I was looking at what makes the various arches use !generic tlb gather
bits and found that for most the reason is the same, so I looked at what
it would take to support those in the generic code as well.
The below is a quick unification, I still need to run through all the
details since they appear to all do the same thing but slightly
different ;-)
I've compile tested it on ia64 and arm (seem to have lost my SH compiler
again).
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
---
arch/Kconfig | 3
arch/arm/Kconfig | 1
arch/arm/include/asm/tlb.h | 90 --------------------
arch/arm/include/asm/tlbflush.h | 5 -
arch/ia64/Kconfig | 1
arch/ia64/include/asm/tlb.h | 178 +---------------------------------------
arch/sh/Kconfig | 1
arch/sh/include/asm/tlb.h | 99 +---------------------
include/asm-generic/tlb.h | 35 +++++++
9 files changed, 59 insertions(+), 354 deletions(-)
Index: linux-2.6/arch/Kconfig
===================================================================
--- linux-2.6.orig/arch/Kconfig
+++ linux-2.6/arch/Kconfig
@@ -181,4 +181,7 @@ config HAVE_ARCH_MUTEX_CPU_RELAX
config HAVE_RCU_TABLE_FREE
bool
+config HAVE_MMU_GATHER_RANGE
+ bool
+
source "kernel/gcov/Kconfig"
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig
+++ linux-2.6/arch/arm/Kconfig
@@ -28,6 +28,7 @@ config ARM
select HAVE_C_RECORDMCOUNT
select HAVE_GENERIC_HARDIRQS
select HAVE_SPARSE_IRQ
+ select HAVE_MMU_GATHER_RANGE if MMU
help
The ARM series is a line of low-power-consumption RISC chip designs
licensed by ARM Ltd and targeted at embedded applications and
Index: linux-2.6/arch/arm/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/arm/include/asm/tlb.h
+++ linux-2.6/arch/arm/include/asm/tlb.h
@@ -23,96 +23,14 @@
#ifndef CONFIG_MMU
#include <linux/pagemap.h>
-#include <asm-generic/tlb.h>
#else /* !CONFIG_MMU */
-#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;
-};
-
-static inline void
-tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
-{
- tlb->mm = mm;
- tlb->fullmm = full_mm_flush;
-}
-
-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();
-}
-
-/*
- * 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);
-}
-
-static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
- free_page_and_swap_cache(page);
- return 0;
-}
-
-static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
- might_sleep();
- __tlb_remove_page(tlb, page);
-}
-
-static inline void tlb_flush_mmu(struct mmu_gather *tlb)
-{
-}
+#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 pte_free_tlb(tlb, ptep, addr) pte_free((tlb)->mm, ptep)
-#define pmd_free_tlb(tlb, pmdp, addr) pmd_free((tlb)->mm, pmdp)
+#endif /* CONFIG_MMU */
-#define tlb_migrate_finish(mm) do { } while (0)
+#include <asm-generic/tlb.h>
-#endif /* CONFIG_MMU */
#endif
Index: linux-2.6/arch/ia64/Kconfig
===================================================================
--- linux-2.6.orig/arch/ia64/Kconfig
+++ linux-2.6/arch/ia64/Kconfig
@@ -25,6 +25,7 @@ config IA64
select HAVE_GENERIC_HARDIRQS
select GENERIC_IRQ_PROBE
select GENERIC_PENDING_IRQ if SMP
+ select HAVE_MMU_GATHER_RANGE
select IRQ_PER_CPU
default y
help
Index: linux-2.6/arch/ia64/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/ia64/include/asm/tlb.h
+++ linux-2.6/arch/ia64/include/asm/tlb.h
@@ -46,30 +46,6 @@
#include <asm/tlbflush.h>
#include <asm/machvec.h>
-#ifdef CONFIG_SMP
-# define tlb_fast_mode(tlb) ((tlb)->nr == ~0U)
-#else
-# define tlb_fast_mode(tlb) (1)
-#endif
-
-/*
- * If we can't allocate a page to make a big batch of page pointers
- * to work on, then just handle a few from the on-stack structure.
- */
-#define IA64_GATHER_BUNDLE 8
-
-struct mmu_gather {
- struct mm_struct *mm;
- unsigned int nr; /* == ~0U => fast mode */
- unsigned int max;
- unsigned char fullmm; /* non-zero means full mm flush */
- unsigned char need_flush; /* really unmapped some PTEs? */
- unsigned long start_addr;
- unsigned long end_addr;
- struct page **pages;
- struct page *local[IA64_GATHER_BUNDLE];
-};
-
struct ia64_tr_entry {
u64 ifa;
u64 itir;
@@ -96,6 +72,12 @@ extern struct ia64_tr_entry *ia64_idtrs[
#define RR_RID_MASK 0x00000000ffffff00L
#define RR_TO_RID(val) ((val >> 8) & 0xffffff)
+static inline void tlb_flush(struct mmu_gather *tlb);
+
+#define tlb_migrate_finish(mm) platform_tlb_migrate_finish(mm)
+
+#include <asm-generic/tlb.h>
+
/*
* Flush the TLB for address range START to END and, if not in fast mode, release the
* freed pages that where gathered up to this point.
@@ -103,12 +85,6 @@ extern struct ia64_tr_entry *ia64_idtrs[
static inline void
ia64_tlb_flush_mmu (struct mmu_gather *tlb, unsigned long start, unsigned long end)
{
- unsigned int nr;
-
- if (!tlb->need_flush)
- return;
- tlb->need_flush = 0;
-
if (tlb->fullmm) {
/*
* Tearing down the entire address space. This happens both as a result
@@ -138,149 +114,11 @@ ia64_tlb_flush_mmu (struct mmu_gather *t
/* now flush the virt. page-table area mapping the address range: */
flush_tlb_range(&vma, ia64_thash(start), ia64_thash(end));
}
-
- /* lastly, release the freed pages */
- nr = tlb->nr;
- if (!tlb_fast_mode(tlb)) {
- unsigned long i;
- tlb->nr = 0;
- tlb->start_addr = ~0UL;
- for (i = 0; i < nr; ++i)
- free_page_and_swap_cache(tlb->pages[i]);
- }
-}
-
-static inline void __tlb_alloc_page(struct mmu_gather *tlb)
-{
- unsigned long addr = __get_free_pages(GFP_NOWAIT | __GFP_NOWARN, 0);
-
- if (addr) {
- tlb->pages = (void *)addr;
- tlb->max = PAGE_SIZE / sizeof(void *);
- }
-}
-
-
-static inline void
-tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
-{
- tlb->mm = mm;
- tlb->max = ARRAY_SIZE(tlb->local);
- tlb->pages = tlb->local;
- /*
- * Use fast mode if only 1 CPU is online.
- *
- * It would be tempting to turn on fast-mode for full_mm_flush as well. But this
- * doesn't work because of speculative accesses and software prefetching: the page
- * table of "mm" may (and usually is) the currently active page table and even
- * though the kernel won't do any user-space accesses during the TLB shoot down, a
- * compiler might use speculation or lfetch.fault on what happens to be a valid
- * user-space address. This in turn could trigger a TLB miss fault (or a VHPT
- * walk) and re-insert a TLB entry we just removed. Slow mode avoids such
- * problems. (We could make fast-mode work by switching the current task to a
- * different "mm" during the shootdown.) --davidm 08/02/2002
- */
- tlb->nr = (num_online_cpus() == 1) ? ~0U : 0;
- tlb->fullmm = full_mm_flush;
- tlb->start_addr = ~0UL;
}
-/*
- * Called at the end of the shootdown operation to free up any resources that were
- * collected.
- */
-static inline void
-tlb_finish_mmu(struct mmu_gather *tlb, unsigned long start, unsigned long end)
+static inline void tlb_flush(struct mmu_gather *tlb)
{
- /*
- * Note: tlb->nr may be 0 at this point, so we can't rely on tlb->start_addr and
- * tlb->end_addr.
- */
- ia64_tlb_flush_mmu(tlb, start, end);
-
- /* keep the page table cache within bounds */
- check_pgt_cache();
-
- if (tlb->pages != tlb->local)
- free_pages((unsigned long)tlb->pages, 0);
+ ia64_tlb_flush_mmu(tlb, tlb->start, tlb->end);
}
-/*
- * Logically, this routine frees PAGE. On MP machines, the actual freeing of the page
- * must be delayed until after the TLB has been flushed (see comments at the beginning of
- * this file).
- */
-static inline int __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 0;
- }
-
- if (!tlb->nr && tlb->pages == tlb->local)
- __tlb_alloc_page(tlb);
-
- tlb->pages[tlb->nr++] = page;
- if (tlb->nr >= tlb->max)
- return 1;
-
- return 0;
-}
-
-static inline void tlb_flush_mmu(struct mmu_gather *tlb)
-{
- ia64_tlb_flush_mmu(tlb, tlb->start_addr, tlb->end_addr);
-}
-
-static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
- might_sleep();
-
- if (__tlb_remove_page(tlb, page))
- tlb_flush_mmu(tlb);
-}
-
-/*
- * Remove TLB entry for PTE mapped at virtual address ADDRESS. This is called for any
- * PTE, not just those pointing to (normal) physical memory.
- */
-static inline void
-__tlb_remove_tlb_entry (struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
-{
- if (tlb->start_addr == ~0UL)
- tlb->start_addr = address;
- tlb->end_addr = address + PAGE_SIZE;
-}
-
-#define tlb_migrate_finish(mm) platform_tlb_migrate_finish(mm)
-
-#define tlb_start_vma(tlb, vma) do { } while (0)
-#define tlb_end_vma(tlb, vma) do { } while (0)
-
-#define tlb_remove_tlb_entry(tlb, ptep, addr) \
-do { \
- tlb->need_flush = 1; \
- __tlb_remove_tlb_entry(tlb, ptep, addr); \
-} while (0)
-
-#define pte_free_tlb(tlb, ptep, address) \
-do { \
- tlb->need_flush = 1; \
- __pte_free_tlb(tlb, ptep, address); \
-} while (0)
-
-#define pmd_free_tlb(tlb, ptep, address) \
-do { \
- tlb->need_flush = 1; \
- __pmd_free_tlb(tlb, ptep, address); \
-} while (0)
-
-#define pud_free_tlb(tlb, pudp, address) \
-do { \
- tlb->need_flush = 1; \
- __pud_free_tlb(tlb, pudp, address); \
-} while (0)
-
#endif /* _ASM_IA64_TLB_H */
Index: linux-2.6/arch/sh/Kconfig
===================================================================
--- linux-2.6.orig/arch/sh/Kconfig
+++ linux-2.6/arch/sh/Kconfig
@@ -22,6 +22,7 @@ config SUPERH
select HAVE_SPARSE_IRQ
select RTC_LIB
select GENERIC_ATOMIC64
+ select HAVE_MMU_GATHER_RANGE if MMU
# Support the deprecated APIs until MFD and GPIOLIB catch up.
select GENERIC_HARDIRQS_NO_DEPRECATED if !MFD_SUPPORT && !GPIOLIB
help
Index: linux-2.6/arch/sh/include/asm/tlb.h
===================================================================
--- linux-2.6.orig/arch/sh/include/asm/tlb.h
+++ linux-2.6/arch/sh/include/asm/tlb.h
@@ -9,101 +9,11 @@
#include <linux/pagemap.h>
#ifdef CONFIG_MMU
-#include <asm/pgalloc.h>
-#include <asm/tlbflush.h>
#include <asm/mmu_context.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 start, end;
-};
-
-static inline void init_tlb_gather(struct mmu_gather *tlb)
-{
- tlb->start = TASK_SIZE;
- tlb->end = 0;
-
- if (tlb->fullmm) {
- tlb->start = 0;
- tlb->end = TASK_SIZE;
- }
-}
-
-static inline void
-tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, unsigned int full_mm_flush)
-{
- tlb->mm = mm;
- tlb->fullmm = full_mm_flush;
-
- init_tlb_gather(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();
-}
-
-static inline void
-tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
-{
- if (tlb->start > address)
- tlb->start = address;
- if (tlb->end < address + PAGE_SIZE)
- tlb->end = address + 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);
-}
-
-static inline void
-tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
-{
- if (!tlb->fullmm && tlb->end) {
- flush_tlb_range(vma, tlb->start, tlb->end);
- init_tlb_gather(tlb);
- }
-}
-
-static inline void tlb_flush_mmu(struct mmu_gather *tlb)
-{
-}
-
-static inline int __tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
- free_page_and_swap_cache(page);
- return 0;
-}
-
-static inline void tlb_remove_page(struct mmu_gather *tlb, struct page *page)
-{
- might_sleep();
- __tlb_remove_page(tlb, 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, pudp, addr) pud_free((tlb)->mm, pudp)
-
-#define tlb_migrate_finish(mm) do { } while (0)
+#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, pudp, addr) pud_free((tlb)->mm, pudp)
#if defined(CONFIG_CPU_SH4) || defined(CONFIG_SUPERH64)
extern void tlb_wire_entry(struct vm_area_struct *, unsigned long, pte_t);
@@ -128,8 +38,9 @@ static inline void tlb_unwire_entry(void
#define __tlb_remove_tlb_entry(tlb, pte, address) do { } while (0)
#define tlb_flush(tlb) do { } while (0)
+#endif /* CONFIG_MMU */
+
#include <asm-generic/tlb.h>
-#endif /* CONFIG_MMU */
#endif /* __ASSEMBLY__ */
#endif /* __ASM_SH_TLB_H */
Index: linux-2.6/include/asm-generic/tlb.h
===================================================================
--- linux-2.6.orig/include/asm-generic/tlb.h
+++ linux-2.6/include/asm-generic/tlb.h
@@ -79,6 +79,10 @@ struct mmu_gather {
fast_mode : 1; /* No batching */
unsigned int fullmm; /* Flush full mm */
+#ifdef CONFIG_HAVE_MMU_GATHER_RANGE
+ unsigned long start, end;
+#endif
+
struct mmu_gather_batch *active;
struct mmu_gather_batch local;
struct page *__pages[8];
@@ -222,6 +226,35 @@ static inline void tlb_remove_page(struc
tlb_flush_mmu(tlb);
}
+#ifdef CONFIG_HAVE_MMU_GATHER_RANGE
+static inline void
+__tlb_remove_tlb_entry(struct mmu_gather *tlb, pte_t *ptep, unsigned long address)
+{
+ if (!tlb->fullmm) {
+ tlb->start = min(tlb->start, address);
+ address += PAGE_SIZE;
+ tlb->end = max(tlb->end, address);
+ }
+}
+
+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->start = TASK_SIZE;
+ tlb->end = 0;
+ }
+}
+
+static inline void
+tlb_end_vma(struct mmu_gather *tlb, struct vm_area_struct *vma)
+{
+ if (!tlb->fullmm && tlb->end)
+ flush_tlb_range(vma, tlb->start, tlb->end);
+}
+#endif
+
/**
* tlb_remove_tlb_entry - remember a pte unmapping for later tlb invalidation.
*
@@ -255,6 +288,8 @@ static inline void tlb_remove_page(struc
__pmd_free_tlb(tlb, pmdp, address); \
} while (0)
+#ifndef tlb_migrate_finish
#define tlb_migrate_finish(mm) do {} while (0)
+#endif
#endif /* _ASM_GENERIC__TLB_H */
Index: linux-2.6/arch/arm/include/asm/tlbflush.h
===================================================================
--- linux-2.6.orig/arch/arm/include/asm/tlbflush.h
+++ linux-2.6/arch/arm/include/asm/tlbflush.h
@@ -10,12 +10,9 @@
#ifndef _ASMARM_TLBFLUSH_H
#define _ASMARM_TLBFLUSH_H
-
-#ifndef CONFIG_MMU
-
#define tlb_flush(tlb) ((void) tlb)
-#else /* CONFIG_MMU */
+#ifdef CONFIG_MMU
#include <asm/glue.h>
--
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