arm: mm: qsd8x50: Fix incorrect permission faults

Handle incorrectly reported permission faults for qsd8650.  On
permission faults, retry MVA to PA conversion.  If retry detects
translation fault.  Report as translation fault.

Cc: Jamie Lokier <jamie@shareable.org>
Signed-off-by: Dave Estes <cestes@quicinc.com>

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 5bd7c89..d3022da 100644 (file)
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -572,6 +572,8 @@ config CPU_TLB_V6
 config CPU_TLB_V7
        bool
 
+config VERIFY_PERMISSION_FAULT
+       bool
 endif
 
 config CPU_HAS_ASID

diff --git a/arch/arm/mm/abort-ev7.S b/arch/arm/mm/abort-ev7.S
index 2e6dc04..ec88b15 100644 (file)
--- a/arch/arm/mm/abort-ev7.S
+++ b/arch/arm/mm/abort-ev7.S
@@ -29,5 +29,26 @@ ENTRY(v7_early_abort)
         * V6 code adjusts the returned DFSR.
         * New designs should not need to patch up faults.
         */
+
+#if defined(CONFIG_VERIFY_PERMISSION_FAULT)
+       /*
+        * Detect erroneous permission failures and fix
+        */
+       ldr     r3, =0x40d                      @ On permission fault
+       and     r3, r1, r3
+       cmp     r3, #0x0d
+       movne   pc, lr
+
+       mcr     p15, 0, r0, c7, c8, 0           @ Retranslate FAR
+       isb
+       mrc     p15, 0, r2, c7, c4, 0           @ Read the PAR
+       and     r3, r2, #0x7b                   @ On translation fault
+       cmp     r3, #0x0b
+       movne   pc, lr
+       bic     r1, r1, #0xf                    @ Fix up FSR FS[5:0]
+       and     r2, r2, #0x7e
+       orr     r1, r1, r2, LSR #1
+#endif
+
        mov     pc, lr
 ENDPROC(v7_early_abort)