On Tue, Feb 16, 2016 at 02:53:39PM +0100, Tomasz Nowicki wrote:
We use generic accessors from access.c by default. However, we already know platforms that need special handling while accessing to PCI config space. These platforms will need different accessors set matched against platform ID, domain, bus touple. Therefore we are going to add (in future) DECLARE_ACPI_MCFG_FIXUP which will register platform specific custom accessors. For now, we let pci_mcfg_get_ops to take acpi_pci_root structure as an arguments and left some space for quirk matching algorithm.
You should not describe the future (because you do not know if/when that will be implemented), you should describe what the patch does in its current form.
"This patch implements MCFG based PCI bus operations through MCFG map function and generic PCI accessors".
Signed-off-by: Tomasz Nowicki tn@semihalf.com Tested-by: Duc Dang dhdang@apm.com Tested-by: Dongdong Liu liudongdong3@huawei.com Tested-by: Hanjun Guo hanjun.guo@linaro.org Tested-by: Graeme Gregory graeme.gregory@linaro.org Tested-by: Sinan Kaya okaya@codeaurora.org
drivers/acpi/pci_mcfg.c | 30 ++++++++++++++++++++++++++++++ include/linux/pci-acpi.h | 12 ++++++++++++ 2 files changed, 42 insertions(+)
diff --git a/drivers/acpi/pci_mcfg.c b/drivers/acpi/pci_mcfg.c index 3282f2a..0062257 100644 --- a/drivers/acpi/pci_mcfg.c +++ b/drivers/acpi/pci_mcfg.c @@ -41,6 +41,36 @@ int __weak raw_pci_write(unsigned int domain, unsigned int bus, return PCIBIOS_DEVICE_NOT_FOUND; } +void __iomem * +pci_mcfg_dev_base(struct pci_bus *bus, unsigned int devfn, int offset) +{
- struct pci_mmcfg_region *cfg;
- cfg = pci_mmconfig_lookup(pci_domain_nr(bus), bus->number);
- if (cfg && cfg->virt)
return cfg->virt +(PCI_MMCFG_BUS_OFFSET(bus->number) | (devfn << 12)) +offset;- return NULL;
+}
+/* Default generic PCI config accessors */ +static struct pci_ops default_pci_mcfg_ops = {
- .map_bus = pci_mcfg_dev_base,
- .read = pci_generic_config_read,
- .write = pci_generic_config_write,
+};
Nit: s/default_pci_mcfg_ops/pci_mcfg_ops
+struct pci_ops *pci_mcfg_get_ops(struct acpi_pci_root *root) +{
- /*
* TODO: Match against platform specific quirks and return* corresponding PCI config space accessor set.*/
Remove this comment, see above.
- return &default_pci_mcfg_ops;
See above.
+}
static void list_add_sorted(struct pci_mmcfg_region *new) { struct pci_mmcfg_region *cfg; diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h index b4f87ba9..3dc6a8c 100644 --- a/include/linux/pci-acpi.h +++ b/include/linux/pci-acpi.h @@ -141,6 +141,18 @@ extern struct list_head pci_mmcfg_list; #define PCI_MMCFG_BUS_OFFSET(bus) ((bus) << 20) #define PCI_MMCFG_OFFSET(bus, devfn) ((bus) << 20 | (devfn) << 12) +#ifdef CONFIG_PCI_MMCONFIG +extern struct pci_ops *pci_mcfg_get_ops(struct acpi_pci_root *root); +extern void __iomem *pci_mcfg_dev_base(struct pci_bus *bus, unsigned int devfn,
int offset);+#else +static inline struct pci_ops *pci_mcfg_get_ops(struct acpi_pci_root *root) +{ return NULL; } +static inline void __iomem *pci_mcfg_dev_base(struct pci_bus *bus,
unsigned int devfn, int offset)+{ return NULL; } +#endif
#else /* CONFIG_ACPI */ static inline void acpi_pci_add_bus(struct pci_bus *bus) { } static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
I think it can even be squashed, anyway:
Reviewed-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com