[ARM] ARMv7 errata: only apply fixes when running on applicable CPU
Currently, whenever an erratum workaround is enabled, it will be
applied whether or not the erratum is relevent for the CPU. This
patch changes this - we check the variant and revision fields in the
main ID register to determine which errata to apply.
We also avoid re-applying erratum 460075 if it has already been applied.
Applying this fix in non-secure mode results in the kernel failing to
boot (or even do anything.)
This fixes booting on some ARMv7 based platforms which otherwise
silently fail.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 3397f1e..a08d9d2 100644
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -184,23 +184,37 @@
stmia r12, {r0-r5, r7, r9, r11, lr}
bl v7_flush_dcache_all
ldmia r12, {r0-r5, r7, r9, r11, lr}
+
+ mrc p15, 0, r0, c0, c0, 0 @ read main ID register
+ and r10, r0, #0xff000000 @ ARM?
+ teq r10, #0x41000000
+ bne 2f
+ and r5, r0, #0x00f00000 @ variant
+ and r6, r0, #0x0000000f @ revision
+ orr r0, r6, r5, lsr #20-4 @ combine variant and revision
+
#ifdef CONFIG_ARM_ERRATA_430973
- mrc p15, 0, r10, c1, c0, 1 @ read aux control register
- orr r10, r10, #(1 << 6) @ set IBE to 1
- mcr p15, 0, r10, c1, c0, 1 @ write aux control register
+ teq r5, #0x00100000 @ only present in r1p*
+ mrceq p15, 0, r10, c1, c0, 1 @ read aux control register
+ orreq r10, r10, #(1 << 6) @ set IBE to 1
+ mcreq p15, 0, r10, c1, c0, 1 @ write aux control register
#endif
#ifdef CONFIG_ARM_ERRATA_458693
- mrc p15, 0, r10, c1, c0, 1 @ read aux control register
- orr r10, r10, #(1 << 5) @ set L1NEON to 1
- orr r10, r10, #(1 << 9) @ set PLDNOP to 1
- mcr p15, 0, r10, c1, c0, 1 @ write aux control register
+ teq r0, #0x20 @ only present in r2p0
+ mrceq p15, 0, r10, c1, c0, 1 @ read aux control register
+ orreq r10, r10, #(1 << 5) @ set L1NEON to 1
+ orreq r10, r10, #(1 << 9) @ set PLDNOP to 1
+ mcreq p15, 0, r10, c1, c0, 1 @ write aux control register
#endif
#ifdef CONFIG_ARM_ERRATA_460075
- mrc p15, 1, r10, c9, c0, 2 @ read L2 cache aux ctrl register
- orr r10, r10, #(1 << 22) @ set the Write Allocate disable bit
- mcr p15, 1, r10, c9, c0, 2 @ write the L2 cache aux ctrl register
+ teq r0, #0x20 @ only present in r2p0
+ mrceq p15, 1, r10, c9, c0, 2 @ read L2 cache aux ctrl register
+ tsteq r10, #1 << 22
+ orreq r10, r10, #(1 << 22) @ set the Write Allocate disable bit
+ mcreq p15, 1, r10, c9, c0, 2 @ write the L2 cache aux ctrl register
#endif
- mov r10, #0
+
+2: mov r10, #0
#ifdef HARVARD_CACHE
mcr p15, 0, r10, c7, c5, 0 @ I+BTB cache invalidate
#endif