Patch "powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N" has been added to the 4.11-stable tree

[<gregkh@linuxfoundation.org>]

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

    powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N

to the 4.11-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-fix-booting-p9-hash-with-config_ppc_radix_mmu-n.patch
and it can be found in the queue-4.11 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 d957fb4d173647640a2b83e7c7e56a580e7fc7e7 Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey@neuling.org>
Date: Wed, 24 May 2017 17:03:26 +1000
Subject: powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N

From: Michael Neuling <mikey@neuling.org>

commit d957fb4d173647640a2b83e7c7e56a580e7fc7e7 upstream.

Currently if you disable CONFIG_PPC_RADIX_MMU you'll crash on boot on
a P9. This is because we still set MMU_FTR_TYPE_RADIX via
ibm,pa-features and MMU_FTR_TYPE_RADIX is what's used for code patching
in much of the asm code (ie. slb_miss_realmode)

This patch fixes the problem by stopping MMU_FTR_TYPE_RADIX from being
set from ibm.pa-features.

We may eventually end up removing the CONFIG_PPC_RADIX_MMU option
completely but until then this fixes the issue.

Fixes: 17a3dd2f5fc7 ("powerpc/mm/radix: Use firmware feature to enable Radix MMU")
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/powerpc/kernel/prom.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -161,7 +161,9 @@ static struct ibm_pa_feature {
 	{ .pabyte = 0,  .pabit = 3, .cpu_features  = CPU_FTR_CTRL },
 	{ .pabyte = 0,  .pabit = 6, .cpu_features  = CPU_FTR_NOEXECUTE },
 	{ .pabyte = 1,  .pabit = 2, .mmu_features  = MMU_FTR_CI_LARGE_PAGE },
+#ifdef CONFIG_PPC_RADIX_MMU
 	{ .pabyte = 40, .pabit = 0, .mmu_features  = MMU_FTR_TYPE_RADIX },
+#endif
 	{ .pabyte = 1,  .pabit = 1, .invert = 1, .cpu_features = CPU_FTR_NODSISRALIGN },
 	{ .pabyte = 5,  .pabit = 0, .cpu_features  = CPU_FTR_REAL_LE,
 				    .cpu_user_ftrs = PPC_FEATURE_TRUE_LE },


Patches currently in stable-queue which might be from mikey@neuling.org are

queue-4.11/powerpc-fix-booting-p9-hash-with-config_ppc_radix_mmu-n.patch