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-rw-r--r--arch/m68k/include/asm/mmu_context.h320
1 files changed, 320 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 000000000..8ed6ac14d
--- /dev/null
+++ b/arch/m68k/include/asm/mmu_context.h
@@ -0,0 +1,320 @@
+/* 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;
+ 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_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:
+ 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 */