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path: root/drivers/vme/bridges/vme_ca91cx42.c
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Diffstat (limited to 'drivers/vme/bridges/vme_ca91cx42.c')
-rw-r--r--drivers/vme/bridges/vme_ca91cx42.c29
1 files changed, 14 insertions, 15 deletions
diff --git a/drivers/vme/bridges/vme_ca91cx42.c b/drivers/vme/bridges/vme_ca91cx42.c
index 1b5d48c578e1..bfb2d3f06738 100644
--- a/drivers/vme/bridges/vme_ca91cx42.c
+++ b/drivers/vme/bridges/vme_ca91cx42.c
@@ -869,14 +869,13 @@ static ssize_t ca91cx42_master_read(struct vme_master_resource *image,
spin_lock(&image->lock);
- /* The following code handles VME address alignment problem
- * in order to assure the maximal data width cycle.
- * We cannot use memcpy_xxx directly here because it
- * may cut data transfer in 8-bits cycles, thus making
- * D16 cycle impossible.
- * From the other hand, the bridge itself assures that
- * maximal configured data cycle is used and splits it
- * automatically for non-aligned addresses.
+ /* The following code handles VME address alignment. We cannot use
+ * memcpy_xxx here because it may cut data transfers in to 8-bit
+ * cycles when D16 or D32 cycles are required on the VME bus.
+ * On the other hand, the bridge itself assures that the maximum data
+ * cycle configured for the transfer is used and splits it
+ * automatically for non-aligned addresses, so we don't want the
+ * overhead of needlessly forcing small transfers for the entire cycle.
*/
if ((uintptr_t)addr & 0x1) {
*(u8 *)buf = ioread8(addr);
@@ -896,9 +895,9 @@ static ssize_t ca91cx42_master_read(struct vme_master_resource *image,
}
count32 = (count - done) & ~0x3;
- if (count32 > 0) {
- memcpy_fromio(buf + done, addr + done, (unsigned int)count);
- done += count32;
+ while (done < count32) {
+ *(u32 *)(buf + done) = ioread32(addr + done);
+ done += 4;
}
if ((count - done) & 0x2) {
@@ -930,7 +929,7 @@ static ssize_t ca91cx42_master_write(struct vme_master_resource *image,
spin_lock(&image->lock);
/* Here we apply for the same strategy we do in master_read
- * function in order to assure D16 cycle when required.
+ * function in order to assure the correct cycles.
*/
if ((uintptr_t)addr & 0x1) {
iowrite8(*(u8 *)buf, addr);
@@ -950,9 +949,9 @@ static ssize_t ca91cx42_master_write(struct vme_master_resource *image,
}
count32 = (count - done) & ~0x3;
- if (count32 > 0) {
- memcpy_toio(addr + done, buf + done, count32);
- done += count32;
+ while (done < count32) {
+ iowrite32(*(u32 *)(buf + done), addr + done);
+ done += 4;
}
if ((count - done) & 0x2) {