Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759625Ab2HKBZv (ORCPT ); Fri, 10 Aug 2012 21:25:51 -0400 Received: from comal.ext.ti.com ([198.47.26.152]:60270 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755116Ab2HKBZm (ORCPT ); Fri, 10 Aug 2012 21:25:42 -0400 From: Cyril Chemparathy To: , CC: , , , , , , Cyril Chemparathy Subject: [PATCH v2 03/22] ARM: use late patch framework for phys-virt patching Date: Fri, 10 Aug 2012 21:24:46 -0400 Message-ID: <1344648306-15619-4-git-send-email-cyril@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1344648306-15619-1-git-send-email-cyril@ti.com> References: <1344648306-15619-1-git-send-email-cyril@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7924 Lines: 278 This patch replaces the original physical offset patching implementation with one that uses the newly added patching framework. In the process, we now unconditionally initialize the __pv_phys_offset and __pv_offset globals in the head.S code. Signed-off-by: Cyril Chemparathy --- arch/arm/Kconfig | 1 + arch/arm/include/asm/memory.h | 26 +++-------- arch/arm/kernel/armksyms.c | 4 -- arch/arm/kernel/head.S | 95 +++++++---------------------------------- arch/arm/kernel/module.c | 5 --- arch/arm/kernel/setup.c | 12 ++++++ arch/arm/kernel/vmlinux.lds.S | 5 --- 7 files changed, 36 insertions(+), 112 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 7e552dc..9ac86ea 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -199,6 +199,7 @@ config ARM_PATCH_PHYS_VIRT default y depends on !XIP_KERNEL && MMU depends on !ARCH_REALVIEW || !SPARSEMEM + select ARM_RUNTIME_PATCH help Patch phys-to-virt and virt-to-phys translation functions at boot and module load time according to the position of the diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index e965f1b..3d93779 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -18,6 +18,8 @@ #include #include +#include + #ifdef CONFIG_NEED_MACH_MEMORY_H #include #endif @@ -151,35 +153,21 @@ #ifndef __virt_to_phys #ifdef CONFIG_ARM_PATCH_PHYS_VIRT -/* - * Constants used to force the right instruction encodings and shifts - * so that all we need to do is modify the 8-bit constant field. - */ -#define __PV_BITS_31_24 0x81000000 - -extern unsigned long __pv_phys_offset; -#define PHYS_OFFSET __pv_phys_offset - -#define __pv_stub(from,to,instr,type) \ - __asm__("@ __pv_stub\n" \ - "1: " instr " %0, %1, %2\n" \ - " .pushsection .pv_table,\"a\"\n" \ - " .long 1b\n" \ - " .popsection\n" \ - : "=r" (to) \ - : "r" (from), "I" (type)) +extern unsigned long __pv_offset; +extern unsigned long __pv_phys_offset; +#define PHYS_OFFSET __virt_to_phys(PAGE_OFFSET) static inline unsigned long __virt_to_phys(unsigned long x) { unsigned long t; - __pv_stub(x, t, "add", __PV_BITS_31_24); + early_patch_imm8("add", t, x, __pv_offset, 0); return t; } static inline unsigned long __phys_to_virt(unsigned long x) { unsigned long t; - __pv_stub(x, t, "sub", __PV_BITS_31_24); + early_patch_imm8("sub", t, x, __pv_offset, 0); return t; } #else diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c index 60d3b73..6b388f8 100644 --- a/arch/arm/kernel/armksyms.c +++ b/arch/arm/kernel/armksyms.c @@ -152,7 +152,3 @@ EXPORT_SYMBOL(mcount); #endif EXPORT_SYMBOL(__gnu_mcount_nc); #endif - -#ifdef CONFIG_ARM_PATCH_PHYS_VIRT -EXPORT_SYMBOL(__pv_phys_offset); -#endif diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S index 3db960e..69a3c09 100644 --- a/arch/arm/kernel/head.S +++ b/arch/arm/kernel/head.S @@ -117,7 +117,7 @@ ENTRY(stext) bl __fixup_smp #endif #ifdef CONFIG_ARM_PATCH_PHYS_VIRT - bl __fixup_pv_table + bl __fixup_pv_offsets #endif bl __create_page_tables @@ -511,92 +511,29 @@ ENDPROC(fixup_smp) #ifdef CONFIG_ARM_PATCH_PHYS_VIRT -/* __fixup_pv_table - patch the stub instructions with the delta between - * PHYS_OFFSET and PAGE_OFFSET, which is assumed to be 16MiB aligned and - * can be expressed by an immediate shifter operand. The stub instruction - * has a form of '(add|sub) rd, rn, #imm'. +/* + * __fixup_pv_offsets - update __pv_offset and __pv_phys_offset based on the + * runtime location of the kernel. */ __HEAD -__fixup_pv_table: +__fixup_pv_offsets: adr r0, 1f - ldmia r0, {r3-r5, r7} + ldmia r0, {r3-r6} sub r3, r0, r3 @ PHYS_OFFSET - PAGE_OFFSET - add r4, r4, r3 @ adjust table start address - add r5, r5, r3 @ adjust table end address - add r7, r7, r3 @ adjust __pv_phys_offset address - str r8, [r7] @ save computed PHYS_OFFSET to __pv_phys_offset - mov r6, r3, lsr #24 @ constant for add/sub instructions - teq r3, r6, lsl #24 @ must be 16MiB aligned -THUMB( it ne @ cross section branch ) - bne __error - str r6, [r7, #4] @ save to __pv_offset - b __fixup_a_pv_table -ENDPROC(__fixup_pv_table) + add r4, r4, r3 @ virt_to_phys(__pv_phys_offset) + add r5, r5, r3 @ virt_to_phys(__pv_offset) + add r6, r6, r3 @ virt_to_phys(PAGE_OFFSET) = PHYS_OFFSET + str r6, [r4] @ save __pv_phys_offset + str r3, [r5] @ save __pv_offset + mov pc, lr +ENDPROC(__fixup_pv_offsets) .align 1: .long . - .long __pv_table_begin - .long __pv_table_end -2: .long __pv_phys_offset - - .text -__fixup_a_pv_table: -#ifdef CONFIG_THUMB2_KERNEL - lsls r6, #24 - beq 2f - 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 2f -1: add r7, r3 - ldrh ip, [r7, #2] - and ip, 0x8f00 - orr ip, r6 @ mask in offset bits 31-24 - strh ip, [r7, #2] -2: cmp r4, r5 - ldrcc r7, [r4], #4 @ use branch for delay slot - bcc 1b - bx lr -#else - b 2f -1: ldr ip, [r7, r3] - bic ip, ip, #0x000000ff - orr ip, ip, r6 @ mask in offset bits 31-24 - str ip, [r7, r3] -2: cmp r4, r5 - ldrcc r7, [r4], #4 @ use branch for delay slot - bcc 1b - mov pc, lr + .long __pv_phys_offset + .long __pv_offset + .long PAGE_OFFSET #endif -ENDPROC(__fixup_a_pv_table) - -ENTRY(fixup_pv_table) - stmfd sp!, {r4 - r7, lr} - ldr r2, 2f @ get address of __pv_phys_offset - mov r3, #0 @ no offset - mov r4, r0 @ r0 = table start - add r5, r0, r1 @ r1 = table size - ldr r6, [r2, #4] @ get __pv_offset - bl __fixup_a_pv_table - ldmfd sp!, {r4 - r7, pc} -ENDPROC(fixup_pv_table) - .align -2: .long __pv_phys_offset - - .data - .globl __pv_phys_offset - .type __pv_phys_offset, %object -__pv_phys_offset: - .long 0 - .size __pv_phys_offset, . - __pv_phys_offset -__pv_offset: - .long 0 -#endif #include "head-common.S" diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c index dcebf80..ac13dd5 100644 --- a/arch/arm/kernel/module.c +++ b/arch/arm/kernel/module.c @@ -317,11 +317,6 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs, maps[i].txt_sec->sh_addr, maps[i].txt_sec->sh_size); #endif -#ifdef CONFIG_ARM_PATCH_PHYS_VIRT - s = find_mod_section(hdr, sechdrs, ".pv_table"); - if (s) - fixup_pv_table((void *)s->sh_addr, s->sh_size); -#endif s = find_mod_section(hdr, sechdrs, ".runtime.patch.table"); if (s) runtime_patch((void *)s->sh_addr, s->sh_size); diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 669bbf0..59e0f57 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -152,6 +152,18 @@ static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', ' DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data); +#ifdef CONFIG_ARM_PATCH_PHYS_VIRT + +/* + * These are initialized in head.S code prior to BSS getting cleared out. + * The initializers here prevent these from landing in the BSS section. + */ +unsigned long __pv_offset = 0xdeadbeef; +unsigned long __pv_phys_offset = 0xdeadbeef; +EXPORT_SYMBOL(__pv_phys_offset); + +#endif + /* * Standard memory resources */ diff --git a/arch/arm/kernel/vmlinux.lds.S b/arch/arm/kernel/vmlinux.lds.S index ea35ca0..2080111 100644 --- a/arch/arm/kernel/vmlinux.lds.S +++ b/arch/arm/kernel/vmlinux.lds.S @@ -162,11 +162,6 @@ SECTIONS __smpalt_end = .; } #endif - .init.pv_table : { - __pv_table_begin = .; - *(.pv_table) - __pv_table_end = .; - } .init.runtime_patch_table : { __runtime_patch_table_begin = .; *(.runtime.patch.table) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/