[libata irq-pio] use PageHighMem() to optimize the kmap_atomic() usage
as done in ide-scsi.c
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 35ee35e..5e750c3 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -2748,7 +2748,6 @@
struct page *page;
unsigned int offset;
unsigned char *buf;
- unsigned long flags;
if (qc->cursect == (qc->nsect - 1))
ap->hsm_task_state = HSM_ST_LAST;
@@ -2762,14 +2761,21 @@
DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
- local_irq_save(flags);
- buf = kmap_atomic(page, KM_IRQ0);
+ if (PageHighMem(page)) {
+ unsigned long flags;
- /* do the actual data transfer */
- ata_data_xfer(ap, buf + offset, ATA_SECT_SIZE, do_write);
+ local_irq_save(flags);
+ buf = kmap_atomic(page, KM_IRQ0);
- kunmap_atomic(buf, KM_IRQ0);
- local_irq_restore(flags);
+ /* do the actual data transfer */
+ ata_data_xfer(ap, buf + offset, ATA_SECT_SIZE, do_write);
+
+ kunmap_atomic(buf, KM_IRQ0);
+ local_irq_restore(flags);
+ } else {
+ buf = page_address(page);
+ ata_data_xfer(ap, buf + offset, ATA_SECT_SIZE, do_write);
+ }
qc->cursect++;
qc->cursg_ofs++;
@@ -2908,7 +2914,6 @@
struct page *page;
unsigned char *buf;
unsigned int offset, count;
- unsigned long flags;
if (qc->curbytes + bytes >= qc->nbytes)
ap->hsm_task_state = HSM_ST_LAST;
@@ -2954,14 +2959,21 @@
DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
- local_irq_save(flags);
- buf = kmap_atomic(page, KM_IRQ0);
+ if (PageHighMem(page)) {
+ unsigned long flags;
- /* do the actual data transfer */
- ata_data_xfer(ap, buf + offset, count, do_write);
+ local_irq_save(flags);
+ buf = kmap_atomic(page, KM_IRQ0);
- kunmap_atomic(buf, KM_IRQ0);
- local_irq_restore(flags);
+ /* do the actual data transfer */
+ ata_data_xfer(ap, buf + offset, count, do_write);
+
+ kunmap_atomic(buf, KM_IRQ0);
+ local_irq_restore(flags);
+ } else {
+ buf = page_address(page);
+ ata_data_xfer(ap, buf + offset, count, do_write);
+ }
bytes -= count;
qc->curbytes += count;