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-rw-r--r--include/asm-sh64/mmu_context.h209
1 files changed, 209 insertions, 0 deletions
diff --git a/include/asm-sh64/mmu_context.h b/include/asm-sh64/mmu_context.h
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+++ b/include/asm-sh64/mmu_context.h
@@ -0,0 +1,209 @@
+#ifndef __ASM_SH64_MMU_CONTEXT_H
+#define __ASM_SH64_MMU_CONTEXT_H
+
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * include/asm-sh64/mmu_context.h
+ *
+ * Copyright (C) 2000, 2001 Paolo Alberelli
+ * Copyright (C) 2003 Paul Mundt
+ *
+ * ASID handling idea taken from MIPS implementation.
+ *
+ */
+
+#ifndef __ASSEMBLY__
+
+/*
+ * Cache of MMU context last used.
+ *
+ * The MMU "context" consists of two things:
+ * (a) TLB cache version (or cycle, top 24 bits of mmu_context_cache)
+ * (b) ASID (Address Space IDentifier, bottom 8 bits of mmu_context_cache)
+ */
+extern unsigned long mmu_context_cache;
+
+#include <linux/config.h>
+#include <asm/page.h>
+
+
+/* Current mm's pgd */
+extern pgd_t *mmu_pdtp_cache;
+
+#define SR_ASID_MASK 0xffffffffff00ffffULL
+#define SR_ASID_SHIFT 16
+
+#define MMU_CONTEXT_ASID_MASK 0x000000ff
+#define MMU_CONTEXT_VERSION_MASK 0xffffff00
+#define MMU_CONTEXT_FIRST_VERSION 0x00000100
+#define NO_CONTEXT 0
+
+/* ASID is 8-bit value, so it can't be 0x100 */
+#define MMU_NO_ASID 0x100
+
+
+/*
+ * Virtual Page Number mask
+ */
+#define MMU_VPN_MASK 0xfffff000
+
+extern __inline__ void
+get_new_mmu_context(struct mm_struct *mm)
+{
+ extern void flush_tlb_all(void);
+ extern void flush_cache_all(void);
+
+ unsigned long mc = ++mmu_context_cache;
+
+ if (!(mc & MMU_CONTEXT_ASID_MASK)) {
+ /* We exhaust ASID of this version.
+ Flush all TLB and start new cycle. */
+ flush_tlb_all();
+ /* We have to flush all caches as ASIDs are
+ used in cache */
+ flush_cache_all();
+ /* Fix version if needed.
+ Note that we avoid version #0/asid #0 to distingush NO_CONTEXT. */
+ if (!mc)
+ mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
+ }
+ mm->context = mc;
+}
+
+/*
+ * Get MMU context if needed.
+ */
+static __inline__ void
+get_mmu_context(struct mm_struct *mm)
+{
+ if (mm) {
+ unsigned long mc = mmu_context_cache;
+ /* Check if we have old version of context.
+ If it's old, we need to get new context with new version. */
+ if ((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK)
+ get_new_mmu_context(mm);
+ }
+}
+
+/*
+ * 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)
+{
+ mm->context = NO_CONTEXT;
+
+ return 0;
+}
+
+/*
+ * Destroy context related info for an mm_struct that is about
+ * to be put to rest.
+ */
+static inline void destroy_context(struct mm_struct *mm)
+{
+ extern void flush_tlb_mm(struct mm_struct *mm);
+
+ /* Well, at least free TLB entries */
+ flush_tlb_mm(mm);
+}
+
+#endif /* __ASSEMBLY__ */
+
+/* Common defines */
+#define TLB_STEP 0x00000010
+#define TLB_PTEH 0x00000000
+#define TLB_PTEL 0x00000008
+
+/* PTEH defines */
+#define PTEH_ASID_SHIFT 2
+#define PTEH_VALID 0x0000000000000001
+#define PTEH_SHARED 0x0000000000000002
+#define PTEH_MATCH_ASID 0x00000000000003ff
+
+#ifndef __ASSEMBLY__
+/* This has to be a common function because the next location to fill
+ * information is shared. */
+extern void __do_tlb_refill(unsigned long address, unsigned long long is_text_not_data, pte_t *pte);
+
+/* Profiling counter. */
+#ifdef CONFIG_SH64_PROC_TLB
+extern unsigned long long calls_to_do_fast_page_fault;
+#endif
+
+static inline unsigned long get_asid(void)
+{
+ unsigned long long sr;
+
+ asm volatile ("getcon " __SR ", %0\n\t"
+ : "=r" (sr));
+
+ sr = (sr >> SR_ASID_SHIFT) & MMU_CONTEXT_ASID_MASK;
+ return (unsigned long) sr;
+}
+
+/* Set ASID into SR */
+static inline void set_asid(unsigned long asid)
+{
+ unsigned long long sr, pc;
+
+ asm volatile ("getcon " __SR ", %0" : "=r" (sr));
+
+ sr = (sr & SR_ASID_MASK) | (asid << SR_ASID_SHIFT);
+
+ /*
+ * It is possible that this function may be inlined and so to avoid
+ * the assembler reporting duplicate symbols we make use of the gas trick
+ * of generating symbols using numerics and forward reference.
+ */
+ asm volatile ("movi 1, %1\n\t"
+ "shlli %1, 28, %1\n\t"
+ "or %0, %1, %1\n\t"
+ "putcon %1, " __SR "\n\t"
+ "putcon %0, " __SSR "\n\t"
+ "movi 1f, %1\n\t"
+ "ori %1, 1 , %1\n\t"
+ "putcon %1, " __SPC "\n\t"
+ "rte\n"
+ "1:\n\t"
+ : "=r" (sr), "=r" (pc) : "0" (sr));
+}
+
+/*
+ * 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_context(struct mm_struct *mm)
+{
+ get_mmu_context(mm);
+ set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
+}
+
+
+static __inline__ void switch_mm(struct mm_struct *prev,
+ struct mm_struct *next,
+ struct task_struct *tsk)
+{
+ if (prev != next) {
+ mmu_pdtp_cache = next->pgd;
+ activate_context(next);
+ }
+}
+
+#define deactivate_mm(tsk,mm) do { } while (0)
+
+#define activate_mm(prev, next) \
+ switch_mm((prev),(next),NULL)
+
+static inline void
+enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_SH64_MMU_CONTEXT_H */