[libata irq-pio] use PageHighMem() to optimize the kmap_atomic() usage (91b8b313) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/scsi/libata-core.c

+26 −14

Original line number	Diff line number	Diff line
		@@ -2748,7 +2748,6 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)
		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;
		@@ -2762,6 +2761,9 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)

		DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");

		if (PageHighMem(page)) {
		unsigned long flags;

		local_irq_save(flags);
		buf = kmap_atomic(page, KM_IRQ0);

		@@ -2770,6 +2772,10 @@ static void ata_pio_sector(struct ata_queued_cmd *qc)

		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 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
		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;
		@@ -2954,6 +2959,9 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)

		DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");

		if (PageHighMem(page)) {
		unsigned long flags;

		local_irq_save(flags);
		buf = kmap_atomic(page, KM_IRQ0);

		@@ -2962,6 +2970,10 @@ static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)

		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;