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Message-Id: <97f32bd4c45ce004550b3853474b3bc7e211ae0d.1560807643.git.christophe.leroy@c-s.fr>
From:   Christophe Leroy <christophe.leroy@c-s.fr>
Subject: [PATCH v2] powerpc/32s: fix suspend/resume when IBATs 4-7 are used
To:     Benjamin Herrenschmidt <benh@kernel.crashing.org>,
        Paul Mackerras <paulus@samba.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        Andreas Schwab <schwab@linux-m68k.org>
Cc:     linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org
Date:   Mon, 17 Jun 2019 21:42:14 +0000 (UTC)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping
kernel text. But the suspend/restore functions only save/restore
BATs 0 to 3, and clears BATs 4 to 7.

Make suspend and restore functions respectively save and reload
the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature.

Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
 v2: using SPRN_DBATxU/xL to avoid build failure.

 arch/powerpc/kernel/swsusp_32.S         | 73 +++++++++++++++++++++++++++++----
 arch/powerpc/platforms/powermac/sleep.S | 68 +++++++++++++++++++++++++++---
 2 files changed, 128 insertions(+), 13 deletions(-)

diff --git a/arch/powerpc/kernel/swsusp_32.S b/arch/powerpc/kernel/swsusp_32.S
index 7a919e9a3400..cbdf86228eaa 100644
--- a/arch/powerpc/kernel/swsusp_32.S
+++ b/arch/powerpc/kernel/swsusp_32.S
@@ -25,11 +25,19 @@
 #define SL_IBAT2	0x48
 #define SL_DBAT3	0x50
 #define SL_IBAT3	0x58
-#define SL_TB		0x60
-#define SL_R2		0x68
-#define SL_CR		0x6c
-#define SL_LR		0x70
-#define SL_R12		0x74	/* r12 to r31 */
+#define SL_DBAT4	0x60
+#define SL_IBAT4	0x68
+#define SL_DBAT5	0x70
+#define SL_IBAT5	0x78
+#define SL_DBAT6	0x80
+#define SL_IBAT6	0x88
+#define SL_DBAT7	0x90
+#define SL_IBAT7	0x98
+#define SL_TB		0xa0
+#define SL_R2		0xa8
+#define SL_CR		0xac
+#define SL_LR		0xb0
+#define SL_R12		0xb4	/* r12 to r31 */
 #define SL_SIZE		(SL_R12 + 80)
 
 	.section .data
@@ -114,6 +122,41 @@ _GLOBAL(swsusp_arch_suspend)
 	mfibatl	r4,3
 	stw	r4,SL_IBAT3+4(r11)
 
+BEGIN_MMU_FTR_SECTION
+	mfspr	r4,SPRN_DBAT4U
+	stw	r4,SL_DBAT4(r11)
+	mfspr	r4,SPRN_DBAT4L
+	stw	r4,SL_DBAT4+4(r11)
+	mfspr	r4,SPRN_DBAT5U
+	stw	r4,SL_DBAT5(r11)
+	mfspr	r4,SPRN_DBAT5L
+	stw	r4,SL_DBAT5+4(r11)
+	mfspr	r4,SPRN_DBAT6U
+	stw	r4,SL_DBAT6(r11)
+	mfspr	r4,SPRN_DBAT6L
+	stw	r4,SL_DBAT6+4(r11)
+	mfspr	r4,SPRN_DBAT7U
+	stw	r4,SL_DBAT7(r11)
+	mfspr	r4,SPRN_DBAT7L
+	stw	r4,SL_DBAT7+4(r11)
+	mfspr	r4,SPRN_IBAT4U
+	stw	r4,SL_IBAT4(r11)
+	mfspr	r4,SPRN_IBAT4L
+	stw	r4,SL_IBAT4+4(r11)
+	mfspr	r4,SPRN_IBAT5U
+	stw	r4,SL_IBAT5(r11)
+	mfspr	r4,SPRN_IBAT5L
+	stw	r4,SL_IBAT5+4(r11)
+	mfspr	r4,SPRN_IBAT6U
+	stw	r4,SL_IBAT6(r11)
+	mfspr	r4,SPRN_IBAT6L
+	stw	r4,SL_IBAT6+4(r11)
+	mfspr	r4,SPRN_IBAT7U
+	stw	r4,SL_IBAT7(r11)
+	mfspr	r4,SPRN_IBAT7L
+	stw	r4,SL_IBAT7+4(r11)
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
+
 #if  0
 	/* Backup various CPU config stuffs */
 	bl	__save_cpu_setup
@@ -279,27 +322,41 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
 	mtibatu	3,r4
 	lwz	r4,SL_IBAT3+4(r11)
 	mtibatl	3,r4
-#endif
-
 BEGIN_MMU_FTR_SECTION
-	li	r4,0
+	lwz	r4,SL_DBAT4(r11)
 	mtspr	SPRN_DBAT4U,r4
+	lwz	r4,SL_DBAT4+4(r11)
 	mtspr	SPRN_DBAT4L,r4
+	lwz	r4,SL_DBAT5(r11)
 	mtspr	SPRN_DBAT5U,r4
+	lwz	r4,SL_DBAT5+4(r11)
 	mtspr	SPRN_DBAT5L,r4
+	lwz	r4,SL_DBAT6(r11)
 	mtspr	SPRN_DBAT6U,r4
+	lwz	r4,SL_DBAT6+4(r11)
 	mtspr	SPRN_DBAT6L,r4
+	lwz	r4,SL_DBAT7(r11)
 	mtspr	SPRN_DBAT7U,r4
+	lwz	r4,SL_DBAT7+4(r11)
 	mtspr	SPRN_DBAT7L,r4
+	lwz	r4,SL_IBAT4(r11)
 	mtspr	SPRN_IBAT4U,r4
+	lwz	r4,SL_IBAT4+4(r11)
 	mtspr	SPRN_IBAT4L,r4
+	lwz	r4,SL_IBAT5(r11)
 	mtspr	SPRN_IBAT5U,r4
+	lwz	r4,SL_IBAT5+4(r11)
 	mtspr	SPRN_IBAT5L,r4
+	lwz	r4,SL_IBAT6(r11)
 	mtspr	SPRN_IBAT6U,r4
+	lwz	r4,SL_IBAT6+4(r11)
 	mtspr	SPRN_IBAT6L,r4
+	lwz	r4,SL_IBAT7(r11)
 	mtspr	SPRN_IBAT7U,r4
+	lwz	r4,SL_IBAT7+4(r11)
 	mtspr	SPRN_IBAT7L,r4
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
+#endif
 
 	/* Flush all TLBs */
 	lis	r4,0x1000
diff --git a/arch/powerpc/platforms/powermac/sleep.S b/arch/powerpc/platforms/powermac/sleep.S
index 6bbcbec97712..bd6085b470b7 100644
--- a/arch/powerpc/platforms/powermac/sleep.S
+++ b/arch/powerpc/platforms/powermac/sleep.S
@@ -33,10 +33,18 @@
 #define SL_IBAT2	0x48
 #define SL_DBAT3	0x50
 #define SL_IBAT3	0x58
-#define SL_TB		0x60
-#define SL_R2		0x68
-#define SL_CR		0x6c
-#define SL_R12		0x70	/* r12 to r31 */
+#define SL_DBAT4	0x60
+#define SL_IBAT4	0x68
+#define SL_DBAT5	0x70
+#define SL_IBAT5	0x78
+#define SL_DBAT6	0x80
+#define SL_IBAT6	0x88
+#define SL_DBAT7	0x90
+#define SL_IBAT7	0x98
+#define SL_TB		0xa0
+#define SL_R2		0xa8
+#define SL_CR		0xac
+#define SL_R12		0xb0	/* r12 to r31 */
 #define SL_SIZE		(SL_R12 + 80)
 
 	.section .text
@@ -121,6 +129,41 @@ _GLOBAL(low_sleep_handler)
 	mfibatl	r4,3
 	stw	r4,SL_IBAT3+4(r1)
 
+BEGIN_MMU_FTR_SECTION
+	mfspr	r4,SPRN_DBAT4U
+	stw	r4,SL_DBAT4(r1)
+	mfspr	r4,SPRN_DBAT4L
+	stw	r4,SL_DBAT4+4(r1)
+	mfspr	r4,SPRN_DBAT5U
+	stw	r4,SL_DBAT5(r1)
+	mfspr	r4,SPRN_DBAT5L
+	stw	r4,SL_DBAT5+4(r1)
+	mfspr	r4,SPRN_DBAT6U
+	stw	r4,SL_DBAT6(r1)
+	mfspr	r4,SPRN_DBAT6L
+	stw	r4,SL_DBAT6+4(r1)
+	mfspr	r4,SPRN_DBAT7U
+	stw	r4,SL_DBAT7(r1)
+	mfspr	r4,SPRN_DBAT7L
+	stw	r4,SL_DBAT7+4(r1)
+	mfspr	r4,SPRN_IBAT4U
+	stw	r4,SL_IBAT4(r1)
+	mfspr	r4,SPRN_IBAT4L
+	stw	r4,SL_IBAT4+4(r1)
+	mfspr	r4,SPRN_IBAT5U
+	stw	r4,SL_IBAT5(r1)
+	mfspr	r4,SPRN_IBAT5L
+	stw	r4,SL_IBAT5+4(r1)
+	mfspr	r4,SPRN_IBAT6U
+	stw	r4,SL_IBAT6(r1)
+	mfspr	r4,SPRN_IBAT6L
+	stw	r4,SL_IBAT6+4(r1)
+	mfspr	r4,SPRN_IBAT7U
+	stw	r4,SL_IBAT7(r1)
+	mfspr	r4,SPRN_IBAT7L
+	stw	r4,SL_IBAT7+4(r1)
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
+
 	/* Backup various CPU config stuffs */
 	bl	__save_cpu_setup
 
@@ -321,22 +364,37 @@ grackle_wake_up:
 	mtibatl	3,r4
 
 BEGIN_MMU_FTR_SECTION
-	li	r4,0
+	lwz	r4,SL_DBAT4(r1)
 	mtspr	SPRN_DBAT4U,r4
+	lwz	r4,SL_DBAT4+4(r1)
 	mtspr	SPRN_DBAT4L,r4
+	lwz	r4,SL_DBAT5(r1)
 	mtspr	SPRN_DBAT5U,r4
+	lwz	r4,SL_DBAT5+4(r1)
 	mtspr	SPRN_DBAT5L,r4
+	lwz	r4,SL_DBAT6(r1)
 	mtspr	SPRN_DBAT6U,r4
+	lwz	r4,SL_DBAT6+4(r1)
 	mtspr	SPRN_DBAT6L,r4
+	lwz	r4,SL_DBAT7(r1)
 	mtspr	SPRN_DBAT7U,r4
+	lwz	r4,SL_DBAT7+4(r1)
 	mtspr	SPRN_DBAT7L,r4
+	lwz	r4,SL_IBAT4(r1)
 	mtspr	SPRN_IBAT4U,r4
+	lwz	r4,SL_IBAT4+4(r1)
 	mtspr	SPRN_IBAT4L,r4
+	lwz	r4,SL_IBAT5(r1)
 	mtspr	SPRN_IBAT5U,r4
+	lwz	r4,SL_IBAT5+4(r1)
 	mtspr	SPRN_IBAT5L,r4
+	lwz	r4,SL_IBAT6(r1)
 	mtspr	SPRN_IBAT6U,r4
+	lwz	r4,SL_IBAT6+4(r1)
 	mtspr	SPRN_IBAT6L,r4
+	lwz	r4,SL_IBAT7(r1)
 	mtspr	SPRN_IBAT7U,r4
+	lwz	r4,SL_IBAT7+4(r1)
 	mtspr	SPRN_IBAT7L,r4
 END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
 
-- 
2.13.3