From: Paul Mundt This adds fixmap support for sh. Signed-off-by: Paul Mundt Signed-off-by: Andrew Morton --- 25-akpm/arch/sh/mm/init.c | 62 +++++++++++++++++++++ 25-akpm/include/asm-sh/fixmap.h | 111 +++++++++++++++++++++++++++++++++++++++ 25-akpm/include/asm-sh/pgtable.h | 5 + 3 files changed, 175 insertions(+), 3 deletions(-) diff -puN arch/sh/mm/init.c~sh-fixmap-support arch/sh/mm/init.c --- 25/arch/sh/mm/init.c~sh-fixmap-support 2004-06-23 20:00:15.845281176 -0700 +++ 25-akpm/arch/sh/mm/init.c 2004-06-23 20:00:15.851280264 -0700 @@ -3,7 +3,7 @@ * linux/arch/sh/mm/init.c * * Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2002 Paul Mundt + * Copyright (C) 2002, 2004 Paul Mundt * * Based on linux/arch/i386/mm/init.c: * Copyright (C) 1995 Linus Torvalds @@ -83,6 +83,66 @@ void show_mem(void) printk("%d pages swap cached\n",cached); } +static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + + pgd = swapper_pg_dir + pgd_index(addr); + if (pgd_none(*pgd)) { + pgd_ERROR(*pgd); + return; + } + + pmd = pmd_offset(pgd, addr); + if (pmd_none(*pmd)) { + pte = (pte_t *)get_zeroed_page(GFP_ATOMIC); + set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER)); + if (pte != pte_offset_kernel(pmd, 0)) { + pmd_ERROR(*pmd); + return; + } + } + + pte = pte_offset_kernel(pmd, addr); + if (!pte_none(*pte)) { + pte_ERROR(*pte); + return; + } + + set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot)); + + __flush_tlb_page(get_asid(), addr); +} + +/* + * As a performance optimization, other platforms preserve the fixmap mapping + * across a context switch, we don't presently do this, but this could be done + * in a similar fashion as to the wired TLB interface that sh64 uses (by way + * of the memorry mapped UTLB configuration) -- this unfortunately forces us to + * give up a TLB entry for each mapping we want to preserve. While this may be + * viable for a small number of fixmaps, it's not particularly useful for + * everything and needs to be carefully evaluated. (ie, we may want this for + * the vsyscall page). + * + * XXX: Perhaps add a _PAGE_WIRED flag or something similar that we can pass + * in at __set_fixmap() time to determine the appropriate behavior to follow. + * + * -- PFM. + */ +void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) +{ + unsigned long address = __fix_to_virt(idx); + + if (idx >= __end_of_fixed_addresses) { + BUG(); + return; + } + + set_pte_phys(address, phys, prot); +} + /* References to section boundaries */ extern char _text, _etext, _edata, __bss_start, _end; diff -puN /dev/null include/asm-sh/fixmap.h --- /dev/null 2003-09-15 06:40:47.000000000 -0700 +++ 25-akpm/include/asm-sh/fixmap.h 2004-06-23 20:00:15.852280112 -0700 @@ -0,0 +1,111 @@ +/* + * fixmap.h: compile-time virtual memory allocation + * + * 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. + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +#include +#include +#include +#ifdef CONFIG_HIGHMEM +#include +#include +#endif + +/* + * Here we define all the compile-time 'special' virtual + * addresses. The point is to have a constant address at + * compile time, but to set the physical address only + * in the boot process. We allocate these special addresses + * from the end of virtual memory (0xfffff000) backwards. + * Also this lets us do fail-safe vmalloc(), we + * can guarantee that these special addresses and + * vmalloc()-ed addresses never overlap. + * + * these 'compile-time allocated' memory buffers are + * fixed-size 4k pages. (or larger if used with an increment + * highger than 1) use fixmap_set(idx,phys) to associate + * physical memory with fixmap indices. + * + * TLB entries of such buffers will not be flushed across + * task switches. + */ + +/* + * on UP currently we will have no trace of the fixmap mechanizm, + * no page table allocations, etc. This might change in the + * future, say framebuffers for the console driver(s) could be + * fix-mapped? + */ +enum fixed_addresses { +#ifdef CONFIG_HIGHMEM + FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, +#endif + __end_of_fixed_addresses +}; + +extern void __set_fixmap (enum fixed_addresses idx, + unsigned long phys, pgprot_t flags); + +#define set_fixmap(idx, phys) \ + __set_fixmap(idx, phys, PAGE_KERNEL) +/* + * Some hardware wants to get fixmapped without caching. + */ +#define set_fixmap_nocache(idx, phys) \ + __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) +/* + * used by vmalloc.c. + * + * Leave one empty page between vmalloc'ed areas and + * the start of the fixmap, and leave one page empty + * at the top of mem.. + */ +#define FIXADDR_TOP (P4SEG - PAGE_SIZE) +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +extern void __this_fixmap_does_not_exist(void); + +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without tranlation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static inline unsigned long fix_to_virt(const unsigned int idx) +{ + /* + * this branch gets completely eliminated after inlining, + * except when someone tries to use fixaddr indices in an + * illegal way. (such as mixing up address types or using + * out-of-range indices). + * + * If it doesn't get removed, the linker will complain + * loudly with a reasonably clear error message.. + */ + if (idx >= __end_of_fixed_addresses) + __this_fixmap_does_not_exist(); + + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#endif diff -puN include/asm-sh/pgtable.h~sh-fixmap-support include/asm-sh/pgtable.h --- 25/include/asm-sh/pgtable.h~sh-fixmap-support 2004-06-23 20:00:15.847280872 -0700 +++ 25-akpm/include/asm-sh/pgtable.h 2004-06-23 20:00:15.853279960 -0700 @@ -3,7 +3,7 @@ /* * Copyright (C) 1999 Niibe Yutaka - * Copyright (C) 2002, 2003 Paul Mundt + * Copyright (C) 2002, 2003, 2004 Paul Mundt */ #include @@ -16,6 +16,7 @@ #ifndef __ASSEMBLY__ #include #include +#include #include extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; @@ -51,7 +52,7 @@ extern unsigned long empty_zero_page[102 * Currently only 4-enty (16kB) is used (see arch/sh/mm/cache.c) */ #define VMALLOC_START (P3SEG+0x00100000) -#define VMALLOC_END P4SEG +#define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE) #define _PAGE_WT 0x001 /* WT-bit on SH-4, 0 on SH-3 */ #define _PAGE_HW_SHARED 0x002 /* SH-bit : page is shared among processes */ _