diff mbox series

[v2,1/6] powerpc: Allow flush_icache_range to work across ranges >4GB

Message ID 20190903052407.16638-2-alastair@au1.ibm.com (mailing list archive)
State Changes Requested
Headers show
Series powerpc: convert cache asm to C | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch next (c317052c95bef1f977b023158e5aa929215f443d)
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked

Commit Message

Alastair D'Silva Sept. 3, 2019, 5:23 a.m. UTC
From: Alastair D'Silva <alastair@d-silva.org>

When calling flush_icache_range with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.

This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.

Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
---
 arch/powerpc/kernel/misc_64.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Christophe Leroy Sept. 14, 2019, 7:46 a.m. UTC | #1
Le 03/09/2019 à 07:23, Alastair D'Silva a écrit :
> From: Alastair D'Silva <alastair@d-silva.org>
> 
> When calling flush_icache_range with a size >4GB, we were masking
> off the upper 32 bits, so we would incorrectly flush a range smaller
> than intended.
> 
> This patch replaces the 32 bit shifts with 64 bit ones, so that
> the full size is accounted for.

Isn't there the same issue in arch/powerpc/kernel/vdso64/cacheflush.S ?

Christophe

> 
> Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
> Cc: stable@vger.kernel.org
> ---
>   arch/powerpc/kernel/misc_64.S | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
> index b55a7b4cb543..9bc0aa9aeb65 100644
> --- a/arch/powerpc/kernel/misc_64.S
> +++ b/arch/powerpc/kernel/misc_64.S
> @@ -82,7 +82,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
>   	subf	r8,r6,r4		/* compute length */
>   	add	r8,r8,r5		/* ensure we get enough */
>   	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of cache block size */
> -	srw.	r8,r8,r9		/* compute line count */
> +	srd.	r8,r8,r9		/* compute line count */
>   	beqlr				/* nothing to do? */
>   	mtctr	r8
>   1:	dcbst	0,r6
> @@ -98,7 +98,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
>   	subf	r8,r6,r4		/* compute length */
>   	add	r8,r8,r5
>   	lwz	r9,ICACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of Icache block size */
> -	srw.	r8,r8,r9		/* compute line count */
> +	srd.	r8,r8,r9		/* compute line count */
>   	beqlr				/* nothing to do? */
>   	mtctr	r8
>   2:	icbi	0,r6
>
Alastair D'Silva Sept. 16, 2019, 3:25 a.m. UTC | #2
On Sat, 2019-09-14 at 09:46 +0200, Christophe Leroy wrote:
> 
> Le 03/09/2019 à 07:23, Alastair D'Silva a écrit :
> > From: Alastair D'Silva <alastair@d-silva.org>
> > 
> > When calling flush_icache_range with a size >4GB, we were masking
> > off the upper 32 bits, so we would incorrectly flush a range
> > smaller
> > than intended.
> > 
> > This patch replaces the 32 bit shifts with 64 bit ones, so that
> > the full size is accounted for.
> 
> Isn't there the same issue in arch/powerpc/kernel/vdso64/cacheflush.S
> ?
> 
> Christophe

Yes, there is. I'll fix it, but I wonder whether anything calls it? I
asked Google, and every mention of it was in the kernel source or
mailing list.

Maybe BenH can chime in?
diff mbox series

Patch

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index b55a7b4cb543..9bc0aa9aeb65 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -82,7 +82,7 @@  END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5		/* ensure we get enough */
 	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of cache block size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	mtctr	r8
 1:	dcbst	0,r6
@@ -98,7 +98,7 @@  END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5
 	lwz	r9,ICACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of Icache block size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	mtctr	r8
 2:	icbi	0,r6