diff options
Diffstat (limited to 'arch/x86/xen/multicalls.c')
| -rw-r--r-- | arch/x86/xen/multicalls.c | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c index cc71f7cf1adc..2474553d1f26 100644 --- a/arch/x86/xen/multicalls.c +++ b/arch/x86/xen/multicalls.c @@ -55,6 +55,7 @@ DEFINE_PER_CPU(unsigned long, xen_mc_irq_flags); void xen_mc_flush(void) { struct mc_buffer *b = &__get_cpu_var(mc_buffer); + struct multicall_entry *mc; int ret = 0; unsigned long flags; int i; @@ -67,7 +68,24 @@ void xen_mc_flush(void) trace_xen_mc_flush(b->mcidx, b->argidx, b->cbidx); - if (b->mcidx) { + switch (b->mcidx) { + case 0: + /* no-op */ + BUG_ON(b->argidx != 0); + break; + + case 1: + /* Singleton multicall - bypass multicall machinery + and just do the call directly. */ + mc = &b->entries[0]; + + mc->result = privcmd_call(mc->op, + mc->args[0], mc->args[1], mc->args[2], + mc->args[3], mc->args[4]); + ret = mc->result < 0; + break; + + default: #if MC_DEBUG memcpy(b->debug, b->entries, b->mcidx * sizeof(struct multicall_entry)); @@ -94,11 +112,10 @@ void xen_mc_flush(void) } } #endif + } - b->mcidx = 0; - b->argidx = 0; - } else - BUG_ON(b->argidx != 0); + b->mcidx = 0; + b->argidx = 0; for (i = 0; i < b->cbidx; i++) { struct callback *cb = &b->callbacks[i]; |