x86: change flush_tlb_others to take a const struct cpumask
Impact: reduce stack usage, use new cpumask API.
This is made a little more tricky by uv_flush_tlb_others which
actually alters its argument, for an IPI to be sent to the remaining
cpus in the mask.
I solve this by allocating a cpumask_var_t for this case and falling back
to IPI should this fail.
To eliminate temporaries in the caller, all flush_tlb_others implementations
now do the this-cpu-elimination step themselves.
Note also the curious "cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask)"
which has been there since pre-git and yet f->flush_cpumask is always zero
at this point.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bea2152..965539e 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -634,35 +634,27 @@
preempt_enable();
}
-static void xen_flush_tlb_others(const cpumask_t *cpus, struct mm_struct *mm,
- unsigned long va)
+static void xen_flush_tlb_others(const struct cpumask *cpus,
+ struct mm_struct *mm, unsigned long va)
{
struct {
struct mmuext_op op;
- cpumask_t mask;
+ DECLARE_BITMAP(mask, NR_CPUS);
} *args;
- cpumask_t cpumask = *cpus;
struct multicall_space mcs;
- /*
- * A couple of (to be removed) sanity checks:
- *
- * - current CPU must not be in mask
- * - mask must exist :)
- */
- BUG_ON(cpus_empty(cpumask));
- BUG_ON(cpu_isset(smp_processor_id(), cpumask));
+ BUG_ON(cpumask_empty(cpus));
BUG_ON(!mm);
- /* If a CPU which we ran on has gone down, OK. */
- cpus_and(cpumask, cpumask, cpu_online_map);
- if (cpus_empty(cpumask))
- return;
-
mcs = xen_mc_entry(sizeof(*args));
args = mcs.args;
- args->mask = cpumask;
- args->op.arg2.vcpumask = &args->mask;
+ args->op.arg2.vcpumask = to_cpumask(args->mask);
+
+ /* Remove us, and any offline CPUS. */
+ cpumask_and(to_cpumask(args->mask), cpus, cpu_online_mask);
+ cpumask_clear_cpu(smp_processor_id(), to_cpumask(args->mask));
+ if (unlikely(cpumask_empty(to_cpumask(args->mask))))
+ goto issue;
if (va == TLB_FLUSH_ALL) {
args->op.cmd = MMUEXT_TLB_FLUSH_MULTI;
@@ -673,6 +665,7 @@
MULTI_mmuext_op(mcs.mc, &args->op, 1, NULL, DOMID_SELF);
+issue:
xen_mc_issue(PARAVIRT_LAZY_MMU);
}