Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 193 insertions, 0 deletions

diff --git a/arch/sh/include/asm/mmu_context.h b/arch/sh/include/asm/mmu_context.h
new file mode 100644
index 000000000..2d0965009
--- /dev/null
+++ b/arch/sh/include/asm/mmu_context.h
@@ -0,0 +1,193 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1999 Niibe Yutaka
+ * Copyright (C) 2003 - 2007 Paul Mundt
+ *
+ * ASID handling idea taken from MIPS implementation.
+ */
+#ifndef __ASM_SH_MMU_CONTEXT_H
+#define __ASM_SH_MMU_CONTEXT_H
+
+#ifdef __KERNEL__
+#include <cpu/mmu_context.h>
+#include <asm/tlbflush.h>
+#include <linux/uaccess.h>
+#include <linux/mm_types.h>
+
+#include <asm/io.h>
+#include <asm-generic/mm_hooks.h>
+
+/*
+ * The MMU "context" consists of two things:
+ *    (a) TLB cache version (or round, cycle whatever expression you like)
+ *    (b) ASID (Address Space IDentifier)
+ */
+#ifdef CONFIG_CPU_HAS_PTEAEX
+#define MMU_CONTEXT_ASID_MASK		0x0000ffff
+#else
+#define MMU_CONTEXT_ASID_MASK		0x000000ff
+#endif
+
+#define MMU_CONTEXT_VERSION_MASK	(~0UL & ~MMU_CONTEXT_ASID_MASK)
+#define MMU_CONTEXT_FIRST_VERSION	(MMU_CONTEXT_ASID_MASK + 1)
+
+/* Impossible ASID value, to differentiate from NO_CONTEXT. */
+#define MMU_NO_ASID			MMU_CONTEXT_FIRST_VERSION
+#define NO_CONTEXT			0UL
+
+#define asid_cache(cpu)		(cpu_data[cpu].asid_cache)
+
+#ifdef CONFIG_MMU
+#define cpu_context(cpu, mm)	((mm)->context.id[cpu])
+
+#define cpu_asid(cpu, mm)	\
+	(cpu_context((cpu), (mm)) & MMU_CONTEXT_ASID_MASK)
+
+/*
+ * Virtual Page Number mask
+ */
+#define MMU_VPN_MASK	0xfffff000
+
+#if defined(CONFIG_SUPERH32)
+#include <asm/mmu_context_32.h>
+#else
+#include <asm/mmu_context_64.h>
+#endif
+
+/*
+ * Get MMU context if needed.
+ */
+static inline void get_mmu_context(struct mm_struct *mm, unsigned int cpu)
+{
+	unsigned long asid = asid_cache(cpu);
+
+	/* Check if we have old version of context. */
+	if (((cpu_context(cpu, mm) ^ asid) & MMU_CONTEXT_VERSION_MASK) == 0)
+		/* It's up to date, do nothing */
+		return;
+
+	/* It's old, we need to get new context with new version. */
+	if (!(++asid & MMU_CONTEXT_ASID_MASK)) {
+		/*
+		 * We exhaust ASID of this version.
+		 * Flush all TLB and start new cycle.
+		 */
+		local_flush_tlb_all();
+
+#ifdef CONFIG_SUPERH64
+		/*
+		 * The SH-5 cache uses the ASIDs, requiring both the I and D
+		 * cache to be flushed when the ASID is exhausted. Weak.
+		 */
+		flush_cache_all();
+#endif
+
+		/*
+		 * Fix version; Note that we avoid version #0
+		 * to distinguish NO_CONTEXT.
+		 */
+		if (!asid)
+			asid = MMU_CONTEXT_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) = NO_CONTEXT;
+
+	return 0;
+}
+
+/*
+ * 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, unsigned int cpu)
+{
+	get_mmu_context(mm, cpu);
+	set_asid(cpu_asid(cpu, mm));
+}
+
+static inline void switch_mm(struct mm_struct *prev,
+			     struct mm_struct *next,
+			     struct task_struct *tsk)
+{
+	unsigned int cpu = smp_processor_id();
+
+	if (likely(prev != next)) {
+		cpumask_set_cpu(cpu, mm_cpumask(next));
+		set_TTB(next->pgd);
+		activate_context(next, cpu);
+	} else
+		if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
+			activate_context(next, cpu);
+}
+
+#define activate_mm(prev, next)		switch_mm((prev),(next),NULL)
+#define deactivate_mm(tsk,mm)		do { } while (0)
+#define enter_lazy_tlb(mm,tsk)		do { } while (0)
+
+#else
+
+#define set_asid(asid)			do { } while (0)
+#define get_asid()			(0)
+#define cpu_asid(cpu, mm)		({ (void)cpu; NO_CONTEXT; })
+#define switch_and_save_asid(asid)	(0)
+#define set_TTB(pgd)			do { } while (0)
+#define get_TTB()			(0)
+
+#include <asm-generic/mmu_context.h>
+
+#endif /* CONFIG_MMU */
+
+#if defined(CONFIG_CPU_SH3) || defined(CONFIG_CPU_SH4)
+/*
+ * If this processor has an MMU, we need methods to turn it off/on ..
+ * paging_init() will also have to be updated for the processor in
+ * question.
+ */
+static inline void enable_mmu(void)
+{
+	unsigned int cpu = smp_processor_id();
+
+	/* Enable MMU */
+	__raw_writel(MMU_CONTROL_INIT, MMUCR);
+	ctrl_barrier();
+
+	if (asid_cache(cpu) == NO_CONTEXT)
+		asid_cache(cpu) = MMU_CONTEXT_FIRST_VERSION;
+
+	set_asid(asid_cache(cpu) & MMU_CONTEXT_ASID_MASK);
+}
+
+static inline void disable_mmu(void)
+{
+	unsigned long cr;
+
+	cr = __raw_readl(MMUCR);
+	cr &= ~MMU_CONTROL_INIT;
+	__raw_writel(cr, MMUCR);
+
+	ctrl_barrier();
+}
+#else
+/*
+ * MMU control handlers for processors lacking memory
+ * management hardware.
+ */
+#define enable_mmu()	do { } while (0)
+#define disable_mmu()	do { } while (0)
+#endif
+
+#endif /* __KERNEL__ */
+#endif /* __ASM_SH_MMU_CONTEXT_H */