[PATCH V8 4/9] acpi, pci: Support IO resources when parsing PCI host bridge resources.

Tomasz Nowicki
2016-05-30T15:15:09Z

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.

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. As a consequence we unmap I/O resources
with pci_unmap_iospace when we release host bridge resources.

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 | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index ae3fe4e..ee3b728 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -720,6 +720,40 @@ next:
}
}

+#ifdef PCI_IOBASE
+static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+{
+ 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;
+}
+#else
+static void acpi_pci_root_remap_iospace(struct resource_entry *entry)
+{
+}
+#endif
+
int acpi_pci_probe_root_resources(struct acpi_pci_root_info *info)
{
int ret;
@@ -740,6 +774,9 @@ 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
@@ -811,6 +848,8 @@ 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);
--
1.9.1