From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60095) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1acrlg-0004cz-Cn for qemu-devel@nongnu.org; Mon, 07 Mar 2016 04:48:01 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1acrld-0006GL-2E for qemu-devel@nongnu.org; Mon, 07 Mar 2016 04:48:00 -0500 Received: from mail-wm0-x231.google.com ([2a00:1450:400c:c09::231]:36057) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1acrlc-0006Fw-P1 for qemu-devel@nongnu.org; Mon, 07 Mar 2016 04:47:57 -0500 Received: by mail-wm0-x231.google.com with SMTP id n186so77155040wmn.1 for ; Mon, 07 Mar 2016 01:47:56 -0800 (PST) Sender: Paolo Bonzini References: <1457229445-25954-1-git-send-email-richard.weiyang@gmail.com> From: Paolo Bonzini Message-ID: <56DD4E49.1090608@redhat.com> Date: Mon, 7 Mar 2016 10:47:53 +0100 MIME-Version: 1.0 In-Reply-To: <1457229445-25954-1-git-send-email-richard.weiyang@gmail.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH] kvm/irqchip: use bitmap utility for gsi tracking List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wei Yang , jan.kiszka@siemens.com Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org On 06/03/2016 02:57, Wei Yang wrote: > 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 > --- > kvm-all.c | 34 ++++++++++------------------------ > 1 file changed, 10 insertions(+), 24 deletions(-) > > diff --git a/kvm-all.c b/kvm-all.c > index bd9e764..ed3f4a2 100644 > --- a/kvm-all.c > +++ b/kvm-all.c > @@ -90,7 +90,7 @@ 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) > Queued, thanks. I will send a pull request today. Paolo