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>
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index 1db8ead..a94dd99 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -456,8 +456,13 @@
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 @@
.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