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ata: libata-sff: replace kmap_atomic() with kmap_local_page()

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kmap_atomic() is deprecated in favour of kmap_local_page(), as described
in Documentation/mm/highmem.rst.

ata_pio_xfer() and __atapi_pio_bytes() each map a single page, pass the
address to ->sff_data_xfer() for one transfer and unmap it again, so the
mapping never leaves the function that created it.

Neither needs the pagefault_disable() and preempt_disable() implied by
kmap_atomic(). ->sff_data_xfer() only moves data between the device and
the mapped buffer, and both functions are reached only through
ata_sff_hsm_move() with the host lock held, whether from the PIO task,
an interrupt handler or EH. kmap_local_page() is fine in all of these.

Assisted-by: LLM sparse
Signed-off-by: Danish Khateeb <danishkhateeb03@gmail.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20260921182448.194307-1-danishkhateeb03@gmail.com
Signed-off-by: Niklas Cassel <cassel@kernel.org>
This commit is contained in:
Danish Khateeb 2026-09-21 13:24:48 -05:00 committed by Niklas Cassel
parent 3bab8c7e0c
commit 02178d4b69
1 changed files with 4 additions and 4 deletions
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8
drivers/ata/libata-sff.c
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@ -580,9 +580,9 @@ static void ata_pio_xfer(struct ata_queued_cmd *qc, struct page *page,
bool do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
unsigned char *buf;
buf = kmap_atomic(page);
buf = kmap_local_page(page);
qc->ap->ops->sff_data_xfer(qc, buf + offset, xfer_size, do_write);
kunmap_atomic(buf);
kunmap_local(buf);
if (!do_write && !PageSlab(page))
flush_dcache_page(page);
@ -763,9 +763,9 @@ static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
trace_atapi_pio_transfer_data(qc, offset, count);
/* do the actual data transfer */
buf = kmap_atomic(page);
buf = kmap_local_page(page);
consumed = ap->ops->sff_data_xfer(qc, buf + offset, count, rw);
kunmap_atomic(buf);
kunmap_local(buf);
bytes -= min(bytes, consumed);
qc->curbytes += count;