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asm-generic/tlb: Introduce CONFIG_HAVE_MMU_GATHER_NO_GATHER=y 

Add the Kconfig option HAVE_MMU_GATHER_NO_GATHER to the generic
mmu_gather code. If the option is set the mmu_gather will not
track individual pages for delayed page free anymore. A platform
that enables the option needs to provide its own implementation
of the __tlb_remove_page_size() function to free pages.

No change in behavior intended.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: linux@armlinux.org.uk
Cc: npiggin@gmail.com
Link: http://lkml.kernel.org/r/20180918125151.31744-2-schwidefsky@de.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Martin Schwidefsky 2018-09-18 14:51:50 +02:00 committed by Ingo Molnar
parent 6137fed082
commit 952a31c9e6
3 changed files with 80 additions and 59 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
arch/Kconfig
View File

@ -389,6 +389,9 @@ config HAVE_RCU_TABLE_NO_INVALIDATE
config HAVE_MMU_GATHER_PAGE_SIZE
bool
config HAVE_MMU_GATHER_NO_GATHER
bool
config ARCH_HAVE_NMI_SAFE_CMPXCHG
bool

9
include/asm-generic/tlb.h
View File

@ -191,6 +191,7 @@ extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
#endif
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
/*
* 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.
@ -215,6 +216,10 @@ struct mmu_gather_batch {
*/
#define MAX_GATHER_BATCH_COUNT (10000UL/MAX_GATHER_BATCH)
extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
int page_size);
#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.
@ -261,6 +266,7 @@ struct mmu_gather {
unsigned int batch_count;
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
struct mmu_gather_batch *active;
struct mmu_gather_batch local;
struct page *__pages[MMU_GATHER_BUNDLE];
@ -268,6 +274,7 @@ struct mmu_gather {
#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
unsigned int page_size;
#endif
#endif
};
void arch_tlb_gather_mmu(struct mmu_gather *tlb,
@ -276,8 +283,6 @@ void tlb_flush_mmu(struct mmu_gather *tlb);
void arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force);
void tlb_flush_mmu_free(struct mmu_gather *tlb);
extern bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page,
int page_size);
static inline void __tlb_adjust_range(struct mmu_gather *tlb,
unsigned long address,

127
mm/mmu_gather.c
View File

@ -13,6 +13,8 @@
#ifdef HAVE_GENERIC_MMU_GATHER
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
static bool tlb_next_batch(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch;
@ -41,37 +43,10 @@ static bool tlb_next_batch(struct mmu_gather *tlb)
return true;
}
void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
unsigned long start, unsigned long end)
{
tlb->mm = mm;
/* Is it from 0 to ~0? */
tlb->fullmm = !(start | (end+1));
tlb->need_flush_all = 0;
tlb->local.next = NULL;
tlb->local.nr = 0;
tlb->local.max = ARRAY_SIZE(tlb->__pages);
tlb->active = &tlb->local;
tlb->batch_count = 0;
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb->batch = NULL;
#endif
#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
tlb->page_size = 0;
#endif
__tlb_reset_range(tlb);
}
void tlb_flush_mmu_free(struct mmu_gather *tlb)
static void tlb_batch_pages_flush(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch;
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb_table_flush(tlb);
#endif
for (batch = &tlb->local; batch && batch->nr; batch = batch->next) {
free_pages_and_swap_cache(batch->pages, batch->nr);
batch->nr = 0;
@ -79,31 +54,10 @@ void tlb_flush_mmu_free(struct mmu_gather *tlb)
tlb->active = &tlb->local;
}
void tlb_flush_mmu(struct mmu_gather *tlb)
{
tlb_flush_mmu_tlbonly(tlb);
tlb_flush_mmu_free(tlb);
}
/* tlb_finish_mmu
* Called at the end of the shootdown operation to free up any resources
* that were required.
*/
void arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force)
static void tlb_batch_list_free(struct mmu_gather *tlb)
{
struct mmu_gather_batch *batch, *next;
if (force) {
__tlb_reset_range(tlb);
__tlb_adjust_range(tlb, start, end - start);
}
tlb_flush_mmu(tlb);
/* keep the page table cache within bounds */
check_pgt_cache();
for (batch = tlb->local.next; batch; batch = next) {
next = batch->next;
free_pages((unsigned long)batch, 0);
@ -111,13 +65,6 @@ void arch_tlb_finish_mmu(struct mmu_gather *tlb,
tlb->local.next = NULL;
}
/* __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. Returns the number of free page slots left.
* When out of page slots we must call tlb_flush_mmu().
*returns true if the caller should flush.
*/
bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_size)
{
struct mmu_gather_batch *batch;
@ -144,6 +91,72 @@ bool __tlb_remove_page_size(struct mmu_gather *tlb, struct page *page, int page_
return false;
}
#endif /* HAVE_MMU_GATHER_NO_GATHER */
void arch_tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
unsigned long start, unsigned long end)
{
tlb->mm = mm;
/* Is it from 0 to ~0? */
tlb->fullmm = !(start | (end+1));
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
tlb->need_flush_all = 0;
tlb->local.next = NULL;
tlb->local.nr = 0;
tlb->local.max = ARRAY_SIZE(tlb->__pages);
tlb->active = &tlb->local;
tlb->batch_count = 0;
#endif
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb->batch = NULL;
#endif
#ifdef CONFIG_HAVE_MMU_GATHER_PAGE_SIZE
tlb->page_size = 0;
#endif
__tlb_reset_range(tlb);
}
void tlb_flush_mmu_free(struct mmu_gather *tlb)
{
#ifdef CONFIG_HAVE_RCU_TABLE_FREE
tlb_table_flush(tlb);
#endif
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
tlb_batch_pages_flush(tlb);
#endif
}
void tlb_flush_mmu(struct mmu_gather *tlb)
{
tlb_flush_mmu_tlbonly(tlb);
tlb_flush_mmu_free(tlb);
}
/* tlb_finish_mmu
* Called at the end of the shootdown operation to free up any resources
* that were required.
*/
void arch_tlb_finish_mmu(struct mmu_gather *tlb,
unsigned long start, unsigned long end, bool force)
{
if (force) {
__tlb_reset_range(tlb);
__tlb_adjust_range(tlb, start, end - start);
}
tlb_flush_mmu(tlb);
/* keep the page table cache within bounds */
check_pgt_cache();
#ifndef CONFIG_HAVE_MMU_GATHER_NO_GATHER
tlb_batch_list_free(tlb);
#endif
}
#endif /* HAVE_GENERIC_MMU_GATHER */
#ifdef CONFIG_HAVE_RCU_TABLE_FREE