From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NDdek-0002Iv-0Z for qemu-devel@nongnu.org; Thu, 26 Nov 2009 07:41:06 -0500 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1NDdef-0002E4-Ja for qemu-devel@nongnu.org; Thu, 26 Nov 2009 07:41:05 -0500 Received: from [199.232.76.173] (port=49001 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NDdef-0002Dm-8w for qemu-devel@nongnu.org; Thu, 26 Nov 2009 07:41:01 -0500 Received: from mx1.redhat.com ([209.132.183.28]:13419) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1NDdee-0000Oj-ME for qemu-devel@nongnu.org; Thu, 26 Nov 2009 07:41:01 -0500 Date: Thu, 26 Nov 2009 14:38:19 +0200 From: "Michael S. Tsirkin" Message-ID: <20091126123819.GA31495@redhat.com> References: <20091125165906.GE24783@redhat.com> <20091126030451.GG25483%yamahata@valinux.co.jp> <20091126095316.GC26861@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091126095316.GC26861@redhat.com> Subject: [Qemu-devel] Re: [PATCH 4/4] pci: interrupt disable bit support List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Isaku Yamahata Cc: qemu-devel@nongnu.org On Thu, Nov 26, 2009 at 11:53:16AM +0200, Michael S. Tsirkin wrote: > On Thu, Nov 26, 2009 at 12:04:51PM +0900, Isaku Yamahata wrote: > > On Wed, Nov 25, 2009 at 06:59:06PM +0200, Michael S. Tsirkin wrote: > > > interrupt disable bit is mandatory in PCI spec, > > > so we must implement it to be spec compliant. > > > > > > Signed-off-by: Michael S. Tsirkin > > > --- > > > hw/pci.c | 57 ++++++++++++++++++++++++++++++++++++++++----------------- > > > hw/pci.h | 4 ++++ > > > 2 files changed, 44 insertions(+), 17 deletions(-) > > > > > > diff --git a/hw/pci.c b/hw/pci.c > > > index 844664b..3daae46 100644 > > > --- a/hw/pci.c > > > +++ b/hw/pci.c > > > @@ -114,12 +114,43 @@ static void pci_update_irq_status(PCIDevice *dev) > > > } > > > } > > > > > > +static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change) > > > +{ > > > + PCIBus *bus; > > > + for (;;) { > > > + bus = pci_dev->bus; > > > + irq_num = bus->map_irq(pci_dev, irq_num); > > > + if (bus->set_irq) > > > + break; > > > + pci_dev = bus->parent_dev; > > > + } > > > + bus->irq_count[irq_num] += change; > > > + bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0); > > > > Let's use ! instead of != 0 for consistency. > > > > This patch simply moves code, so it's better to keep it > the same - this way git blame can find it. > A separate patch to clean this might be a good idea. > > > > +} > > > + > > > +/* Update irq disabled field after config space change, > > > + * assert/deassert interrupts if necessary. */ > > > +static void pci_update_irq_disabled(PCIDevice *d) > > > +{ > > > + int i; > > > + int disabled = !!(pci_get_word(d->config + PCI_COMMAND) & > > > + PCI_COMMAND_INTX_DISABLE); > > > + if (disabled == d->irq_disabled) > > > + return; > > > + d->irq_disabled = disabled; > > > + for (i = 0; i < ARRAY_SIZE(d->irq_state); ++i) { > > > + int state = d->irq_state[i]; > > > + pci_change_irq_level(d, i, disabled ? -state : state); > > > + } > > > +} > > > + > > > > "if (!changed) return" check is in pci_set_irq(). > > So if d->irq_state[i] == 0, bus->set_irq() will be called again. > > I suppose this isn't your intention. > > Good catch, thanks! Thinking about this more, in fact, it is harmless to call set_irq with the same level as th old one, and this is not on datapath. So yes, this is the intention. > > I suppose !changed check should be in pci_change_irq_level() instead of pci_set_irq(). > > > > The fix is different: in fact pci_update_irq_disabled > should never call pci_change_irq_level with change value 0. > that -state should have been 1 - state. > I'll fix this. Thanks! In fact, you were right. While calling pci_change_irq_level with change 0 is harmless, it's cleaner to move the check within that function. I'll do that. > > > static void pci_device_reset(PCIDevice *dev) > > > { > > > int r; > > > > > > memset(dev->irq_state, 0, sizeof dev->irq_state); > > > dev->irq_status = 0; > > > + dev->irq_disabled = 0; > > > pci_update_irq_status(dev); > > > dev->config[PCI_COMMAND] &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | > > > PCI_COMMAND_MASTER); > > > @@ -345,6 +376,7 @@ int pci_device_load(PCIDevice *s, QEMUFile *f) > > > } > > > /* Restore the interrupt status bit. */ > > > pci_update_irq_status(s); > > > + pci_update_irq_disabled(s); > > > return ret; > > > } > > > > > > @@ -458,7 +490,8 @@ static void pci_init_wmask(PCIDevice *dev) > > > dev->wmask[PCI_CACHE_LINE_SIZE] = 0xff; > > > dev->wmask[PCI_INTERRUPT_LINE] = 0xff; > > > pci_set_word(dev->wmask + PCI_COMMAND, > > > - PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); > > > + PCI_COMMAND_IO | PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER | > > > + PCI_COMMAND_INTX_DISABLE); > > > > > > memset(dev->wmask + PCI_CONFIG_HEADER_SIZE, 0xff, > > > config_size - PCI_CONFIG_HEADER_SIZE); > > > @@ -903,26 +936,14 @@ void pci_default_write_config(PCIDevice *d, uint32_t addr, uint32_t val, int l) > > > ranges_overlap(addr, l, PCI_ROM_ADDRESS1, 4) || > > > range_covers_byte(addr, l, PCI_COMMAND)) > > > pci_update_mappings(d); > > > + > > > + if (range_covers_byte(addr, l, PCI_COMMAND)) > > > + pci_update_irq_disabled(d); > > > } > > > > > > /***********************************************************/ > > > /* generic PCI irq support */ > > > > > > -static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change) > > > -{ > > > - PCIBus *bus; > > > - for (;;) { > > > - bus = pci_dev->bus; > > > - irq_num = bus->map_irq(pci_dev, irq_num); > > > - if (bus->set_irq) > > > - break; > > > - pci_dev = bus->parent_dev; > > > - } > > > - bus->irq_count[irq_num] += change; > > > - bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0); > > > -} > > > - > > > - > > > /* 0 <= irq_num <= 3. level must be 0 or 1 */ > > > static void pci_set_irq(void *opaque, int irq_num, int level) > > > { > > > @@ -935,7 +956,9 @@ static void pci_set_irq(void *opaque, int irq_num, int level) > > > > > > pci_dev->irq_state[irq_num] = level; > > > pci_dev->irq_status += change; > > > - pci_update_irq_status(s); > > > + pci_update_irq_status(pci_dev); > > > + if (pci_dev->irq_disabled) > > > + return; > > > pci_change_irq_level(pci_dev, irq_num, change); > > > } > > > > > > diff --git a/hw/pci.h b/hw/pci.h > > > index c3f2c3f..994b8bc 100644 > > > --- a/hw/pci.h > > > +++ b/hw/pci.h > > > @@ -101,6 +101,7 @@ typedef struct PCIIORegion { > > > #define PCI_COMMAND_IO 0x1 /* Enable response in I/O space */ > > > #define PCI_COMMAND_MEMORY 0x2 /* Enable response in Memory space */ > > > #define PCI_COMMAND_MASTER 0x4 /* Enable bus master */ > > > +#define PCI_COMMAND_INTX_DISABLE 0x400 /* INTx Emulation Disable */ > > > #define PCI_STATUS 0x06 /* 16 bits */ > > > #define PCI_STATUS_INTERRUPT 0x08 > > > #define PCI_REVISION_ID 0x08 /* 8 bits */ > > > @@ -226,6 +227,9 @@ struct PCIDevice { > > > /* Sum of all irq levels. Used to implement irq status register. */ > > > int irq_status; > > > > > > + /* Whether interrupts are disabled by command bit. */ > > > + int irq_disabled; > > > + > > > /* Capability bits */ > > > uint32_t cap_present; > > > > > > > -- > > yamahata