unicore32 core architecture: mm related: generic codes

This patch includes generic codes for memory management.

Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 98 insertions, 0 deletions

diff --git a/arch/unicore32/include/asm/tlb.h b/arch/unicore32/include/asm/tlb.h
new file mode 100644
index 000000000000..02ee40e47a0d
--- /dev/null
+++ b/arch/unicore32/include/asm/tlb.h
@@ -0,0 +1,98 @@
+/*
+ * linux/arch/unicore32/include/asm/tlb.h
+ *
+ * Code specific to PKUnity SoC and UniCore ISA
+ *
+ * Copyright (C) 2001-2010 GUAN Xue-tao
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#ifndef __UNICORE_TLB_H__
+#define __UNICORE_TLB_H__
+
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+#include <asm/pgalloc.h>
+
+/*
+ * TLB handling.  This allows us to remove pages from the page
+ * tables, and efficiently handle the TLB issues.
+ */
+struct mmu_gather {
+	struct mm_struct	*mm;
+	unsigned int		fullmm;
+	unsigned long		range_start;
+	unsigned long		range_end;
+};
+
+DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+static inline struct mmu_gather *
+tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
+{
+	struct mmu_gather *tlb = &get_cpu_var(mmu_gathers);
+
+	tlb->mm = mm;
+	tlb->fullmm = full_mm_flush;
+
+	return tlb;
+}
+
+static inline void
+tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+	if (tlb->fullmm)
+		flush_tlb_mm(tlb->mm);
+
+	/* keep the page table cache within bounds */
+	check_pgt_cache();
+
+	put_cpu_var(mmu_gathers);
+}
+
+/*
+ * Memorize the range for the TLB flush.
+ */
+static inline void
+tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long addr)
+{
+	if (!tlb->fullmm) {
+		if (addr < tlb->range_start)
+			tlb->range_start = addr;
+		if (addr + PAGE_SIZE > tlb->range_end)
+			tlb->range_end = addr + PAGE_SIZE;
+	}
+}
+
+/*
+ * In the case of tlb vma handling, we can optimise these away in the
+ * case where we're doing a full MM flush.  When we're doing a munmap,
+ * the vmas are adjusted to only cover the region to be torn down.
+ */
+static inline void
+tlb_start_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+	if (!tlb->fullmm) {
+		flush_cache_range(vma, vma->vm_start, vma->vm_end);
+		tlb->range_start = TASK_SIZE;
+		tlb->range_end = 0;
+	}
+}
+
+static inline void
+tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+	if (!tlb->fullmm && tlb->range_end > 0)
+		flush_tlb_range(vma, tlb->range_start, tlb->range_end);
+}
+
+#define tlb_remove_page(tlb, page)	free_page_and_swap_cache(page)
+#define pte_free_tlb(tlb, ptep, addr)	pte_free((tlb)->mm, ptep)
+#define pmd_free_tlb(tlb, pmdp, addr)	pmd_free((tlb)->mm, pmdp)
+#define pud_free_tlb(tlb, x, addr)      do { } while (0)
+
+#define tlb_migrate_finish(mm)		do { } while (0)
+
+#endif