| Message ID | 20221123205219.31748-6-anirudh.venkataramanan@intel.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 350d351389e9f3885697de477986f1f891f95fda |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Remove uses of kmap_atomic() | expand |
On mercoledì 23 novembre 2022 21:52:18 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: Ira Weiny <ira.weiny@intel.com> > Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> > Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> > --- > v1 -> v2: Update commit message > --- > drivers/net/ethernet/sun/sunvnet_common.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Thanks, Fabio > diff --git a/drivers/net/ethernet/sun/sunvnet_common.c > b/drivers/net/ethernet/sun/sunvnet_common.c index 80fde5f..a6211b9 100644 > --- a/drivers/net/ethernet/sun/sunvnet_common.c > +++ b/drivers/net/ethernet/sun/sunvnet_common.c > @@ -1085,13 +1085,13 @@ static inline int vnet_skb_map(struct ldc_channel *lp, > struct sk_buff *skb, u8 *vaddr; > > if (nc < ncookies) { > - vaddr = kmap_atomic(skb_frag_page(f)); > + vaddr = kmap_local_page(skb_frag_page(f)); > blen = skb_frag_size(f); > blen += 8 - (blen & 7); > err = ldc_map_single(lp, vaddr + skb_frag_off(f), > blen, cookies + nc, ncookies - nc, > map_perm); > - kunmap_atomic(vaddr); > + kunmap_local(vaddr); > } else { > err = -EMSGSIZE; > } > -- > 2.37.2
diff --git a/drivers/net/ethernet/sun/sunvnet_common.c b/drivers/net/ethernet/sun/sunvnet_common.c index 80fde5f..a6211b9 100644 --- a/drivers/net/ethernet/sun/sunvnet_common.c +++ b/drivers/net/ethernet/sun/sunvnet_common.c @@ -1085,13 +1085,13 @@ static inline int vnet_skb_map(struct ldc_channel *lp, struct sk_buff *skb, u8 *vaddr; if (nc < ncookies) { - vaddr = kmap_atomic(skb_frag_page(f)); + vaddr = kmap_local_page(skb_frag_page(f)); blen = skb_frag_size(f); blen += 8 - (blen & 7); err = ldc_map_single(lp, vaddr + skb_frag_off(f), blen, cookies + nc, ncookies - nc, map_perm); - kunmap_atomic(vaddr); + kunmap_local(vaddr); } else { err = -EMSGSIZE; }
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: Ira Weiny <ira.weiny@intel.com> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> --- v1 -> v2: Update commit message --- drivers/net/ethernet/sun/sunvnet_common.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)