Platforms that have memory mapped IO port (such as ARM64) need special handling for PCI I/O resources. For host bridge's resource probing case these resources need to be fixed up with pci_register_io_range/pci_remap_iospace etc.
Furthermore, the same I/O resources need to be released after hotplug removal so that it can be re-added back by the pci_remap_iospace function during insertion. Therefore we implement new pci_unmap_iospace call which unmaps I/O space as the symmetry to pci_remap_iospace.
Signed-off-by: Jayachandran C jchandra@broadcom.com Signed-off-by: Sinan Kaya okaya@codeaurora.org Signed-off-by: Tomasz Nowicki tn@semihalf.com --- drivers/acpi/pci_root.c | 33 +++++++++++++++++++++++++++++++++ drivers/pci/pci.c | 24 ++++++++++++++++++++++++ include/linux/pci.h | 1 + 3 files changed, 58 insertions(+)
diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c index d9a70c4..815b6ca 100644 --- a/drivers/acpi/pci_root.c +++ b/drivers/acpi/pci_root.c @@ -742,6 +742,34 @@ next: resource_list_add_tail(entry, resources); } } +static void acpi_pci_root_remap_iospace(struct resource_entry *entry) +{ +#ifdef PCI_IOBASE + struct resource *res = entry->res; + resource_size_t cpu_addr = res->start; + resource_size_t pci_addr = cpu_addr - entry->offset; + resource_size_t length = resource_size(res); + unsigned long port; + + if (pci_register_io_range(cpu_addr, length)) + goto err; + + port = pci_address_to_pio(cpu_addr); + if (port == (unsigned long)-1) + goto err; + + res->start = port; + res->end = port + length - 1; + entry->offset = port - pci_addr; + + if (pci_remap_iospace(res, cpu_addr) < 0) + goto err; + pr_info("Remapped I/O %pa to %pR\n", &cpu_addr, res); + return; +err: + res->flags |= IORESOURCE_DISABLED; +#endif +}
int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info) { @@ -763,6 +791,9 @@ int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info) "no IO and memory resources present in _CRS\n"); else { resource_list_for_each_entry_safe(entry, tmp, list) { + if (entry->res->flags & IORESOURCE_IO) + acpi_pci_root_remap_iospace(entry); + if (entry->res->flags & IORESOURCE_DISABLED) resource_list_destroy_entry(entry); else @@ -834,6 +865,8 @@ static void acpi_pci_root_release_info(struct pci_host_bridge *bridge)
resource_list_for_each_entry(entry, &bridge->windows) { res = entry->res; + if (res->flags & IORESOURCE_IO) + pci_unmap_iospace(res); if (res->parent && (res->flags & (IORESOURCE_MEM | IORESOURCE_IO))) release_resource(res); diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 89e9996..c0f8a4e 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -26,6 +26,7 @@ #include <linux/device.h> #include <linux/pm_runtime.h> #include <linux/pci_hotplug.h> +#include <linux/vmalloc.h> #include <asm/setup.h> #include <linux/aer.h> #include "pci.h" @@ -3168,6 +3169,29 @@ int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) #endif }
+/** + * pci_unmap_iospace - Unmap the memory mapped I/O space + * @res: resource to be unmapped + * + * Unmap the CPU virtual address @res from virtual address space. + * Only architectures that have memory mapped IO functions defined + * (and the PCI_IOBASE value defined) should call this function. + */ +void pci_unmap_iospace(struct resource *res) +{ +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; + + unmap_kernel_range(vaddr, resource_size(res)); +#else + /* + * This architecture does not have memory mapped I/O space, + * so this function should never be called. + */ + WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); +#endif +} + static void __pci_set_master(struct pci_dev *dev, bool enable) { u16 old_cmd, cmd; diff --git a/include/linux/pci.h b/include/linux/pci.h index c28adb4..df1f33d 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1168,6 +1168,7 @@ int pci_register_io_range(phys_addr_t addr, resource_size_t size); unsigned long pci_address_to_pio(phys_addr_t addr); phys_addr_t pci_pio_to_address(unsigned long pio); int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); +void pci_unmap_iospace(struct resource *res);
static inline pci_bus_addr_t pci_bus_address(struct pci_dev *pdev, int bar) {