diff options
| -rw-r--r-- | hw/pci-host/versatile.c | 105 |
1 files changed, 99 insertions, 6 deletions
diff --git a/hw/pci-host/versatile.c b/hw/pci-host/versatile.c index 8f8612c..5d543a9 100644 --- a/hw/pci-host/versatile.c +++ b/hw/pci-host/versatile.c @@ -13,6 +13,28 @@ #include "hw/pci/pci_host.h" #include "exec/address-spaces.h" +/* Old and buggy versions of QEMU used the wrong mapping from + * PCI IRQs to system interrupt lines. Unfortunately the Linux + * kernel also had the corresponding bug in setting up interrupts + * (so older kernels work on QEMU and not on real hardware). + * We automatically detect these broken kernels and flip back + * to the broken irq mapping by spotting guest writes to the + * PCI_INTERRUPT_LINE register to see where the guest thinks + * interrupts are going to be routed. So we start in state + * ASSUME_OK on reset, and transition to either BROKEN or + * FORCE_OK at the first write to an INTERRUPT_LINE register for + * a slot where broken and correct interrupt mapping would differ. + * Once in either BROKEN or FORCE_OK we never transition again; + * this allows a newer kernel to use the INTERRUPT_LINE + * registers arbitrarily once it has indicated that it isn't + * broken in its init code somewhere. + */ +enum { + PCI_VPB_IRQMAP_ASSUME_OK, + PCI_VPB_IRQMAP_BROKEN, + PCI_VPB_IRQMAP_FORCE_OK, +}; + typedef struct { PCIHostState parent_obj; @@ -26,6 +48,9 @@ typedef struct { /* Constant for life of device: */ int realview; + + /* Variable state: */ + uint8_t irq_mapping; } PCIVPBState; #define TYPE_VERSATILE_PCI "versatile_pci" @@ -44,14 +69,27 @@ static inline uint32_t vpb_pci_config_addr(hwaddr addr) static void pci_vpb_config_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) { - pci_data_write(opaque, vpb_pci_config_addr(addr), val, size); + PCIVPBState *s = opaque; + if (!s->realview && (addr & 0xff) == PCI_INTERRUPT_LINE + && s->irq_mapping == PCI_VPB_IRQMAP_ASSUME_OK) { + uint8_t devfn = addr >> 8; + if ((PCI_SLOT(devfn) % PCI_NUM_PINS) != 2) { + if (val == 27) { + s->irq_mapping = PCI_VPB_IRQMAP_BROKEN; + } else { + s->irq_mapping = PCI_VPB_IRQMAP_FORCE_OK; + } + } + } + pci_data_write(&s->pci_bus, vpb_pci_config_addr(addr), val, size); } static uint64_t pci_vpb_config_read(void *opaque, hwaddr addr, unsigned size) { + PCIVPBState *s = opaque; uint32_t val; - val = pci_data_read(opaque, vpb_pci_config_addr(addr), size); + val = pci_data_read(&s->pci_bus, vpb_pci_config_addr(addr), size); return val; } @@ -63,7 +101,47 @@ static const MemoryRegionOps pci_vpb_config_ops = { static int pci_vpb_map_irq(PCIDevice *d, int irq_num) { - return irq_num; + PCIVPBState *s = container_of(d->bus, PCIVPBState, pci_bus); + + if (s->irq_mapping == PCI_VPB_IRQMAP_BROKEN) { + /* Legacy broken IRQ mapping for compatibility with old and + * buggy Linux guests + */ + return irq_num; + } + + /* Slot to IRQ mapping for RealView Platform Baseboard 926 backplane + * name slot IntA IntB IntC IntD + * A 31 IRQ28 IRQ29 IRQ30 IRQ27 + * B 30 IRQ27 IRQ28 IRQ29 IRQ30 + * C 29 IRQ30 IRQ27 IRQ28 IRQ29 + * Slot C is for the host bridge; A and B the peripherals. + * Our output irqs 0..3 correspond to the baseboard's 27..30. + * + * This mapping function takes account of an oddity in the PB926 + * board wiring, where the FPGA's P_nINTA input is connected to + * the INTB connection on the board PCI edge connector, P_nINTB + * is connected to INTC, and so on, so everything is one number + * further round from where you might expect. + */ + return pci_swizzle_map_irq_fn(d, irq_num + 2); +} + +static int pci_vpb_rv_map_irq(PCIDevice *d, int irq_num) +{ + /* Slot to IRQ mapping for RealView EB and PB1176 backplane + * name slot IntA IntB IntC IntD + * A 31 IRQ50 IRQ51 IRQ48 IRQ49 + * B 30 IRQ49 IRQ50 IRQ51 IRQ48 + * C 29 IRQ48 IRQ49 IRQ50 IRQ51 + * Slot C is for the host bridge; A and B the peripherals. + * Our output irqs 0..3 correspond to the baseboard's 48..51. + * + * The PB1176 and EB boards don't have the PB926 wiring oddity + * described above; P_nINTA connects to INTA, P_nINTB to INTB + * and so on, which is why this mapping function is different. + */ + return pci_swizzle_map_irq_fn(d, irq_num + 3); } static void pci_vpb_set_irq(void *opaque, int irq_num, int level) @@ -73,6 +151,13 @@ static void pci_vpb_set_irq(void *opaque, int irq_num, int level) qemu_set_irq(pic[irq_num], level); } +static void pci_vpb_reset(DeviceState *d) +{ + PCIVPBState *s = PCI_VPB(d); + + s->irq_mapping = PCI_VPB_IRQMAP_ASSUME_OK; +} + static void pci_vpb_init(Object *obj) { PCIHostState *h = PCI_HOST_BRIDGE(obj); @@ -95,13 +180,20 @@ static void pci_vpb_realize(DeviceState *dev, Error **errp) { PCIVPBState *s = PCI_VPB(dev); SysBusDevice *sbd = SYS_BUS_DEVICE(dev); + pci_map_irq_fn mapfn; int i; for (i = 0; i < 4; i++) { sysbus_init_irq(sbd, &s->irq[i]); } - pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, pci_vpb_map_irq, s->irq, 4); + if (s->realview) { + mapfn = pci_vpb_rv_map_irq; + } else { + mapfn = pci_vpb_map_irq; + } + + pci_bus_irqs(&s->pci_bus, pci_vpb_set_irq, mapfn, s->irq, 4); /* ??? Register memory space. */ @@ -110,10 +202,10 @@ static void pci_vpb_realize(DeviceState *dev, Error **errp) * 1 : PCI config window * 2 : PCI IO window */ - memory_region_init_io(&s->mem_config, &pci_vpb_config_ops, &s->pci_bus, + memory_region_init_io(&s->mem_config, &pci_vpb_config_ops, s, "pci-vpb-selfconfig", 0x1000000); sysbus_init_mmio(sbd, &s->mem_config); - memory_region_init_io(&s->mem_config2, &pci_vpb_config_ops, &s->pci_bus, + memory_region_init_io(&s->mem_config2, &pci_vpb_config_ops, s, "pci-vpb-config", 0x1000000); sysbus_init_mmio(sbd, &s->mem_config2); @@ -159,6 +251,7 @@ static void pci_vpb_class_init(ObjectClass *klass, void *data) DeviceClass *dc = DEVICE_CLASS(klass); dc->realize = pci_vpb_realize; + dc->reset = pci_vpb_reset; } static const TypeInfo pci_vpb_info = { |