Merge branch 'versatile/fixes' into fixes

From Peter Maydell:
These patches fix a number of issues with the PCI controller
code for mach-versatile:

(1) The irq mapping matched neither hardware nor QEMU; we correct
it to match the hardware, which means it will also work on recent
(1.5 or later) QEMU.

(2) The code was confused between the PCI I/O window (at 0x43000000)
and the first PCI memory window (at 0x44000000), which meant that
PCI devices using PCI PIO rather than MMIO didn't work. This is
fixed (and some variables/labels are renamed to avoid further
confusion in future).

(3) The SMAP register offsets were all off-by-four, though by
fluke this didn't actually have any ill effects.

All these changes have been tested on real hardware (PB926
plus the PCI backplane), as well as on QEMU. I have confirmed
that IRQs and PCI PIO and MMIO work OK.

PCI bus-master DMA doesn't seem to work on h/w -- as far as I can
tell the device is correctly managing to DMA to the right places
in memory, but every other 32 bit word is corrupt (at least judging
from rtl8139 debug dumps of the frames it's receiving). I'm not
sure what's going on here, but since this is disjoint from
the irq and I/O issues I don't think that applying the
patches that fix those should be stalled on trying to debug
DMA problems. (DMA works fine on QEMU, incidentally.)

* versatile/fixes:
  ARM: PCI: versatile: Fix SMAP register offsets
  ARM: PCI: versatile: Fix PCI I/O
  ARM: PCI: versatile: Fix map_irq function to match hardware

Signed-off-by: Olof Johansson <olof@lixom.net>

2 files changed, 32 insertions, 17 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 e92e5e0705bc..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
@@ -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;
 
@@ -295,6 +295,19 @@ int __init pci_versatile_setup(int nr, struct pci_sys_data *sys)
         __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
          */
         pci_slot_ignore |= (1 << myslot);
@@ -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;
 }