1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/usb/core/buffer.c b/drivers/usb/core/buffer.c
new file mode 100644
index 00000000000..b7827df21f4
--- /dev/null
+++ b/drivers/usb/core/buffer.c
@@ -0,0 +1,154 @@
+/*
+ * 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/config.h>
+#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>
+
+
+#ifdef CONFIG_USB_DEBUG
+	#define DEBUG
+#else
+	#undef DEBUG
+#endif
+
+#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;
+
+	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,
+	int			mem_flags,
+	dma_addr_t		*dma
+)
+{
+	struct usb_hcd		*hcd = bus->hcpriv;
+	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->hcpriv;
+	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);
+}