Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
new file mode 100644
index 0000000..faff403
--- /dev/null
+++ b/include/asm-generic/tlb.h
@@ -0,0 +1,160 @@
+/* asm-generic/tlb.h
+ *
+ * Generic TLB shootdown code
+ *
+ * Copyright 2001 Red Hat, Inc.
+ * Based on code from mm/memory.c Copyright Linus Torvalds and others.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#ifndef _ASM_GENERIC__TLB_H
+#define _ASM_GENERIC__TLB_H
+
+#include <linux/config.h>
+#include <linux/swap.h>
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+
+/*
+ * For UP we don't need to worry about TLB flush
+ * and page free order so much..
+ */
+#ifdef CONFIG_SMP
+ #define FREE_PTE_NR 506
+ #define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
+#else
+ #define FREE_PTE_NR 1
+ #define tlb_fast_mode(tlb) 1
+#endif
+
+/* struct mmu_gather is an opaque type used by the mm code for passing around
+ * any data needed by arch specific code for tlb_remove_page. This structure
+ * can be per-CPU or per-MM as the page table lock is held for the duration of
+ * TLB shootdown.
+ */
+struct mmu_gather {
+ struct mm_struct *mm;
+ unsigned int nr; /* set to ~0U means fast mode */
+ unsigned int need_flush;/* Really unmapped some ptes? */
+ unsigned int fullmm; /* non-zero means full mm flush */
+ unsigned long freed;
+ struct page * pages[FREE_PTE_NR];
+};
+
+/* Users of the generic TLB shootdown code must declare this storage space. */
+DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+/* tlb_gather_mmu
+ * Return a pointer to an initialized struct mmu_gather.
+ */
+static inline struct mmu_gather *
+tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
+{
+ struct mmu_gather *tlb = &per_cpu(mmu_gathers, smp_processor_id());
+
+ tlb->mm = mm;
+
+ /* Use fast mode if only one CPU is online */
+ tlb->nr = num_online_cpus() > 1 ? 0U : ~0U;
+
+ tlb->fullmm = full_mm_flush;
+ tlb->freed = 0;
+
+ return tlb;
+}
+
+static inline void
+tlb_flush_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+ if (!tlb->need_flush)
+ return;
+ tlb->need_flush = 0;
+ tlb_flush(tlb);
+ if (!tlb_fast_mode(tlb)) {
+ free_pages_and_swap_cache(tlb->pages, tlb->nr);
+ tlb->nr = 0;
+ }
+}
+
+/* tlb_finish_mmu
+ * Called at the end of the shootdown operation to free up any resources
+ * that were required. The page table lock is still held at this point.
+ */
+static inline void
+tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+{
+ int freed = tlb->freed;
+ struct mm_struct *mm = tlb->mm;
+ int rss = get_mm_counter(mm, rss);
+
+ if (rss < freed)
+ freed = rss;
+ add_mm_counter(mm, rss, -freed);
+ tlb_flush_mmu(tlb, start, end);
+
+ /* keep the page table cache within bounds */
+ check_pgt_cache();
+}
+
+static inline unsigned int
+tlb_is_full_mm(struct mmu_gather *tlb)
+{
+ return tlb->fullmm;
+}
+
+/* tlb_remove_page
+ * Must perform the equivalent to __free_pte(pte_get_and_clear(ptep)), while
+ * handling the additional races in SMP caused by other CPUs caching valid
+ * mappings in their TLBs.
+ */
+static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
+{
+ tlb->need_flush = 1;
+ if (tlb_fast_mode(tlb)) {
+ free_page_and_swap_cache(page);
+ return;
+ }
+ tlb->pages[tlb->nr++] = page;
+ if (tlb->nr >= FREE_PTE_NR)
+ tlb_flush_mmu(tlb, 0, 0);
+}
+
+/**
+ * tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
+ *
+ * Record the fact that pte's were really umapped in ->need_flush, so we can
+ * later optimise away the tlb invalidate. This helps when userspace is
+ * unmapping already-unmapped pages, which happens quite a lot.
+ */
+#define tlb_remove_tlb_entry(tlb, ptep, address) \
+ do { \
+ tlb->need_flush = 1; \
+ __tlb_remove_tlb_entry(tlb, ptep, address); \
+ } while (0)
+
+#define pte_free_tlb(tlb, ptep) \
+ do { \
+ tlb->need_flush = 1; \
+ __pte_free_tlb(tlb, ptep); \
+ } while (0)
+
+#ifndef __ARCH_HAS_4LEVEL_HACK
+#define pud_free_tlb(tlb, pudp) \
+ do { \
+ tlb->need_flush = 1; \
+ __pud_free_tlb(tlb, pudp); \
+ } while (0)
+#endif
+
+#define pmd_free_tlb(tlb, pmdp) \
+ do { \
+ tlb->need_flush = 1; \
+ __pmd_free_tlb(tlb, pmdp); \
+ } while (0)
+
+#define tlb_migrate_finish(mm) do {} while (0)
+
+#endif /* _ASM_GENERIC__TLB_H */