From f9b71fef12f0d6ac5c7051cfd87f7700f78c56b6 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 22 Aug 2013 17:47:48 +0100 Subject: [PATCH 1/3] ARM: PCI: versatile: Fix map_irq function to match hardware The PCI controller code for the Versatile board has never had the correct IRQ mapping for hardware. For many years it had an odd mapping ("all interrupts are int 27") which aligned with the equivalent bug in QEMU. However as of commit 1bc39ac5dab265 the mapping changed and no longer matched either hardware or QEMU, with the result that any PCI card beyond the first in QEMU would not have functioning interrupts; for example a boot with a SCSI controller would time out as follows: ------------ sym0: <895a> rev 0x0 at pci 0000:00:0d.0 irq 92 sym0: SCSI BUS has been reset. scsi0 : sym-2.2.3 [...] scsi 0:0:0:0: ABORT operation started scsi 0:0:0:0: ABORT operation timed-out. scsi 0:0:0:0: DEVICE RESET operation started scsi 0:0:0:0: DEVICE RESET operation timed-out. scsi 0:0:0:0: BUS RESET operation started scsi 0:0:0:0: BUS RESET operation timed-out. scsi 0:0:0:0: HOST RESET operation started sym0: SCSI BUS has been reset ------------ Fix the mapping so that it matches real hardware (checked against the schematics for PB926 and backplane, and tested against the hardware). This allows PCI cards using interrupts to work on hardware for the first time; this change will also work with QEMU 1.5 or later, where the equivalent bugs in the modelling of the hardware have been fixed. Although QEMU will attempt to autodetect whether the kernel is expecting the long-standing "everything is int 27" mapping or the one hardware has, for certainty we force it into "definitely behave like hardware mode"; this will avoid unexpected surprises later if we implement sparse irqs. This is harmless on hardware. Thanks to Paul Gortmaker for bisecting the problem and finding an initial solution, to Russell King for providing the correct interrupt mapping, and to Guenter Roeck for providing an initial version of this patch and prodding me into relocating the hardware and retesting everything. Signed-off-by: Peter Maydell Cc: stable@vger.kernel.org Reviewed-by: Linus Walleij Signed-off-by: Kevin Hilman --- arch/arm/mach-versatile/pci.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c index e92e5e0705bc..234740d90385 100644 --- a/arch/arm/mach-versatile/pci.c +++ b/arch/arm/mach-versatile/pci.c @@ -294,6 +294,19 @@ int __init pci_versatile_setup(int nr, struct pci_sys_data *sys) __raw_writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_1); __raw_writel(PHYS_OFFSET, local_pci_cfg_base + PCI_BASE_ADDRESS_2); + /* + * For many years the kernel and QEMU were symbiotically buggy + * in that they both assumed the same broken IRQ mapping. + * QEMU therefore attempts to auto-detect old broken kernels + * so that they still work on newer QEMU as they did on old + * QEMU. Since we now use the correct (ie matching-hardware) + * IRQ mapping we write a definitely different value to a + * PCI_INTERRUPT_LINE register to tell QEMU that we expect + * real hardware behaviour and it need not be backwards + * compatible for us. This write is harmless on real hardware. + */ + __raw_writel(0, VERSATILE_PCI_VIRT_BASE+PCI_INTERRUPT_LINE); + /* * Do not to map Versatile FPGA PCI device into memory space */ @@ -327,13 +340,13 @@ static int __init versatile_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) { int irq; - /* slot, pin, irq - * 24 1 IRQ_SIC_PCI0 - * 25 1 IRQ_SIC_PCI1 - * 26 1 IRQ_SIC_PCI2 - * 27 1 IRQ_SIC_PCI3 + /* + * Slot INTA INTB INTC INTD + * 31 PCI1 PCI2 PCI3 PCI0 + * 30 PCI0 PCI1 PCI2 PCI3 + * 29 PCI3 PCI0 PCI1 PCI2 */ - irq = IRQ_SIC_PCI0 + ((slot - 24 + pin - 1) & 3); + irq = IRQ_SIC_PCI0 + ((slot + 2 + pin - 1) & 3); return irq; } From 829f9fedee30cde2ec15e88d57ec11074db791e2 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 22 Aug 2013 17:47:49 +0100 Subject: [PATCH 2/3] ARM: PCI: versatile: Fix PCI I/O The versatile PCI controller code was confused between the PCI I/O window (at 0x43000000) and the first PCI memory window (at 0x44000000). Pass the correct base address to pci_remap_io() so that PCI I/O accesses work. Since the first PCI memory window isn't used at all (it's an odd size), rename the associated variables and labels so that it's clear that it isn't related to the I/O window. This has been tested and confirmed to fix PCI I/O accesses both on physical PB926+PCI backplane hardware and on QEMU. Signed-off-by: Peter Maydell Cc: stable@vger.kernel.org Reviewed-by: Linus Walleij Signed-off-by: Kevin Hilman --- arch/arm/mach-versatile/include/mach/platform.h | 2 ++ arch/arm/mach-versatile/pci.c | 16 ++++++++-------- 2 files changed, 10 insertions(+), 8 deletions(-) diff --git a/arch/arm/mach-versatile/include/mach/platform.h b/arch/arm/mach-versatile/include/mach/platform.h index ec087407b163..6f938ccb0c54 100644 --- a/arch/arm/mach-versatile/include/mach/platform.h +++ b/arch/arm/mach-versatile/include/mach/platform.h @@ -231,12 +231,14 @@ /* PCI space */ #define VERSATILE_PCI_BASE 0x41000000 /* PCI Interface */ #define VERSATILE_PCI_CFG_BASE 0x42000000 +#define VERSATILE_PCI_IO_BASE 0x43000000 #define VERSATILE_PCI_MEM_BASE0 0x44000000 #define VERSATILE_PCI_MEM_BASE1 0x50000000 #define VERSATILE_PCI_MEM_BASE2 0x60000000 /* Sizes of above maps */ #define VERSATILE_PCI_BASE_SIZE 0x01000000 #define VERSATILE_PCI_CFG_BASE_SIZE 0x02000000 +#define VERSATILE_PCI_IO_BASE_SIZE 0x01000000 #define VERSATILE_PCI_MEM_BASE0_SIZE 0x0c000000 /* 32Mb */ #define VERSATILE_PCI_MEM_BASE1_SIZE 0x10000000 /* 256Mb */ #define VERSATILE_PCI_MEM_BASE2_SIZE 0x10000000 /* 256Mb */ diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c index 234740d90385..1e48878cc768 100644 --- a/arch/arm/mach-versatile/pci.c +++ b/arch/arm/mach-versatile/pci.c @@ -170,8 +170,8 @@ static struct pci_ops pci_versatile_ops = { .write = versatile_write_config, }; -static struct resource io_mem = { - .name = "PCI I/O space", +static struct resource unused_mem = { + .name = "PCI unused", .start = VERSATILE_PCI_MEM_BASE0, .end = VERSATILE_PCI_MEM_BASE0+VERSATILE_PCI_MEM_BASE0_SIZE-1, .flags = IORESOURCE_MEM, @@ -195,9 +195,9 @@ static int __init pci_versatile_setup_resources(struct pci_sys_data *sys) { int ret = 0; - ret = request_resource(&iomem_resource, &io_mem); + ret = request_resource(&iomem_resource, &unused_mem); if (ret) { - printk(KERN_ERR "PCI: unable to allocate I/O " + printk(KERN_ERR "PCI: unable to allocate unused " "memory region (%d)\n", ret); goto out; } @@ -205,7 +205,7 @@ static int __init pci_versatile_setup_resources(struct pci_sys_data *sys) if (ret) { printk(KERN_ERR "PCI: unable to allocate non-prefetchable " "memory region (%d)\n", ret); - goto release_io_mem; + goto release_unused_mem; } ret = request_resource(&iomem_resource, &pre_mem); if (ret) { @@ -225,8 +225,8 @@ static int __init pci_versatile_setup_resources(struct pci_sys_data *sys) release_non_mem: release_resource(&non_mem); - release_io_mem: - release_resource(&io_mem); + release_unused_mem: + release_resource(&unused_mem); out: return ret; } @@ -246,7 +246,7 @@ int __init pci_versatile_setup(int nr, struct pci_sys_data *sys) goto out; } - ret = pci_ioremap_io(0, VERSATILE_PCI_MEM_BASE0); + ret = pci_ioremap_io(0, VERSATILE_PCI_IO_BASE); if (ret) goto out; From 99f2b130370b904ca5300079243fdbcafa2c708b Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 22 Aug 2013 17:47:50 +0100 Subject: [PATCH 3/3] ARM: PCI: versatile: Fix SMAP register offsets The SMAP register offsets in the versatile PCI controller code were all off by four. (This didn't have any observable bad effects because on this board PHYS_OFFSET is zero, and (a) writing zero to the flags register at offset 0x10 has no effect and (b) the reset value of the SMAP register is zero anyway, so failing to write SMAP2 didn't matter.) Signed-off-by: Peter Maydell Cc: stable@vger.kernel.org Reviewed-by: Linus Walleij Signed-off-by: Kevin Hilman --- arch/arm/mach-versatile/pci.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-versatile/pci.c b/arch/arm/mach-versatile/pci.c index 1e48878cc768..c97be4ea76d2 100644 --- a/arch/arm/mach-versatile/pci.c +++ b/arch/arm/mach-versatile/pci.c @@ -43,9 +43,9 @@ #define PCI_IMAP0 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x0) #define PCI_IMAP1 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x4) #define PCI_IMAP2 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x8) -#define PCI_SMAP0 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x10) -#define PCI_SMAP1 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x14) -#define PCI_SMAP2 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x18) +#define PCI_SMAP0 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x14) +#define PCI_SMAP1 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x18) +#define PCI_SMAP2 __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0x1c) #define PCI_SELFID __IO_ADDRESS(VERSATILE_PCI_CORE_BASE+0xc) #define DEVICE_ID_OFFSET 0x00