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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_DMA_MINALIGN.
38 */
39 if (ARCH_DMA_MINALIGN <= 32)
40 ; /* Original value is okay */
41 else if (ARCH_DMA_MINALIGN <= 64)
42 pool_max[0] = 64;
43 else if (ARCH_DMA_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 *
55 * Context: task context, might sleep
56 *
57 * Call this as part of initializing a host controller that uses the dma
58 * memory allocators. It initializes some pools of dma-coherent memory that
59 * will be shared by all drivers using that controller.
60 *
61 * Call hcd_buffer_destroy() to clean up after using those pools.
62 *
63 * Return: 0 if successful. A negative errno value otherwise.
64 */
65int hcd_buffer_create(struct usb_hcd *hcd)
66{
67 char name[16];
68 int i, size;
69
70 if (hcd->localmem_pool || !hcd_uses_dma(hcd))
71 return 0;
72
73 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
74 size = pool_max[i];
75 if (!size)
76 continue;
77 snprintf(name, sizeof(name), "buffer-%d", size);
78 hcd->pool[i] = dma_pool_create(name, hcd->self.sysdev,
79 size, size, 0);
80 if (!hcd->pool[i]) {
81 hcd_buffer_destroy(hcd);
82 return -ENOMEM;
83 }
84 }
85 return 0;
86}
87
88
89/**
90 * hcd_buffer_destroy - deallocate buffer pools
91 * @hcd: the bus whose buffer pools are to be destroyed
92 *
93 * Context: task context, might sleep
94 *
95 * This frees the buffer pools created by hcd_buffer_create().
96 */
97void hcd_buffer_destroy(struct usb_hcd *hcd)
98{
99 int i;
100
101 if (!IS_ENABLED(CONFIG_HAS_DMA))
102 return;
103
104 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
105 dma_pool_destroy(hcd->pool[i]);
106 hcd->pool[i] = NULL;
107 }
108}
109
110
111/* sometimes alloc/free could use kmalloc with GFP_DMA, for
112 * better sharing and to leverage mm/slab.c intelligence.
113 */
114
115void *hcd_buffer_alloc(
116 struct usb_bus *bus,
117 size_t size,
118 gfp_t mem_flags,
119 dma_addr_t *dma
120)
121{
122 struct usb_hcd *hcd = bus_to_hcd(bus);
123 int i;
124
125 if (size == 0)
126 return NULL;
127
128 if (hcd->localmem_pool)
129 return gen_pool_dma_alloc(hcd->localmem_pool, size, dma);
130
131 /* some USB hosts just use PIO */
132 if (!hcd_uses_dma(hcd)) {
133 *dma = ~(dma_addr_t) 0;
134 return kmalloc(size, mem_flags);
135 }
136
137 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
138 if (size <= pool_max[i])
139 return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
140 }
141 return dma_alloc_coherent(hcd->self.sysdev, size, dma, mem_flags);
142}
143
144void hcd_buffer_free(
145 struct usb_bus *bus,
146 size_t size,
147 void *addr,
148 dma_addr_t dma
149)
150{
151 struct usb_hcd *hcd = bus_to_hcd(bus);
152 int i;
153
154 if (!addr)
155 return;
156
157 if (hcd->localmem_pool) {
158 gen_pool_free(hcd->localmem_pool, (unsigned long)addr, size);
159 return;
160 }
161
162 if (!hcd_uses_dma(hcd)) {
163 kfree(addr);
164 return;
165 }
166
167 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
168 if (size <= pool_max[i]) {
169 dma_pool_free(hcd->pool[i], addr, dma);
170 return;
171 }
172 }
173 dma_free_coherent(hcd->self.sysdev, size, addr, dma);
174}
175
176void *hcd_buffer_alloc_pages(struct usb_hcd *hcd,
177 size_t size, gfp_t mem_flags, dma_addr_t *dma)
178{
179 if (size == 0)
180 return NULL;
181
182 if (hcd->localmem_pool)
183 return gen_pool_dma_alloc_align(hcd->localmem_pool,
184 size, dma, PAGE_SIZE);
185
186 /* some USB hosts just use PIO */
187 if (!hcd_uses_dma(hcd)) {
188 *dma = DMA_MAPPING_ERROR;
189 return (void *)__get_free_pages(mem_flags,
190 get_order(size));
191 }
192
193 return dma_alloc_coherent(hcd->self.sysdev,
194 size, dma, mem_flags);
195}
196
197void hcd_buffer_free_pages(struct usb_hcd *hcd,
198 size_t size, void *addr, dma_addr_t dma)
199{
200 if (!addr)
201 return;
202
203 if (hcd->localmem_pool) {
204 gen_pool_free(hcd->localmem_pool,
205 (unsigned long)addr, size);
206 return;
207 }
208
209 if (!hcd_uses_dma(hcd)) {
210 free_pages((unsigned long)addr, get_order(size));
211 return;
212 }
213
214 dma_free_coherent(hcd->self.sysdev, size, addr, dma);
215}
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 size_t pool_max[HCD_BUFFER_POOLS] = {
26 32, 128, 512, 2048,
27};
28
29void __init usb_init_pool_max(void)
30{
31 /*
32 * The pool_max values must never be smaller than
33 * ARCH_KMALLOC_MINALIGN.
34 */
35 if (ARCH_KMALLOC_MINALIGN <= 32)
36 ; /* Original value is okay */
37 else if (ARCH_KMALLOC_MINALIGN <= 64)
38 pool_max[0] = 64;
39 else if (ARCH_KMALLOC_MINALIGN <= 128)
40 pool_max[0] = 0; /* Don't use this pool */
41 else
42 BUILD_BUG(); /* We don't allow this */
43}
44
45/* SETUP primitives */
46
47/**
48 * hcd_buffer_create - initialize buffer pools
49 * @hcd: the bus whose buffer pools are to be initialized
50 * Context: !in_interrupt()
51 *
52 * Call this as part of initializing a host controller that uses the dma
53 * memory allocators. It initializes some pools of dma-coherent memory that
54 * will be shared by all drivers using that controller.
55 *
56 * Call hcd_buffer_destroy() to clean up after using those pools.
57 *
58 * Return: 0 if successful. A negative errno value otherwise.
59 */
60int hcd_buffer_create(struct usb_hcd *hcd)
61{
62 char name[16];
63 int i, size;
64
65 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
66 (!hcd->self.controller->dma_mask &&
67 !(hcd->driver->flags & HCD_LOCAL_MEM)))
68 return 0;
69
70 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
71 size = pool_max[i];
72 if (!size)
73 continue;
74 snprintf(name, sizeof(name), "buffer-%d", size);
75 hcd->pool[i] = dma_pool_create(name, hcd->self.controller,
76 size, size, 0);
77 if (!hcd->pool[i]) {
78 hcd_buffer_destroy(hcd);
79 return -ENOMEM;
80 }
81 }
82 return 0;
83}
84
85
86/**
87 * hcd_buffer_destroy - deallocate buffer pools
88 * @hcd: the bus whose buffer pools are to be destroyed
89 * Context: !in_interrupt()
90 *
91 * This frees the buffer pools created by hcd_buffer_create().
92 */
93void hcd_buffer_destroy(struct usb_hcd *hcd)
94{
95 int i;
96
97 if (!IS_ENABLED(CONFIG_HAS_DMA))
98 return;
99
100 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
101 struct dma_pool *pool = hcd->pool[i];
102
103 if (pool) {
104 dma_pool_destroy(pool);
105 hcd->pool[i] = NULL;
106 }
107 }
108}
109
110
111/* sometimes alloc/free could use kmalloc with GFP_DMA, for
112 * better sharing and to leverage mm/slab.c intelligence.
113 */
114
115void *hcd_buffer_alloc(
116 struct usb_bus *bus,
117 size_t size,
118 gfp_t mem_flags,
119 dma_addr_t *dma
120)
121{
122 struct usb_hcd *hcd = bus_to_hcd(bus);
123 int i;
124
125 /* some USB hosts just use PIO */
126 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
127 (!bus->controller->dma_mask &&
128 !(hcd->driver->flags & HCD_LOCAL_MEM))) {
129 *dma = ~(dma_addr_t) 0;
130 return kmalloc(size, mem_flags);
131 }
132
133 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
134 if (size <= pool_max[i])
135 return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
136 }
137 return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
138}
139
140void hcd_buffer_free(
141 struct usb_bus *bus,
142 size_t size,
143 void *addr,
144 dma_addr_t dma
145)
146{
147 struct usb_hcd *hcd = bus_to_hcd(bus);
148 int i;
149
150 if (!addr)
151 return;
152
153 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
154 (!bus->controller->dma_mask &&
155 !(hcd->driver->flags & HCD_LOCAL_MEM))) {
156 kfree(addr);
157 return;
158 }
159
160 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
161 if (size <= pool_max[i]) {
162 dma_pool_free(hcd->pool[i], addr, dma);
163 return;
164 }
165 }
166 dma_free_coherent(hcd->self.controller, size, addr, dma);
167}