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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, regardles 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, or returns a negative
47 * errno value on error.
48 *
49 * Call hcd_buffer_destroy() to clean up after using those pools.
50 */
51int hcd_buffer_create(struct usb_hcd *hcd)
52{
53 char name[16];
54 int i, size;
55
56 if (!hcd->self.controller->dma_mask &&
57 !(hcd->driver->flags & HCD_LOCAL_MEM))
58 return 0;
59
60 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
61 size = pool_max[i];
62 if (!size)
63 continue;
64 snprintf(name, sizeof name, "buffer-%d", size);
65 hcd->pool[i] = dma_pool_create(name, hcd->self.controller,
66 size, size, 0);
67 if (!hcd->pool[i]) {
68 hcd_buffer_destroy(hcd);
69 return -ENOMEM;
70 }
71 }
72 return 0;
73}
74
75
76/**
77 * hcd_buffer_destroy - deallocate buffer pools
78 * @hcd: the bus whose buffer pools are to be destroyed
79 * Context: !in_interrupt()
80 *
81 * This frees the buffer pools created by hcd_buffer_create().
82 */
83void hcd_buffer_destroy(struct usb_hcd *hcd)
84{
85 int i;
86
87 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
88 struct dma_pool *pool = hcd->pool[i];
89 if (pool) {
90 dma_pool_destroy(pool);
91 hcd->pool[i] = NULL;
92 }
93 }
94}
95
96
97/* sometimes alloc/free could use kmalloc with GFP_DMA, for
98 * better sharing and to leverage mm/slab.c intelligence.
99 */
100
101void *hcd_buffer_alloc(
102 struct usb_bus *bus,
103 size_t size,
104 gfp_t mem_flags,
105 dma_addr_t *dma
106)
107{
108 struct usb_hcd *hcd = bus_to_hcd(bus);
109 int i;
110
111 /* some USB hosts just use PIO */
112 if (!bus->controller->dma_mask &&
113 !(hcd->driver->flags & HCD_LOCAL_MEM)) {
114 *dma = ~(dma_addr_t) 0;
115 return kmalloc(size, mem_flags);
116 }
117
118 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
119 if (size <= pool_max[i])
120 return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
121 }
122 return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
123}
124
125void hcd_buffer_free(
126 struct usb_bus *bus,
127 size_t size,
128 void *addr,
129 dma_addr_t dma
130)
131{
132 struct usb_hcd *hcd = bus_to_hcd(bus);
133 int i;
134
135 if (!addr)
136 return;
137
138 if (!bus->controller->dma_mask &&
139 !(hcd->driver->flags & HCD_LOCAL_MEM)) {
140 kfree(addr);
141 return;
142 }
143
144 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
145 if (size <= pool_max[i]) {
146 dma_pool_free(hcd->pool[i], addr, dma);
147 return;
148 }
149 }
150 dma_free_coherent(hcd->self.controller, size, addr, dma);
151}
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/usb.h>
20#include <linux/usb/hcd.h>
21
22
23/*
24 * DMA-Coherent Buffers
25 */
26
27/* FIXME tune these based on pool statistics ... */
28static size_t pool_max[HCD_BUFFER_POOLS] = {
29 32, 128, 512, 2048,
30};
31
32void __init usb_init_pool_max(void)
33{
34 /*
35 * The pool_max values must never be smaller than
36 * ARCH_KMALLOC_MINALIGN.
37 */
38 if (ARCH_KMALLOC_MINALIGN <= 32)
39 ; /* Original value is okay */
40 else if (ARCH_KMALLOC_MINALIGN <= 64)
41 pool_max[0] = 64;
42 else if (ARCH_KMALLOC_MINALIGN <= 128)
43 pool_max[0] = 0; /* Don't use this pool */
44 else
45 BUILD_BUG(); /* We don't allow this */
46}
47
48/* SETUP primitives */
49
50/**
51 * hcd_buffer_create - initialize buffer pools
52 * @hcd: the bus whose buffer pools are to be initialized
53 * Context: !in_interrupt()
54 *
55 * Call this as part of initializing a host controller that uses the dma
56 * memory allocators. It initializes some pools of dma-coherent memory that
57 * will be shared by all drivers using that controller.
58 *
59 * Call hcd_buffer_destroy() to clean up after using those pools.
60 *
61 * Return: 0 if successful. A negative errno value otherwise.
62 */
63int hcd_buffer_create(struct usb_hcd *hcd)
64{
65 char name[16];
66 int i, size;
67
68 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
69 (!is_device_dma_capable(hcd->self.sysdev) &&
70 !(hcd->driver->flags & HCD_LOCAL_MEM)))
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 * Context: !in_interrupt()
93 *
94 * This frees the buffer pools created by hcd_buffer_create().
95 */
96void hcd_buffer_destroy(struct usb_hcd *hcd)
97{
98 int i;
99
100 if (!IS_ENABLED(CONFIG_HAS_DMA))
101 return;
102
103 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
104 struct dma_pool *pool = hcd->pool[i];
105
106 if (pool) {
107 dma_pool_destroy(pool);
108 hcd->pool[i] = NULL;
109 }
110 }
111}
112
113
114/* sometimes alloc/free could use kmalloc with GFP_DMA, for
115 * better sharing and to leverage mm/slab.c intelligence.
116 */
117
118void *hcd_buffer_alloc(
119 struct usb_bus *bus,
120 size_t size,
121 gfp_t mem_flags,
122 dma_addr_t *dma
123)
124{
125 struct usb_hcd *hcd = bus_to_hcd(bus);
126 int i;
127
128 if (size == 0)
129 return NULL;
130
131 /* some USB hosts just use PIO */
132 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
133 (!is_device_dma_capable(bus->sysdev) &&
134 !(hcd->driver->flags & HCD_LOCAL_MEM))) {
135 *dma = ~(dma_addr_t) 0;
136 return kmalloc(size, mem_flags);
137 }
138
139 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
140 if (size <= pool_max[i])
141 return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
142 }
143 return dma_alloc_coherent(hcd->self.sysdev, size, dma, mem_flags);
144}
145
146void hcd_buffer_free(
147 struct usb_bus *bus,
148 size_t size,
149 void *addr,
150 dma_addr_t dma
151)
152{
153 struct usb_hcd *hcd = bus_to_hcd(bus);
154 int i;
155
156 if (!addr)
157 return;
158
159 if (!IS_ENABLED(CONFIG_HAS_DMA) ||
160 (!is_device_dma_capable(bus->sysdev) &&
161 !(hcd->driver->flags & HCD_LOCAL_MEM))) {
162 kfree(addr);
163 return;
164 }
165
166 for (i = 0; i < HCD_BUFFER_POOLS; i++) {
167 if (size <= pool_max[i]) {
168 dma_pool_free(hcd->pool[i], addr, dma);
169 return;
170 }
171 }
172 dma_free_coherent(hcd->self.sysdev, size, addr, dma);
173}