| Message ID | 20221123205219.31748-7-anirudh.venkataramanan@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | c3a8d375f3b996e6e9a32e2b8249b6d704b358e3 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Remove uses of kmap_atomic() | expand |
On Wed, Nov 23, 2022 at 12:52:19PM -0800, Anirudh Venkataramanan wrote: > kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace > kmap_atomic() and kunmap_atomic() with kmap_local_page() and kunmap_local() > respectively. > > Note that kmap_atomic() disables preemption and page-fault processing, but > kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has > to check if the code being executed between the map/unmap implicitly > depends on page-faults and/or preemption being disabled. If yes, then code > to disable page-faults and/or preemption should also be added for > functional correctness. That however doesn't appear to be the case here, > so just kmap_local_page() is used. > > Also note that the page being mapped is not allocated by the driver, and so > the driver doesn't know if the page is in normal memory. This is the reason > kmap_local_page() is used as opposed to page_address(). > > I don't have hardware, so this change has only been compile tested. > > Cc: Michael Jamet <michael.jamet@intel.com> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
On mercoledì 23 novembre 2022 21:52:19 CET Anirudh Venkataramanan wrote: > kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace > kmap_atomic() and kunmap_atomic() with kmap_local_page() and kunmap_local() > respectively. > > Note that kmap_atomic() disables preemption and page-fault processing, but > kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has > to check if the code being executed between the map/unmap implicitly > depends on page-faults and/or preemption being disabled. If yes, then code > to disable page-faults and/or preemption should also be added for > functional correctness. That however doesn't appear to be the case here, > so just kmap_local_page() is used. > > Also note that the page being mapped is not allocated by the driver, and so > the driver doesn't know if the page is in normal memory. This is the reason > kmap_local_page() is used as opposed to page_address(). > > I don't have hardware, so this change has only been compile tested. > > Cc: Michael Jamet <michael.jamet@intel.com> > Cc: Mika Westerberg <mika.westerberg@linux.intel.com> > Cc: Yehezkel Bernat <YehezkelShB@gmail.com> > Cc: Ira Weiny <ira.weiny@intel.com> > Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> > Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> > --- > drivers/net/thunderbolt.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Thanks, Fabio > diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c > index a52ee2b..b20cd37 100644 > --- a/drivers/net/thunderbolt.c > +++ b/drivers/net/thunderbolt.c > @@ -1051,7 +1051,7 @@ static void *tbnet_kmap_frag(struct sk_buff *skb, > unsigned int frag_num, const skb_frag_t *frag = > &skb_shinfo(skb)->frags[frag_num]; > > *len = skb_frag_size(frag); > - return kmap_atomic(skb_frag_page(frag)) + skb_frag_off(frag); > + return kmap_local_page(skb_frag_page(frag)) + skb_frag_off(frag); > } > > static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, > @@ -1109,7 +1109,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, > dest += len; > > if (unmap) { > - kunmap_atomic(src); > + kunmap_local(src); > unmap = false; > } > > @@ -1147,7 +1147,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, > dest += len; > > if (unmap) { > - kunmap_atomic(src); > + kunmap_local(src); > unmap = false; > } > > @@ -1162,7 +1162,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, > memcpy(dest, src, data_len); > > if (unmap) > - kunmap_atomic(src); > + kunmap_local(src); > > if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1)) > goto err_drop; > -- > 2.37.2
diff --git a/drivers/net/thunderbolt.c b/drivers/net/thunderbolt.c index a52ee2b..b20cd37 100644 --- a/drivers/net/thunderbolt.c +++ b/drivers/net/thunderbolt.c @@ -1051,7 +1051,7 @@ static void *tbnet_kmap_frag(struct sk_buff *skb, unsigned int frag_num, const skb_frag_t *frag = &skb_shinfo(skb)->frags[frag_num]; *len = skb_frag_size(frag); - return kmap_atomic(skb_frag_page(frag)) + skb_frag_off(frag); + return kmap_local_page(skb_frag_page(frag)) + skb_frag_off(frag); } static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, @@ -1109,7 +1109,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, dest += len; if (unmap) { - kunmap_atomic(src); + kunmap_local(src); unmap = false; } @@ -1147,7 +1147,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, dest += len; if (unmap) { - kunmap_atomic(src); + kunmap_local(src); unmap = false; } @@ -1162,7 +1162,7 @@ static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb, memcpy(dest, src, data_len); if (unmap) - kunmap_atomic(src); + kunmap_local(src); if (!tbnet_xmit_csum_and_map(net, skb, frames, frame_index + 1)) goto err_drop;
kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace kmap_atomic() and kunmap_atomic() with kmap_local_page() and kunmap_local() respectively. Note that kmap_atomic() disables preemption and page-fault processing, but kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has to check if the code being executed between the map/unmap implicitly depends on page-faults and/or preemption being disabled. If yes, then code to disable page-faults and/or preemption should also be added for functional correctness. That however doesn't appear to be the case here, so just kmap_local_page() is used. Also note that the page being mapped is not allocated by the driver, and so the driver doesn't know if the page is in normal memory. This is the reason kmap_local_page() is used as opposed to page_address(). I don't have hardware, so this change has only been compile tested. Cc: Michael Jamet <michael.jamet@intel.com> Cc: Mika Westerberg <mika.westerberg@linux.intel.com> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> --- drivers/net/thunderbolt.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)