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 <m...@redhat.com>
> > ---
> > 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!
> 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!
> > 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
