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-rw-r--r--arch/csky/include/asm/asid.h78
-rw-r--r--arch/csky/include/asm/mmu.h2
-rw-r--r--arch/csky/include/asm/mmu_context.h114
-rw-r--r--arch/csky/include/asm/pgtable.h2
4 files changed, 91 insertions, 105 deletions
diff --git a/arch/csky/include/asm/asid.h b/arch/csky/include/asm/asid.h
new file mode 100644
index 000000000000..ac08b0ffbe1f
--- /dev/null
+++ b/arch/csky/include/asm/asid.h
@@ -0,0 +1,78 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_ASM_ASID_H
+#define __ASM_ASM_ASID_H
+
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/cpumask.h>
+#include <linux/percpu.h>
+#include <linux/spinlock.h>
+
+struct asid_info
+{
+ atomic64_t generation;
+ unsigned long *map;
+ atomic64_t __percpu *active;
+ u64 __percpu *reserved;
+ u32 bits;
+ /* Lock protecting the structure */
+ raw_spinlock_t lock;
+ /* Which CPU requires context flush on next call */
+ cpumask_t flush_pending;
+ /* Number of ASID allocated by context (shift value) */
+ unsigned int ctxt_shift;
+ /* Callback to locally flush the context. */
+ void (*flush_cpu_ctxt_cb)(void);
+};
+
+#define NUM_ASIDS(info) (1UL << ((info)->bits))
+#define NUM_CTXT_ASIDS(info) (NUM_ASIDS(info) >> (info)->ctxt_shift)
+
+#define active_asid(info, cpu) *per_cpu_ptr((info)->active, cpu)
+
+void asid_new_context(struct asid_info *info, atomic64_t *pasid,
+ unsigned int cpu, struct mm_struct *mm);
+
+/*
+ * Check the ASID is still valid for the context. If not generate a new ASID.
+ *
+ * @pasid: Pointer to the current ASID batch
+ * @cpu: current CPU ID. Must have been acquired throught get_cpu()
+ */
+static inline void asid_check_context(struct asid_info *info,
+ atomic64_t *pasid, unsigned int cpu,
+ struct mm_struct *mm)
+{
+ u64 asid, old_active_asid;
+
+ asid = atomic64_read(pasid);
+
+ /*
+ * The memory ordering here is subtle.
+ * If our active_asid is non-zero and the ASID matches the current
+ * generation, then we update the active_asid entry with a relaxed
+ * cmpxchg. Racing with a concurrent rollover means that either:
+ *
+ * - We get a zero back from the cmpxchg and end up waiting on the
+ * lock. Taking the lock synchronises with the rollover and so
+ * we are forced to see the updated generation.
+ *
+ * - We get a valid ASID back from the cmpxchg, which means the
+ * relaxed xchg in flush_context will treat us as reserved
+ * because atomic RmWs are totally ordered for a given location.
+ */
+ old_active_asid = atomic64_read(&active_asid(info, cpu));
+ if (old_active_asid &&
+ !((asid ^ atomic64_read(&info->generation)) >> info->bits) &&
+ atomic64_cmpxchg_relaxed(&active_asid(info, cpu),
+ old_active_asid, asid))
+ return;
+
+ asid_new_context(info, pasid, cpu, mm);
+}
+
+int asid_allocator_init(struct asid_info *info,
+ u32 bits, unsigned int asid_per_ctxt,
+ void (*flush_cpu_ctxt_cb)(void));
+
+#endif
diff --git a/arch/csky/include/asm/mmu.h b/arch/csky/include/asm/mmu.h
index cb344675ccc4..b382a14ea4ec 100644
--- a/arch/csky/include/asm/mmu.h
+++ b/arch/csky/include/asm/mmu.h
@@ -5,7 +5,7 @@
#define __ASM_CSKY_MMU_H
typedef struct {
- unsigned long asid[NR_CPUS];
+ atomic64_t asid;
void *vdso;
} mm_context_t;
diff --git a/arch/csky/include/asm/mmu_context.h b/arch/csky/include/asm/mmu_context.h
index 734db3a122e1..0285b0ad18b6 100644
--- a/arch/csky/include/asm/mmu_context.h
+++ b/arch/csky/include/asm/mmu_context.h
@@ -16,122 +16,32 @@
#define TLBMISS_HANDLER_SETUP_PGD(pgd) \
setup_pgd(__pa(pgd), false)
+
#define TLBMISS_HANDLER_SETUP_PGD_KERNEL(pgd) \
setup_pgd(__pa(pgd), true)
-#define cpu_context(cpu, mm) ((mm)->context.asid[cpu])
-#define cpu_asid(cpu, mm) (cpu_context((cpu), (mm)) & ASID_MASK)
-#define asid_cache(cpu) (cpu_data[cpu].asid_cache)
+#define ASID_MASK ((1 << CONFIG_CPU_ASID_BITS) - 1)
+#define cpu_asid(mm) (atomic64_read(&mm->context.asid) & ASID_MASK)
-#define ASID_FIRST_VERSION (1 << CONFIG_CPU_ASID_BITS)
-#define ASID_INC 0x1
-#define ASID_MASK (ASID_FIRST_VERSION - 1)
-#define ASID_VERSION_MASK ~ASID_MASK
+#define init_new_context(tsk,mm) ({ atomic64_set(&(mm)->context.asid, 0); 0; })
+#define activate_mm(prev,next) switch_mm(prev, next, current)
#define destroy_context(mm) do {} while (0)
#define enter_lazy_tlb(mm, tsk) do {} while (0)
#define deactivate_mm(tsk, mm) do {} while (0)
-/*
- * All unused by hardware upper bits will be considered
- * as a software asid extension.
- */
-static inline void
-get_new_mmu_context(struct mm_struct *mm, unsigned long cpu)
-{
- unsigned long asid = asid_cache(cpu);
-
- asid += ASID_INC;
- if (!(asid & ASID_MASK)) {
- flush_tlb_all(); /* start new asid cycle */
- if (!asid) /* fix version if needed */
- asid = ASID_FIRST_VERSION;
- }
- cpu_context(cpu, mm) = asid_cache(cpu) = asid;
-}
-
-/*
- * Initialize the context related info for a new mm_struct
- * instance.
- */
-static inline int
-init_new_context(struct task_struct *tsk, struct mm_struct *mm)
-{
- int i;
-
- for_each_online_cpu(i)
- cpu_context(i, mm) = 0;
- return 0;
-}
-
-static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
- struct task_struct *tsk)
-{
- unsigned int cpu = smp_processor_id();
- unsigned long flags;
-
- local_irq_save(flags);
- /* Check if our ASID is of an older version and thus invalid */
- if ((cpu_context(cpu, next) ^ asid_cache(cpu)) & ASID_VERSION_MASK)
- get_new_mmu_context(next, cpu);
- write_mmu_entryhi(cpu_asid(cpu, next));
- TLBMISS_HANDLER_SETUP_PGD(next->pgd);
-
- /*
- * Mark current->active_mm as not "active" anymore.
- * We don't want to mislead possible IPI tlb flush routines.
- */
- cpumask_clear_cpu(cpu, mm_cpumask(prev));
- cpumask_set_cpu(cpu, mm_cpumask(next));
+void check_and_switch_context(struct mm_struct *mm, unsigned int cpu);
- local_irq_restore(flags);
-}
-
-/*
- * After we have set current->mm to a new value, this activates
- * the context for the new mm so we see the new mappings.
- */
static inline void
-activate_mm(struct mm_struct *prev, struct mm_struct *next)
+switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk)
{
- unsigned long flags;
- int cpu = smp_processor_id();
-
- local_irq_save(flags);
+ unsigned int cpu = smp_processor_id();
- /* Unconditionally get a new ASID. */
- get_new_mmu_context(next, cpu);
+ if (prev != next)
+ check_and_switch_context(next, cpu);
- write_mmu_entryhi(cpu_asid(cpu, next));
TLBMISS_HANDLER_SETUP_PGD(next->pgd);
-
- /* mark mmu ownership change */
- cpumask_clear_cpu(cpu, mm_cpumask(prev));
- cpumask_set_cpu(cpu, mm_cpumask(next));
-
- local_irq_restore(flags);
-}
-
-/*
- * If mm is currently active_mm, we can't really drop it. Instead,
- * we will get a new one for it.
- */
-static inline void
-drop_mmu_context(struct mm_struct *mm, unsigned int cpu)
-{
- unsigned long flags;
-
- local_irq_save(flags);
-
- if (cpumask_test_cpu(cpu, mm_cpumask(mm))) {
- get_new_mmu_context(mm, cpu);
- write_mmu_entryhi(cpu_asid(cpu, mm));
- } else {
- /* will get a new context next time */
- cpu_context(cpu, mm) = 0;
- }
-
- local_irq_restore(flags);
+ write_mmu_entryhi(next->context.asid.counter);
}
-
#endif /* __ASM_CSKY_MMU_CONTEXT_H */
diff --git a/arch/csky/include/asm/pgtable.h b/arch/csky/include/asm/pgtable.h
index dcea277c09ae..c429a6f347de 100644
--- a/arch/csky/include/asm/pgtable.h
+++ b/arch/csky/include/asm/pgtable.h
@@ -290,8 +290,6 @@ static inline pte_t *pte_offset(pmd_t *dir, unsigned long address)
extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
extern void paging_init(void);
-extern void show_jtlb_table(void);
-
void update_mmu_cache(struct vm_area_struct *vma, unsigned long address,
pte_t *pte);