score: Add support for Sunplus S+core architecture

This is the complete set of new arch Score's files for linux.
Score instruction set support 16bits, 32bits and 64bits instruction,
Score SOC had been used in game machine and LCD TV.

Signed-off-by: Chen Liqin <liqin.chen@sunplusct.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 113 insertions, 0 deletions

diff --git a/arch/score/include/asm/mmu_context.h b/arch/score/include/asm/mmu_context.h
new file mode 100644
index 000000000000..2644577c96e8
--- /dev/null
+++ b/arch/score/include/asm/mmu_context.h
@@ -0,0 +1,113 @@
+#ifndef _ASM_SCORE_MMU_CONTEXT_H
+#define _ASM_SCORE_MMU_CONTEXT_H
+
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <asm-generic/mm_hooks.h>
+
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/scoreregs.h>
+
+/*
+ * For the fast tlb miss handlers, we keep a per cpu array of pointers
+ * to the current pgd for each processor. Also, the proc. id is stuffed
+ * into the context register.
+ */
+extern unsigned long asid_cache;
+extern unsigned long pgd_current;
+
+#define TLBMISS_HANDLER_SETUP_PGD(pgd) (pgd_current = (unsigned long)(pgd))
+
+#define TLBMISS_HANDLER_SETUP()				\
+do {							\
+	write_c0_context(0);				\
+	TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir)	\
+} while (0)
+
+/*
+ * All unused by hardware upper bits will be considered
+ * as a software asid extension.
+ */
+#define ASID_VERSION_MASK	0xfffff000
+#define ASID_FIRST_VERSION	0x1000
+
+/* PEVN    --------- VPN ---------- --ASID--- -NA- */
+/* binary: 0000 0000 0000 0000 0000 0000 0001 0000 */
+/* binary: 0000 0000 0000 0000 0000 1111 1111 0000 */
+#define ASID_INC	0x10
+#define ASID_MASK	0xff0
+
+static inline void enter_lazy_tlb(struct mm_struct *mm,
+				struct task_struct *tsk)
+{}
+
+static inline void
+get_new_mmu_context(struct mm_struct *mm)
+{
+	unsigned long asid = asid_cache + ASID_INC;
+
+	if (!(asid & ASID_MASK)) {
+		local_flush_tlb_all();		/* start new asid cycle */
+		if (!asid)			/* fix version if needed */
+			asid = ASID_FIRST_VERSION;
+	}
+
+	mm->context = asid;
+	asid_cache = 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)
+{
+	mm->context = 0;
+	return 0;
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+			struct task_struct *tsk)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	if ((next->context ^ asid_cache) & ASID_VERSION_MASK)
+		get_new_mmu_context(next);
+
+	pevn_set(next->context);
+	TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+	local_irq_restore(flags);
+}
+
+/*
+ * 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)
+{}
+
+static inline void
+deactivate_mm(struct task_struct *task, struct mm_struct *mm)
+{}
+
+/*
+ * 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)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	get_new_mmu_context(next);
+	pevn_set(next->context);
+	TLBMISS_HANDLER_SETUP_PGD(next->pgd);
+	local_irq_restore(flags);
+}
+
+#endif /* _ASM_SCORE_MMU_CONTEXT_H */