x86/mm: Abstract switching CR3

In preparation to adding additional PCID flushing, abstract the
loading of a new ASID into CR3.

[ PeterZ: Split out from big combo patch ]

Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Eduardo Valentin <eduval@amazon.com>
Cc: Greg KH <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: aliguori@amazon.com
Cc: daniel.gruss@iaik.tugraz.at
Cc: hughd@google.com
Cc: keescook@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Dave Hansen 2017-12-04 15:07:58 +01:00 committed by Ingo Molnar
parent 2ea907c4fe
commit 48e111982c

View File

@ -100,6 +100,24 @@ static void choose_new_asid(struct mm_struct *next, u64 next_tlb_gen,
*need_flush = true;
}
static void load_new_mm_cr3(pgd_t *pgdir, u16 new_asid, bool need_flush)
{
unsigned long new_mm_cr3;
if (need_flush) {
new_mm_cr3 = build_cr3(pgdir, new_asid);
} else {
new_mm_cr3 = build_cr3_noflush(pgdir, new_asid);
}
/*
* Caution: many callers of this function expect
* that load_cr3() is serializing and orders TLB
* fills with respect to the mm_cpumask writes.
*/
write_cr3(new_mm_cr3);
}
void leave_mm(int cpu)
{
struct mm_struct *loaded_mm = this_cpu_read(cpu_tlbstate.loaded_mm);
@ -230,7 +248,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
if (need_flush) {
this_cpu_write(cpu_tlbstate.ctxs[new_asid].ctx_id, next->context.ctx_id);
this_cpu_write(cpu_tlbstate.ctxs[new_asid].tlb_gen, next_tlb_gen);
write_cr3(build_cr3(next->pgd, new_asid));
load_new_mm_cr3(next->pgd, new_asid, true);
/*
* NB: This gets called via leave_mm() in the idle path
@ -243,7 +261,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, TLB_FLUSH_ALL);
} else {
/* The new ASID is already up to date. */
write_cr3(build_cr3_noflush(next->pgd, new_asid));
load_new_mm_cr3(next->pgd, new_asid, false);
/* See above wrt _rcuidle. */
trace_tlb_flush_rcuidle(TLB_FLUSH_ON_TASK_SWITCH, 0);