ARM: P2V: extend to 16-bit translation offsets

MSM's memory is aligned to 2MB, which is more than we can do with our
existing method as we're limited to the upper 8 bits.  Extend this by
using two instructions to 16 bits, automatically selected when MSM is
enabled.

Acked-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Tested-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 14 insertions, 1 deletions

diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 1db8ead2e33..a94dd99d54c 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -456,8 +456,13 @@ __fixup_pv_table:
         add     r4, r4, r3      @ adjust table start address
         add     r5, r5, r3      @ adjust table end address
         str     r8, [r7, r3]!   @ save computed PHYS_OFFSET to __pv_phys_offset
+#ifndef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT
         mov     r6, r3, lsr #24 @ constant for add/sub instructions
         teq     r3, r6, lsl #24 @ must be 16MiB aligned
+#else
+        mov     r6, r3, lsr #16 @ constant for add/sub instructions
+        teq     r3, r6, lsl #16 @ must be 64kiB aligned
+#endif
         bne     __error
         str     r6, [r7, #4]    @ save to __pv_offset
         b       __fixup_a_pv_table
@@ -471,10 +476,18 @@ ENDPROC(__fixup_pv_table)
 
         .text
 __fixup_a_pv_table:
+#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT
+        and     r0, r6, #255    @ offset bits 23-16
+        mov     r6, r6, lsr #8  @ offset bits 31-24
+#else
+        mov     r0, #0          @ just in case...
+#endif
         b       3f
 2:      ldr     ip, [r7, r3]
         bic     ip, ip, #0x000000ff
-        orr     ip, ip, r6
+        tst     ip, #0x400      @ rotate shift tells us LS or MS byte
+        orrne   ip, ip, r6      @ mask in offset bits 31-24
+        orreq   ip, ip, r0      @ mask in offset bits 23-16
         str     ip, [r7, r3]
 3:      cmp     r4, r5
         ldrcc   r7, [r4], #4    @ use branch for delay slot