Changeset 98893ede in mainline

Timestamp:

2018-01-31T17:00:39Z (7 years ago)

Author:

Ondřej Hlavatý <aearsis@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

50206e9

Parents:

3b60ea0

Message:

libusb: dma_buffers optimization

Location:

uspace/lib/usb

Files:

• include/usb/dma_buffer.h (modified) (1 diff)
• src/dma_buffer.c (modified) (4 diffs)

uspace/lib/usb/include/usb/dma_buffer.h

@@ -55 +55 @@
 } dma_buffer_t;
 
-extern dma_policy_t dma_policy_default;
-
 extern int dma_buffer_alloc(dma_buffer_t *db, size_t size);
-extern int dma_buffer_alloc_policy(dma_buffer_t *, size_t, dma_policy_t);
+extern int dma_buffer_alloc_policy(dma_buffer_t *, size_t, const dma_policy_t *);
 extern void dma_buffer_free(dma_buffer_t *);
 extern uintptr_t dma_buffer_phys(const dma_buffer_t *, void *);

uspace/lib/usb/src/dma_buffer.c

@@ -39 +39 @@
 #include "usb/dma_buffer.h"
 
-dma_policy_t dma_policy_default = {
+const dma_policy_t dma_policy_default = {
         .use64 = false,
         .alignment = PAGE_SIZE,
@@ -45 +45 @@
 
 /**
- * Allocate a DMA buffer.
- *
- * @param[in] db dma_buffer_t structure to fill
- * @param[in] policy dma_policy_t structure to guide
- * @param[in] size Size of the required memory space
- * @return Error code.
+ * The routine of allocating a DMA buffer. Inlined to force optimization for the
+ * default policy.
  */
-int dma_buffer_alloc_policy(dma_buffer_t *db, size_t size, dma_policy_t policy)
+static inline int dma_buffer_alloc_internal(dma_buffer_t *db,
+    size_t size, const dma_policy_t *policy)
 {
         assert(db);
 
-        if (policy.alignment > PAGE_SIZE)
+        if (policy->alignment > PAGE_SIZE)
                 return EINVAL;
 
-        const size_t aligned_size = ALIGN_UP(size, policy.alignment);
+        const size_t aligned_size = ALIGN_UP(size, policy->alignment);
         const size_t real_size = ALIGN_UP(aligned_size, PAGE_SIZE);
-        const uintptr_t flags = policy.use64 ? 0 : DMAMEM_4GiB;
+        const uintptr_t flags = policy->use64 ? 0 : DMAMEM_4GiB;
 
         uintptr_t phys;
@@ -71 +68 @@
 
         if (ret == EOK) {
-                /* Poison, accessing it should be enough to make sure
-                 * the location is mapped, but poison works better */
-                memset(address, 0x5, real_size);
                 db->virt = address;
                 db->phys = phys;
         }
         return ret;
+}
+
+/**
+ * Allocate a DMA buffer.
+ *
+ * @param[in] db dma_buffer_t structure to fill
+ * @param[in] size Size of the required memory space
+ * @param[in] policy dma_policy_t structure to guide
+ * @return Error code.
+ */
+int dma_buffer_alloc_policy(dma_buffer_t *db, size_t size,
+    const dma_policy_t *policy)
+{
+        return dma_buffer_alloc_internal(db, size, policy);
 }
 
@@ -89 +97 @@
 int dma_buffer_alloc(dma_buffer_t *db, size_t size)
 {
-        return dma_buffer_alloc_policy(db, size, dma_policy_default);
+        return dma_buffer_alloc_internal(db, size, &dma_policy_default);
 }