linux/arch/x86/include/asm/mmu.h
Andy Lutomirski f39681ed0f x86/mm: Give each mm TLB flush generation a unique ID
This adds two new variables to mmu_context_t: ctx_id and tlb_gen.
ctx_id uniquely identifies the mm_struct and will never be reused.
For a given mm_struct (and hence ctx_id), tlb_gen is a monotonic
count of the number of times that a TLB flush has been requested.
The pair (ctx_id, tlb_gen) can be used as an identifier for TLB
flush actions and will be used in subsequent patches to reliably
determine whether all needed TLB flushes have occurred on a given
CPU.

This patch is split out for ease of review.  By itself, it has no
real effect other than creating and updating the new variables.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Nadav Amit <nadav.amit@gmail.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/413a91c24dab3ed0caa5f4e4d017d87b0857f920.1498751203.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-05 10:52:56 +02:00

64 lines
1.5 KiB
C

#ifndef _ASM_X86_MMU_H
#define _ASM_X86_MMU_H
#include <linux/spinlock.h>
#include <linux/mutex.h>
#include <linux/atomic.h>
/*
* x86 has arch-specific MMU state beyond what lives in mm_struct.
*/
typedef struct {
/*
* ctx_id uniquely identifies this mm_struct. A ctx_id will never
* be reused, and zero is not a valid ctx_id.
*/
u64 ctx_id;
/*
* Any code that needs to do any sort of TLB flushing for this
* mm will first make its changes to the page tables, then
* increment tlb_gen, then flush. This lets the low-level
* flushing code keep track of what needs flushing.
*
* This is not used on Xen PV.
*/
atomic64_t tlb_gen;
#ifdef CONFIG_MODIFY_LDT_SYSCALL
struct ldt_struct *ldt;
#endif
#ifdef CONFIG_X86_64
/* True if mm supports a task running in 32 bit compatibility mode. */
unsigned short ia32_compat;
#endif
struct mutex lock;
void __user *vdso; /* vdso base address */
const struct vdso_image *vdso_image; /* vdso image in use */
atomic_t perf_rdpmc_allowed; /* nonzero if rdpmc is allowed */
#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS
/*
* One bit per protection key says whether userspace can
* use it or not. protected by mmap_sem.
*/
u16 pkey_allocation_map;
s16 execute_only_pkey;
#endif
#ifdef CONFIG_X86_INTEL_MPX
/* address of the bounds directory */
void __user *bd_addr;
#endif
} mm_context_t;
#define INIT_MM_CONTEXT(mm) \
.context = { \
.ctx_id = 1, \
}
void leave_mm(int cpu);
#endif /* _ASM_X86_MMU_H */