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IDE: Save a call to PageHighMem()

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PageHighMem() isn't cheap so avoid calling it twice on the same page.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jean Delvare 2009-06-23 04:12:24 -07:00 committed by David S. Miller
parent 90bc1a658a
commit a907905219
1 changed files with 4 additions and 2 deletions
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6
drivers/ide/ide-taskfile.c
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@ -236,6 +236,7 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
while (len) {
unsigned nr_bytes = min(len, cursg->length - cmd->cursg_ofs);
int page_is_high;
if (nr_bytes > PAGE_SIZE)
nr_bytes = PAGE_SIZE;
@ -247,7 +248,8 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
page = nth_page(page, (offset >> PAGE_SHIFT));
offset %= PAGE_SIZE;
if (PageHighMem(page))
page_is_high = PageHighMem(page);
if (page_is_high)
local_irq_save(flags);
buf = kmap_atomic(page, KM_BIO_SRC_IRQ) + offset;
@ -268,7 +270,7 @@ void ide_pio_bytes(ide_drive_t *drive, struct ide_cmd *cmd,
kunmap_atomic(buf, KM_BIO_SRC_IRQ);
if (PageHighMem(page))
if (page_is_high)
local_irq_restore(flags);
len -= nr_bytes;