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author | James Hogan <james.hogan@imgtec.com> | 2012-10-09 09:54:17 (GMT) |
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committer | James Hogan <james.hogan@imgtec.com> | 2013-03-02 20:09:20 (GMT) |
commit | bbc17704d5d3a8e4325dae74c2a2e77218c26057 (patch) | |
tree | fe13881c1f85fa781e3ac413216954dd946fafae /arch/metag/include | |
parent | e624e95bd88f94fc70bbe612789bcac44c6f0923 (diff) | |
download | linux-bbc17704d5d3a8e4325dae74c2a2e77218c26057.tar.xz |
metag: Highmem support
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Diffstat (limited to 'arch/metag/include')
-rw-r--r-- | arch/metag/include/asm/fixmap.h | 99 | ||||
-rw-r--r-- | arch/metag/include/asm/highmem.h | 62 |
2 files changed, 161 insertions, 0 deletions
diff --git a/arch/metag/include/asm/fixmap.h b/arch/metag/include/asm/fixmap.h new file mode 100644 index 0000000..3331275 --- /dev/null +++ b/arch/metag/include/asm/fixmap.h @@ -0,0 +1,99 @@ +/* + * 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 <asm/pgtable.h> +#ifdef CONFIG_HIGHMEM +#include <linux/threads.h> +#include <asm/kmap_types.h> +#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 the consistent memory region 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 + * higher 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. + */ +enum fixed_addresses { +#define FIX_N_COLOURS 8 +#ifdef CONFIG_HIGHMEM + /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_BEGIN, + FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, +#endif + __end_of_fixed_addresses +}; + +#define FIXADDR_TOP (CONSISTENT_START - PAGE_SIZE) +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#define FIXADDR_START ((FIXADDR_TOP - FIXADDR_SIZE) & PMD_MASK) + +#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); +} + +#define kmap_get_fixmap_pte(vaddr) \ + pte_offset_kernel( \ + pmd_offset(pud_offset(pgd_offset_k(vaddr), (vaddr)), (vaddr)), \ + (vaddr) \ + ) + +/* + * Called from pgtable_init() + */ +extern void fixrange_init(unsigned long start, unsigned long end, + pgd_t *pgd_base); + + +#endif diff --git a/arch/metag/include/asm/highmem.h b/arch/metag/include/asm/highmem.h new file mode 100644 index 0000000..6646a15 --- /dev/null +++ b/arch/metag/include/asm/highmem.h @@ -0,0 +1,62 @@ +#ifndef _ASM_HIGHMEM_H +#define _ASM_HIGHMEM_H + +#include <asm/cacheflush.h> +#include <asm/kmap_types.h> +#include <asm/fixmap.h> + +/* + * Right now we initialize only a single pte table. It can be extended + * easily, subsequent pte tables have to be allocated in one physical + * chunk of RAM. + */ +/* + * Ordering is (from lower to higher memory addresses): + * + * high_memory + * Persistent kmap area + * PKMAP_BASE + * fixed_addresses + * FIXADDR_START + * FIXADDR_TOP + * Vmalloc area + * VMALLOC_START + * VMALLOC_END + */ +#define PKMAP_BASE (FIXADDR_START - PMD_SIZE) +#define LAST_PKMAP PTRS_PER_PTE +#define LAST_PKMAP_MASK (LAST_PKMAP - 1) +#define PKMAP_NR(virt) (((virt) - PKMAP_BASE) >> PAGE_SHIFT) +#define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) + +#define kmap_prot PAGE_KERNEL + +static inline void flush_cache_kmaps(void) +{ + flush_cache_all(); +} + +/* declarations for highmem.c */ +extern unsigned long highstart_pfn, highend_pfn; + +extern pte_t *pkmap_page_table; + +extern void *kmap_high(struct page *page); +extern void kunmap_high(struct page *page); + +extern void kmap_init(void); + +/* + * The following functions are already defined by <linux/highmem.h> + * when CONFIG_HIGHMEM is not set. + */ +#ifdef CONFIG_HIGHMEM +extern void *kmap(struct page *page); +extern void kunmap(struct page *page); +extern void *kmap_atomic(struct page *page); +extern void __kunmap_atomic(void *kvaddr); +extern void *kmap_atomic_pfn(unsigned long pfn); +extern struct page *kmap_atomic_to_page(void *ptr); +#endif + +#endif |