[linux-2.6-block.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, 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 size_t pool_max[HCD_BUFFER_POOLS] = {
	32, 128, 512, 2048,
};

void __init usb_init_pool_max(void)
{
	/*
	 * The pool_max values must never be smaller than
	 * ARCH_KMALLOC_MINALIGN.
	 */
	if (ARCH_KMALLOC_MINALIGN <= 32)
		;			/* Original value is okay */
	else if (ARCH_KMALLOC_MINALIGN <= 64)
		pool_max[0] = 64;
	else if (ARCH_KMALLOC_MINALIGN <= 128)
		pool_max[0] = 0;	/* Don't use this pool */
	else
		BUILD_BUG();		/* We don't allow this */
}

/* 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 (!IS_ENABLED(CONFIG_HAS_DMA) ||
	    (!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;

	if (!IS_ENABLED(CONFIG_HAS_DMA))
		return;

	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 (!IS_ENABLED(CONFIG_HAS_DMA) ||
	    (!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 (!IS_ENABLED(CONFIG_HAS_DMA) ||
	    (!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);
}
Commit	Line	Data
	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 ... */
	25	static size_t pool_max[HCD_BUFFER_POOLS] = {
	26	32, 128, 512, 2048,
	27	};
	28
	29	void __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	*/
	60	int 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	*/
	93	void 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
	115	void *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
	140	void 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	}