153 lines
3.3 KiB
C
153 lines
3.3 KiB
C
/*
|
|
* DMA memory management for framework level HCD code (hc_driver)
|
|
*
|
|
* This implementation plugs in through generic "usb_bus" level methods,
|
|
* and should work with all USB controllers, regardless of bus type.
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/device.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/io.h>
|
|
#include <linux/dma-mapping.h>
|
|
#include <linux/dmapool.h>
|
|
#include <linux/usb.h>
|
|
#include <linux/usb/hcd.h>
|
|
|
|
|
|
/*
|
|
* DMA-Coherent Buffers
|
|
*/
|
|
|
|
/* FIXME tune these based on pool statistics ... */
|
|
static const size_t pool_max[HCD_BUFFER_POOLS] = {
|
|
/* platforms without dma-friendly caches might need to
|
|
* prevent cacheline sharing...
|
|
*/
|
|
32,
|
|
128,
|
|
512,
|
|
PAGE_SIZE / 2
|
|
/* bigger --> allocate pages */
|
|
};
|
|
|
|
|
|
/* SETUP primitives */
|
|
|
|
/**
|
|
* hcd_buffer_create - initialize buffer pools
|
|
* @hcd: the bus whose buffer pools are to be initialized
|
|
* Context: !in_interrupt()
|
|
*
|
|
* Call this as part of initializing a host controller that uses the dma
|
|
* memory allocators. It initializes some pools of dma-coherent memory that
|
|
* will be shared by all drivers using that controller.
|
|
*
|
|
* Call hcd_buffer_destroy() to clean up after using those pools.
|
|
*
|
|
* Return: 0 if successful. A negative errno value otherwise.
|
|
*/
|
|
int hcd_buffer_create(struct usb_hcd *hcd)
|
|
{
|
|
char name[16];
|
|
int i, size;
|
|
|
|
if (!hcd->self.controller->dma_mask &&
|
|
!(hcd->driver->flags & HCD_LOCAL_MEM))
|
|
return 0;
|
|
|
|
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
|
|
size = pool_max[i];
|
|
if (!size)
|
|
continue;
|
|
snprintf(name, sizeof name, "buffer-%d", size);
|
|
hcd->pool[i] = dma_pool_create(name, hcd->self.controller,
|
|
size, size, 0);
|
|
if (!hcd->pool[i]) {
|
|
hcd_buffer_destroy(hcd);
|
|
return -ENOMEM;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
/**
|
|
* hcd_buffer_destroy - deallocate buffer pools
|
|
* @hcd: the bus whose buffer pools are to be destroyed
|
|
* Context: !in_interrupt()
|
|
*
|
|
* This frees the buffer pools created by hcd_buffer_create().
|
|
*/
|
|
void hcd_buffer_destroy(struct usb_hcd *hcd)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
|
|
struct dma_pool *pool = hcd->pool[i];
|
|
if (pool) {
|
|
dma_pool_destroy(pool);
|
|
hcd->pool[i] = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
/* sometimes alloc/free could use kmalloc with GFP_DMA, for
|
|
* better sharing and to leverage mm/slab.c intelligence.
|
|
*/
|
|
|
|
void *hcd_buffer_alloc(
|
|
struct usb_bus *bus,
|
|
size_t size,
|
|
gfp_t mem_flags,
|
|
dma_addr_t *dma
|
|
)
|
|
{
|
|
struct usb_hcd *hcd = bus_to_hcd(bus);
|
|
int i;
|
|
|
|
/* some USB hosts just use PIO */
|
|
if (!bus->controller->dma_mask &&
|
|
!(hcd->driver->flags & HCD_LOCAL_MEM)) {
|
|
*dma = ~(dma_addr_t) 0;
|
|
return kmalloc(size, mem_flags);
|
|
}
|
|
|
|
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
|
|
if (size <= pool_max[i])
|
|
return dma_pool_alloc(hcd->pool[i], mem_flags, dma);
|
|
}
|
|
return dma_alloc_coherent(hcd->self.controller, size, dma, mem_flags);
|
|
}
|
|
|
|
void hcd_buffer_free(
|
|
struct usb_bus *bus,
|
|
size_t size,
|
|
void *addr,
|
|
dma_addr_t dma
|
|
)
|
|
{
|
|
struct usb_hcd *hcd = bus_to_hcd(bus);
|
|
int i;
|
|
|
|
if (!addr)
|
|
return;
|
|
|
|
if (!bus->controller->dma_mask &&
|
|
!(hcd->driver->flags & HCD_LOCAL_MEM)) {
|
|
kfree(addr);
|
|
return;
|
|
}
|
|
|
|
for (i = 0; i < HCD_BUFFER_POOLS; i++) {
|
|
if (size <= pool_max[i]) {
|
|
dma_pool_free(hcd->pool[i], addr, dma);
|
|
return;
|
|
}
|
|
}
|
|
dma_free_coherent(hcd->self.controller, size, addr, dma);
|
|
}
|