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authorArthur Benilov <arthur.benilov@gmail.com>2010-09-24 19:26:13 +0200
committerGreg Kroah-Hartman <gregkh@suse.de>2010-09-30 04:33:26 -0700
commit53059aa05988761a738fa8bc082bbf3c5d4462d1 (patch)
tree1d260afd6dce5e55389516d444570e4e6bc42c37 /drivers
parent0abd242839eac8437521101c9361c095728eded3 (diff)
Staging: vme: Assure D16 cycle if required in master_read and master_write
From a95892fc2246d6dc45f57b7dd68f32b9b28bd0f7 Mon Sep 17 00:00:00 2001 From: Arthur Benilov <arthur.benilov@gmail.com> Date: Fri, 24 Sep 2010 13:51:07 +0200 Subject: [PATCH] Staging: vme: Assure D16 cycle if required in master_read and master_write memcpy_fromio() and memcpy_toio() functions apply internally to __memcpy() that performs data transfer in 32-bits or 8-bits blocks (at least on x86). This makes impossible to perform D16 cycle with ca91cx42 bridge. Provided modification assures performing data transfer with 32, 16, and 8 bits chunks. Signed-off-by: Arthur Benilov <arthur.benilov@iba-group.com> Signed-off-by: Martyn Welch <martyn.welch@ge.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/vme/bridges/vme_ca91cx42.c94
1 files changed, 89 insertions, 5 deletions
diff --git a/drivers/staging/vme/bridges/vme_ca91cx42.c b/drivers/staging/vme/bridges/vme_ca91cx42.c
index 06bd793c52b5..4d745623211b 100644
--- a/drivers/staging/vme/bridges/vme_ca91cx42.c
+++ b/drivers/staging/vme/bridges/vme_ca91cx42.c
@@ -848,12 +848,57 @@ ssize_t ca91cx42_master_read(struct vme_master_resource *image, void *buf,
size_t count, loff_t offset)
{
ssize_t retval;
+ void *addr = image->kern_base + offset;
+ unsigned int done = 0;
+ unsigned int count32;
+
+ if (count == 0)
+ return 0;
spin_lock(&(image->lock));
- memcpy_fromio(buf, image->kern_base + offset, (unsigned int)count);
- retval = count;
+ /* 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.
+ */
+ if ((int)addr & 0x1) {
+ *(u8 *)buf = ioread8(addr);
+ done += 1;
+ if (done == count)
+ goto out;
+ }
+ if ((int)addr & 0x2) {
+ if ((count - done) < 2) {
+ *(u8 *)(buf + done) = ioread8(addr + done);
+ done += 1;
+ goto out;
+ } else {
+ *(u16 *)(buf + done) = ioread16(addr + done);
+ done += 2;
+ }
+ }
+ count32 = (count - done) & ~0x3;
+ if (count32 > 0) {
+ memcpy_fromio(buf + done, addr + done, (unsigned int)count);
+ done += count32;
+ }
+
+ if ((count - done) & 0x2) {
+ *(u16 *)(buf + done) = ioread16(addr + done);
+ done += 2;
+ }
+ if ((count - done) & 0x1) {
+ *(u8 *)(buf + done) = ioread8(addr + done);
+ done += 1;
+ }
+out:
+ retval = count;
spin_unlock(&(image->lock));
return retval;
@@ -862,15 +907,54 @@ ssize_t ca91cx42_master_read(struct vme_master_resource *image, void *buf,
ssize_t ca91cx42_master_write(struct vme_master_resource *image, void *buf,
size_t count, loff_t offset)
{
- int retval = 0;
+ ssize_t retval;
+ void *addr = image->kern_base + offset;
+ unsigned int done = 0;
+ unsigned int count32;
+
+ if (count == 0)
+ return 0;
spin_lock(&(image->lock));
- memcpy_toio(image->kern_base + offset, buf, (unsigned int)count);
+ /* Here we apply for the same strategy we do in master_read
+ * function in order to assure D16 cycle when required.
+ */
+ if ((int)addr & 0x1) {
+ iowrite8(*(u8 *)buf, addr);
+ done += 1;
+ if (done == count)
+ goto out;
+ }
+ if ((int)addr & 0x2) {
+ if ((count - done) < 2) {
+ iowrite8(*(u8 *)(buf + done), addr + done);
+ done += 1;
+ goto out;
+ } else {
+ iowrite16(*(u16 *)(buf + done), addr + done);
+ done += 2;
+ }
+ }
+
+ count32 = (count - done) & ~0x3;
+ if (count32 > 0) {
+ memcpy_toio(addr + done, buf + done, count32);
+ done += count32;
+ }
+
+ if ((count - done) & 0x2) {
+ iowrite16(*(u16 *)(buf + done), addr + done);
+ done += 2;
+ }
+ if ((count - done) & 0x1) {
+ iowrite8(*(u8 *)(buf + done), addr + done);
+ done += 1;
+ }
+out:
retval = count;
spin_unlock(&(image->lock));
-
return retval;
}