From c022630633624a75b3b58f43dd3c6cc896a56cff Mon Sep 17 00:00:00 2001 From: "Steven J. Hill" Date: Fri, 6 Jul 2012 21:56:01 +0200 Subject: [PATCH] MIPS: Refactor 'clear_page' and 'copy_page' functions. Remove usage of the '__attribute__((alias("...")))' hack that aliased to integer arrays containing micro-assembled instructions. This hack breaks when building a microMIPS kernel. It also makes the code much easier to understand. [ralf@linux-mips.org: Added back export of the clear_page and copy_page symbols so certain modules will work again. Also fixed build with CONFIG_SIBYTE_DMA_PAGEOPS enabled.] Signed-off-by: Steven J. Hill Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/3866/ Acked-by: David Daney Signed-off-by: Ralf Baechle --- arch/mips/kernel/mips_ksyms.c | 8 ++++- arch/mips/mm/Makefile | 4 +-- arch/mips/mm/page-funcs.S | 50 ++++++++++++++++++++++++++++++ arch/mips/mm/page.c | 67 +++++++++++------------------------------ 4 files changed, 77 insertions(+), 52 deletions(-) create mode 100644 arch/mips/mm/page-funcs.S --- a/arch/mips/kernel/mips_ksyms.c +++ b/arch/mips/kernel/mips_ksyms.c @@ -5,7 +5,7 @@ * License. See the file "COPYING" in the main directory of this archive * for more details. * - * Copyright (C) 1996, 97, 98, 99, 2000, 01, 03, 04, 05 by Ralf Baechle + * Copyright (C) 1996, 97, 98, 99, 2000, 01, 03, 04, 05, 12 by Ralf Baechle * Copyright (C) 1999, 2000, 01 Silicon Graphics, Inc. */ #include @@ -35,6 +35,12 @@ EXPORT_SYMBOL(memmove); EXPORT_SYMBOL(kernel_thread); /* + * Functions that operate on entire pages. Mostly used by memory management. + */ +EXPORT_SYMBOL(clear_page); +EXPORT_SYMBOL(copy_page); + +/* * Userspace access stuff. */ EXPORT_SYMBOL(__copy_user); --- a/arch/mips/mm/Makefile +++ b/arch/mips/mm/Makefile @@ -3,8 +3,8 @@ # obj-y += cache.o dma-default.o extable.o fault.o \ - gup.o init.o mmap.o page.o tlbex.o \ - tlbex-fault.o uasm.o + gup.o init.o mmap.o page.o page-funcs.o \ + tlbex.o tlbex-fault.o uasm.o obj-$(CONFIG_32BIT) += ioremap.o pgtable-32.o obj-$(CONFIG_64BIT) += pgtable-64.o --- /dev/null +++ b/arch/mips/mm/page-funcs.S @@ -0,0 +1,50 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Micro-assembler generated clear_page/copy_page functions. + * + * Copyright (C) 2012 MIPS Technologies, Inc. + * Copyright (C) 2012 Ralf Baechle + */ +#include +#include + +#ifdef CONFIG_SIBYTE_DMA_PAGEOPS +#define cpu_clear_page_function_name clear_page_cpu +#define cpu_copy_page_function_name copy_page_cpu +#else +#define cpu_clear_page_function_name clear_page +#define cpu_copy_page_function_name copy_page +#endif + +/* + * Maximum sizes: + * + * R4000 128 bytes S-cache: 0x058 bytes + * R4600 v1.7: 0x05c bytes + * R4600 v2.0: 0x060 bytes + * With prefetching, 16 word strides 0x120 bytes + */ +EXPORT(__clear_page_start) +LEAF(cpu_clear_page_function_name) +1: j 1b /* Dummy, will be replaced. */ + .space 288 +END(cpu_clear_page_function_name) +EXPORT(__clear_page_end) + +/* + * Maximum sizes: + * + * R4000 128 bytes S-cache: 0x11c bytes + * R4600 v1.7: 0x080 bytes + * R4600 v2.0: 0x07c bytes + * With prefetching, 16 word strides 0x540 bytes + */ +EXPORT(__copy_page_start) +LEAF(cpu_copy_page_function_name) +1: j 1b /* Dummy, will be replaced. */ + .space 1344 +END(cpu_copy_page_function_name) +EXPORT(__copy_page_end) --- a/arch/mips/mm/page.c +++ b/arch/mips/mm/page.c @@ -6,6 +6,7 @@ * Copyright (C) 2003, 04, 05 Ralf Baechle (ralf@linux-mips.org) * Copyright (C) 2007 Maciej W. Rozycki * Copyright (C) 2008 Thiemo Seufer + * Copyright (C) 2012 MIPS Technologies, Inc. */ #include #include @@ -72,45 +73,6 @@ static struct uasm_reloc __cpuinitdata r #define cpu_is_r4600_v1_x() ((read_c0_prid() & 0xfffffff0) == 0x00002010) #define cpu_is_r4600_v2_x() ((read_c0_prid() & 0xfffffff0) == 0x00002020) -/* - * Maximum sizes: - * - * R4000 128 bytes S-cache: 0x058 bytes - * R4600 v1.7: 0x05c bytes - * R4600 v2.0: 0x060 bytes - * With prefetching, 16 word strides 0x120 bytes - */ - -static u32 clear_page_array[0x120 / 4]; - -#ifdef CONFIG_SIBYTE_DMA_PAGEOPS -void clear_page_cpu(void *page) __attribute__((alias("clear_page_array"))); -#else -void clear_page(void *page) __attribute__((alias("clear_page_array"))); -#endif - -EXPORT_SYMBOL(clear_page); - -/* - * Maximum sizes: - * - * R4000 128 bytes S-cache: 0x11c bytes - * R4600 v1.7: 0x080 bytes - * R4600 v2.0: 0x07c bytes - * With prefetching, 16 word strides 0x540 bytes - */ -static u32 copy_page_array[0x540 / 4]; - -#ifdef CONFIG_SIBYTE_DMA_PAGEOPS -void -copy_page_cpu(void *to, void *from) __attribute__((alias("copy_page_array"))); -#else -void copy_page(void *to, void *from) __attribute__((alias("copy_page_array"))); -#endif - -EXPORT_SYMBOL(copy_page); - - static int pref_bias_clear_store __cpuinitdata; static int pref_bias_copy_load __cpuinitdata; static int pref_bias_copy_store __cpuinitdata; @@ -283,10 +245,15 @@ static inline void __cpuinit build_clear } } +extern u32 __clear_page_start; +extern u32 __clear_page_end; +extern u32 __copy_page_start; +extern u32 __copy_page_end; + void __cpuinit build_clear_page(void) { int off; - u32 *buf = (u32 *)&clear_page_array; + u32 *buf = &__clear_page_start; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; int i; @@ -357,17 +324,17 @@ void __cpuinit build_clear_page(void) uasm_i_jr(&buf, RA); uasm_i_nop(&buf); - BUG_ON(buf > clear_page_array + ARRAY_SIZE(clear_page_array)); + BUG_ON(buf > &__clear_page_end); uasm_resolve_relocs(relocs, labels); pr_debug("Synthesized clear page handler (%u instructions).\n", - (u32)(buf - clear_page_array)); + (u32)(buf - &__clear_page_start)); pr_debug("\t.set push\n"); pr_debug("\t.set noreorder\n"); - for (i = 0; i < (buf - clear_page_array); i++) - pr_debug("\t.word 0x%08x\n", clear_page_array[i]); + for (i = 0; i < (buf - &__clear_page_start); i++) + pr_debug("\t.word 0x%08x\n", (&__clear_page_start)[i]); pr_debug("\t.set pop\n"); } @@ -428,7 +395,7 @@ static inline void build_copy_store_pref void __cpuinit build_copy_page(void) { int off; - u32 *buf = (u32 *)©_page_array; + u32 *buf = &__copy_page_start; struct uasm_label *l = labels; struct uasm_reloc *r = relocs; int i; @@ -596,21 +563,23 @@ void __cpuinit build_copy_page(void) uasm_i_jr(&buf, RA); uasm_i_nop(&buf); - BUG_ON(buf > copy_page_array + ARRAY_SIZE(copy_page_array)); + BUG_ON(buf > &__copy_page_end); uasm_resolve_relocs(relocs, labels); pr_debug("Synthesized copy page handler (%u instructions).\n", - (u32)(buf - copy_page_array)); + (u32)(buf - &__copy_page_start)); pr_debug("\t.set push\n"); pr_debug("\t.set noreorder\n"); - for (i = 0; i < (buf - copy_page_array); i++) - pr_debug("\t.word 0x%08x\n", copy_page_array[i]); + for (i = 0; i < (buf - &__copy_page_start); i++) + pr_debug("\t.word 0x%08x\n", (&__copy_page_start)[i]); pr_debug("\t.set pop\n"); } #ifdef CONFIG_SIBYTE_DMA_PAGEOPS +extern void clear_page_cpu(void *page); +extern void copy_page_cpu(void *to, void *from); /* * Pad descriptors to cacheline, since each is exclusively owned by a