Patch "powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB" has been added to the 4.19-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     powerpc-allow-flush_-inval_-dcache_range-to-work-across-ranges-4gb.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From alastair@au1.ibm.com  Tue Aug 27 08:18:42 2019
From: "Alastair D'Silva" <alastair@au1.ibm.com>
Date: Wed, 21 Aug 2019 10:19:27 +1000
Subject: powerpc: Allow flush_(inval_)dcache_range to work across ranges >4GB
To: alastair@d-silva.org
Cc: stable@vger.kernel.org, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>, Thomas Gleixner <tglx@linutronix.de>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Allison Randal <allison@lohutok.net>, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Message-ID: <20190821001929.4253-1-alastair@au1.ibm.com>


From: Alastair D'Silva <alastair@d-silva.org>

The upstream commit:
22e9c88d486a ("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
has a similar effect, but since it is a rewrite of the assembler to C, is
too invasive for stable. This patch is a minimal fix to address the issue in
assembler.

This patch applies cleanly to v5.2, v4.19 & v4.14.

When calling flush_(inval_)dcache_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>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/misc_64.S |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -135,7 +135,7 @@ _GLOBAL_TOC(flush_dcache_range)
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5		/* ensure we get enough */
 	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)	/* Get log-2 of dcache block size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	mtctr	r8
 0:	dcbst	0,r6
@@ -153,7 +153,7 @@ _GLOBAL(flush_inval_dcache_range)
 	subf	r8,r6,r4		/* compute length */
 	add	r8,r8,r5		/* ensure we get enough */
 	lwz	r9,DCACHEL1LOGBLOCKSIZE(r10)/* Get log-2 of dcache block size */
-	srw.	r8,r8,r9		/* compute line count */
+	srd.	r8,r8,r9		/* compute line count */
 	beqlr				/* nothing to do? */
 	sync
 	isync


Patches currently in stable-queue which might be from alastair@au1.ibm.com are

queue-4.19/powerpc-allow-flush_-inval_-dcache_range-to-work-across-ranges-4gb.patch