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| author | Nicolas Pitre <nicolas.pitre@linaro.org> | 2011-02-21 05:53:35 (GMT) |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2011-03-10 16:43:45 (GMT) |
| commit | b511d75d6150892e67c8ebfa9dc8eb37ebd02aa3 (patch) | |
| tree | 0cec12cd64edeecac2b737f2788b012eab538285 /arch | |
| parent | 80f0aad77f3e1e9d9e518b09ac46963d628ae2be (diff) | |
| download | linux-b511d75d6150892e67c8ebfa9dc8eb37ebd02aa3.tar.xz | |
ARM: 6747/1: P2V: Thumb2 support
Adding Thumb2 support to the runtime patching of the virt_to_phys and
phys_to_virt opcodes.
Tested both the 8-bit and the 16-bit fixups, using different placements
in memory to exercize all code paths.
Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Reviewed-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/arm/Kconfig | 4 | ||||
| -rw-r--r-- | arch/arm/kernel/head.S | 49 |
2 files changed, 50 insertions, 3 deletions
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b357c29..0233c8f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -194,13 +194,13 @@ config VECTORS_BASE config ARM_PATCH_PHYS_VIRT bool "Patch physical to virtual translations at runtime (EXPERIMENTAL)" depends on EXPERIMENTAL - depends on !XIP_KERNEL && !THUMB2_KERNEL && MMU + depends on !XIP_KERNEL && MMU depends on !ARCH_REALVIEW || !SPARSEMEM help Patch phys-to-virt translation functions at runtime according to the position of the kernel in system memory. - This can only be used with non-XIP, non-Thumb2, MMU kernels where + This can only be used with non-XIP with MMU kernels where the base of physical memory is at a 16MB boundary. config ARM_PATCH_PHYS_VIRT_16BIT diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 591a2ea..6a87261 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -461,7 +461,8 @@ __fixup_pv_table: sub r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET 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 + add r7, r7, r3 @ adjust __pv_phys_offset address + str r8, [r7] @ 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 @@ -469,6 +470,7 @@ __fixup_pv_table: mov r6, r3, lsr #16 @ constant for add/sub instructions teq r3, r6, lsl #16 @ must be 64kiB aligned #endif +THUMB( it ne @ cross section branch ) bne __error str r6, [r7, #4] @ save to __pv_offset b __fixup_a_pv_table @@ -482,6 +484,50 @@ ENDPROC(__fixup_pv_table) .text __fixup_a_pv_table: +#ifdef CONFIG_THUMB2_KERNEL +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + lsls r0, r6, #24 + lsr r6, #8 + beq 1f + clz r7, r0 + lsr r0, #24 + lsl r0, r7 + bic r0, 0x0080 + lsrs r7, #1 + orrcs r0, #0x0080 + orr r0, r0, r7, lsl #12 +#endif +1: lsls r6, #24 + beq 4f + clz r7, r6 + lsr r6, #24 + lsl r6, r7 + bic r6, #0x0080 + lsrs r7, #1 + orrcs r6, #0x0080 + orr r6, r6, r7, lsl #12 + orr r6, #0x4000 + b 4f +2: @ at this point the C flag is always clear + add r7, r3 +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT + ldrh ip, [r7] + tst ip, 0x0400 @ the i bit tells us LS or MS byte + beq 3f + cmp r0, #0 @ set C flag, and ... + biceq ip, 0x0400 @ immediate zero value has a special encoding + streqh ip, [r7] @ that requires the i bit cleared +#endif +3: ldrh ip, [r7, #2] + and ip, 0x8f00 + orrcc ip, r6 @ mask in offset bits 31-24 + orrcs ip, r0 @ mask in offset bits 23-16 + strh ip, [r7, #2] +4: cmp r4, r5 + ldrcc r7, [r4], #4 @ use branch for delay slot + bcc 2b + bx lr +#else #ifdef CONFIG_ARM_PATCH_PHYS_VIRT_16BIT and r0, r6, #255 @ offset bits 23-16 mov r6, r6, lsr #8 @ offset bits 31-24 @@ -499,6 +545,7 @@ __fixup_a_pv_table: ldrcc r7, [r4], #4 @ use branch for delay slot bcc 2b mov pc, lr +#endif ENDPROC(__fixup_a_pv_table) ENTRY(fixup_pv_table) |