diff options
Diffstat (limited to 'arch/m68k/include/asm/mmu_context.h')
-rw-r--r-- | arch/m68k/include/asm/mmu_context.h | 322 |
1 files changed, 322 insertions, 0 deletions
diff --git a/arch/m68k/include/asm/mmu_context.h b/arch/m68k/include/asm/mmu_context.h new file mode 100644 index 0000000000..141bbdfad9 --- /dev/null +++ b/arch/m68k/include/asm/mmu_context.h @@ -0,0 +1,322 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __M68K_MMU_CONTEXT_H +#define __M68K_MMU_CONTEXT_H + +#include <asm-generic/mm_hooks.h> +#include <linux/mm_types.h> + +#ifdef CONFIG_MMU + +#if defined(CONFIG_COLDFIRE) + +#include <asm/atomic.h> +#include <asm/bitops.h> +#include <asm/mcfmmu.h> +#include <asm/mmu.h> + +#define NO_CONTEXT 256 +#define LAST_CONTEXT 255 +#define FIRST_CONTEXT 1 + +extern unsigned long context_map[]; +extern mm_context_t next_mmu_context; + +extern atomic_t nr_free_contexts; +extern struct mm_struct *context_mm[LAST_CONTEXT+1]; +extern void steal_context(void); + +static inline void get_mmu_context(struct mm_struct *mm) +{ + mm_context_t ctx; + + if (mm->context != NO_CONTEXT) + return; + while (arch_atomic_dec_and_test_lt(&nr_free_contexts)) { + atomic_inc(&nr_free_contexts); + steal_context(); + } + 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; + mm->context = ctx; + context_mm[ctx] = mm; +} + +/* + * Set up the context for a new address space. + */ +#define init_new_context(tsk, mm) (((mm)->context = NO_CONTEXT), 0) + +/* + * We're finished using the context for an address space. + */ +#define destroy_context destroy_context +static inline void destroy_context(struct mm_struct *mm) +{ + if (mm->context != NO_CONTEXT) { + clear_bit(mm->context, context_map); + mm->context = NO_CONTEXT; + atomic_inc(&nr_free_contexts); + } +} + +static inline void set_context(mm_context_t context, pgd_t *pgd) +{ + __asm__ __volatile__ ("movec %0,%%asid" : : "d" (context)); +} + +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + get_mmu_context(tsk->mm); + set_context(tsk->mm->context, next->pgd); +} + +/* + * After we have set current->mm to a new value, this activates + * the context for the new mm so we see the new mappings. + */ +#define activate_mm activate_mm +static inline void activate_mm(struct mm_struct *active_mm, + struct mm_struct *mm) +{ + get_mmu_context(mm); + set_context(mm->context, mm->pgd); +} + +#define prepare_arch_switch(next) load_ksp_mmu(next) + +static inline void load_ksp_mmu(struct task_struct *task) +{ + unsigned long flags; + struct mm_struct *mm; + int asid; + pgd_t *pgd; + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *pte = NULL; + unsigned long mmuar; + + local_irq_save(flags); + mmuar = task->thread.ksp; + + /* Search for a valid TLB entry, if one is found, don't remap */ + mmu_write(MMUAR, mmuar); + mmu_write(MMUOR, MMUOR_STLB | MMUOR_ADR); + if (mmu_read(MMUSR) & MMUSR_HIT) + goto end; + + if (mmuar >= PAGE_OFFSET) { + mm = &init_mm; + } else { + pr_info("load_ksp_mmu: non-kernel mm found: 0x%p\n", task->mm); + mm = task->mm; + } + + if (!mm) + goto bug; + + pgd = pgd_offset(mm, mmuar); + if (pgd_none(*pgd)) + goto bug; + + p4d = p4d_offset(pgd, mmuar); + if (p4d_none(*p4d)) + goto bug; + + pud = pud_offset(p4d, mmuar); + if (pud_none(*pud)) + goto bug; + + pmd = pmd_offset(pud, mmuar); + if (pmd_none(*pmd)) + goto bug; + + pte = (mmuar >= PAGE_OFFSET) ? pte_offset_kernel(pmd, mmuar) + : pte_offset_map(pmd, mmuar); + if (!pte || pte_none(*pte) || !pte_present(*pte)) + goto bug; + + set_pte(pte, pte_mkyoung(*pte)); + asid = mm->context & 0xff; + if (!pte_dirty(*pte) && mmuar <= PAGE_OFFSET) + set_pte(pte, pte_wrprotect(*pte)); + + mmu_write(MMUTR, (mmuar & PAGE_MASK) | (asid << MMUTR_IDN) | + (((int)(pte->pte) & (int)CF_PAGE_MMUTR_MASK) + >> CF_PAGE_MMUTR_SHIFT) | MMUTR_V); + + mmu_write(MMUDR, (pte_val(*pte) & PAGE_MASK) | + ((pte->pte) & CF_PAGE_MMUDR_MASK) | MMUDR_SZ_8KB | MMUDR_X); + + mmu_write(MMUOR, MMUOR_ACC | MMUOR_UAA); + + goto end; + +bug: + pr_info("ksp load failed: mm=0x%p ksp=0x08%lx\n", mm, mmuar); +end: + if (pte && mmuar < PAGE_OFFSET) + pte_unmap(pte); + local_irq_restore(flags); +} + +#elif defined(CONFIG_SUN3) +#include <asm/sun3mmu.h> +#include <linux/sched.h> + +extern unsigned long get_free_context(struct mm_struct *mm); +extern void clear_context(unsigned long context); + +/* set the context for a new task to unmapped */ +#define init_new_context init_new_context +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + mm->context = SUN3_INVALID_CONTEXT; + return 0; +} + +/* find the context given to this process, and if it hasn't already + got one, go get one for it. */ +static inline void get_mmu_context(struct mm_struct *mm) +{ + if (mm->context == SUN3_INVALID_CONTEXT) + mm->context = get_free_context(mm); +} + +/* flush context if allocated... */ +#define destroy_context destroy_context +static inline void destroy_context(struct mm_struct *mm) +{ + if (mm->context != SUN3_INVALID_CONTEXT) + clear_context(mm->context); +} + +static inline void activate_context(struct mm_struct *mm) +{ + get_mmu_context(mm); + sun3_put_context(mm->context); +} + +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + activate_context(tsk->mm); +} + +#define activate_mm activate_mm +static inline void activate_mm(struct mm_struct *prev_mm, + struct mm_struct *next_mm) +{ + activate_context(next_mm); +} + +#else + +#include <asm/setup.h> +#include <asm/page.h> +#include <asm/cacheflush.h> + +#define init_new_context init_new_context +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + mm->context = virt_to_phys(mm->pgd); + return 0; +} + +static inline void switch_mm_0230(struct mm_struct *mm) +{ + unsigned long crp[2] = { + 0x80000000 | _PAGE_TABLE, mm->context + }; + unsigned long tmp; + + asm volatile (".chip 68030"); + + /* flush MC68030/MC68020 caches (they are virtually addressed) */ + asm volatile ( + "movec %%cacr,%0;" + "orw %1,%0; " + "movec %0,%%cacr" + : "=d" (tmp) : "di" (FLUSH_I_AND_D)); + + /* Switch the root pointer. For a 030-only kernel, + * avoid flushing the whole ATC, we only need to + * flush the user entries. The 68851 does this by + * itself. Avoid a runtime check here. + */ + asm volatile ( +#ifdef CPU_M68030_ONLY + "pmovefd %0,%%crp; " + "pflush #0,#4" +#else + "pmove %0,%%crp" +#endif + : : "m" (crp[0])); + + asm volatile (".chip 68k"); +} + +static inline void switch_mm_0460(struct mm_struct *mm) +{ + asm volatile (".chip 68040"); + + /* flush address translation cache (user entries) */ + asm volatile ("pflushan"); + + /* switch the root pointer */ + asm volatile ("movec %0,%%urp" : : "r" (mm->context)); + + if (CPU_IS_060) { + unsigned long tmp; + + /* clear user entries in the branch cache */ + asm volatile ( + "movec %%cacr,%0; " + "orl %1,%0; " + "movec %0,%%cacr" + : "=d" (tmp): "di" (0x00200000)); + } + + asm volatile (".chip 68k"); +} + +static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) +{ + if (prev != next) { + if (CPU_IS_020_OR_030) + switch_mm_0230(next); + else + switch_mm_0460(next); + } +} + +#define activate_mm activate_mm +static inline void activate_mm(struct mm_struct *prev_mm, + struct mm_struct *next_mm) +{ + next_mm->context = virt_to_phys(next_mm->pgd); + + if (CPU_IS_020_OR_030) + switch_mm_0230(next_mm); + else + switch_mm_0460(next_mm); +} + +#endif + +#include <asm-generic/mmu_context.h> + +#else /* !CONFIG_MMU */ + +#include <asm-generic/nommu_context.h> + +#endif /* CONFIG_MMU */ +#endif /* __M68K_MMU_CONTEXT_H */ |