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FAILED: patch "[PATCH] powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N" failed to apply to 4.9-stable tree

PATCH [email protected] 1 participant 1 message Jun 5, 2017

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The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From d957fb4d173647640a2b83e7c7e56a580e7fc7e7 Mon Sep 17 00:00:00 2001

From: Michael Neuling <[email protected]>
Date: Wed, 24 May 2017 17:03:26 +1000
Subject: [PATCH] powerpc: Fix booting P9 hash with CONFIG_PPC_RADIX_MMU=N

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")
arch/powerpc/kernel/prom.c +2 -0
index 40c4887c27b6..f83056297441 100644
@@ -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 },