From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/arch/mips/mm/highmem.c | 141 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 141 insertions(+) create mode 100644 kernel/arch/mips/mm/highmem.c (limited to 'kernel/arch/mips/mm/highmem.c') diff --git a/kernel/arch/mips/mm/highmem.c b/kernel/arch/mips/mm/highmem.c new file mode 100644 index 000000000..11661cbc1 --- /dev/null +++ b/kernel/arch/mips/mm/highmem.c @@ -0,0 +1,141 @@ +#include +#include +#include +#include +#include +#include +#include + +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) +{ + unsigned long vaddr; + int idx, type; + + preempt_disable(); + pagefault_disable(); + if (!PageHighMem(page)) + return page_address(page); + + type = kmap_atomic_idx_push(); + 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) +{ + unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; + int type __maybe_unused; + + if (vaddr < FIXADDR_START) { // FIXME + pagefault_enable(); + preempt_enable(); + return; + } + + type = kmap_atomic_idx(); +#ifdef CONFIG_DEBUG_HIGHMEM + { + int idx = type + KM_TYPE_NR * smp_processor_id(); + + 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 + kmap_atomic_idx_pop(); + pagefault_enable(); + preempt_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) +{ + unsigned long vaddr; + int idx, type; + + preempt_disable(); + pagefault_disable(); + + type = kmap_atomic_idx_push(); + 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); +} -- cgit 1.2.3-korg