| Message ID | 20210518101405.1048860-3-aisheng.dong@nxp.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: mm: a few small cleanups | expand |
On Tue, May 18, 2021 at 06:14:03PM +0800, Dong Aisheng wrote: > 'count - 1' is confusing and not comply with the real code running. > 'count' actually represents the extra entries required, no need minus 1. > > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> This looks right to me, but I'm not all that familiar with this code. Steve, does this make sense to you? Mark. > --- > arch/arm64/kernel/head.S | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > index 96873dfa67fd..b70db34458ec 100644 > --- a/arch/arm64/kernel/head.S > +++ b/arch/arm64/kernel/head.S > @@ -195,7 +195,7 @@ SYM_CODE_END(preserve_boot_args) > and \iend, \iend, \istart // iend = (vend >> shift) & (ptrs - 1) > mov \istart, \ptrs > mul \istart, \istart, \count > - add \iend, \iend, \istart // iend += (count - 1) * ptrs > + add \iend, \iend, \istart // iend += count * ptrs > // our entries span multiple tables > > lsr \istart, \vstart, \shift > -- > 2.25.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Tue, May 18, 2021 at 01:35:11PM +0100, Mark Rutland wrote: > On Tue, May 18, 2021 at 06:14:03PM +0800, Dong Aisheng wrote: > > 'count - 1' is confusing and not comply with the real code running. > > 'count' actually represents the extra entries required, no need minus 1. > > > > Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> > > This looks right to me, but I'm not all that familiar with this code. > > Steve, does this make sense to you? > > Mark. > > > --- > > arch/arm64/kernel/head.S | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S > > index 96873dfa67fd..b70db34458ec 100644 > > --- a/arch/arm64/kernel/head.S > > +++ b/arch/arm64/kernel/head.S > > @@ -195,7 +195,7 @@ SYM_CODE_END(preserve_boot_args) > > and \iend, \iend, \istart // iend = (vend >> shift) & (ptrs - 1) > > mov \istart, \ptrs > > mul \istart, \istart, \count > > - add \iend, \iend, \istart // iend += (count - 1) * ptrs > > + add \iend, \iend, \istart // iend += count * ptrs > > // our entries span multiple tables The comment was updated to match the code. The code also looks ok to me: iend is inclusive and count denotes the extra entries required rather than the actual number of entries. Also cc'ing Will, I think he missed this series. Acked-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 96873dfa67fd..b70db34458ec 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -195,7 +195,7 @@ SYM_CODE_END(preserve_boot_args) and \iend, \iend, \istart // iend = (vend >> shift) & (ptrs - 1) mov \istart, \ptrs mul \istart, \istart, \count - add \iend, \iend, \istart // iend += (count - 1) * ptrs + add \iend, \iend, \istart // iend += count * ptrs // our entries span multiple tables lsr \istart, \vstart, \shift
'count - 1' is confusing and not comply with the real code running. 'count' actually represents the extra entries required, no need minus 1. Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com> --- arch/arm64/kernel/head.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)