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authorDiana Craciun <Diana.Craciun@freescale.com>2013-03-14 15:55:11 +0100
committerScott Wood <scottwood@freescale.com>2014-01-11 00:34:04 +0100
commited2ddc56e758d516c5699260ada4d68434dfe1dc (patch)
tree2dd135e9887680a3c34c88344da9319b5784676e /arch/powerpc
parentpowerpc/booke-64: fix tlbsrx. path in bolted tlb handler (diff)
downloadlinux-ed2ddc56e758d516c5699260ada4d68434dfe1dc.tar.xz
linux-ed2ddc56e758d516c5699260ada4d68434dfe1dc.zip
powerpc: Replaced tlbilx with tlbwe in the initialization code
On Freescale e6500 cores EPCR[DGTMI] controls whether guest supervisor state can execute TLB management instructions. If EPCR[DGTMI]=0 tlbwe and tlbilx are allowed to execute normally in the guest state. A hypervisor may choose to virtualize TLB1 and for this purpose it may use IPROT to protect the entries for being invalidated by the guest. However, because tlbwe and tlbilx execution in the guest state are sharing the same bit, it is not possible to have a scenario where tlbwe is allowed to be executed in guest state and tlbilx traps. When guest TLB management instructions are allowed to be executed in guest state the guest cannot use tlbilx to invalidate TLB1 guest entries. Linux is using tlbilx in the boot code to invalidate the temporary entries it creates when initializing the MMU. The patch is replacing the usage of tlbilx in initialization code with tlbwe with VALID bit cleared. Linux is also using tlbilx in other contexts (like huge pages or indirect entries) but removing the tlbilx from the initialization code offers the possibility to have scenarios under hypervisor which are not using huge pages or indirect entries. Signed-off-by: Diana Craciun <Diana.Craciun@freescale.com> Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/exceptions-64e.S10
1 files changed, 2 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 4d5a0b1034e8..063b65dd4f27 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -1068,12 +1068,9 @@ skpinv: addi r6,r6,1 /* Increment */
mtspr SPRN_MAS0,r3
tlbre
mfspr r6,SPRN_MAS1
- rlwinm r6,r6,0,2,0 /* clear IPROT */
+ rlwinm r6,r6,0,2,31 /* clear IPROT and VALID */
mtspr SPRN_MAS1,r6
tlbwe
-
- /* Invalidate TLB1 */
- PPC_TLBILX_ALL(0,R0)
sync
isync
@@ -1127,12 +1124,9 @@ skpinv: addi r6,r6,1 /* Increment */
mtspr SPRN_MAS0,r4
tlbre
mfspr r5,SPRN_MAS1
- rlwinm r5,r5,0,2,0 /* clear IPROT */
+ rlwinm r5,r5,0,2,31 /* clear IPROT and VALID */
mtspr SPRN_MAS1,r5
tlbwe
-
- /* Invalidate TLB1 */
- PPC_TLBILX_ALL(0,R0)
sync
isync