Many PCI controllers' configuration space accesses are memory mapped
varying only in address calculation and access checks. There are 2 main
access methods: a decoded address space such as ECAM or a single address
and data register similar to x86. This implementation can support both
cases as well as be used in cases that need additional pre or post access
handling.
A new pci_ops member map_bus is introduced which can do access checks and
any necessary setup. It returns the address to use for the configuration
space access. The access types supported are 32-bit only accesses or
correct byte, word, or dword sized accesses.
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
I've converted a few drivers already. I'll send patches for them after
some feedback on this. Most already have some function similar to what is
needed for map_bus, so the conversion is pretty simple. This certainly
isn't a complete list of possible users. The diffstat so far looks like
this:
arch/arm/mach-cns3xxx/pcie.c | 46 +++-------------------
arch/arm/mach-integrator/pci_v3.c | 61 +++---------------------------
arch/arm/mach-ks8695/pci.c | 75 +++---------------------------------
arch/arm/mach-sa1100/pci-nanoengine.c | 94 ++++-----------------------------------------
arch/powerpc/platforms/powermac/pci.c | 206 +++++++++++++++++++--------------------------------------------------------------------------------
arch/powerpc/sysdev/fsl_pci.c | 46 ++--------------------
drivers/pci/host/pci-host-generic.c | 51 ++-----------------------
drivers/pci/host/pci-rcar-gen2.c | 51 ++-----------------------
drivers/pci/host/pci-tegra.c | 55 ++-------------------------
drivers/pci/host/pci-xgene.c | 150 +++++-------------------------------------------------------------------
drivers/pci/host/pcie-xilinx.c | 88 +++++-------------------------------------
11 files changed, 93 insertions(+), 830 deletions(-)
Rob
drivers/pci/access.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/pci.h | 11 +++++++
2 files changed, 94 insertions(+)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 49dd766..9a29f7a 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -67,6 +67,89 @@ EXPORT_SYMBOL(pci_bus_write_config_byte);
EXPORT_SYMBOL(pci_bus_write_config_word);
EXPORT_SYMBOL(pci_bus_write_config_dword);
+int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ void __iomem *addr;
+
+ addr = bus->ops->map_bus(bus, devfn, where);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ if (size == 1)
+ *val = readb(addr);
+ else if (size == 2)
+ *val = readw(addr);
+ else
+ *val = readl(addr);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ void __iomem *addr;
+
+ addr = bus->ops->map_bus(bus, devfn, where);
+ if (!addr)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (size == 1)
+ writeb(val, addr);
+ else if (size == 2)
+ writew(val, addr);
+ else
+ writel(val, addr);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val)
+{
+ void __iomem *addr;
+
+ addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
+ if (!addr) {
+ *val = ~0;
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ }
+
+ *val = readl(addr);
+
+ if (size <= 2)
+ *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
+int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val)
+{
+ void __iomem *addr;
+ u32 mask, tmp;
+
+ addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
+ if (!addr)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+
+ if (size == 4) {
+ writel(val, addr);
+ return PCIBIOS_SUCCESSFUL;
+ } else {
+ mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
+ }
+
+ tmp = readl(addr) & mask;
+ tmp |= val << ((where & 0x3) * 8);
+ writel(tmp, addr);
+
+ return PCIBIOS_SUCCESSFUL;
+}
+
/**
* pci_bus_set_ops - Set raw operations of pci bus
* @bus: pci bus struct
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 360a966..e7fd519 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -560,6 +560,7 @@ static inline int pcibios_err_to_errno(int err)
/* Low-level architecture-dependent routines */
struct pci_ops {
+ void __iomem *(*map_bus)(struct pci_bus *bus, unsigned int devfn, int where);
int (*read)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val);
int (*write)(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val);
};
@@ -857,6 +858,16 @@ int pci_bus_write_config_word(struct pci_bus *bus, unsigned int devfn,
int where, u16 val);
int pci_bus_write_config_dword(struct pci_bus *bus, unsigned int devfn,
int where, u32 val);
+
+int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val);
+int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val);
+int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 *val);
+int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
+ int where, int size, u32 val);
+
struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops);
static inline int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
--
2.1.0
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