pci: interrupt status bit implementation

interrupt status is a mandatory feature in PCI spec,
so devices must implement it to be spec compliant.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Isaku Yamahata <yamahata@valinux.co.jp>
This commit is contained in:
Michael S. Tsirkin 2009-11-25 15:44:40 +02:00
parent d036bb215e
commit f9bf77dd1f
2 changed files with 26 additions and 1 deletions

View File

@ -128,11 +128,23 @@ static void pci_change_irq_level(PCIDevice *pci_dev, int irq_num, int change)
bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0); bus->set_irq(bus->irq_opaque, irq_num, bus->irq_count[irq_num] != 0);
} }
/* Update interrupt status bit in config space on interrupt
* state change. */
static void pci_update_irq_status(PCIDevice *dev)
{
if (dev->irq_state) {
dev->config[PCI_STATUS] |= PCI_STATUS_INTERRUPT;
} else {
dev->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT;
}
}
static void pci_device_reset(PCIDevice *dev) static void pci_device_reset(PCIDevice *dev)
{ {
int r; int r;
dev->irq_state = 0; dev->irq_state = 0;
pci_update_irq_status(dev);
dev->config[PCI_COMMAND] &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY | dev->config[PCI_COMMAND] &= ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY |
PCI_COMMAND_MASTER); PCI_COMMAND_MASTER);
dev->config[PCI_CACHE_LINE_SIZE] = 0x0; dev->config[PCI_CACHE_LINE_SIZE] = 0x0;
@ -377,12 +389,23 @@ static inline const VMStateDescription *pci_get_vmstate(PCIDevice *s)
void pci_device_save(PCIDevice *s, QEMUFile *f) void pci_device_save(PCIDevice *s, QEMUFile *f)
{ {
/* Clear interrupt status bit: it is implicit
* in irq_state which we are saving.
* This makes us compatible with old devices
* which never set or clear this bit. */
s->config[PCI_STATUS] &= ~PCI_STATUS_INTERRUPT;
vmstate_save_state(f, pci_get_vmstate(s), s); vmstate_save_state(f, pci_get_vmstate(s), s);
/* Restore the interrupt status bit. */
pci_update_irq_status(s);
} }
int pci_device_load(PCIDevice *s, QEMUFile *f) int pci_device_load(PCIDevice *s, QEMUFile *f)
{ {
return vmstate_load_state(f, pci_get_vmstate(s), s, s->version_id); int ret;
ret = vmstate_load_state(f, pci_get_vmstate(s), s, s->version_id);
/* Restore the interrupt status bit. */
pci_update_irq_status(s);
return ret;
} }
static int pci_set_default_subsystem_id(PCIDevice *pci_dev) static int pci_set_default_subsystem_id(PCIDevice *pci_dev)
@ -955,6 +978,7 @@ static void pci_set_irq(void *opaque, int irq_num, int level)
return; return;
pci_set_irq_state(pci_dev, irq_num, level); pci_set_irq_state(pci_dev, irq_num, level);
pci_update_irq_status(pci_dev);
pci_change_irq_level(pci_dev, irq_num, change); pci_change_irq_level(pci_dev, irq_num, change);
} }

View File

@ -102,6 +102,7 @@ typedef struct PCIIORegion {
#define PCI_COMMAND_MEMORY 0x2 /* Enable response in Memory space */ #define PCI_COMMAND_MEMORY 0x2 /* Enable response in Memory space */
#define PCI_COMMAND_MASTER 0x4 /* Enable bus master */ #define PCI_COMMAND_MASTER 0x4 /* Enable bus master */
#define PCI_STATUS 0x06 /* 16 bits */ #define PCI_STATUS 0x06 /* 16 bits */
#define PCI_STATUS_INTERRUPT 0x08
#define PCI_REVISION_ID 0x08 /* 8 bits */ #define PCI_REVISION_ID 0x08 /* 8 bits */
#define PCI_CLASS_PROG 0x09 /* Reg. Level Programming Interface */ #define PCI_CLASS_PROG 0x09 /* Reg. Level Programming Interface */
#define PCI_CLASS_DEVICE 0x0a /* Device class */ #define PCI_CLASS_DEVICE 0x0a /* Device class */