Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

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 000000000000..b7827df21f48
--- /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);
+}