[PATCH 03/13] sparc: mmu_gather rework

Peter Zijlstra
2011-03-02T17:59:28Z

[-- Attachment #1: peter_zijlstra-sparc-preemptible_mmu_gather.patch --]
[-- Type: text/plain, Size: 10575 bytes --]

Rework the sparc mmu_gather usage to conform to the new world order :-)

Sparc mmu_gather does two things:
- tracks vaddrs to unhash
- tracks pages to free

Split these two things like powerpc has done and keep the vaddrs
in per-cpu data structures and flush them on context switch.

The remaining bits can then use the generic mmu_gather.

Acked-by: David Miller <davem@davemloft.net>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
arch/sparc/include/asm/pgalloc_64.h | 3 +
arch/sparc/include/asm/pgtable_64.h | 15 ++++-
arch/sparc/include/asm/tlb_64.h | 91 ++---------------------------------
arch/sparc/include/asm/tlbflush_64.h | 12 +++-
arch/sparc/mm/tlb.c | 43 +++++++++-------
arch/sparc/mm/tsb.c | 15 +++--
6 files changed, 63 insertions(+), 116 deletions(-)

Index: linux-2.6/arch/sparc/include/asm/pgalloc_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/pgalloc_64.h
+++ linux-2.6/arch/sparc/include/asm/pgalloc_64.h
@@ -78,4 +78,7 @@ static inline void check_pgt_cache(void)
quicklist_trim(0, NULL, 25, 16);
}

+#define __pte_free_tlb(tlb, pte, addr) pte_free((tlb)->mm, pte)
+#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
+
#endif /* _SPARC64_PGALLOC_H */
Index: linux-2.6/arch/sparc/include/asm/tlb_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/tlb_64.h
+++ linux-2.6/arch/sparc/include/asm/tlb_64.h
@@ -7,66 +7,11 @@
#include <asm/tlbflush.h>
#include <asm/mmu_context.h>

-#define TLB_BATCH_NR 192
-
-/*
- * 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(bp) ((bp)->pages_nr == ~0U)
-#else
- #define FREE_PTE_NR 1
- #define tlb_fast_mode(bp) 1
-#endif
-
-struct mmu_gather {
- struct mm_struct *mm;
- unsigned int pages_nr;
- unsigned int need_flush;
- unsigned int fullmm;
- unsigned int tlb_nr;
- unsigned long vaddrs[TLB_BATCH_NR];
- struct page *pages[FREE_PTE_NR];
-};
-
-DECLARE_PER_CPU(struct mmu_gather, mmu_gathers);
-
#ifdef CONFIG_SMP
extern void smp_flush_tlb_pending(struct mm_struct *,
unsigned long, unsigned long *);
#endif

-extern void __flush_tlb_pending(unsigned long, unsigned long, unsigned long *);
-extern void flush_tlb_pending(void);
-
-static inline struct mmu_gather *tlb_gather_mmu(struct mm_struct *mm, unsigned int full_mm_flush)
-{
- struct mmu_gather *mp = &get_cpu_var(mmu_gathers);
-
- BUG_ON(mp->tlb_nr);
-
- mp->mm = mm;
- mp->pages_nr = num_online_cpus() > 1 ? 0U : ~0U;
- mp->fullmm = full_mm_flush;
-
- return mp;
-}
-
-
-static inline void tlb_flush_mmu(struct mmu_gather *mp)
-{
- if (!mp->fullmm)
- flush_tlb_pending();
- if (mp->need_flush) {
- free_pages_and_swap_cache(mp->pages, mp->pages_nr);
- mp->pages_nr = 0;
- mp->need_flush = 0;
- }
-
-}
-
#ifdef CONFIG_SMP
extern void smp_flush_tlb_mm(struct mm_struct *mm);
#define do_flush_tlb_mm(mm) smp_flush_tlb_mm(mm)
@@ -74,38 +19,14 @@ extern void smp_flush_tlb_mm(struct mm_s
#define do_flush_tlb_mm(mm) __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT)
#endif

-static inline void tlb_finish_mmu(struct mmu_gather *mp, unsigned long start, unsigned long end)
-{
- tlb_flush_mmu(mp);
-
- if (mp->fullmm)
- mp->fullmm = 0;
-
- /* keep the page table cache within bounds */
- check_pgt_cache();
-
- put_cpu_var(mmu_gathers);
-}
-
-static inline void tlb_remove_page(struct mmu_gather *mp, struct page *page)
-{
- if (tlb_fast_mode(mp)) {
- free_page_and_swap_cache(page);
- return;
- }
- mp->need_flush = 1;
- mp->pages[mp->pages_nr++] = page;
- if (mp->pages_nr >= FREE_PTE_NR)
- tlb_flush_mmu(mp);
-}
-
-#define tlb_remove_tlb_entry(mp,ptep,addr) do { } while (0)
-#define pte_free_tlb(mp, ptepage, addr) pte_free((mp)->mm, ptepage)
-#define pmd_free_tlb(mp, pmdp, addr) pmd_free((mp)->mm, pmdp)
-#define pud_free_tlb(tlb,pudp, addr) __pud_free_tlb(tlb,pudp,addr)
+extern void __flush_tlb_pending(unsigned long, unsigned long, unsigned long *);
+extern void flush_tlb_pending(void);

-#define tlb_migrate_finish(mm) do { } while (0)
#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, address) do { } while (0)
+#define tlb_flush(tlb) flush_tlb_pending()
+
+#include <asm-generic/tlb.h>

#endif /* _SPARC64_TLB_H */
Index: linux-2.6/arch/sparc/include/asm/tlbflush_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/tlbflush_64.h
+++ linux-2.6/arch/sparc/include/asm/tlbflush_64.h
@@ -5,9 +5,17 @@
#include <asm/mmu_context.h>

/* TSB flush operations. */
-struct mmu_gather;
+
+#define TLB_BATCH_NR 192
+
+struct tlb_batch {
+ struct mm_struct *mm;
+ unsigned long tlb_nr;
+ unsigned long vaddrs[TLB_BATCH_NR];
+};
+
extern void flush_tsb_kernel_range(unsigned long start, unsigned long end);
-extern void flush_tsb_user(struct mmu_gather *mp);
+extern void flush_tsb_user(struct tlb_batch *tb);

/* TLB flush operations. */

Index: linux-2.6/arch/sparc/mm/tlb.c
===================================================================
--- linux-2.6.orig/arch/sparc/mm/tlb.c
+++ linux-2.6/arch/sparc/mm/tlb.c
@@ -19,33 +19,34 @@

/* Heavily inspired by the ppc64 code. */

-DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);

void flush_tlb_pending(void)
{
- struct mmu_gather *mp = &get_cpu_var(mmu_gathers);
+ struct tlb_batch *tb = &get_cpu_var(tlb_batch);

- if (mp->tlb_nr) {
- flush_tsb_user(mp);
+ if (tb->tlb_nr) {
+ flush_tsb_user(tb);

- if (CTX_VALID(mp->mm->context)) {
+ if (CTX_VALID(tb->mm->context)) {
#ifdef CONFIG_SMP
- smp_flush_tlb_pending(mp->mm, mp->tlb_nr,
- &mp->vaddrs[0]);
+ smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
+ &tb->vaddrs[0]);
#else
- __flush_tlb_pending(CTX_HWBITS(mp->mm->context),
- mp->tlb_nr, &mp->vaddrs[0]);
+ __flush_tlb_pending(CTX_HWBITS(tb->mm->context),
+ tb->tlb_nr, &tb->vaddrs[0]);
#endif
}
- mp->tlb_nr = 0;
+ tb->tlb_nr = 0;
}

- put_cpu_var(mmu_gathers);
+ put_cpu_var(tlb_batch);
}

-void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig)
+void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+ pte_t *ptep, pte_t orig, int fullmm)
{
- struct mmu_gather *mp = &__get_cpu_var(mmu_gathers);
+ struct tlb_batch *tb = &get_cpu_var(tlb_batch);
unsigned long nr;

vaddr &= PAGE_MASK;
@@ -77,21 +78,25 @@ void tlb_batch_add(struct mm_struct *mm,

no_cache_flush:

- if (mp->fullmm)
+ if (fullmm) {
+ put_cpu_var(tlb_batch);
return;
+ }

- nr = mp->tlb_nr;
+ nr = tb->tlb_nr;

- if (unlikely(nr != 0 && mm != mp->mm)) {
+ if (unlikely(nr != 0 && mm != tb->mm)) {
flush_tlb_pending();
nr = 0;
}

if (nr == 0)
- mp->mm = mm;
+ tb->mm = mm;

- mp->vaddrs[nr] = vaddr;
- mp->tlb_nr = ++nr;
+ tb->vaddrs[nr] = vaddr;
+ tb->tlb_nr = ++nr;
if (nr >= TLB_BATCH_NR)
flush_tlb_pending();
+
+ put_cpu_var(tlb_batch);
}
Index: linux-2.6/arch/sparc/mm/tsb.c
===================================================================
--- linux-2.6.orig/arch/sparc/mm/tsb.c
+++ linux-2.6/arch/sparc/mm/tsb.c
@@ -47,12 +47,13 @@ void flush_tsb_kernel_range(unsigned lon
}
}

-static void __flush_tsb_one(struct mmu_gather *mp, unsigned long hash_shift, unsigned long tsb, unsigned long nentries)
+static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
+ unsigned long tsb, unsigned long nentries)
{
unsigned long i;

- for (i = 0; i < mp->tlb_nr; i++) {
- unsigned long v = mp->vaddrs[i];
+ for (i = 0; i < tb->tlb_nr; i++) {
+ unsigned long v = tb->vaddrs[i];
unsigned long tag, ent, hash;

v &= ~0x1UL;
@@ -65,9 +66,9 @@ static void __flush_tsb_one(struct mmu_g
}
}

-void flush_tsb_user(struct mmu_gather *mp)
+void flush_tsb_user(struct tlb_batch *tb)
{
- struct mm_struct *mm = mp->mm;
+ struct mm_struct *mm = tb->mm;
unsigned long nentries, base, flags;

spin_lock_irqsave(&mm->context.lock, flags);
@@ -76,7 +77,7 @@ void flush_tsb_user(struct mmu_gather *m
nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
if (tlb_type == cheetah_plus || tlb_type == hypervisor)
base = __pa(base);
- __flush_tsb_one(mp, PAGE_SHIFT, base, nentries);
+ __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);

#ifdef CONFIG_HUGETLB_PAGE
if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
@@ -84,7 +85,7 @@ void flush_tsb_user(struct mmu_gather *m
nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
if (tlb_type == cheetah_plus || tlb_type == hypervisor)
base = __pa(base);
- __flush_tsb_one(mp, HPAGE_SHIFT, base, nentries);
+ __flush_tsb_one(tb, HPAGE_SHIFT, base, nentries);
}
#endif
spin_unlock_irqrestore(&mm->context.lock, flags);
Index: linux-2.6/arch/sparc/include/asm/pgtable_64.h
===================================================================
--- linux-2.6.orig/arch/sparc/include/asm/pgtable_64.h
+++ linux-2.6/arch/sparc/include/asm/pgtable_64.h
@@ -655,9 +655,11 @@ static inline int pte_special(pte_t pte)
#define pte_unmap(pte) do { } while (0)

/* Actual page table PTE updates. */
-extern void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr, pte_t *ptep, pte_t orig);
+extern void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
+ pte_t *ptep, pte_t orig, int fullmm);

-static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte)
+static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte, int fullmm)
{
pte_t orig = *ptep;

@@ -670,12 +672,19 @@ static inline void set_pte_at(struct mm_
* and SUN4V pte layout, so this inline test is fine.
*/
if (likely(mm != &init_mm) && (pte_val(orig) & _PAGE_VALID))
- tlb_batch_add(mm, addr, ptep, orig);
+ tlb_batch_add(mm, addr, ptep, orig, fullmm);
}

+#define set_pte_at(mm,addr,ptep,pte) \
+ __set_pte_at((mm), (addr), (ptep), (pte), 0)
+
#define pte_clear(mm,addr,ptep) \
set_pte_at((mm), (addr), (ptep), __pte(0UL))

+#define __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
+#define pte_clear_not_present_full(mm,addr,ptep,fullmm) \
+ __set_pte_at((mm), (addr), (ptep), __pte(0UL), (fullmm))
+
#ifdef DCACHE_ALIASING_POSSIBLE
#define __HAVE_ARCH_MOVE_PTE
#define move_pte(pte, prot, old_addr, new_addr) \