From 8269fb7082f49b5facddbbe1072bc382b2741add Mon Sep 17 00:00:00 2001 From: Wei Yang Date: Sun, 6 Mar 2016 01:57:25 +0000 Subject: [PATCH] kvm/irqchip: use bitmap utility for gsi tracking By using utilities in bitops and bitmap, this patch tries to make it more friendly to audience. No functional change. Signed-off-by: Wei Yang Message-Id: <1457229445-25954-1-git-send-email-richard.weiyang@gmail.com> Signed-off-by: Paolo Bonzini --- kvm-all.c | 34 ++++++++++------------------------ 1 file changed, 10 insertions(+), 24 deletions(-) diff --git a/kvm-all.c b/kvm-all.c index 161200edb0..44c0464261 100644 --- a/kvm-all.c +++ b/kvm-all.c @@ -89,7 +89,7 @@ struct KVMState #ifdef KVM_CAP_IRQ_ROUTING struct kvm_irq_routing *irq_routes; int nr_allocated_irq_routes; - uint32_t *used_gsi_bitmap; + unsigned long *used_gsi_bitmap; unsigned int gsi_count; QTAILQ_HEAD(msi_hashtab, KVMMSIRoute) msi_hashtab[KVM_MSI_HASHTAB_SIZE]; #endif @@ -951,12 +951,12 @@ typedef struct KVMMSIRoute { static void set_gsi(KVMState *s, unsigned int gsi) { - s->used_gsi_bitmap[gsi / 32] |= 1U << (gsi % 32); + set_bit(gsi, s->used_gsi_bitmap); } static void clear_gsi(KVMState *s, unsigned int gsi) { - s->used_gsi_bitmap[gsi / 32] &= ~(1U << (gsi % 32)); + clear_bit(gsi, s->used_gsi_bitmap); } void kvm_init_irq_routing(KVMState *s) @@ -965,17 +965,9 @@ void kvm_init_irq_routing(KVMState *s) gsi_count = kvm_check_extension(s, KVM_CAP_IRQ_ROUTING) - 1; if (gsi_count > 0) { - unsigned int gsi_bits, i; - /* Round up so we can search ints using ffs */ - gsi_bits = ALIGN(gsi_count, 32); - s->used_gsi_bitmap = g_malloc0(gsi_bits / 8); + s->used_gsi_bitmap = bitmap_new(gsi_count); s->gsi_count = gsi_count; - - /* Mark any over-allocated bits as already in use */ - for (i = gsi_count; i < gsi_bits; i++) { - set_gsi(s, i); - } } s->irq_routes = g_malloc0(sizeof(*s->irq_routes)); @@ -1105,9 +1097,7 @@ static void kvm_flush_dynamic_msi_routes(KVMState *s) static int kvm_irqchip_get_virq(KVMState *s) { - uint32_t *word = s->used_gsi_bitmap; - int max_words = ALIGN(s->gsi_count, 32) / 32; - int i, zeroes; + int next_virq; /* * PIC and IOAPIC share the first 16 GSI numbers, thus the available @@ -1120,16 +1110,12 @@ static int kvm_irqchip_get_virq(KVMState *s) } /* Return the lowest unused GSI in the bitmap */ - for (i = 0; i < max_words; i++) { - zeroes = ctz32(~word[i]); - if (zeroes == 32) { - continue; - } - - return zeroes + i * 32; + next_virq = find_first_zero_bit(s->used_gsi_bitmap, s->gsi_count); + if (next_virq >= s->gsi_count) { + return -ENOSPC; + } else { + return next_virq; } - return -ENOSPC; - } static KVMMSIRoute *kvm_lookup_msi_route(KVMState *s, MSIMessage msg)