| Message ID | 20221005101951.3165-4-adrian.hunter@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mmc: Replace kmap_atomic() with kmap_local_page() | expand |
> kmap_local_page() is equivalent to kmap_atomic() except that it does not > disable page faults or preemption. Where possible kmap_local_page() is > preferred to kmap_atomic() - refer kernel highmem documentation. > > In this case, there is no need to disable page faults or preemption, so replace > kmap_atomic() with kmap_local_page(), and, correspondingly, > kunmap_atomic() with kunmap_local(). > > Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> > --- > drivers/mmc/host/sdhci.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index > 31d87ec7d055..fb6e9a81f198 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -697,12 +697,12 @@ static int sdhci_pre_dma_transfer(struct sdhci_host > *host, > > static char *sdhci_kmap_atomic(struct scatterlist *sg) { > - return kmap_atomic(sg_page(sg)) + sg->offset; > + return kmap_local_page(sg_page(sg)) + sg->offset; > } > > static void sdhci_kunmap_atomic(void *buffer) { > - kunmap_atomic(buffer); > + kunmap_local(buffer); kmap_local_page documentation, indicates that the unmapping should be done in reverse order. Isn't it something that the callers of sdhci_kunmap_atomic now needs to attend? Thanks, Avri > } > > void sdhci_adma_write_desc(struct sdhci_host *host, void **desc, > -- > 2.25.1
On 6/10/22 10:03, Avri Altman wrote: >> kmap_local_page() is equivalent to kmap_atomic() except that it does not >> disable page faults or preemption. Where possible kmap_local_page() is >> preferred to kmap_atomic() - refer kernel highmem documentation. >> >> In this case, there is no need to disable page faults or preemption, so replace >> kmap_atomic() with kmap_local_page(), and, correspondingly, >> kunmap_atomic() with kunmap_local(). >> >> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> >> --- >> drivers/mmc/host/sdhci.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index >> 31d87ec7d055..fb6e9a81f198 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -697,12 +697,12 @@ static int sdhci_pre_dma_transfer(struct sdhci_host >> *host, >> >> static char *sdhci_kmap_atomic(struct scatterlist *sg) { >> - return kmap_atomic(sg_page(sg)) + sg->offset; >> + return kmap_local_page(sg_page(sg)) + sg->offset; >> } >> >> static void sdhci_kunmap_atomic(void *buffer) { >> - kunmap_atomic(buffer); >> + kunmap_local(buffer); > kmap_local_page documentation, indicates that the unmapping should be done in reverse order. > Isn't it something that the callers of sdhci_kunmap_atomic now needs to attend? Nesting is strictly ordered in either case, so there is no change there. i.e. the map management is stack based
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index 31d87ec7d055..fb6e9a81f198 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -697,12 +697,12 @@ static int sdhci_pre_dma_transfer(struct sdhci_host *host, static char *sdhci_kmap_atomic(struct scatterlist *sg) { - return kmap_atomic(sg_page(sg)) + sg->offset; + return kmap_local_page(sg_page(sg)) + sg->offset; } static void sdhci_kunmap_atomic(void *buffer) { - kunmap_atomic(buffer); + kunmap_local(buffer); } void sdhci_adma_write_desc(struct sdhci_host *host, void **desc,
kmap_local_page() is equivalent to kmap_atomic() except that it does not disable page faults or preemption. Where possible kmap_local_page() is preferred to kmap_atomic() - refer kernel highmem documentation. In this case, there is no need to disable page faults or preemption, so replace kmap_atomic() with kmap_local_page(), and, correspondingly, kunmap_atomic() with kunmap_local(). Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> --- drivers/mmc/host/sdhci.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)