1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * (c) Copyright 2006, 2007 Hewlett-Packard Development Company, L.P.
  4 *	Bjorn Helgaas <bjorn.helgaas@hp.com>
  5 */
  6
  7#include <linux/compiler.h>
  8#include <linux/module.h>
  9#include <linux/efi.h>
 10#include <linux/io.h>
 11#include <linux/mm.h>
 12#include <linux/vmalloc.h>
 13#include <asm/io.h>
 14#include <asm/meminit.h>
 15
 16static inline void __iomem *
 17__ioremap_uc(unsigned long phys_addr)
 18{
 19	return (void __iomem *) (__IA64_UNCACHED_OFFSET | phys_addr);
 20}
 21
 22void __iomem *
 23early_ioremap (unsigned long phys_addr, unsigned long size)
 24{
 25	u64 attr;
 26	attr = kern_mem_attribute(phys_addr, size);
 27	if (attr & EFI_MEMORY_WB)
 28		return (void __iomem *) phys_to_virt(phys_addr);
 29	return __ioremap_uc(phys_addr);
 30}
 31
 32void __iomem *
 33ioremap (unsigned long phys_addr, unsigned long size)
 34{
 35	void __iomem *addr;
 36	struct vm_struct *area;
 37	unsigned long offset;
 38	pgprot_t prot;
 39	u64 attr;
 40	unsigned long gran_base, gran_size;
 41	unsigned long page_base;
 42
 43	/*
 44	 * For things in kern_memmap, we must use the same attribute
 45	 * as the rest of the kernel.  For more details, see
 46	 * Documentation/ia64/aliasing.rst.
 47	 */
 48	attr = kern_mem_attribute(phys_addr, size);
 49	if (attr & EFI_MEMORY_WB)
 50		return (void __iomem *) phys_to_virt(phys_addr);
 51	else if (attr & EFI_MEMORY_UC)
 52		return __ioremap_uc(phys_addr);
 53
 54	/*
 55	 * Some chipsets don't support UC access to memory.  If
 56	 * WB is supported for the whole granule, we prefer that.
 57	 */
 58	gran_base = GRANULEROUNDDOWN(phys_addr);
 59	gran_size = GRANULEROUNDUP(phys_addr + size) - gran_base;
 60	if (efi_mem_attribute(gran_base, gran_size) & EFI_MEMORY_WB)
 61		return (void __iomem *) phys_to_virt(phys_addr);
 62
 63	/*
 64	 * WB is not supported for the whole granule, so we can't use
 65	 * the region 7 identity mapping.  If we can safely cover the
 66	 * area with kernel page table mappings, we can use those
 67	 * instead.
 68	 */
 69	page_base = phys_addr & PAGE_MASK;
 70	size = PAGE_ALIGN(phys_addr + size) - page_base;
 71	if (efi_mem_attribute(page_base, size) & EFI_MEMORY_WB) {
 72		prot = PAGE_KERNEL;
 73
 74		/*
 75		 * Mappings have to be page-aligned
 76		 */
 77		offset = phys_addr & ~PAGE_MASK;
 78		phys_addr &= PAGE_MASK;
 79
 80		/*
 81		 * Ok, go for it..
 82		 */
 83		area = get_vm_area(size, VM_IOREMAP);
 84		if (!area)
 85			return NULL;
 86
 87		area->phys_addr = phys_addr;
 88		addr = (void __iomem *) area->addr;
 89		if (ioremap_page_range((unsigned long) addr,
 90				(unsigned long) addr + size, phys_addr, prot)) {
 91			vunmap((void __force *) addr);
 92			return NULL;
 93		}
 94
 95		return (void __iomem *) (offset + (char __iomem *)addr);
 96	}
 97
 98	return __ioremap_uc(phys_addr);
 99}
100EXPORT_SYMBOL(ioremap);
101
102void __iomem *
103ioremap_uc(unsigned long phys_addr, unsigned long size)
104{
105	if (kern_mem_attribute(phys_addr, size) & EFI_MEMORY_WB)
106		return NULL;
107
108	return __ioremap_uc(phys_addr);
109}
110EXPORT_SYMBOL(ioremap_uc);
111
112void
113early_iounmap (volatile void __iomem *addr, unsigned long size)
114{
115}
116
117void
118iounmap (volatile void __iomem *addr)
119{
120	if (REGION_NUMBER(addr) == RGN_GATE)
121		vunmap((void *) ((unsigned long) addr & PAGE_MASK));
122}
123EXPORT_SYMBOL(iounmap);