[PATCH] revert ide-scsi highmem cleanup
Jeff Garzik <jgarzik@pobox.com> points out that this was wrong: we need to
disable local interrupts while holding KM_IRQ0 due to IRQ sharing.
And holding interrupts off during a big PIO opration is expensive, so we only
want to do that if we know the page was highmem.
So revert commit 17fd47ab4d33e764216b87006d8118fa050b4c92
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index 00d6a66..a440ea3 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -180,12 +180,22 @@
return;
}
count = min(pc->sg->length - pc->b_count, bcount);
- buf = kmap_atomic(pc->sg->page, KM_IRQ0);
- drive->hwif->atapi_input_bytes(drive,
- buf + pc->b_count + pc->sg->offset, count);
- kunmap_atomic(buf, KM_IRQ0);
- bcount -= count;
- pc->b_count += count;
+ if (PageHighMem(pc->sg->page)) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ buf = kmap_atomic(pc->sg->page, KM_IRQ0) +
+ pc->sg->offset;
+ drive->hwif->atapi_input_bytes(drive,
+ buf + pc->b_count, count);
+ kunmap_atomic(buf - pc->sg->offset, KM_IRQ0);
+ local_irq_restore(flags);
+ } else {
+ buf = page_address(pc->sg->page) + pc->sg->offset;
+ drive->hwif->atapi_input_bytes(drive,
+ buf + pc->b_count, count);
+ }
+ bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
pc->sg++;
pc->b_count = 0;
@@ -205,12 +215,22 @@
return;
}
count = min(pc->sg->length - pc->b_count, bcount);
- buf = kmap_atomic(pc->sg->page, KM_IRQ0);
- drive->hwif->atapi_output_bytes(drive,
- buf + pc->b_count + pc->sg->offset, count);
- kunmap_atomic(buf, KM_IRQ0);
- bcount -= count;
- pc->b_count += count;
+ if (PageHighMem(pc->sg->page)) {
+ unsigned long flags;
+
+ local_irq_save(flags);
+ buf = kmap_atomic(pc->sg->page, KM_IRQ0) +
+ pc->sg->offset;
+ drive->hwif->atapi_output_bytes(drive,
+ buf + pc->b_count, count);
+ kunmap_atomic(buf - pc->sg->offset, KM_IRQ0);
+ local_irq_restore(flags);
+ } else {
+ buf = page_address(pc->sg->page) + pc->sg->offset;
+ drive->hwif->atapi_output_bytes(drive,
+ buf + pc->b_count, count);
+ }
+ bcount -= count; pc->b_count += count;
if (pc->b_count == pc->sg->length) {
pc->sg++;
pc->b_count = 0;