IDE: Improve DMA transfers by increasing the buffer size

(Ian Jackson)


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@4132 c046a42c-6fe2-441c-8c8c-71466251a162

hw/ide.c

@@ -202,6 +202,12 @@
 /* set to 1 set disable mult support */
 #define MAX_MULT_SECTORS 16
 
+#define IDE_DMA_BUF_SECTORS 256
+
+#if (IDE_DMA_BUF_SECTORS < MAX_MULT_SECTORS)
+#error "IDE_DMA_BUF_SECTORS must be bigger or equal to MAX_MULT_SECTORS"
+#endif
+
 /* ATAPI defines */
 
 #define ATAPI_PACKET_SIZE 12
@@ -899,8 +905,8 @@ static void ide_read_dma_cb(void *opaque, int ret)
 
     /* launch next transfer */
     n = s->nsector;
-    if (n > MAX_MULT_SECTORS)
-        n = MAX_MULT_SECTORS;
+    if (n > IDE_DMA_BUF_SECTORS)
+        n = IDE_DMA_BUF_SECTORS;
     s->io_buffer_index = 0;
     s->io_buffer_size = n * 512;
 #ifdef DEBUG_AIO
@@ -998,8 +1004,8 @@ static void ide_write_dma_cb(void *opaque, int ret)
 
     /* launch next transfer */
     n = s->nsector;
-    if (n > MAX_MULT_SECTORS)
-        n = MAX_MULT_SECTORS;
+    if (n > IDE_DMA_BUF_SECTORS)
+        n = IDE_DMA_BUF_SECTORS;
     s->io_buffer_index = 0;
     s->io_buffer_size = n * 512;
 
@@ -1293,8 +1299,8 @@ static void ide_atapi_cmd_read_dma_cb(void *opaque, int ret)
         data_offset = 16;
     } else {
         n = s->packet_transfer_size >> 11;
-        if (n > (MAX_MULT_SECTORS / 4))
-            n = (MAX_MULT_SECTORS / 4);
+        if (n > (IDE_DMA_BUF_SECTORS / 4))
+            n = (IDE_DMA_BUF_SECTORS / 4);
         s->io_buffer_size = n * 2048;
         data_offset = 0;
     }
@@ -2524,7 +2530,7 @@ static void ide_init2(IDEState *ide_state,
 
     for(i = 0; i < 2; i++) {
         s = ide_state + i;
-        s->io_buffer = qemu_memalign(512, MAX_MULT_SECTORS*512 + 4);
+        s->io_buffer = qemu_memalign(512, IDE_DMA_BUF_SECTORS*512 + 4);
         if (i == 0)
             s->bs = hd0;
         else