patch-2.4.22 linux-2.4.22/arch/arm/common/pcipool.c
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- Lines: 392
- Date:
2003-08-25 04:44:39.000000000 -0700
- Orig file:
linux-2.4.21/arch/arm/common/pcipool.c
- Orig date:
1969-12-31 16:00:00.000000000 -0800
diff -urN linux-2.4.21/arch/arm/common/pcipool.c linux-2.4.22/arch/arm/common/pcipool.c
@@ -0,0 +1,391 @@
+/*
+ NOTE:
+
+ this code was lifted straight out of drivers/pci/pci.c;
+ when compiling for the Intel StrongARM SA-1110/SA-1111 the
+ usb-ohci.c driver needs these routines even when the architecture
+ has no pci bus...
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/bitops.h>
+
+#include <asm/page.h>
+
+/*
+ * Pool allocator ... wraps the pci_alloc_consistent page allocator, so
+ * small blocks are easily used by drivers for bus mastering controllers.
+ * This should probably be sharing the guts of the slab allocator.
+ */
+
+struct pci_pool { /* the pool */
+ struct list_head page_list;
+ spinlock_t lock;
+ size_t blocks_per_page;
+ size_t size;
+ struct pci_dev *dev;
+ size_t allocation;
+ char name [32];
+ wait_queue_head_t waitq;
+};
+
+struct pci_page { /* cacheable header for 'allocation' bytes */
+ struct list_head page_list;
+ void *vaddr;
+ dma_addr_t dma;
+ unsigned long bitmap [0];
+};
+
+#define POOL_TIMEOUT_JIFFIES ((100 /* msec */ * HZ) / 1000)
+#define POOL_POISON_BYTE 0xa7
+
+// #define CONFIG_PCIPOOL_DEBUG
+
+static inline const char *slot_name(const struct pci_pool *pool)
+{
+ const struct pci_dev *pdev = pool->dev;
+
+ if (pdev == 0)
+ return "[0]";
+
+ else if (dev_is_sa1111(pdev))
+ return "[SA-1111]";
+ else
+ return pdev->slot_name;
+}
+
+
+/**
+ * pci_pool_create - Creates a pool of pci consistent memory blocks, for dma.
+ * @name: name of pool, for diagnostics
+ * @pdev: pci device that will be doing the DMA
+ * @size: size of the blocks in this pool.
+ * @align: alignment requirement for blocks; must be a power of two
+ * @allocation: returned blocks won't cross this boundary (or zero)
+ * @mem_flags: SLAB_* flags.
+ *
+ * Returns a pci allocation pool with the requested characteristics, or
+ * null if one can't be created. Given one of these pools, pci_pool_alloc()
+ * may be used to allocate memory. Such memory will all have "consistent"
+ * DMA mappings, accessible by the device and its driver without using
+ * cache flushing primitives. The actual size of blocks allocated may be
+ * larger than requested because of alignment.
+ *
+ * If allocation is nonzero, objects returned from pci_pool_alloc() won't
+ * cross that size boundary. This is useful for devices which have
+ * addressing restrictions on individual DMA transfers, such as not crossing
+ * boundaries of 4KBytes.
+ */
+struct pci_pool *
+pci_pool_create (const char *name, struct pci_dev *pdev,
+ size_t size, size_t align, size_t allocation, int mem_flags)
+{
+ struct pci_pool *retval;
+
+ if (align == 0)
+ align = 1;
+ if (size == 0)
+ return 0;
+ else if (size < align)
+ size = align;
+ else if ((size % align) != 0) {
+ size += align + 1;
+ size &= ~(align - 1);
+ }
+
+ if (allocation == 0) {
+ if (PAGE_SIZE < size)
+ allocation = size;
+ else
+ allocation = PAGE_SIZE;
+ // FIXME: round up for less fragmentation
+ } else if (allocation < size)
+ return 0;
+
+ if (!(retval = kmalloc (sizeof *retval, mem_flags)))
+ return retval;
+
+ strncpy (retval->name, name, sizeof retval->name);
+ retval->name [sizeof retval->name - 1] = 0;
+
+ retval->dev = pdev;
+ INIT_LIST_HEAD (&retval->page_list);
+ spin_lock_init (&retval->lock);
+ retval->size = size;
+ retval->allocation = allocation;
+ retval->blocks_per_page = allocation / size;
+ init_waitqueue_head (&retval->waitq);
+
+#ifdef CONFIG_PCIPOOL_DEBUG
+ printk (KERN_DEBUG "pcipool create %s/%s size %d, %d/page (%d alloc)\n",
+ slot_name(retval), retval->name, size,
+ retval->blocks_per_page, allocation);
+#endif
+
+ return retval;
+}
+
+
+static struct pci_page *
+pool_alloc_page (struct pci_pool *pool, int mem_flags)
+{
+ struct pci_page *page;
+ int mapsize;
+
+ mapsize = pool->blocks_per_page;
+ mapsize = (mapsize + BITS_PER_LONG - 1) / BITS_PER_LONG;
+ mapsize *= sizeof (long);
+
+ page = (struct pci_page *) kmalloc (mapsize + sizeof *page, mem_flags);
+ if (!page)
+ return 0;
+ page->vaddr = pci_alloc_consistent (pool->dev,
+ pool->allocation,
+ &page->dma);
+ if (page->vaddr) {
+ memset (page->bitmap, 0xff, mapsize); // bit set == free
+#ifdef CONFIG_DEBUG_SLAB
+ memset (page->vaddr, POOL_POISON_BYTE, pool->allocation);
+#endif
+ list_add (&page->page_list, &pool->page_list);
+ } else {
+ kfree (page);
+ page = 0;
+ }
+ return page;
+}
+
+
+static inline int
+is_page_busy (int blocks, unsigned long *bitmap)
+{
+ while (blocks > 0) {
+ if (*bitmap++ != ~0UL)
+ return 1;
+ blocks -= BITS_PER_LONG;
+ }
+ return 0;
+}
+
+static void
+pool_free_page (struct pci_pool *pool, struct pci_page *page)
+{
+ dma_addr_t dma = page->dma;
+
+#ifdef CONFIG_DEBUG_SLAB
+ memset (page->vaddr, POOL_POISON_BYTE, pool->allocation);
+#endif
+ pci_free_consistent (pool->dev, pool->allocation, page->vaddr, dma);
+ list_del (&page->page_list);
+ kfree (page);
+}
+
+
+/**
+ * pci_pool_destroy - destroys a pool of pci memory blocks.
+ * @pool: pci pool that will be destroyed
+ *
+ * Caller guarantees that no more memory from the pool is in use,
+ * and that nothing will try to use the pool after this call.
+ */
+void
+pci_pool_destroy (struct pci_pool *pool)
+{
+ unsigned long flags;
+
+#ifdef CONFIG_PCIPOOL_DEBUG
+ printk (KERN_DEBUG "pcipool destroy %s/%s\n",
+ slot_name(pool), pool->name);
+#endif
+
+ spin_lock_irqsave (&pool->lock, flags);
+ while (!list_empty (&pool->page_list)) {
+ struct pci_page *page;
+ page = list_entry (pool->page_list.next,
+ struct pci_page, page_list);
+ if (is_page_busy (pool->blocks_per_page, page->bitmap)) {
+ printk (KERN_ERR "pci_pool_destroy %s/%s, %p busy\n",
+ slot_name(pool), pool->name, page->vaddr);
+ /* leak the still-in-use consistent memory */
+ list_del (&page->page_list);
+ kfree (page);
+ } else
+ pool_free_page (pool, page);
+ }
+ spin_unlock_irqrestore (&pool->lock, flags);
+ kfree (pool);
+}
+
+
+/**
+ * pci_pool_alloc - get a block of consistent memory
+ * @pool: pci pool that will produce the block
+ * @mem_flags: SLAB_KERNEL or SLAB_ATOMIC
+ * @handle: pointer to dma address of block
+ *
+ * This returns the kernel virtual address of a currently unused block,
+ * and reports its dma address through the handle.
+ * If such a memory block can't be allocated, null is returned.
+ */
+void *
+pci_pool_alloc (struct pci_pool *pool, int mem_flags, dma_addr_t *handle)
+{
+ unsigned long flags;
+ struct list_head *entry;
+ struct pci_page *page;
+ int map, block;
+ size_t offset;
+ void *retval;
+
+restart:
+ spin_lock_irqsave (&pool->lock, flags);
+ list_for_each (entry, &pool->page_list) {
+ int i;
+ page = list_entry (entry, struct pci_page, page_list);
+ /* only cachable accesses here ... */
+ for (map = 0, i = 0;
+ i < pool->blocks_per_page;
+ i += BITS_PER_LONG, map++) {
+ if (page->bitmap [map] == 0)
+ continue;
+ block = ffz (~ page->bitmap [map]);
+ if ((i + block) < pool->blocks_per_page) {
+ clear_bit (block, &page->bitmap [map]);
+ offset = (BITS_PER_LONG * map) + block;
+ offset *= pool->size;
+ goto ready;
+ }
+ }
+ }
+ if (!(page = pool_alloc_page (pool, mem_flags))) {
+ if (mem_flags == SLAB_KERNEL) {
+ DECLARE_WAITQUEUE (wait, current);
+
+ current->state = TASK_INTERRUPTIBLE;
+ add_wait_queue (&pool->waitq, &wait);
+ spin_unlock_irqrestore (&pool->lock, flags);
+
+ schedule_timeout (POOL_TIMEOUT_JIFFIES);
+
+ current->state = TASK_RUNNING;
+ remove_wait_queue (&pool->waitq, &wait);
+ goto restart;
+ }
+ retval = 0;
+ goto done;
+ }
+
+ clear_bit (0, &page->bitmap [0]);
+ offset = 0;
+ready:
+ retval = offset + page->vaddr;
+ *handle = offset + page->dma;
+done:
+ spin_unlock_irqrestore (&pool->lock, flags);
+ return retval;
+}
+
+
+static struct pci_page *
+pool_find_page (struct pci_pool *pool, dma_addr_t dma)
+{
+ unsigned long flags;
+ struct list_head *entry;
+ struct pci_page *page;
+
+ spin_lock_irqsave (&pool->lock, flags);
+ list_for_each (entry, &pool->page_list) {
+ page = list_entry (entry, struct pci_page, page_list);
+ if (dma < page->dma)
+ continue;
+ if (dma < (page->dma + pool->allocation))
+ goto done;
+ }
+ page = 0;
+done:
+ spin_unlock_irqrestore (&pool->lock, flags);
+ return page;
+}
+
+
+/**
+ * pci_pool_free - put block back into pci pool
+ * @pool: the pci pool holding the block
+ * @vaddr: virtual address of block
+ * @dma: dma address of block
+ *
+ * Caller promises neither device nor driver will again touch this block
+ * unless it is first re-allocated.
+ */
+void
+pci_pool_free (struct pci_pool *pool, void *vaddr, dma_addr_t dma)
+{
+ struct pci_page *page;
+ unsigned long flags;
+ int map, block;
+
+ if ((page = pool_find_page (pool, dma)) == 0) {
+ printk (KERN_ERR "pci_pool_free %s/%s, %p/%lx (bad dma)\n",
+ pool->dev ? pool->dev->slot_name : NULL,
+ pool->name, vaddr, (unsigned long) dma);
+ return;
+ }
+
+ block = dma - page->dma;
+ block /= pool->size;
+ map = block / BITS_PER_LONG;
+ block %= BITS_PER_LONG;
+
+#ifdef CONFIG_DEBUG_SLAB
+ if (((dma - page->dma) + (void *)page->vaddr) != vaddr) {
+ printk (KERN_ERR "pci_pool_free %s/%s, %p (bad vaddr)/%lx\n",
+ pool->dev ? pool->dev->slot_name : NULL,
+ pool->name, vaddr, (unsigned long) dma);
+ return;
+ }
+ if (page->bitmap [map] & (1UL << block)) {
+ printk (KERN_ERR "pci_pool_free %s/%s, dma %x already free\n",
+ pool->dev ? pool->dev->slot_name : NULL,
+ pool->name, dma);
+ return;
+ }
+ memset (vaddr, POOL_POISON_BYTE, pool->size);
+#endif
+
+ spin_lock_irqsave (&pool->lock, flags);
+ set_bit (block, &page->bitmap [map]);
+ if (waitqueue_active (&pool->waitq))
+ wake_up (&pool->waitq);
+ /*
+ * Resist a temptation to do
+ * if (!is_page_busy(bpp, page->bitmap)) pool_free_page(pool, page);
+ * it is not interrupt safe. Better have empty pages hang around.
+ */
+ spin_unlock_irqrestore (&pool->lock, flags);
+}
+
+
+EXPORT_SYMBOL (pci_pool_create);
+EXPORT_SYMBOL (pci_pool_destroy);
+EXPORT_SYMBOL (pci_pool_alloc);
+EXPORT_SYMBOL (pci_pool_free);
+
+/* **************************************** */
+
+static int __init pcipool_init(void)
+{
+ MOD_INC_USE_COUNT; /* never unload */
+
+ return 0;
+}
+module_init(pcipool_init);
+
+MODULE_LICENSE("GPL");
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