FAILED: patch "[PATCH] powerpc/fsl_booke: Avoid creating duplicate tlb1 entry" failed to apply to 4.4-stable tree

PATCH [email protected] 1 participant 1 message Apr 15, 2020

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2020-04-15 13:17 UTC #0 lore raw

The patch below does not apply to the 4.4-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 ------------------

From aa4113340ae6c2811e046f08c2bc21011d20a072 Mon Sep 17 00:00:00 2001
From: Laurentiu Tudor <[email protected]>
Date: Thu, 23 Jan 2020 11:19:25 +0000
Subject: [PATCH] powerpc/fsl_booke: Avoid creating duplicate tlb1 entry

In the current implementation, the call to loadcam_multi() is wrapped between switch_to_as1() and restore_to_as0() calls so, when it tries to create its own temporary AS=1 TLB1 entry, it ends up duplicating the existing one created by switch_to_as1(). Add a check to skip creating the temporary entry if already running in AS=1.

Fixes d9e1831a4202 ("powerpc/85xx: Load all early TLB entries at once")

Cc [email protected] # v4.4+

Signed-off-by Laurentiu Tudor <[email protected]>

Acked-by Scott Wood <[email protected]>

Signed-off-by Michael Ellerman <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

arch/powerpc/mm/nohash/tlb_low.S +11 -1

index 2ca407cedbe7..eaeee402f96e 100644
@@ -397,7 +397,7 @@ _GLOBAL(set_context)
  * extern void loadcam_entry(unsigned int index)
  *
  * Load TLBCAM[index] entry in to the L2 CAM MMU
- * Must preserve r7, r8, r9, and r10
+ * Must preserve r7, r8, r9, r10 and r11
  */
 _GLOBAL(loadcam_entry)
 	mflr	r5

@@ -433,6 +433,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS)
  */
 _GLOBAL(loadcam_multi)
 	mflr	r8
+	/* Don't switch to AS=1 if already there */
+	mfmsr	r11
+	andi.	r11,r11,MSR_IS
+	bne	10f
 
 	/*
 	 * Set up temporary TLB entry that is the same as what we're

@@ -458,6 +462,7 @@ _GLOBAL(loadcam_multi)
 	mtmsr	r6
 	isync
 
+10:
 	mr	r9,r3
 	add	r10,r3,r4
 2:	bl	loadcam_entry

@@ -466,6 +471,10 @@ _GLOBAL(loadcam_multi)
 	mr	r3,r9
 	blt	2b
 
+	/* Don't return to AS=0 if we were in AS=1 at function start */
+	andi.	r11,r11,MSR_IS
+	bne	3f
+
 	/* Return to AS=0 and clear the temporary entry */
 	mfmsr	r6
 	rlwinm.	r6,r6,0,~(MSR_IS|MSR_DS)

@@ -481,6 +490,7 @@ _GLOBAL(loadcam_multi)
 	tlbwe
 	isync
 
+3:
 	mtlr	r8
 	blr
 #endif