/* * Copyright 2010 Tilera Corporation. All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for * more details. */ #ifndef _ASM_TILE_MMU_CONTEXT_H #define _ASM_TILE_MMU_CONTEXT_H #include <linux/smp.h> #include <linux/mm_types.h> #include <asm/setup.h> #include <asm/page.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> #include <asm/homecache.h> #include <asm-generic/mm_hooks.h> static inline int init_new_context(struct task_struct *tsk, struct mm_struct *mm) { return 0; } /* * Note that arch/tile/kernel/head_NN.S and arch/tile/mm/migrate_NN.S * also call hv_install_context(). */ static inline void __install_page_table(pgd_t *pgdir, int asid, pgprot_t prot) { /* FIXME: DIRECTIO should not always be set. FIXME. */ int rc = hv_install_context(__pa(pgdir), prot, asid, HV_CTX_DIRECTIO | CTX_PAGE_FLAG); if (rc < 0) panic("hv_install_context failed: %d", rc); } static inline void install_page_table(pgd_t *pgdir, int asid) { pte_t *ptep = virt_to_kpte((unsigned long)pgdir); __install_page_table(pgdir, asid, *ptep); } /* * "Lazy" TLB mode is entered when we are switching to a kernel task, * which borrows the mm of the previous task. The goal of this * optimization is to avoid having to install a new page table. On * early x86 machines (where the concept originated) you couldn't do * anything short of a full page table install for invalidation, so * handling a remote TLB invalidate required doing a page table * re-install. Someone clearly decided that it was silly to keep * doing this while in "lazy" TLB mode, so the optimization involves * installing the swapper page table instead the first time one * occurs, and clearing the cpu out of cpu_vm_mask, so the cpu running * the kernel task doesn't need to take any more interrupts. At that * point it's then necessary to explicitly reinstall it when context * switching back to the original mm. * * On Tile, we have to do a page-table install whenever DMA is enabled, * so in that case lazy mode doesn't help anyway. And more generally, * we have efficient per-page TLB shootdown, and don't expect to spend * that much time in kernel tasks in general, so just leaving the * kernel task borrowing the old page table, but handling TLB * shootdowns, is a reasonable thing to do. And importantly, this * lets us use the hypervisor's internal APIs for TLB shootdown, which * means we don't have to worry about having TLB shootdowns blocked * when Linux is disabling interrupts; see the page migration code for * an example of where it's important for TLB shootdowns to complete * even when interrupts are disabled at the Linux level. */ static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *t) { #if CHIP_HAS_TILE_DMA() /* * We have to do an "identity" page table switch in order to * clear any pending DMA interrupts. */ if (current->thread.tile_dma_state.enabled) install_page_table(mm->pgd, __this_cpu_read(current_asid)); #endif } static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) { if (likely(prev != next)) { int cpu = smp_processor_id(); /* Pick new ASID. */ int asid = __this_cpu_read(current_asid) + 1; if (asid > max_asid) { asid = min_asid; local_flush_tlb(); } __this_cpu_write(current_asid, asid); /* Clear cpu from the old mm, and set it in the new one. */ cpumask_clear_cpu(cpu, mm_cpumask(prev)); cpumask_set_cpu(cpu, mm_cpumask(next)); /* Re-load page tables */ install_page_table(next->pgd, asid); /* See how we should set the red/black cache info */ check_mm_caching(prev, next); /* * Since we're changing to a new mm, we have to flush * the icache in case some physical page now being mapped * has subsequently been repurposed and has new code. */ __flush_icache(); } } static inline void activate_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm) { switch_mm(prev_mm, next_mm, NULL); } #define destroy_context(mm) do { } while (0) #define deactivate_mm(tsk, mm) do { } while (0) #endif /* _ASM_TILE_MMU_CONTEXT_H */
Name | Type | Size | Permission | Actions |
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Kbuild | File | 439 B | 0644 |
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asm-offsets.h | File | 35 B | 0644 |
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atomic.h | File | 5.14 KB | 0644 |
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atomic_32.h | File | 8.91 KB | 0644 |
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atomic_64.h | File | 5.51 KB | 0644 |
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backtrace.h | File | 3.98 KB | 0644 |
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barrier.h | File | 2.89 KB | 0644 |
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bitops.h | File | 2.37 KB | 0644 |
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bitops_32.h | File | 4.01 KB | 0644 |
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bitops_64.h | File | 2.67 KB | 0644 |
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cache.h | File | 2.6 KB | 0644 |
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cacheflush.h | File | 4.94 KB | 0644 |
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checksum.h | File | 1.23 KB | 0644 |
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cmpxchg.h | File | 3.47 KB | 0644 |
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compat.h | File | 7.38 KB | 0644 |
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current.h | File | 947 B | 0644 |
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delay.h | File | 1.1 KB | 0644 |
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device.h | File | 978 B | 0644 |
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div64.h | File | 319 B | 0644 |
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dma-mapping.h | File | 1.82 KB | 0644 |
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dma.h | File | 762 B | 0644 |
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elf.h | File | 5.42 KB | 0644 |
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fixmap.h | File | 2.73 KB | 0644 |
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ftrace.h | File | 1.08 KB | 0644 |
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futex.h | File | 4.23 KB | 0644 |
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hardirq.h | File | 1.28 KB | 0644 |
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hardwall.h | File | 1.08 KB | 0644 |
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highmem.h | File | 2.08 KB | 0644 |
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homecache.h | File | 4.21 KB | 0644 |
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hugetlb.h | File | 3.04 KB | 0644 |
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hv_driver.h | File | 1.92 KB | 0644 |
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ide.h | File | 758 B | 0644 |
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insn.h | File | 1.79 KB | 0644 |
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io.h | File | 12.43 KB | 0644 |
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irq.h | File | 3.11 KB | 0644 |
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irq_work.h | File | 283 B | 0644 |
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irqflags.h | File | 10.55 KB | 0644 |
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jump_label.h | File | 1.47 KB | 0644 |
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kdebug.h | File | 769 B | 0644 |
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kexec.h | File | 2.23 KB | 0644 |
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kgdb.h | File | 1.99 KB | 0644 |
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kmap_types.h | File | 1.02 KB | 0644 |
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kprobes.h | File | 2.19 KB | 0644 |
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linkage.h | File | 1.46 KB | 0644 |
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mmu.h | File | 965 B | 0644 |
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mmu_context.h | File | 4.5 KB | 0644 |
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mmzone.h | File | 2.07 KB | 0644 |
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module.h | File | 1.12 KB | 0644 |
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page.h | File | 10.32 KB | 0644 |
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pci.h | File | 6.58 KB | 0644 |
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percpu.h | File | 1.79 KB | 0644 |
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perf_event.h | File | 766 B | 0644 |
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pgalloc.h | File | 4.76 KB | 0644 |
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pgtable.h | File | 15.66 KB | 0644 |
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pgtable_32.h | File | 4.08 KB | 0644 |
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pgtable_64.h | File | 5.11 KB | 0644 |
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pmc.h | File | 2.15 KB | 0644 |
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processor.h | File | 10.62 KB | 0644 |
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ptrace.h | File | 2.96 KB | 0644 |
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sections.h | File | 1.37 KB | 0644 |
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setup.h | File | 1.63 KB | 0644 |
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sigframe.h | File | 956 B | 0644 |
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signal.h | File | 1.07 KB | 0644 |
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smp.h | File | 3.98 KB | 0644 |
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spinlock.h | File | 741 B | 0644 |
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spinlock_32.h | File | 2.9 KB | 0644 |
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spinlock_64.h | File | 3.88 KB | 0644 |
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spinlock_types.h | File | 1.58 KB | 0644 |
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stack.h | File | 2.59 KB | 0644 |
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string.h | File | 1.19 KB | 0644 |
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switch_to.h | File | 2.75 KB | 0644 |
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syscall.h | File | 2.88 KB | 0644 |
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syscalls.h | File | 2.35 KB | 0644 |
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thread_info.h | File | 5.54 KB | 0644 |
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tile-desc.h | File | 650 B | 0644 |
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tile-desc_32.h | File | 12.54 KB | 0644 |
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tile-desc_64.h | File | 10.83 KB | 0644 |
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timex.h | File | 1.71 KB | 0644 |
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tlb.h | File | 878 B | 0644 |
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tlbflush.h | File | 3.99 KB | 0644 |
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topology.h | File | 1.52 KB | 0644 |
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traps.h | File | 2.44 KB | 0644 |
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uaccess.h | File | 12.77 KB | 0644 |
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unaligned.h | File | 1.56 KB | 0644 |
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unistd.h | File | 777 B | 0644 |
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user.h | File | 717 B | 0644 |
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vdso.h | File | 1.84 KB | 0644 |
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vga.h | File | 1.05 KB | 0644 |
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word-at-a-time.h | File | 1.07 KB | 0644 |
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