powerpc/83xx: Also save/restore SPRG4-7 during suspend

BugLink: https://bugs.launchpad.net/bugs/1822271

commit 36da5ff0 upstream.

The 83xx has 8 SPRG registers and uses at least SPRG4
for DTLB handling LRU.

Fixes: 2319f123 ("powerpc/mm: e300c2/c3/c4 TLB errata workaround")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Juerg Haefliger <juerg.haefliger@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/powerpc/platforms/83xx/suspend-asm.S

@@ -26,13 +26,13 @@
 #define SS_MSR		0x74
 #define SS_SDR1		0x78
 #define SS_LR		0x7c
-#define SS_SPRG		0x80 /* 4 SPRGs */
-#define SS_DBAT		0x90 /* 8 DBATs */
-#define SS_IBAT		0xd0 /* 8 IBATs */
-#define SS_TB		0x110
-#define SS_CR		0x118
-#define SS_GPREG	0x11c /* r12-r31 */
-#define STATE_SAVE_SIZE 0x16c
+#define SS_SPRG		0x80 /* 8 SPRGs */
+#define SS_DBAT		0xa0 /* 8 DBATs */
+#define SS_IBAT		0xe0 /* 8 IBATs */
+#define SS_TB		0x120
+#define SS_CR		0x128
+#define SS_GPREG	0x12c /* r12-r31 */
+#define STATE_SAVE_SIZE 0x17c
 
 	.section .data
 	.align	5
@@ -103,6 +103,16 @@ _GLOBAL(mpc83xx_enter_deep_sleep)
 	stw	r7, SS_SPRG+12(r3)
 	stw	r8, SS_SDR1(r3)
 
+	mfspr	r4, SPRN_SPRG4
+	mfspr	r5, SPRN_SPRG5
+	mfspr	r6, SPRN_SPRG6
+	mfspr	r7, SPRN_SPRG7
+
+	stw	r4, SS_SPRG+16(r3)
+	stw	r5, SS_SPRG+20(r3)
+	stw	r6, SS_SPRG+24(r3)
+	stw	r7, SS_SPRG+28(r3)
+
 	mfspr	r4, SPRN_DBAT0U
 	mfspr	r5, SPRN_DBAT0L
 	mfspr	r6, SPRN_DBAT1U
@@ -493,6 +503,16 @@ mpc83xx_deep_resume:
 	mtspr	SPRN_IBAT7U, r6
 	mtspr	SPRN_IBAT7L, r7
 
+	lwz	r4, SS_SPRG+16(r3)
+	lwz	r5, SS_SPRG+20(r3)
+	lwz	r6, SS_SPRG+24(r3)
+	lwz	r7, SS_SPRG+28(r3)
+
+	mtspr	SPRN_SPRG4, r4
+	mtspr	SPRN_SPRG5, r5
+	mtspr	SPRN_SPRG6, r6
+	mtspr	SPRN_SPRG7, r7
+
 	lwz	r4, SS_SPRG+0(r3)
 	lwz	r5, SS_SPRG+4(r3)
 	lwz	r6, SS_SPRG+8(r3)