From patchwork Mon Mar 28 15:05:29 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 88616 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id E9206B6F8B for ; Tue, 29 Mar 2011 02:14:31 +1100 (EST) Received: from localhost ([127.0.0.1]:36860 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q4E9D-00007S-4J for incoming@patchwork.ozlabs.org; Mon, 28 Mar 2011 11:14:27 -0400 Received: from [140.186.70.92] (port=59656 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q4E0q-0001pk-Ge for qemu-devel@nongnu.org; Mon, 28 Mar 2011 11:05:53 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q4E0b-0004wQ-PC for qemu-devel@nongnu.org; Mon, 28 Mar 2011 11:05:48 -0400 Received: from mail.valinux.co.jp ([210.128.90.3]:52004) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q4E0b-0004vS-86 for qemu-devel@nongnu.org; Mon, 28 Mar 2011 11:05:33 -0400 Received: from ps.local.valinux.co.jp (vagw.valinux.co.jp [210.128.90.14]) by mail.valinux.co.jp (Postfix) with SMTP id 9F4CF1892E; Tue, 29 Mar 2011 00:05:30 +0900 (JST) Received: (nullmailer pid 26615 invoked by uid 1000); Mon, 28 Mar 2011 15:05:30 -0000 From: Isaku Yamahata To: qemu-devel@nongnu.org Date: Tue, 29 Mar 2011 00:05:29 +0900 Message-Id: <1a5082a31fc17d686ec9451ea1a936bf4c8f58a2.1301324539.git.yamahata@valinux.co.jp> X-Mailer: git-send-email 1.7.1.1 In-Reply-To: References: In-Reply-To: References: X-Virus-Scanned: clamav-milter 0.95.2 at va-mail.local.valinux.co.jp X-Virus-Status: Clean X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 210.128.90.3 Cc: yamahata@valinux.co.jp, mst@redhat.com Subject: [Qemu-devel] [PATCH v6 3/4] piix_pci: optimize set irq path X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org optimize irq routing in piix_pic.c which has been a TODO. So far piix3 tracks each pirq level and checks whether a given pic pins is asserted by seeing if each pirq is mapped into the pic pin. This is independent on irq routing, but data path is on slow path. Given that irq routing is rarely changed and asserting pic pins is on data path, the path that asserts pic pins should be optimized and chainging irq routing should be on slow path. The new behavior with this patch series is to use bitmap which is addressed by pirq and pic pins with a given irq routing. When pirq is asserted, the bitmap is set and see if the pic pins is asserted by checking the bitmaps. When irq routing is changed, rebuild the bitmap and re-assert pic pins. Cc: Michael S. Tsirkin Signed-off-by: Isaku Yamahata --- Changes v4 -> v5: - fix piix_set_irq_pic() Changes v3 -> v4: - replace irq_num with pirq or pci_intx Changes v1 -> v2: - some minor clean ups - commit log message --- hw/piix_pci.c | 101 +++++++++++++++++++++++++++++++++++++++++++++++--------- 1 files changed, 84 insertions(+), 17 deletions(-) diff --git a/hw/piix_pci.c b/hw/piix_pci.c index 35e420c..7ffb821 100644 --- a/hw/piix_pci.c +++ b/hw/piix_pci.c @@ -37,10 +37,27 @@ typedef PCIHostState I440FXState; +#define PIIX_NUM_PIC_IRQS 16 /* i8259 * 2 */ #define PIIX_NUM_PIRQS 4ULL /* PIRQ[A-D] */ +#define PIIX_PIRQC 0x60 typedef struct PIIX3State { PCIDevice dev; + + /* + * bitmap to track pic levels. + * The pic level is the logical OR of all the PCI irqs mapped to it + * So one PIC level is tracked by PIIX_NUM_PIRQS bits. + * + * PIRQ is mapped to PIC pins, we track it by + * PIIX_NUM_PIRQS * PIIX_NUM_PIC_IRQS = 64 bits with + * pic_irq * PIIX_NUM_PIRQS + pirq + */ +#if PIIX_NUM_PIC_IRQS * PIIX_NUM_PIRQS > 64 +#error "unable to encode pic state in 64bit in pic_levels." +#endif + uint64_t pic_levels; + qemu_irq *pic; /* This member isn't used. Just for save/load compatibility */ @@ -59,16 +76,16 @@ struct PCII440FXState { #define I440FX_PAM_SIZE 7 #define I440FX_SMRAM 0x72 -static void piix3_set_irq(void *opaque, int irq_num, int level); +static void piix3_set_irq(void *opaque, int pirq, int level); /* return the global irq number corresponding to a given device irq pin. We could also use the bus number to have a more precise mapping. */ -static int pci_slot_get_pirq(PCIDevice *pci_dev, int irq_num) +static int pci_slot_get_pirq(PCIDevice *pci_dev, int pci_intx) { int slot_addend; slot_addend = (pci_dev->devfn >> 3) - 1; - return (irq_num + slot_addend) & 3; + return (pci_intx + slot_addend) & 3; } static void update_pam(PCII440FXState *d, uint32_t start, uint32_t end, int r) @@ -256,25 +273,64 @@ PCIBus *i440fx_init(PCII440FXState **pi440fx_state, int *piix3_devfn, qemu_irq * } /* PIIX3 PCI to ISA bridge */ +static void piix3_set_irq_pic(PIIX3State *piix3, int pic_irq) +{ + qemu_set_irq(piix3->pic[pic_irq], + !!(piix3->pic_levels & + (((1UL << PIIX_NUM_PIRQS) - 1) << + (pic_irq * PIIX_NUM_PIRQS)))); +} -static void piix3_set_irq(void *opaque, int irq_num, int level) +static void piix3_set_irq_level(PIIX3State *piix3, int pirq, int level, + bool propagate) +{ + int pic_irq; + uint64_t mask; + + pic_irq = piix3->dev.config[PIIX_PIRQC + pirq]; + if (pic_irq >= PIIX_NUM_PIC_IRQS) { + return; + } + + mask = 1ULL << ((pic_irq * PIIX_NUM_PIRQS) + pirq); + piix3->pic_levels &= ~mask; + piix3->pic_levels |= mask * !!level; + + if (propagate) { + piix3_set_irq_pic(piix3, pic_irq); + } +} + +static void piix3_set_irq(void *opaque, int pirq, int level) { - int i, pic_irq, pic_level; PIIX3State *piix3 = opaque; + piix3_set_irq_level(piix3, pirq, level, true); +} - /* now we change the pic irq level according to the piix irq mappings */ - /* XXX: optimize */ - pic_irq = piix3->dev.config[0x60 + irq_num]; - if (pic_irq < 16) { - /* The pic level is the logical OR of all the PCI irqs mapped - to it */ - pic_level = 0; - for (i = 0; i < 4; i++) { - if (pic_irq == piix3->dev.config[0x60 + i]) { - pic_level |= pci_bus_get_irq_level(piix3->dev.bus, i); - } +/* irq routing is changed. so rebuild bitmap */ +static void piix3_update_irq_levels(PIIX3State *piix3) +{ + int pirq; + + piix3->pic_levels = 0; + for (pirq = 0; pirq < PIIX_NUM_PIRQS; pirq++) { + piix3_set_irq_level(piix3, pirq, + pci_bus_get_irq_level(piix3->dev.bus, pirq), + false); + } +} + +static void piix3_write_config(PCIDevice *dev, + uint32_t address, uint32_t val, int len) +{ + pci_default_write_config(dev, address, val, len); + if (ranges_overlap(address, len, PIIX_PIRQC, 4)) { + PIIX3State *piix3 = DO_UPCAST(PIIX3State, dev, dev); + int pic_irq; + piix3_update_irq_levels(piix3); + for (pic_irq = 0; pic_irq < PIIX_NUM_PIC_IRQS; pic_irq++) { + piix3_set_irq_pic(piix3, pic_irq); } - qemu_set_irq(piix3->pic[pic_irq], pic_level); } } @@ -314,6 +370,15 @@ static void piix3_reset(void *opaque) pci_conf[0xab] = 0x00; pci_conf[0xac] = 0x00; pci_conf[0xae] = 0x00; + + d->pic_levels = 0; +} + +static int piix3_post_load(void *opaque, int version_id) +{ + PIIX3State *piix3 = opaque; + piix3_update_irq_levels(piix3); + return 0; } static void piix3_pre_save(void *opaque) @@ -332,6 +397,7 @@ static const VMStateDescription vmstate_piix3 = { .version_id = 3, .minimum_version_id = 2, .minimum_version_id_old = 2, + .post_load = piix3_post_load, .pre_save = piix3_pre_save, .fields = (VMStateField []) { VMSTATE_PCI_DEVICE(dev, PIIX3State), @@ -375,6 +441,7 @@ static PCIDeviceInfo i440fx_info[] = { .qdev.no_user = 1, .no_hotplug = 1, .init = piix3_initfn, + .config_write = piix3_write_config, },{ /* end of list */ }