diff options
Diffstat (limited to 'arch/tile/include/asm/mmu_context.h')
| -rw-r--r-- | arch/tile/include/asm/mmu_context.h | 137 |
1 files changed, 0 insertions, 137 deletions
diff --git a/arch/tile/include/asm/mmu_context.h b/arch/tile/include/asm/mmu_context.h deleted file mode 100644 index 45a4b4c424cf..000000000000 --- a/arch/tile/include/asm/mmu_context.h +++ /dev/null @@ -1,137 +0,0 @@ -/* - * 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 */ |