[deliverable/linux.git] / drivers / usb / core / buffer.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, regardles of bus type.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/mm.h>
#include <asm/io.h>
#include <asm/scatterlist.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/usb.h>
#include "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, or returns a negative
 * errno value on error.
 *
 * Call hcd_buffer_destroy() to clean up after using those pools.
 */
int hcd_buffer_create (struct usb_hcd *hcd)
{
	char		name [16];
	int 		i, size;

	if (!hcd->self.controller->dma_mask)
		return 0;

	for (i = 0; i < HCD_BUFFER_POOLS; i++) { 
		if (!(size = pool_max [i]))
			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 SLAB_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) {
		*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, 0);
}

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) {
		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);
}
Commit	Line	Data
1da177e4 LT	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
1da177e4 LT	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 <asm/io.h>
	14	#include <asm/scatterlist.h>
	15	#include <linux/dma-mapping.h>
	16	#include <linux/dmapool.h>
1da177e4 LT	17	#include <linux/usb.h>
	18	#include "hcd.h"
	19
	20
	21	/*
	22	* DMA-Coherent Buffers
	23	*/
	24
	25	/* FIXME tune these based on pool statistics ... */
	26	static const size_t pool_max [HCD_BUFFER_POOLS] = {
	27	/* platforms without dma-friendly caches might need to
	28	* prevent cacheline sharing...
	29	*/
	30	32,
	31	128,
	32	512,
	33	PAGE_SIZE / 2
	34	/* bigger --> allocate pages */
	35	};
	36
	37
	38	/* SETUP primitives */
	39
	40	/**
	41	* hcd_buffer_create - initialize buffer pools
	42	* @hcd: the bus whose buffer pools are to be initialized
	43	* Context: !in_interrupt()
	44	*
	45	* Call this as part of initializing a host controller that uses the dma
	46	* memory allocators. It initializes some pools of dma-coherent memory that
	47	* will be shared by all drivers using that controller, or returns a negative
	48	* errno value on error.
	49	*
	50	* Call hcd_buffer_destroy() to clean up after using those pools.
	51	*/
	52	int hcd_buffer_create (struct usb_hcd *hcd)
	53	{
	54	char name [16];
	55	int i, size;
	56
bd39b7f1 CH	57	if (!hcd->self.controller->dma_mask)
	58	return 0;
	59
1da177e4 LT	60	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
	61	if (!(size = pool_max [i]))
	62	continue;
	63	snprintf (name, sizeof name, "buffer-%d", size);
	64	hcd->pool [i] = dma_pool_create (name, hcd->self.controller,
	65	size, size, 0);
	66	if (!hcd->pool [i]) {
	67	hcd_buffer_destroy (hcd);
	68	return -ENOMEM;
	69	}
	70	}
	71	return 0;
	72	}
	73
	74
	75	/**
	76	* hcd_buffer_destroy - deallocate buffer pools
	77	* @hcd: the bus whose buffer pools are to be destroyed
	78	* Context: !in_interrupt()
	79	*
	80	* This frees the buffer pools created by hcd_buffer_create().
	81	*/
	82	void hcd_buffer_destroy (struct usb_hcd *hcd)
	83	{
	84	int i;
	85
	86	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
	87	struct dma_pool *pool = hcd->pool [i];
	88	if (pool) {
	89	dma_pool_destroy (pool);
	90	hcd->pool[i] = NULL;
	91	}
	92	}
	93	}
	94
	95
	96	/* sometimes alloc/free could use kmalloc with SLAB_DMA, for
	97	* better sharing and to leverage mm/slab.c intelligence.
	98	*/
	99
	100	void *hcd_buffer_alloc (
	101	struct usb_bus *bus,
	102	size_t size,
55016f10	103	gfp_t mem_flags,
1da177e4 LT	104	dma_addr_t *dma
	105	)
	106	{
17200583	107	struct usb_hcd *hcd = bus_to_hcd(bus);
1da177e4 LT	108	int i;
	109
	110	/* some USB hosts just use PIO */
	111	if (!bus->controller->dma_mask) {
	112	*dma = ~(dma_addr_t) 0;
	113	return kmalloc (size, mem_flags);
	114	}
	115
	116	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
	117	if (size <= pool_max [i])
	118	return dma_pool_alloc (hcd->pool [i], mem_flags, dma);
	119	}
	120	return dma_alloc_coherent (hcd->self.controller, size, dma, 0);
	121	}
	122
	123	void hcd_buffer_free (
	124	struct usb_bus *bus,
	125	size_t size,
	126	void *addr,
	127	dma_addr_t dma
	128	)
	129	{
17200583	130	struct usb_hcd *hcd = bus_to_hcd(bus);
1da177e4 LT	131	int i;
	132
	133	if (!addr)
	134	return;
	135
	136	if (!bus->controller->dma_mask) {
	137	kfree (addr);
	138	return;
	139	}
	140
	141	for (i = 0; i < HCD_BUFFER_POOLS; i++) {
	142	if (size <= pool_max [i]) {
	143	dma_pool_free (hcd->pool [i], addr, dma);
	144	return;
	145	}
	146	}
	147	dma_free_coherent (hcd->self.controller, size, addr, dma);
	148	}