From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001
From: André Fabian Silva Delgado <emulatorman@parabola.nu>
Date: Wed, 5 Aug 2015 17:04:01 -0300
Subject: Initial import

---
 arch/sh/mm/tlbex_32.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 arch/sh/mm/tlbex_32.c

(limited to 'arch/sh/mm/tlbex_32.c')

diff --git a/arch/sh/mm/tlbex_32.c b/arch/sh/mm/tlbex_32.c
new file mode 100644
index 000000000..382262dc0
--- /dev/null
+++ b/arch/sh/mm/tlbex_32.c
@@ -0,0 +1,78 @@
+/*
+ * TLB miss handler for SH with an MMU.
+ *
+ *  Copyright (C) 1999  Niibe Yutaka
+ *  Copyright (C) 2003 - 2012  Paul Mundt
+ *
+ * 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 <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/kprobes.h>
+#include <linux/kdebug.h>
+#include <asm/mmu_context.h>
+#include <asm/thread_info.h>
+
+/*
+ * Called with interrupts disabled.
+ */
+asmlinkage int __kprobes
+handle_tlbmiss(struct pt_regs *regs, unsigned long error_code,
+	       unsigned long address)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte;
+	pte_t entry;
+
+	/*
+	 * We don't take page faults for P1, P2, and parts of P4, these
+	 * are always mapped, whether it be due to legacy behaviour in
+	 * 29-bit mode, or due to PMB configuration in 32-bit mode.
+	 */
+	if (address >= P3SEG && address < P3_ADDR_MAX) {
+		pgd = pgd_offset_k(address);
+	} else {
+		if (unlikely(address >= TASK_SIZE || !current->mm))
+			return 1;
+
+		pgd = pgd_offset(current->mm, address);
+	}
+
+	pud = pud_offset(pgd, address);
+	if (pud_none_or_clear_bad(pud))
+		return 1;
+	pmd = pmd_offset(pud, address);
+	if (pmd_none_or_clear_bad(pmd))
+		return 1;
+	pte = pte_offset_kernel(pmd, address);
+	entry = *pte;
+	if (unlikely(pte_none(entry) || pte_not_present(entry)))
+		return 1;
+	if (unlikely(error_code && !pte_write(entry)))
+		return 1;
+
+	if (error_code)
+		entry = pte_mkdirty(entry);
+	entry = pte_mkyoung(entry);
+
+	set_pte(pte, entry);
+
+#if defined(CONFIG_CPU_SH4) && !defined(CONFIG_SMP)
+	/*
+	 * SH-4 does not set MMUCR.RC to the corresponding TLB entry in
+	 * the case of an initial page write exception, so we need to
+	 * flush it in order to avoid potential TLB entry duplication.
+	 */
+	if (error_code == FAULT_CODE_INITIAL)
+		local_flush_tlb_one(get_asid(), address & PAGE_MASK);
+#endif
+
+	set_thread_fault_code(error_code);
+	update_mmu_cache(NULL, address, pte);
+
+	return 0;
+}
-- 
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