diff options
Diffstat (limited to 'arch/powerpc/mm/mmu_context_book3s64.c')
| -rw-r--r-- | arch/powerpc/mm/mmu_context_book3s64.c | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c new file mode 100644 index 000000000000..b5288b460bef --- /dev/null +++ b/arch/powerpc/mm/mmu_context_book3s64.c @@ -0,0 +1,178 @@ +/* + * MMU context allocation for 64-bit kernels. + * + * Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org> + * + * 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/sched.h> +#include <linux/kernel.h> +#include <linux/errno.h> +#include <linux/string.h> +#include <linux/types.h> +#include <linux/mm.h> +#include <linux/spinlock.h> +#include <linux/idr.h> +#include <linux/export.h> +#include <linux/gfp.h> +#include <linux/slab.h> + +#include <asm/mmu_context.h> +#include <asm/pgalloc.h> + +#include "icswx.h" + +static DEFINE_SPINLOCK(mmu_context_lock); +static DEFINE_IDA(mmu_context_ida); + +int __init_new_context(void) +{ + int index; + int err; + +again: + if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL)) + return -ENOMEM; + + spin_lock(&mmu_context_lock); + err = ida_get_new_above(&mmu_context_ida, 1, &index); + spin_unlock(&mmu_context_lock); + + if (err == -EAGAIN) + goto again; + else if (err) + return err; + + if (index > MAX_USER_CONTEXT) { + spin_lock(&mmu_context_lock); + ida_remove(&mmu_context_ida, index); + spin_unlock(&mmu_context_lock); + return -ENOMEM; + } + + return index; +} +EXPORT_SYMBOL_GPL(__init_new_context); +static int radix__init_new_context(struct mm_struct *mm, int index) +{ + unsigned long rts_field; + + /* + * set the process table entry, + */ + rts_field = 3ull << PPC_BITLSHIFT(2); + process_tb[index].prtb0 = cpu_to_be64(rts_field | __pa(mm->pgd) | RADIX_PGD_INDEX_SIZE); + return 0; +} + +int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +{ + int index; + + index = __init_new_context(); + if (index < 0) + return index; + + if (radix_enabled()) { + radix__init_new_context(mm, index); + } else { + + /* The old code would re-promote on fork, we don't do that + * when using slices as it could cause problem promoting slices + * that have been forced down to 4K + */ + if (slice_mm_new_context(mm)) + slice_set_user_psize(mm, mmu_virtual_psize); + subpage_prot_init_new_context(mm); + } + mm->context.id = index; +#ifdef CONFIG_PPC_ICSWX + mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL); + if (!mm->context.cop_lockp) { + __destroy_context(index); + subpage_prot_free(mm); + mm->context.id = MMU_NO_CONTEXT; + return -ENOMEM; + } + spin_lock_init(mm->context.cop_lockp); +#endif /* CONFIG_PPC_ICSWX */ + +#ifdef CONFIG_PPC_64K_PAGES + mm->context.pte_frag = NULL; +#endif +#ifdef CONFIG_SPAPR_TCE_IOMMU + mm_iommu_init(&mm->context); +#endif + return 0; +} + +void __destroy_context(int context_id) +{ + spin_lock(&mmu_context_lock); + ida_remove(&mmu_context_ida, context_id); + spin_unlock(&mmu_context_lock); +} +EXPORT_SYMBOL_GPL(__destroy_context); + +#ifdef CONFIG_PPC_64K_PAGES +static void destroy_pagetable_page(struct mm_struct *mm) +{ + int count; + void *pte_frag; + struct page *page; + + pte_frag = mm->context.pte_frag; + if (!pte_frag) + return; + + page = virt_to_page(pte_frag); + /* drop all the pending references */ + count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT; + /* We allow PTE_FRAG_NR fragments from a PTE page */ + if (page_ref_sub_and_test(page, PTE_FRAG_NR - count)) { + pgtable_page_dtor(page); + free_hot_cold_page(page, 0); + } +} + +#else +static inline void destroy_pagetable_page(struct mm_struct *mm) +{ + return; +} +#endif + + +void destroy_context(struct mm_struct *mm) +{ +#ifdef CONFIG_SPAPR_TCE_IOMMU + mm_iommu_cleanup(&mm->context); +#endif + +#ifdef CONFIG_PPC_ICSWX + drop_cop(mm->context.acop, mm); + kfree(mm->context.cop_lockp); + mm->context.cop_lockp = NULL; +#endif /* CONFIG_PPC_ICSWX */ + + if (radix_enabled()) + process_tb[mm->context.id].prtb1 = 0; + else + subpage_prot_free(mm); + destroy_pagetable_page(mm); + __destroy_context(mm->context.id); + mm->context.id = MMU_NO_CONTEXT; +} + +#ifdef CONFIG_PPC_RADIX_MMU +void radix__switch_mmu_context(struct mm_struct *prev, struct mm_struct *next) +{ + mtspr(SPRN_PID, next->context.id); + asm volatile("isync": : :"memory"); +} +#endif |