1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * DMA memory management for framework level HCD code (hc_driver)
  4 *
  5 * This implementation plugs in through generic "usb_bus" level methods,
  6 * and should work with all USB controllers, regardless of bus type.
  7 *
  8 * Released under the GPLv2 only.
  9 */
 10
 11#include <linux/module.h>
 12#include <linux/kernel.h>
 13#include <linux/slab.h>
 14#include <linux/device.h>
 15#include <linux/mm.h>
 16#include <linux/io.h>
 17#include <linux/dma-mapping.h>
 18#include <linux/dmapool.h>
 19#include <linux/genalloc.h>
 20#include <linux/usb.h>
 21#include <linux/usb/hcd.h>
 22
 23
 24/*
 25 * DMA-Coherent Buffers
 26 */
 27
 28/* FIXME tune these based on pool statistics ... */
 29static size_t pool_max[HCD_BUFFER_POOLS] = {
 30	32, 128, 512, 2048,
 
 
 
 
 
 
 
 31};
 32
 33void __init usb_init_pool_max(void)
 34{
 35	/*
 36	 * The pool_max values must never be smaller than
 37	 * ARCH_KMALLOC_MINALIGN.
 38	 */
 39	if (ARCH_KMALLOC_MINALIGN <= 32)
 40		;			/* Original value is okay */
 41	else if (ARCH_KMALLOC_MINALIGN <= 64)
 42		pool_max[0] = 64;
 43	else if (ARCH_KMALLOC_MINALIGN <= 128)
 44		pool_max[0] = 0;	/* Don't use this pool */
 45	else
 46		BUILD_BUG();		/* We don't allow this */
 47}
 48
 49/* SETUP primitives */
 50
 51/**
 52 * hcd_buffer_create - initialize buffer pools
 53 * @hcd: the bus whose buffer pools are to be initialized
 54 * Context: !in_interrupt()
 55 *
 56 * Call this as part of initializing a host controller that uses the dma
 57 * memory allocators.  It initializes some pools of dma-coherent memory that
 58 * will be shared by all drivers using that controller.
 59 *
 60 * Call hcd_buffer_destroy() to clean up after using those pools.
 61 *
 62 * Return: 0 if successful. A negative errno value otherwise.
 63 */
 64int hcd_buffer_create(struct usb_hcd *hcd)
 65{
 66	char		name[16];
 67	int		i, size;
 68
 69	if (hcd->localmem_pool || !hcd_uses_dma(hcd))
 
 70		return 0;
 71
 72	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
 73		size = pool_max[i];
 74		if (!size)
 75			continue;
 76		snprintf(name, sizeof(name), "buffer-%d", size);
 77		hcd->pool[i] = dma_pool_create(name, hcd->self.sysdev,
 78				size, size, 0);
 79		if (!hcd->pool[i]) {
 80			hcd_buffer_destroy(hcd);
 81			return -ENOMEM;
 82		}
 83	}
 84	return 0;
 85}
 86
 87
 88/**
 89 * hcd_buffer_destroy - deallocate buffer pools
 90 * @hcd: the bus whose buffer pools are to be destroyed
 91 * Context: !in_interrupt()
 92 *
 93 * This frees the buffer pools created by hcd_buffer_create().
 94 */
 95void hcd_buffer_destroy(struct usb_hcd *hcd)
 96{
 97	int i;
 98
 99	if (!IS_ENABLED(CONFIG_HAS_DMA))
100		return;
101
102	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
103		dma_pool_destroy(hcd->pool[i]);
104		hcd->pool[i] = NULL;
 
 
 
105	}
106}
107
108
109/* sometimes alloc/free could use kmalloc with GFP_DMA, for
110 * better sharing and to leverage mm/slab.c intelligence.
111 */
112
113void *hcd_buffer_alloc(
114	struct usb_bus		*bus,
115	size_t			size,
116	gfp_t			mem_flags,
117	dma_addr_t		*dma
118)
119{
120	struct usb_hcd		*hcd = bus_to_hcd(bus);
121	int			i;
122
123	if (size == 0)
124		return NULL;
125
126	if (hcd->localmem_pool)
127		return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);
128
129	/* some USB hosts just use PIO */
130	if (!hcd_uses_dma(hcd)) {
 
131		*dma = ~(dma_addr_t) 0;
132		return kmalloc(size, mem_flags);
133	}
134
135	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
136		if (size <= pool_max[i])
137			return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
138	}
139	return dma_alloc_coherent(hcd->self.sysdev, size, dma, mem_flags);
140}
141
142void hcd_buffer_free(
143	struct usb_bus		*bus,
144	size_t			size,
145	void			*addr,
146	dma_addr_t		dma
147)
148{
149	struct usb_hcd		*hcd = bus_to_hcd(bus);
150	int			i;
151
152	if (!addr)
153		return;
154
155	if (hcd->localmem_pool) {
156		gen_pool_free(hcd->localmem_pool, (unsigned long)addr, size);
157		return;
158	}
159
160	if (!hcd_uses_dma(hcd)) {
161		kfree(addr);
162		return;
163	}
164
165	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
166		if (size <= pool_max[i]) {
167			dma_pool_free(hcd->pool[i], addr, dma);
168			return;
169		}
170	}
171	dma_free_coherent(hcd->self.sysdev, size, addr, dma);
172}

 
  1/*
  2 * DMA memory management for framework level HCD code (hc_driver)
  3 *
  4 * This implementation plugs in through generic "usb_bus" level methods,
  5 * and should work with all USB controllers, regardless of bus type.
 
 
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/kernel.h>
 10#include <linux/slab.h>
 11#include <linux/device.h>
 12#include <linux/mm.h>
 13#include <linux/io.h>
 14#include <linux/dma-mapping.h>
 15#include <linux/dmapool.h>
 
 16#include <linux/usb.h>
 17#include <linux/usb/hcd.h>
 18
 19
 20/*
 21 * DMA-Coherent Buffers
 22 */
 23
 24/* FIXME tune these based on pool statistics ... */
 25static const size_t	pool_max[HCD_BUFFER_POOLS] = {
 26	/* platforms without dma-friendly caches might need to
 27	 * prevent cacheline sharing...
 28	 */
 29	32,
 30	128,
 31	512,
 32	PAGE_SIZE / 2
 33	/* bigger --> allocate pages */
 34};
 35
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 36
 37/* SETUP primitives */
 38
 39/**
 40 * hcd_buffer_create - initialize buffer pools
 41 * @hcd: the bus whose buffer pools are to be initialized
 42 * Context: !in_interrupt()
 43 *
 44 * Call this as part of initializing a host controller that uses the dma
 45 * memory allocators.  It initializes some pools of dma-coherent memory that
 46 * will be shared by all drivers using that controller.
 47 *
 48 * Call hcd_buffer_destroy() to clean up after using those pools.
 49 *
 50 * Return: 0 if successful. A negative errno value otherwise.
 51 */
 52int hcd_buffer_create(struct usb_hcd *hcd)
 53{
 54	char		name[16];
 55	int		i, size;
 56
 57	if (!hcd->self.controller->dma_mask &&
 58	    !(hcd->driver->flags & HCD_LOCAL_MEM))
 59		return 0;
 60
 61	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
 62		size = pool_max[i];
 63		if (!size)
 64			continue;
 65		snprintf(name, sizeof name, "buffer-%d", size);
 66		hcd->pool[i] = dma_pool_create(name, hcd->self.controller,
 67				size, size, 0);
 68		if (!hcd->pool[i]) {
 69			hcd_buffer_destroy(hcd);
 70			return -ENOMEM;
 71		}
 72	}
 73	return 0;
 74}
 75
 76
 77/**
 78 * hcd_buffer_destroy - deallocate buffer pools
 79 * @hcd: the bus whose buffer pools are to be destroyed
 80 * Context: !in_interrupt()
 81 *
 82 * This frees the buffer pools created by hcd_buffer_create().
 83 */
 84void hcd_buffer_destroy(struct usb_hcd *hcd)
 85{
 86	int i;
 87
 
 
 
 88	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
 89		struct dma_pool *pool = hcd->pool[i];
 90		if (pool) {
 91			dma_pool_destroy(pool);
 92			hcd->pool[i] = NULL;
 93		}
 94	}
 95}
 96
 97
 98/* sometimes alloc/free could use kmalloc with GFP_DMA, for
 99 * better sharing and to leverage mm/slab.c intelligence.
100 */
101
102void *hcd_buffer_alloc(
103	struct usb_bus		*bus,
104	size_t			size,
105	gfp_t			mem_flags,
106	dma_addr_t		*dma
107)
108{
109	struct usb_hcd		*hcd = bus_to_hcd(bus);
110	int			i;
111
 
 
 
 
 
 
112	/* some USB hosts just use PIO */
113	if (!bus->controller->dma_mask &&
114	    !(hcd->driver->flags & HCD_LOCAL_MEM)) {
115		*dma = ~(dma_addr_t) 0;
116		return kmalloc(size, mem_flags);
117	}
118
119	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
120		if (size <= pool_max[i])
121			return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
122	}
123	return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
124}
125
126void hcd_buffer_free(
127	struct usb_bus		*bus,
128	size_t			size,
129	void			*addr,
130	dma_addr_t		dma
131)
132{
133	struct usb_hcd		*hcd = bus_to_hcd(bus);
134	int			i;
135
136	if (!addr)
137		return;
138
139	if (!bus->controller->dma_mask &&
140	    !(hcd->driver->flags & HCD_LOCAL_MEM)) {
 
 
 
 
141		kfree(addr);
142		return;
143	}
144
145	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
146		if (size <= pool_max[i]) {
147			dma_pool_free(hcd->pool[i], addr, dma);
148			return;
149		}
150	}
151	dma_free_coherent(hcd->self.controller, size, addr, dma);
152}