summaryrefslogtreecommitdiff
path: root/arch/tile/include/asm/mmu_context.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/tile/include/asm/mmu_context.h')
-rw-r--r--arch/tile/include/asm/mmu_context.h137
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 */