diff options
author | Roman Yeryomin <roman@advem.lv> | 2012-09-13 00:40:35 +0300 |
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committer | Roman Yeryomin <roman@advem.lv> | 2012-12-03 00:13:21 +0200 |
commit | 5deb3317cb51ac52de922bb55f8492624018906d (patch) | |
tree | c2fbe6346699d9bb0f2100490c3029519bb8fde8 /target/linux/realtek/files/arch/rlx/mm/highmem.c | |
parent | 0239d37124f9184b478a42de8a7fa1bc85a6a6fe (diff) |
Add realtek target files
Signed-off-by: Roman Yeryomin <roman@advem.lv>
Diffstat (limited to 'target/linux/realtek/files/arch/rlx/mm/highmem.c')
-rw-r--r-- | target/linux/realtek/files/arch/rlx/mm/highmem.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/target/linux/realtek/files/arch/rlx/mm/highmem.c b/target/linux/realtek/files/arch/rlx/mm/highmem.c new file mode 100644 index 000000000..2b1309b25 --- /dev/null +++ b/target/linux/realtek/files/arch/rlx/mm/highmem.c @@ -0,0 +1,130 @@ +#include <linux/module.h> +#include <linux/highmem.h> +#include <asm/fixmap.h> +#include <asm/tlbflush.h> + +static pte_t *kmap_pte; + +unsigned long highstart_pfn, highend_pfn; + +void *__kmap(struct page *page) +{ + void *addr; + + might_sleep(); + if (!PageHighMem(page)) + return page_address(page); + addr = kmap_high(page); + flush_tlb_one((unsigned long)addr); + + return addr; +} +EXPORT_SYMBOL(__kmap); + +void __kunmap(struct page *page) +{ + BUG_ON(in_interrupt()); + if (!PageHighMem(page)) + return; + kunmap_high(page); +} +EXPORT_SYMBOL(__kunmap); + +/* + * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because + * no global lock is needed and because the kmap code must perform a global TLB + * invalidation when the kmap pool wraps. + * + * However when holding an atomic kmap is is not legal to sleep, so atomic + * kmaps are appropriate for short, tight code paths only. + */ + +void *__kmap_atomic(struct page *page, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ + pagefault_disable(); + if (!PageHighMem(page)) + return page_address(page); + + debug_kmap_atomic(type); + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); +#ifdef CONFIG_DEBUG_HIGHMEM + BUG_ON(!pte_none(*(kmap_pte - idx))); +#endif + set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL)); + local_flush_tlb_one((unsigned long)vaddr); + + return (void*) vaddr; +} +EXPORT_SYMBOL(__kmap_atomic); + +void __kunmap_atomic(void *kvaddr, enum km_type type) +{ +#ifdef CONFIG_DEBUG_HIGHMEM + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); + + if (vaddr < FIXADDR_START) { // FIXME + pagefault_enable(); + return; + } + + BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); + + /* + * force other mappings to Oops if they'll try to access + * this pte without first remap it + */ + pte_clear(&init_mm, vaddr, kmap_pte-idx); + local_flush_tlb_one(vaddr); +#endif + + pagefault_enable(); +} +EXPORT_SYMBOL(__kunmap_atomic); + +/* + * This is the same as kmap_atomic() but can map memory that doesn't + * have a struct page associated with it. + */ +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + pagefault_disable(); + + debug_kmap_atomic(type); + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(kmap_pte-idx, pfn_pte(pfn, PAGE_KERNEL)); + flush_tlb_one(vaddr); + + return (void*) vaddr; +} + +struct page *__kmap_atomic_to_page(void *ptr) +{ + unsigned long idx, vaddr = (unsigned long)ptr; + pte_t *pte; + + if (vaddr < FIXADDR_START) + return virt_to_page(ptr); + + idx = virt_to_fix(vaddr); + pte = kmap_pte - (idx - FIX_KMAP_BEGIN); + return pte_page(*pte); +} + +void __init kmap_init(void) +{ + unsigned long kmap_vstart; + + /* cache the first kmap pte */ + kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN); + kmap_pte = kmap_get_fixmap_pte(kmap_vstart); +} |