Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / usb / core / buffer.c

diff --git a/kernel/drivers/usb/core/buffer.c b/kernel/drivers/usb/core/buffer.c
new file mode 100644 (file)
index 0000000..506b969
--- /dev/null
+++ b/kernel/drivers/usb/core/buffer.c
@@ -0,0 +1,160 @@
+/*
+ * 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 (!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;
+
+       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 (!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 (!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);
+}