diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/powerpc/mm/mmu_context_hash32.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/powerpc/mm/mmu_context_hash32.c | 119 |
1 files changed, 0 insertions, 119 deletions
diff --git a/ANDROID_3.4.5/arch/powerpc/mm/mmu_context_hash32.c b/ANDROID_3.4.5/arch/powerpc/mm/mmu_context_hash32.c deleted file mode 100644 index 78fef672..00000000 --- a/ANDROID_3.4.5/arch/powerpc/mm/mmu_context_hash32.c +++ /dev/null @@ -1,119 +0,0 @@ -/* - * This file contains the routines for handling the MMU on those - * PowerPC implementations where the MMU substantially follows the - * architecture specification. This includes the 6xx, 7xx, 7xxx, - * 8260, and POWER3 implementations but excludes the 8xx and 4xx. - * -- paulus - * - * Derived from arch/ppc/mm/init.c: - * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) - * - * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) - * and Cort Dougan (PReP) (cort@cs.nmt.edu) - * Copyright (C) 1996 Paul Mackerras - * - * Derived from "arch/i386/mm/init.c" - * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds - * - * 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; either version - * 2 of the License, or (at your option) any later version. - * - */ - -#include <linux/mm.h> -#include <linux/init.h> -#include <linux/export.h> - -#include <asm/mmu_context.h> -#include <asm/tlbflush.h> - -/* - * On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs - * (virtual segment identifiers) for each context. Although the - * hardware supports 24-bit VSIDs, and thus >1 million contexts, - * we only use 32,768 of them. That is ample, since there can be - * at most around 30,000 tasks in the system anyway, and it means - * that we can use a bitmap to indicate which contexts are in use. - * Using a bitmap means that we entirely avoid all of the problems - * that we used to have when the context number overflowed, - * particularly on SMP systems. - * -- paulus. - */ -#define NO_CONTEXT ((unsigned long) -1) -#define LAST_CONTEXT 32767 -#define FIRST_CONTEXT 1 - -/* - * This function defines the mapping from contexts to VSIDs (virtual - * segment IDs). We use a skew on both the context and the high 4 bits - * of the 32-bit virtual address (the "effective segment ID") in order - * to spread out the entries in the MMU hash table. Note, if this - * function is changed then arch/ppc/mm/hashtable.S will have to be - * changed to correspond. - * - * - * CTX_TO_VSID(ctx, va) (((ctx) * (897 * 16) + ((va) >> 28) * 0x111) \ - * & 0xffffff) - */ - -static unsigned long next_mmu_context; -static unsigned long context_map[LAST_CONTEXT / BITS_PER_LONG + 1]; - -unsigned long __init_new_context(void) -{ - unsigned long ctx = next_mmu_context; - - while (test_and_set_bit(ctx, context_map)) { - ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx); - if (ctx > LAST_CONTEXT) - ctx = 0; - } - next_mmu_context = (ctx + 1) & LAST_CONTEXT; - - return ctx; -} -EXPORT_SYMBOL_GPL(__init_new_context); - -/* - * Set up the context for a new address space. - */ -int init_new_context(struct task_struct *t, struct mm_struct *mm) -{ - mm->context.id = __init_new_context(); - - return 0; -} - -/* - * Free a context ID. Make sure to call this with preempt disabled! - */ -void __destroy_context(unsigned long ctx) -{ - clear_bit(ctx, context_map); -} -EXPORT_SYMBOL_GPL(__destroy_context); - -/* - * We're finished using the context for an address space. - */ -void destroy_context(struct mm_struct *mm) -{ - preempt_disable(); - if (mm->context.id != NO_CONTEXT) { - __destroy_context(mm->context.id); - mm->context.id = NO_CONTEXT; - } - preempt_enable(); -} - -/* - * Initialize the context management stuff. - */ -void __init mmu_context_init(void) -{ - /* Reserve context 0 for kernel use */ - context_map[0] = (1 << FIRST_CONTEXT) - 1; - next_mmu_context = FIRST_CONTEXT; -} |