[PATCH] powerpc: Add legacy PCI access via sysfs (v3)
Benjamin Herrenschmidt
benh at kernel.crashing.org
Tue Oct 14 11:55:31 EST 2008
This patch adds support for legacy_io and legacy_mem files in
bus class directories in sysfs for powerpc
Signed-off-by: Benjamin Herrenschmidt <benh at kernel.crashing.org>
---
This is version 3, this time after doing a "quilt ref" and thus
getting a patch that actually useful. Sorry about the mishap.
arch/powerpc/include/asm/pci-bridge.h | 7 +
arch/powerpc/include/asm/pci.h | 11 ++
arch/powerpc/kernel/pci-common.c | 136 +++++++++++++++++++++++++++++++++-
3 files changed, 153 insertions(+), 1 deletion(-)
--- linux-work.orig/arch/powerpc/include/asm/pci.h 2008-10-03 19:47:08.000000000 +1000
+++ linux-work/arch/powerpc/include/asm/pci.h 2008-10-10 10:50:46.000000000 +1100
@@ -123,6 +123,16 @@ int pci_mmap_page_range(struct pci_dev *
/* Tell drivers/pci/proc.c that we have pci_mmap_page_range() */
#define HAVE_PCI_MMAP 1
+extern int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val,
+ size_t count);
+extern int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val,
+ size_t count);
+extern int pci_mmap_legacy_page_range(struct pci_bus *bus,
+ struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state);
+
+#define HAVE_PCI_LEGACY 1
+
#if defined(CONFIG_PPC64) || defined(CONFIG_NOT_COHERENT_CACHE)
/*
* For 64-bit kernels, pci_unmap_{single,page} is not a nop.
@@ -226,5 +236,6 @@ extern void pci_resource_to_user(const s
extern void pcibios_do_bus_setup(struct pci_bus *bus);
extern void pcibios_fixup_of_probed_bus(struct pci_bus *bus);
+
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_PCI_H */
Index: linux-work/arch/powerpc/kernel/pci-common.c
===================================================================
--- linux-work.orig/arch/powerpc/kernel/pci-common.c 2008-10-03 19:47:08.000000000 +1000
+++ linux-work/arch/powerpc/kernel/pci-common.c 2008-10-14 11:32:38.000000000 +1100
@@ -452,7 +452,8 @@ pgprot_t pci_phys_mem_access_prot(struct
pci_dev_put(pdev);
}
- DBG("non-PCI map for %lx, prot: %lx\n", offset, prot);
+ DBG("non-PCI map for %llx, prot: %lx\n",
+ (unsigned long long)offset, prot);
return __pgprot(prot);
}
@@ -491,6 +492,131 @@ int pci_mmap_page_range(struct pci_dev *
return ret;
}
+/* This provides legacy IO read access on a bus */
+int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
+{
+ unsigned long offset;
+ struct pci_controller *hose = pci_bus_to_host(bus);
+ struct resource *rp = &hose->io_resource;
+ void __iomem *addr;
+
+ /* Check if port can be supported by that bus. We only check
+ * the ranges of the PHB though, not the bus itself as the rules
+ * for forwarding legacy cycles down bridges are not our problem
+ * here. So if the host bridge supports it, we do it.
+ */
+ offset = (unsigned long)hose->io_base_virt - _IO_BASE;
+ offset += port;
+
+ if (!(rp->flags & IORESOURCE_IO))
+ return -ENXIO;
+ if (offset < rp->start || (offset + size) > rp->end)
+ return -ENXIO;
+ addr = hose->io_base_virt + port;
+
+ switch(size) {
+ case 1:
+ *((u8 *)val) = in_8(addr);
+ return 1;
+ case 2:
+ if (port & 1)
+ return -EINVAL;
+ *((u16 *)val) = in_le16(addr);
+ return 2;
+ case 4:
+ if (port & 3)
+ return -EINVAL;
+ *((u32 *)val) = in_le32(addr);
+ return 4;
+ }
+ return -EINVAL;
+}
+
+/* This provides legacy IO write access on a bus */
+int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
+{
+ unsigned long offset;
+ struct pci_controller *hose = pci_bus_to_host(bus);
+ struct resource *rp = &hose->io_resource;
+ void __iomem *addr;
+
+ /* Check if port can be supported by that bus. We only check
+ * the ranges of the PHB though, not the bus itself as the rules
+ * for forwarding legacy cycles down bridges are not our problem
+ * here. So if the host bridge supports it, we do it.
+ */
+ offset = (unsigned long)hose->io_base_virt - _IO_BASE;
+ offset += port;
+
+ if (!(rp->flags & IORESOURCE_IO))
+ return -ENXIO;
+ if (offset < rp->start || (offset + size) > rp->end)
+ return -ENXIO;
+ addr = hose->io_base_virt + port;
+
+ /* WARNING: The generic code is idiotic. It gets passed a pointer
+ * to what can be a 1, 2 or 4 byte quantity and always reads that
+ * as a u32, which means that we have to correct the location of
+ * the data read within those 32 bits for size 1 and 2
+ */
+ switch(size) {
+ case 1:
+ out_8(addr, val >> 24);
+ return 1;
+ case 2:
+ if (port & 1)
+ return -EINVAL;
+ out_le16(addr, val >> 16);
+ return 2;
+ case 4:
+ if (port & 3)
+ return -EINVAL;
+ out_le32(addr, val);
+ return 4;
+ }
+ return -EINVAL;
+}
+
+/* This provides legacy IO or memory mmap access on a bus */
+int pci_mmap_legacy_page_range(struct pci_bus *bus,
+ struct vm_area_struct *vma,
+ enum pci_mmap_state mmap_state)
+{
+ struct pci_controller *hose = pci_bus_to_host(bus);
+ resource_size_t offset =
+ ((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
+ resource_size_t size = vma->vm_end - vma->vm_start;
+ struct resource *rp;
+
+ pr_debug("pci_mmap_legacy_page_range(%04x:%02x, %s @%llx..%llx)\n",
+ pci_domain_nr(bus), bus->number,
+ mmap_state == pci_mmap_mem ? "MEM" : "IO",
+ (unsigned long long)offset,
+ (unsigned long long)(offset + size - 1));
+
+ if (mmap_state == pci_mmap_mem) {
+ if ((offset + size) > hose->isa_mem_size)
+ return -ENXIO;
+ offset += hose->isa_mem_phys;
+ } else {
+ unsigned long io_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
+ unsigned long roffset = offset + io_offset;
+ rp = &hose->io_resource;
+ if (!(rp->flags & IORESOURCE_IO))
+ return -ENXIO;
+ if (roffset < rp->start || (roffset + size) > rp->end)
+ return -ENXIO;
+ offset += hose->io_base_phys;
+ }
+ pr_debug(" -> mapping phys %llx\n", (unsigned long long)offset);
+
+ vma->vm_pgoff = offset >> PAGE_SHIFT;
+ vma->vm_page_prot |= _PAGE_NO_CACHE | _PAGE_GUARDED;
+ return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
void pci_resource_to_user(const struct pci_dev *dev, int bar,
const struct resource *rsrc,
resource_size_t *start, resource_size_t *end)
@@ -593,6 +719,12 @@ void __devinit pci_process_bridge_OF_ran
cpu_addr = of_translate_address(dev, ranges + 3);
size = of_read_number(ranges + pna + 3, 2);
ranges += np;
+
+ /* If we failed translation or got a zero-sized region
+ * (some FW try to feed us with non sensical zero sized regions
+ * such as power3 which look like some kind of attempt at exposing
+ * the VGA memory hole)
+ */
if (cpu_addr == OF_BAD_ADDR || size == 0)
continue;
@@ -666,6 +798,8 @@ void __devinit pci_process_bridge_OF_ran
isa_hole = memno;
if (primary || isa_mem_base == 0)
isa_mem_base = cpu_addr;
+ hose->isa_mem_phys = cpu_addr;
+ hose->isa_mem_size = size;
}
/* We get the PCI/Mem offset from the first range or
Index: linux-work/arch/powerpc/include/asm/pci-bridge.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/pci-bridge.h 2008-10-09 16:13:40.000000000 +1100
+++ linux-work/arch/powerpc/include/asm/pci-bridge.h 2008-10-09 16:15:04.000000000 +1100
@@ -74,6 +74,13 @@ struct pci_controller {
unsigned long pci_io_size;
#endif
+ /* Some machines have a special region to forward the ISA
+ * "memory" cycles such as VGA memory regions. Left to 0
+ * if unsupported
+ */
+ resource_size_t isa_mem_phys;
+ resource_size_t isa_mem_size;
+
struct pci_ops *ops;
unsigned int __iomem *cfg_addr;
void __iomem *cfg_data;
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