
1276	spin_lock_irqsave(&mapping->lock, flags);
1277	bitmap_clear(mapping->bitmaps[bitmap_index], start, count);
1278	spin_unlock_irqrestore(&mapping->lock, flags);
1279}
1280
1281/* We'll try 2M, 1M, 64K, and finally 4K; array must end with 0! */
1282static const int iommu_order_array[] = { 9, 8, 4, 0 };
1283
1284static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
1285					  gfp_t gfp, unsigned long attrs,
1286					  int coherent_flag)
1287{
1288	struct page **pages;
1289	int count = size >> PAGE_SHIFT;
1290	int array_size = count * sizeof(struct page *);
1291	int i = 0;
1292	int order_idx = 0;
1293
1294	if (array_size <= PAGE_SIZE)
1295		pages = kzalloc(array_size, GFP_KERNEL);
1296	else
1297		pages = vzalloc(array_size);
1298	if (!pages)
1299		return NULL;
1300
1301	if (attrs & DMA_ATTR_FORCE_CONTIGUOUS)
1302	{
1303		unsigned long order = get_order(size);
1304		struct page *page;
1305
1306		page = dma_alloc_from_contiguous(dev, count, order, gfp);
 
1307		if (!page)
1308			goto error;
1309
1310		__dma_clear_buffer(page, size, coherent_flag);
1311
1312		for (i = 0; i < count; i++)
1313			pages[i] = page + i;
1314
1315		return pages;
1316	}
1317
1318	/* Go straight to 4K chunks if caller says it's OK. */
1319	if (attrs & DMA_ATTR_ALLOC_SINGLE_PAGES)
1320		order_idx = ARRAY_SIZE(iommu_order_array) - 1;
1321
1322	/*
1323	 * IOMMU can map any pages, so himem can also be used here
1324	 */
1325	gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
1326
1327	while (count) {
1328		int j, order;
1329
1330		order = iommu_order_array[order_idx];
1331
1332		/* Drop down when we get small */
1333		if (__fls(count) < order) {
1334			order_idx++;
1335			continue;
1336		}
1337
1338		if (order) {
1339			/* See if it's easy to allocate a high-order chunk */
1340			pages[i] = alloc_pages(gfp | __GFP_NORETRY, order);
1341
1342			/* Go down a notch at first sign of pressure */
1343			if (!pages[i]) {
1344				order_idx++;
1345				continue;
1346			}
1347		} else {
1348			pages[i] = alloc_pages(gfp, 0);
1349			if (!pages[i])
1350				goto error;
1351		}
1352
1353		if (order) {
1354			split_page(pages[i], order);
1355			j = 1 << order;
1356			while (--j)
1357				pages[i + j] = pages[i] + j;
1358		}
1359
1360		__dma_clear_buffer(pages[i], PAGE_SIZE << order, coherent_flag);
1361		i += 1 << order;
1362		count -= 1 << order;
1363	}
1364
1365	return pages;
1366error:
1367	while (i--)
1368		if (pages[i])
1369			__free_pages(pages[i], 0);
1370	kvfree(pages);
1371	return NULL;
1372}
1373
1374static int __iommu_free_buffer(struct device *dev, struct page **pages,
1375			       size_t size, unsigned long attrs)
1376{
1377	int count = size >> PAGE_SHIFT;
1378	int i;
1379
1380	if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
1381		dma_release_from_contiguous(dev, pages[0], count);
1382	} else {
1383		for (i = 0; i < count; i++)
1384			if (pages[i])
1385				__free_pages(pages[i], 0);
1386	}
1387
1388	kvfree(pages);
1389	return 0;
1390}
1391
1392/*
1393 * Create a CPU mapping for a specified pages
1394 */
1395static void *
1396__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
1397		    const void *caller)
1398{
1399	return dma_common_pages_remap(pages, size,
1400			VM_ARM_DMA_CONSISTENT | VM_USERMAP, prot, caller);
1401}
1402
1403/*
1404 * Create a mapping in device IO address space for specified pages
1405 */
1406static dma_addr_t
1407__iommu_create_mapping(struct device *dev, struct page **pages, size_t size,
1408		       unsigned long attrs)
1409{
1410	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1411	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
1412	dma_addr_t dma_addr, iova;
1413	int i;
1414
1415	dma_addr = __alloc_iova(mapping, size);
1416	if (dma_addr == ARM_MAPPING_ERROR)
1417		return dma_addr;
1418
1419	iova = dma_addr;
1420	for (i = 0; i < count; ) {
1421		int ret;
1422
1423		unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
1424		phys_addr_t phys = page_to_phys(pages[i]);
1425		unsigned int len, j;
1426
1427		for (j = i + 1; j < count; j++, next_pfn++)
1428			if (page_to_pfn(pages[j]) != next_pfn)
1429				break;
1430
1431		len = (j - i) << PAGE_SHIFT;
1432		ret = iommu_map(mapping->domain, iova, phys, len,
1433				__dma_info_to_prot(DMA_BIDIRECTIONAL, attrs));
1434		if (ret < 0)
1435			goto fail;
1436		iova += len;
1437		i = j;
1438	}
1439	return dma_addr;
1440fail:
1441	iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
1442	__free_iova(mapping, dma_addr, size);
1443	return ARM_MAPPING_ERROR;
1444}
1445
1446static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
1447{
1448	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1449
1450	/*
1451	 * add optional in-page offset from iova to size and align
1452	 * result to page size
1453	 */
1454	size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
1455	iova &= PAGE_MASK;
1456
1457	iommu_unmap(mapping->domain, iova, size);
1458	__free_iova(mapping, iova, size);
1459	return 0;
1460}
1461
1462static struct page **__atomic_get_pages(void *addr)
1463{
1464	struct page *page;
1465	phys_addr_t phys;
1466
1467	phys = gen_pool_virt_to_phys(atomic_pool, (unsigned long)addr);
1468	page = phys_to_page(phys);
1469
1470	return (struct page **)page;
1471}
1472
1473static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
1474{
1475	struct vm_struct *area;
1476
1477	if (__in_atomic_pool(cpu_addr, PAGE_SIZE))
1478		return __atomic_get_pages(cpu_addr);
1479
1480	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
1481		return cpu_addr;
1482
1483	area = find_vm_area(cpu_addr);
1484	if (area && (area->flags & VM_ARM_DMA_CONSISTENT))
1485		return area->pages;
1486	return NULL;
1487}
1488
1489static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
1490				  dma_addr_t *handle, int coherent_flag,
1491				  unsigned long attrs)
1492{
1493	struct page *page;
1494	void *addr;
1495
1496	if (coherent_flag  == COHERENT)
1497		addr = __alloc_simple_buffer(dev, size, gfp, &page);
1498	else
1499		addr = __alloc_from_pool(size, &page);
1500	if (!addr)
1501		return NULL;
1502
1503	*handle = __iommu_create_mapping(dev, &page, size, attrs);
1504	if (*handle == ARM_MAPPING_ERROR)
1505		goto err_mapping;
1506
1507	return addr;
1508
1509err_mapping:
1510	__free_from_pool(addr, size);
1511	return NULL;
1512}
1513
1514static void __iommu_free_atomic(struct device *dev, void *cpu_addr,
1515			dma_addr_t handle, size_t size, int coherent_flag)
1516{
1517	__iommu_remove_mapping(dev, handle, size);
1518	if (coherent_flag == COHERENT)
1519		__dma_free_buffer(virt_to_page(cpu_addr), size);
1520	else
1521		__free_from_pool(cpu_addr, size);
1522}
1523
1524static void *__arm_iommu_alloc_attrs(struct device *dev, size_t size,
1525	    dma_addr_t *handle, gfp_t gfp, unsigned long attrs,
1526	    int coherent_flag)
1527{
1528	pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL);
1529	struct page **pages;
1530	void *addr = NULL;
1531
1532	*handle = ARM_MAPPING_ERROR;
1533	size = PAGE_ALIGN(size);
1534
1535	if (coherent_flag  == COHERENT || !gfpflags_allow_blocking(gfp))
1536		return __iommu_alloc_simple(dev, size, gfp, handle,
1537					    coherent_flag, attrs);
1538
1539	/*
1540	 * Following is a work-around (a.k.a. hack) to prevent pages
1541	 * with __GFP_COMP being passed to split_page() which cannot
1542	 * handle them.  The real problem is that this flag probably
1543	 * should be 0 on ARM as it is not supported on this
1544	 * platform; see CONFIG_HUGETLBFS.
1545	 */
1546	gfp &= ~(__GFP_COMP);
1547
1548	pages = __iommu_alloc_buffer(dev, size, gfp, attrs, coherent_flag);
1549	if (!pages)
1550		return NULL;
1551
1552	*handle = __iommu_create_mapping(dev, pages, size, attrs);
1553	if (*handle == ARM_MAPPING_ERROR)
1554		goto err_buffer;
1555
1556	if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
1557		return pages;
1558
1559	addr = __iommu_alloc_remap(pages, size, gfp, prot,
1560				   __builtin_return_address(0));
1561	if (!addr)
1562		goto err_mapping;
1563
1564	return addr;
1565
1566err_mapping:
1567	__iommu_remove_mapping(dev, *handle, size);
1568err_buffer:
1569	__iommu_free_buffer(dev, pages, size, attrs);
1570	return NULL;
1571}
1572
1573static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
1574	    dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
1575{
1576	return __arm_iommu_alloc_attrs(dev, size, handle, gfp, attrs, NORMAL);
1577}
1578
1579static void *arm_coherent_iommu_alloc_attrs(struct device *dev, size_t size,
1580		    dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
1581{
1582	return __arm_iommu_alloc_attrs(dev, size, handle, gfp, attrs, COHERENT);
1583}
1584
1585static int __arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
1586		    void *cpu_addr, dma_addr_t dma_addr, size_t size,
1587		    unsigned long attrs)
1588{
1589	unsigned long uaddr = vma->vm_start;
1590	unsigned long usize = vma->vm_end - vma->vm_start;
1591	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
1592	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
1593	unsigned long off = vma->vm_pgoff;
1594
1595	if (!pages)
1596		return -ENXIO;
1597
1598	if (off >= nr_pages || (usize >> PAGE_SHIFT) > nr_pages - off)
1599		return -ENXIO;
1600
1601	pages += off;
1602
1603	do {
1604		int ret = vm_insert_page(vma, uaddr, *pages++);
1605		if (ret) {
1606			pr_err("Remapping memory failed: %d\n", ret);
1607			return ret;
1608		}
1609		uaddr += PAGE_SIZE;
1610		usize -= PAGE_SIZE;
1611	} while (usize > 0);
1612
1613	return 0;
1614}
1615static int arm_iommu_mmap_attrs(struct device *dev,
1616		struct vm_area_struct *vma, void *cpu_addr,
1617		dma_addr_t dma_addr, size_t size, unsigned long attrs)
1618{
1619	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
1620
1621	return __arm_iommu_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, attrs);
1622}
1623
1624static int arm_coherent_iommu_mmap_attrs(struct device *dev,
1625		struct vm_area_struct *vma, void *cpu_addr,
1626		dma_addr_t dma_addr, size_t size, unsigned long attrs)
1627{
1628	return __arm_iommu_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, attrs);
1629}
1630
1631/*
1632 * free a page as defined by the above mapping.
1633 * Must not be called with IRQs disabled.
1634 */
1635void __arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
1636	dma_addr_t handle, unsigned long attrs, int coherent_flag)
1637{
1638	struct page **pages;
1639	size = PAGE_ALIGN(size);
1640
1641	if (coherent_flag == COHERENT || __in_atomic_pool(cpu_addr, size)) {
1642		__iommu_free_atomic(dev, cpu_addr, handle, size, coherent_flag);
1643		return;
1644	}
1645
1646	pages = __iommu_get_pages(cpu_addr, attrs);
1647	if (!pages) {
1648		WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
1649		return;
1650	}
1651
1652	if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) == 0) {
1653		dma_common_free_remap(cpu_addr, size,
1654			VM_ARM_DMA_CONSISTENT | VM_USERMAP);
1655	}
1656
1657	__iommu_remove_mapping(dev, handle, size);
1658	__iommu_free_buffer(dev, pages, size, attrs);
1659}
1660
1661void arm_iommu_free_attrs(struct device *dev, size_t size,
1662		    void *cpu_addr, dma_addr_t handle, unsigned long attrs)
 
1663{
1664	__arm_iommu_free_attrs(dev, size, cpu_addr, handle, attrs, NORMAL);
1665}
1666
1667void arm_coherent_iommu_free_attrs(struct device *dev, size_t size,
1668		    void *cpu_addr, dma_addr_t handle, unsigned long attrs)
1669{
1670	__arm_iommu_free_attrs(dev, size, cpu_addr, handle, attrs, COHERENT);
1671}
1672
1673static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
1674				 void *cpu_addr, dma_addr_t dma_addr,
1675				 size_t size, unsigned long attrs)
1676{
1677	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
1678	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
1679
1680	if (!pages)
1681		return -ENXIO;
1682
1683	return sg_alloc_table_from_pages(sgt, pages, count, 0, size,
1684					 GFP_KERNEL);
1685}
1686
1687/*
1688 * Map a part of the scatter-gather list into contiguous io address space
1689 */
1690static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
1691			  size_t size, dma_addr_t *handle,
1692			  enum dma_data_direction dir, unsigned long attrs,
1693			  bool is_coherent)
1694{
1695	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1696	dma_addr_t iova, iova_base;
1697	int ret = 0;
1698	unsigned int count;
1699	struct scatterlist *s;
1700	int prot;
1701
1702	size = PAGE_ALIGN(size);
1703	*handle = ARM_MAPPING_ERROR;
1704
1705	iova_base = iova = __alloc_iova(mapping, size);
1706	if (iova == ARM_MAPPING_ERROR)
1707		return -ENOMEM;
1708
1709	for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) {
1710		phys_addr_t phys = page_to_phys(sg_page(s));
1711		unsigned int len = PAGE_ALIGN(s->offset + s->length);
1712
1713		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
1714			__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1715
1716		prot = __dma_info_to_prot(dir, attrs);
1717
1718		ret = iommu_map(mapping->domain, iova, phys, len, prot);
1719		if (ret < 0)
1720			goto fail;
1721		count += len >> PAGE_SHIFT;
1722		iova += len;
1723	}
1724	*handle = iova_base;
1725
1726	return 0;
1727fail:
1728	iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
1729	__free_iova(mapping, iova_base, size);
1730	return ret;
1731}
1732
1733static int __iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
1734		     enum dma_data_direction dir, unsigned long attrs,
1735		     bool is_coherent)
1736{
1737	struct scatterlist *s = sg, *dma = sg, *start = sg;
1738	int i, count = 0;
1739	unsigned int offset = s->offset;
1740	unsigned int size = s->offset + s->length;
1741	unsigned int max = dma_get_max_seg_size(dev);
1742
1743	for (i = 1; i < nents; i++) {
1744		s = sg_next(s);
1745
1746		s->dma_address = ARM_MAPPING_ERROR;
1747		s->dma_length = 0;
1748
1749		if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
1750			if (__map_sg_chunk(dev, start, size, &dma->dma_address,
1751			    dir, attrs, is_coherent) < 0)
1752				goto bad_mapping;
1753
1754			dma->dma_address += offset;
1755			dma->dma_length = size - offset;
1756
1757			size = offset = s->offset;
1758			start = s;
1759			dma = sg_next(dma);
1760			count += 1;
1761		}
1762		size += s->length;
1763	}
1764	if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir, attrs,
1765		is_coherent) < 0)
1766		goto bad_mapping;
1767
1768	dma->dma_address += offset;
1769	dma->dma_length = size - offset;
1770
1771	return count+1;
1772
1773bad_mapping:
1774	for_each_sg(sg, s, count, i)
1775		__iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
1776	return 0;
1777}
1778
1779/**
1780 * arm_coherent_iommu_map_sg - map a set of SG buffers for streaming mode DMA
1781 * @dev: valid struct device pointer
1782 * @sg: list of buffers
1783 * @nents: number of buffers to map
1784 * @dir: DMA transfer direction
1785 *
1786 * Map a set of i/o coherent buffers described by scatterlist in streaming
1787 * mode for DMA. The scatter gather list elements are merged together (if
1788 * possible) and tagged with the appropriate dma address and length. They are
1789 * obtained via sg_dma_{address,length}.
1790 */
1791int arm_coherent_iommu_map_sg(struct device *dev, struct scatterlist *sg,
1792		int nents, enum dma_data_direction dir, unsigned long attrs)
1793{
1794	return __iommu_map_sg(dev, sg, nents, dir, attrs, true);
1795}
1796
1797/**
1798 * arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA
1799 * @dev: valid struct device pointer
1800 * @sg: list of buffers
1801 * @nents: number of buffers to map
1802 * @dir: DMA transfer direction
1803 *
1804 * Map a set of buffers described by scatterlist in streaming mode for DMA.
1805 * The scatter gather list elements are merged together (if possible) and
1806 * tagged with the appropriate dma address and length. They are obtained via
1807 * sg_dma_{address,length}.
1808 */
1809int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg,
1810		int nents, enum dma_data_direction dir, unsigned long attrs)
1811{
1812	return __iommu_map_sg(dev, sg, nents, dir, attrs, false);
1813}
1814
1815static void __iommu_unmap_sg(struct device *dev, struct scatterlist *sg,
1816		int nents, enum dma_data_direction dir,
1817		unsigned long attrs, bool is_coherent)
1818{
1819	struct scatterlist *s;
1820	int i;
1821
1822	for_each_sg(sg, s, nents, i) {
1823		if (sg_dma_len(s))
1824			__iommu_remove_mapping(dev, sg_dma_address(s),
1825					       sg_dma_len(s));
1826		if (!is_coherent && (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
1827			__dma_page_dev_to_cpu(sg_page(s), s->offset,
1828					      s->length, dir);
1829	}
1830}
1831
1832/**
1833 * arm_coherent_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
1834 * @dev: valid struct device pointer
1835 * @sg: list of buffers
1836 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
1837 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1838 *
1839 * Unmap a set of streaming mode DMA translations.  Again, CPU access
1840 * rules concerning calls here are the same as for dma_unmap_single().
1841 */
1842void arm_coherent_iommu_unmap_sg(struct device *dev, struct scatterlist *sg,
1843		int nents, enum dma_data_direction dir,
1844		unsigned long attrs)
1845{
1846	__iommu_unmap_sg(dev, sg, nents, dir, attrs, true);
1847}
1848
1849/**
1850 * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
1851 * @dev: valid struct device pointer
1852 * @sg: list of buffers
1853 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
1854 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1855 *
1856 * Unmap a set of streaming mode DMA translations.  Again, CPU access
1857 * rules concerning calls here are the same as for dma_unmap_single().
1858 */
1859void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
1860			enum dma_data_direction dir,
1861			unsigned long attrs)
 
1862{
1863	__iommu_unmap_sg(dev, sg, nents, dir, attrs, false);
1864}
1865
1866/**
1867 * arm_iommu_sync_sg_for_cpu
1868 * @dev: valid struct device pointer
1869 * @sg: list of buffers
1870 * @nents: number of buffers to map (returned from dma_map_sg)
1871 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1872 */
1873void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 
1874			int nents, enum dma_data_direction dir)
1875{
1876	struct scatterlist *s;
1877	int i;
1878
1879	for_each_sg(sg, s, nents, i)
1880		__dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
1881
1882}
1883
1884/**
1885 * arm_iommu_sync_sg_for_device
1886 * @dev: valid struct device pointer
1887 * @sg: list of buffers
1888 * @nents: number of buffers to map (returned from dma_map_sg)
1889 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1890 */
1891void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 
1892			int nents, enum dma_data_direction dir)
1893{
1894	struct scatterlist *s;
1895	int i;
1896
1897	for_each_sg(sg, s, nents, i)
1898		__dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1899}
1900
1901
1902/**
1903 * arm_coherent_iommu_map_page
1904 * @dev: valid struct device pointer
1905 * @page: page that buffer resides in
1906 * @offset: offset into page for start of buffer
1907 * @size: size of buffer to map
1908 * @dir: DMA transfer direction
1909 *
1910 * Coherent IOMMU aware version of arm_dma_map_page()
1911 */
1912static dma_addr_t arm_coherent_iommu_map_page(struct device *dev, struct page *page,
1913	     unsigned long offset, size_t size, enum dma_data_direction dir,
1914	     unsigned long attrs)
1915{
1916	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1917	dma_addr_t dma_addr;
1918	int ret, prot, len = PAGE_ALIGN(size + offset);
1919
1920	dma_addr = __alloc_iova(mapping, len);
1921	if (dma_addr == ARM_MAPPING_ERROR)
1922		return dma_addr;
1923
1924	prot = __dma_info_to_prot(dir, attrs);
1925
1926	ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, prot);
1927	if (ret < 0)
1928		goto fail;
1929
1930	return dma_addr + offset;
1931fail:
1932	__free_iova(mapping, dma_addr, len);
1933	return ARM_MAPPING_ERROR;
1934}
1935
1936/**
1937 * arm_iommu_map_page
1938 * @dev: valid struct device pointer
1939 * @page: page that buffer resides in
1940 * @offset: offset into page for start of buffer
1941 * @size: size of buffer to map
1942 * @dir: DMA transfer direction
1943 *
1944 * IOMMU aware version of arm_dma_map_page()
1945 */
1946static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
1947	     unsigned long offset, size_t size, enum dma_data_direction dir,
1948	     unsigned long attrs)
1949{
1950	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
1951		__dma_page_cpu_to_dev(page, offset, size, dir);
1952
1953	return arm_coherent_iommu_map_page(dev, page, offset, size, dir, attrs);
1954}
1955
1956/**
1957 * arm_coherent_iommu_unmap_page
1958 * @dev: valid struct device pointer
1959 * @handle: DMA address of buffer
1960 * @size: size of buffer (same as passed to dma_map_page)
1961 * @dir: DMA transfer direction (same as passed to dma_map_page)
1962 *
1963 * Coherent IOMMU aware version of arm_dma_unmap_page()
1964 */
1965static void arm_coherent_iommu_unmap_page(struct device *dev, dma_addr_t handle,
1966		size_t size, enum dma_data_direction dir, unsigned long attrs)
1967{
1968	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1969	dma_addr_t iova = handle & PAGE_MASK;
1970	int offset = handle & ~PAGE_MASK;
1971	int len = PAGE_ALIGN(size + offset);
1972
1973	if (!iova)
1974		return;
1975
1976	iommu_unmap(mapping->domain, iova, len);
1977	__free_iova(mapping, iova, len);
1978}
1979
1980/**
1981 * arm_iommu_unmap_page
1982 * @dev: valid struct device pointer
1983 * @handle: DMA address of buffer
1984 * @size: size of buffer (same as passed to dma_map_page)
1985 * @dir: DMA transfer direction (same as passed to dma_map_page)
1986 *
1987 * IOMMU aware version of arm_dma_unmap_page()
1988 */
1989static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
1990		size_t size, enum dma_data_direction dir, unsigned long attrs)
1991{
1992	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
1993	dma_addr_t iova = handle & PAGE_MASK;
1994	struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1995	int offset = handle & ~PAGE_MASK;
1996	int len = PAGE_ALIGN(size + offset);
1997
1998	if (!iova)
1999		return;
2000
2001	if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
2002		__dma_page_dev_to_cpu(page, offset, size, dir);
2003
2004	iommu_unmap(mapping->domain, iova, len);
2005	__free_iova(mapping, iova, len);
2006}
2007
2008/**
2009 * arm_iommu_map_resource - map a device resource for DMA
2010 * @dev: valid struct device pointer
2011 * @phys_addr: physical address of resource
2012 * @size: size of resource to map
2013 * @dir: DMA transfer direction
2014 */
2015static dma_addr_t arm_iommu_map_resource(struct device *dev,
2016		phys_addr_t phys_addr, size_t size,
2017		enum dma_data_direction dir, unsigned long attrs)
2018{
2019	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
2020	dma_addr_t dma_addr;
2021	int ret, prot;
2022	phys_addr_t addr = phys_addr & PAGE_MASK;
2023	unsigned int offset = phys_addr & ~PAGE_MASK;
2024	size_t len = PAGE_ALIGN(size + offset);
2025
2026	dma_addr = __alloc_iova(mapping, len);
2027	if (dma_addr == ARM_MAPPING_ERROR)
2028		return dma_addr;
2029
2030	prot = __dma_info_to_prot(dir, attrs) | IOMMU_MMIO;
2031
2032	ret = iommu_map(mapping->domain, dma_addr, addr, len, prot);
2033	if (ret < 0)
2034		goto fail;
2035
2036	return dma_addr + offset;
2037fail:
2038	__free_iova(mapping, dma_addr, len);
2039	return ARM_MAPPING_ERROR;
2040}
2041
2042/**
2043 * arm_iommu_unmap_resource - unmap a device DMA resource
2044 * @dev: valid struct device pointer
2045 * @dma_handle: DMA address to resource
2046 * @size: size of resource to map
2047 * @dir: DMA transfer direction
2048 */
2049static void arm_iommu_unmap_resource(struct device *dev, dma_addr_t dma_handle,
2050		size_t size, enum dma_data_direction dir,
2051		unsigned long attrs)
2052{
2053	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
2054	dma_addr_t iova = dma_handle & PAGE_MASK;
2055	unsigned int offset = dma_handle & ~PAGE_MASK;
2056	size_t len = PAGE_ALIGN(size + offset);
2057
2058	if (!iova)
2059		return;
2060
2061	iommu_unmap(mapping->domain, iova, len);
2062	__free_iova(mapping, iova, len);
2063}
2064
2065static void arm_iommu_sync_single_for_cpu(struct device *dev,
2066		dma_addr_t handle, size_t size, enum dma_data_direction dir)
2067{
2068	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
2069	dma_addr_t iova = handle & PAGE_MASK;
2070	struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
2071	unsigned int offset = handle & ~PAGE_MASK;
2072
2073	if (!iova)
2074		return;
2075
2076	__dma_page_dev_to_cpu(page, offset, size, dir);
2077}
2078
2079static void arm_iommu_sync_single_for_device(struct device *dev,
2080		dma_addr_t handle, size_t size, enum dma_data_direction dir)
2081{
2082	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
2083	dma_addr_t iova = handle & PAGE_MASK;
2084	struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
2085	unsigned int offset = handle & ~PAGE_MASK;
2086
2087	if (!iova)
2088		return;
2089
2090	__dma_page_cpu_to_dev(page, offset, size, dir);
2091}
2092
2093const struct dma_map_ops iommu_ops = {
2094	.alloc		= arm_iommu_alloc_attrs,
2095	.free		= arm_iommu_free_attrs,
2096	.mmap		= arm_iommu_mmap_attrs,
2097	.get_sgtable	= arm_iommu_get_sgtable,
2098
2099	.map_page		= arm_iommu_map_page,
2100	.unmap_page		= arm_iommu_unmap_page,
2101	.sync_single_for_cpu	= arm_iommu_sync_single_for_cpu,
2102	.sync_single_for_device	= arm_iommu_sync_single_for_device,
2103
2104	.map_sg			= arm_iommu_map_sg,
2105	.unmap_sg		= arm_iommu_unmap_sg,
2106	.sync_sg_for_cpu	= arm_iommu_sync_sg_for_cpu,
2107	.sync_sg_for_device	= arm_iommu_sync_sg_for_device,
2108
2109	.map_resource		= arm_iommu_map_resource,
2110	.unmap_resource		= arm_iommu_unmap_resource,
2111
2112	.mapping_error		= arm_dma_mapping_error,
2113	.dma_supported		= arm_dma_supported,
2114};
2115
2116const struct dma_map_ops iommu_coherent_ops = {
2117	.alloc		= arm_coherent_iommu_alloc_attrs,
2118	.free		= arm_coherent_iommu_free_attrs,
2119	.mmap		= arm_coherent_iommu_mmap_attrs,
2120	.get_sgtable	= arm_iommu_get_sgtable,
2121
2122	.map_page	= arm_coherent_iommu_map_page,
2123	.unmap_page	= arm_coherent_iommu_unmap_page,
2124
2125	.map_sg		= arm_coherent_iommu_map_sg,
2126	.unmap_sg	= arm_coherent_iommu_unmap_sg,
2127
2128	.map_resource	= arm_iommu_map_resource,
2129	.unmap_resource	= arm_iommu_unmap_resource,
2130
2131	.mapping_error		= arm_dma_mapping_error,
2132	.dma_supported		= arm_dma_supported,
2133};
2134
2135/**
2136 * arm_iommu_create_mapping
2137 * @bus: pointer to the bus holding the client device (for IOMMU calls)
2138 * @base: start address of the valid IO address space
2139 * @size: maximum size of the valid IO address space
2140 *
2141 * Creates a mapping structure which holds information about used/unused
2142 * IO address ranges, which is required to perform memory allocation and
2143 * mapping with IOMMU aware functions.
2144 *
2145 * The client device need to be attached to the mapping with
2146 * arm_iommu_attach_device function.
2147 */
2148struct dma_iommu_mapping *
2149arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, u64 size)
2150{
2151	unsigned int bits = size >> PAGE_SHIFT;
2152	unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
2153	struct dma_iommu_mapping *mapping;
2154	int extensions = 1;
2155	int err = -ENOMEM;
2156
2157	/* currently only 32-bit DMA address space is supported */
2158	if (size > DMA_BIT_MASK(32) + 1)
2159		return ERR_PTR(-ERANGE);
2160
2161	if (!bitmap_size)
2162		return ERR_PTR(-EINVAL);
2163
2164	if (bitmap_size > PAGE_SIZE) {
2165		extensions = bitmap_size / PAGE_SIZE;
2166		bitmap_size = PAGE_SIZE;
2167	}
2168
2169	mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
2170	if (!mapping)
2171		goto err;
2172
2173	mapping->bitmap_size = bitmap_size;
2174	mapping->bitmaps = kzalloc(extensions * sizeof(unsigned long *),
2175				GFP_KERNEL);
2176	if (!mapping->bitmaps)
2177		goto err2;
2178
2179	mapping->bitmaps[0] = kzalloc(bitmap_size, GFP_KERNEL);
2180	if (!mapping->bitmaps[0])
2181		goto err3;
2182
2183	mapping->nr_bitmaps = 1;
2184	mapping->extensions = extensions;
2185	mapping->base = base;
2186	mapping->bits = BITS_PER_BYTE * bitmap_size;
2187
2188	spin_lock_init(&mapping->lock);
2189
2190	mapping->domain = iommu_domain_alloc(bus);
2191	if (!mapping->domain)
2192		goto err4;
2193
2194	kref_init(&mapping->kref);
2195	return mapping;
2196err4:
2197	kfree(mapping->bitmaps[0]);
2198err3:
2199	kfree(mapping->bitmaps);
2200err2:
2201	kfree(mapping);
2202err:
2203	return ERR_PTR(err);
2204}
2205EXPORT_SYMBOL_GPL(arm_iommu_create_mapping);
2206
2207static void release_iommu_mapping(struct kref *kref)
2208{
2209	int i;
2210	struct dma_iommu_mapping *mapping =
2211		container_of(kref, struct dma_iommu_mapping, kref);
2212
2213	iommu_domain_free(mapping->domain);
2214	for (i = 0; i < mapping->nr_bitmaps; i++)
2215		kfree(mapping->bitmaps[i]);
2216	kfree(mapping->bitmaps);
2217	kfree(mapping);
2218}
2219
2220static int extend_iommu_mapping(struct dma_iommu_mapping *mapping)
2221{
2222	int next_bitmap;
2223
2224	if (mapping->nr_bitmaps >= mapping->extensions)
2225		return -EINVAL;
2226
2227	next_bitmap = mapping->nr_bitmaps;
2228	mapping->bitmaps[next_bitmap] = kzalloc(mapping->bitmap_size,
2229						GFP_ATOMIC);
2230	if (!mapping->bitmaps[next_bitmap])
2231		return -ENOMEM;
2232
2233	mapping->nr_bitmaps++;
2234
2235	return 0;
2236}
2237
2238void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
2239{
2240	if (mapping)
2241		kref_put(&mapping->kref, release_iommu_mapping);
2242}
2243EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
2244
2245static int __arm_iommu_attach_device(struct device *dev,
2246				     struct dma_iommu_mapping *mapping)
2247{
2248	int err;
2249
2250	err = iommu_attach_device(mapping->domain, dev);
2251	if (err)
2252		return err;
2253
2254	kref_get(&mapping->kref);
2255	to_dma_iommu_mapping(dev) = mapping;
2256
2257	pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
2258	return 0;
2259}
2260
2261/**
2262 * arm_iommu_attach_device
2263 * @dev: valid struct device pointer
2264 * @mapping: io address space mapping structure (returned from
2265 *	arm_iommu_create_mapping)
2266 *
2267 * Attaches specified io address space mapping to the provided device.
2268 * This replaces the dma operations (dma_map_ops pointer) with the
2269 * IOMMU aware version.
2270 *
2271 * More than one client might be attached to the same io address space
2272 * mapping.
2273 */
2274int arm_iommu_attach_device(struct device *dev,
2275			    struct dma_iommu_mapping *mapping)
2276{
2277	int err;
2278
2279	err = __arm_iommu_attach_device(dev, mapping);
2280	if (err)
2281		return err;
2282
2283	set_dma_ops(dev, &iommu_ops);
2284	return 0;
2285}
2286EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
2287
2288/**
2289 * arm_iommu_detach_device
2290 * @dev: valid struct device pointer
2291 *
2292 * Detaches the provided device from a previously attached map.
2293 * This voids the dma operations (dma_map_ops pointer)
2294 */
2295void arm_iommu_detach_device(struct device *dev)
2296{
2297	struct dma_iommu_mapping *mapping;
2298
2299	mapping = to_dma_iommu_mapping(dev);
2300	if (!mapping) {
2301		dev_warn(dev, "Not attached\n");
2302		return;
2303	}
2304
2305	iommu_detach_device(mapping->domain, dev);
2306	kref_put(&mapping->kref, release_iommu_mapping);
2307	to_dma_iommu_mapping(dev) = NULL;
2308	set_dma_ops(dev, NULL);
2309
2310	pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
2311}
2312EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
2313
2314static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
2315{
2316	return coherent ? &iommu_coherent_ops : &iommu_ops;
2317}
2318
2319static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
2320				    const struct iommu_ops *iommu)
2321{
2322	struct dma_iommu_mapping *mapping;
2323
2324	if (!iommu)
2325		return false;
2326
2327	mapping = arm_iommu_create_mapping(dev->bus, dma_base, size);
2328	if (IS_ERR(mapping)) {
2329		pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n",
2330				size, dev_name(dev));
2331		return false;
2332	}
2333
2334	if (__arm_iommu_attach_device(dev, mapping)) {
2335		pr_warn("Failed to attached device %s to IOMMU_mapping\n",
2336				dev_name(dev));
2337		arm_iommu_release_mapping(mapping);
2338		return false;
2339	}
2340
2341	return true;
2342}
2343
2344static void arm_teardown_iommu_dma_ops(struct device *dev)
2345{
2346	struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
2347
2348	if (!mapping)
2349		return;
2350
2351	arm_iommu_detach_device(dev);
2352	arm_iommu_release_mapping(mapping);
2353}
2354
2355#else
2356
2357static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size,
2358				    const struct iommu_ops *iommu)
2359{
2360	return false;
2361}
2362
2363static void arm_teardown_iommu_dma_ops(struct device *dev) { }
2364
2365#define arm_get_iommu_dma_map_ops arm_get_dma_map_ops
2366
2367#endif	/* CONFIG_ARM_DMA_USE_IOMMU */
2368
2369static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
2370{
2371	return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
2372}
2373
2374void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
2375			const struct iommu_ops *iommu, bool coherent)
2376{
2377	const struct dma_map_ops *dma_ops;
2378
2379	dev->archdata.dma_coherent = coherent;
 
 
 
2380
2381	/*
2382	 * Don't override the dma_ops if they have already been set. Ideally
2383	 * this should be the only location where dma_ops are set, remove this
2384	 * check when all other callers of set_dma_ops will have disappeared.
2385	 */
2386	if (dev->dma_ops)
2387		return;
2388
2389	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
2390		dma_ops = arm_get_iommu_dma_map_ops(coherent);
2391	else
2392		dma_ops = arm_get_dma_map_ops(coherent);
2393
2394	set_dma_ops(dev, dma_ops);
2395
2396#ifdef CONFIG_XEN
2397	if (xen_initial_domain()) {
2398		dev->archdata.dev_dma_ops = dev->dma_ops;
2399		dev->dma_ops = xen_dma_ops;
2400	}
2401#endif
2402	dev->archdata.dma_ops_setup = true;
2403}
2404
2405void arch_teardown_dma_ops(struct device *dev)
2406{
2407	if (!dev->archdata.dma_ops_setup)
2408		return;
2409
2410	arm_teardown_iommu_dma_ops(dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2411}