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authorTomasz Nowicki <tn@semihalf.com>2016-05-30 17:14:22 +0200
committerGraeme Gregory <graeme.gregory@linaro.org>2016-06-07 14:09:23 +0100
commite9ecc14f69837944becb3e1b34c4f30f9faeb038 (patch)
tree27e3f8f1e52a02b261323bee2e15108eb028e297
parentd495683e95654f5a6f4091fc9c5b2f4a3b7468c5 (diff)
downloadleg-kernel-e9ecc14f69837944becb3e1b34c4f30f9faeb038.tar.gz
pci, acpi: ARM64 support for ACPI based generic PCI host controller
This patch implements pci_acpi_scan_root call so that ARM64 can start using ACPI to setup and enumerate PCI buses. The implementation of pci_acpi_scan_root() looks up config space regions through MCFG interface. Then ECAM library is doing a new mapping and attach generic ECAM ops which are used for accessing config space. On ARM64, ACPI and DT can be enabled together, and in that case we need to use generic domains. In order to do that we implement ARM64 specific way of retrieving domain number from pci_config_window structure. Since we enable PCI for ACPI we need to implement raw_pci_{read|write} at the same time. ARM64 provides RAW accessors as long as there is correlated valid pci_bus structure, but not before. Signed-off-by: Tomasz Nowicki <tn@semihalf.com> Signed-off-by: Jayachandran C <jchandra@broadcom.com>
-rw-r--r--arch/arm64/Kconfig2
-rw-r--r--arch/arm64/kernel/pci.c120
-rw-r--r--include/linux/pci.h5
3 files changed, 122 insertions, 5 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 5a0a691d4220..4806cde37b5f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -3,6 +3,7 @@ config ARM64
select ACPI_CCA_REQUIRED if ACPI
select ACPI_GENERIC_GSI if ACPI
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
+ select ACPI_MCFG if ACPI
select ARCH_HAS_DEVMEM_IS_ALLOWED
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select ARCH_HAS_ELF_RANDOMIZE
@@ -96,6 +97,7 @@ config ARM64
select OF_EARLY_FLATTREE
select OF_NUMA if NUMA && OF
select OF_RESERVED_MEM
+ select PCI_ECAM if ACPI
select PERF_USE_VMALLOC
select POWER_RESET
select POWER_SUPPLY
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 3663be10d665..39f2a4064643 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -17,7 +17,9 @@
#include <linux/mm.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
+#include <linux/pci.h>
#include <linux/pci-acpi.h>
+#include <linux/pci-ecam.h>
#include <linux/slab.h>
/*
@@ -71,13 +73,21 @@ int pcibios_alloc_irq(struct pci_dev *dev)
int raw_pci_read(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *val)
{
- return -ENXIO;
+ struct pci_bus *b = pci_find_bus(domain, bus);
+
+ if (!b)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ return b->ops->read(b, devfn, reg, len, val);
}
int raw_pci_write(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 val)
{
- return -ENXIO;
+ struct pci_bus *b = pci_find_bus(domain, bus);
+
+ if (!b)
+ return PCIBIOS_DEVICE_NOT_FOUND;
+ return b->ops->write(b, devfn, reg, len, val);
}
#ifdef CONFIG_NUMA
@@ -91,11 +101,111 @@ EXPORT_SYMBOL(pcibus_to_node);
#endif
#ifdef CONFIG_ACPI
-/* Root bridge scanning */
+
+struct acpi_pci_generic_root_info {
+ struct acpi_pci_root_info common;
+ struct pci_config_window *cfg; /* config space mapping */
+};
+
+int acpi_pci_bus_domain_nr(struct pci_bus *bus)
+{
+ struct pci_config_window *cfg = bus->sysdata;
+ struct acpi_device *adev = to_acpi_device(cfg->parent);
+ struct acpi_pci_root *root = acpi_driver_data(adev);
+
+ return root->segment;
+}
+
+int pcibios_root_bridge_prepare(struct pci_host_bridge *bridge)
+{
+ if (!acpi_disabled) {
+ struct pci_config_window *cfg = bridge->bus->sysdata;
+ struct acpi_device *adev = to_acpi_device(cfg->parent);
+ ACPI_COMPANION_SET(&bridge->dev, adev);
+ }
+
+ return 0;
+}
+
+/*
+ * Lookup the bus range for the domain in MCFG, and set up config space
+ * mapping.
+ */
+static int pci_acpi_setup_ecam_mapping(struct acpi_pci_root *root,
+ struct acpi_pci_generic_root_info *ri)
+{
+ struct resource *bus_res = &root->secondary;
+ u16 seg = root->segment;
+ struct pci_config_window *cfg;
+ struct resource cfgres;
+ unsigned int bsz;
+ int err;
+
+ err = pci_mcfg_lookup(root);
+ if (err) {
+ pr_err("%04x:%pR MCFG region not found\n", seg, bus_res);
+ return err;
+ }
+
+ bsz = 1 << pci_generic_ecam_ops.bus_shift;
+ cfgres.start = root->mcfg_addr + bus_res->start * bsz;
+ cfgres.end = cfgres.start + resource_size(bus_res) * bsz - 1;
+ cfgres.flags = IORESOURCE_MEM;
+ cfg = pci_ecam_create(&root->device->dev, &cfgres, bus_res,
+ &pci_generic_ecam_ops);
+ if (IS_ERR(cfg)) {
+ pr_err("%04x:%pR error %ld mapping CAM\n", seg, bus_res,
+ PTR_ERR(cfg));
+ return PTR_ERR(cfg);
+ }
+
+ ri->cfg = cfg;
+ return 0;
+}
+
+/* release_info: free resrouces allocated by init_info */
+static void pci_acpi_generic_release_info(struct acpi_pci_root_info *ci)
+{
+ struct acpi_pci_generic_root_info *ri;
+
+ ri = container_of(ci, struct acpi_pci_generic_root_info, common);
+ pci_ecam_free(ri->cfg);
+ kfree(ri);
+}
+
+static struct acpi_pci_root_ops acpi_pci_root_ops = {
+ .release_info = pci_acpi_generic_release_info,
+};
+
+/* Interface called from ACPI code to setup PCI host controller */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
- /* TODO: Should be revisited when implementing PCI on ACPI */
- return NULL;
+ int node = acpi_get_node(root->device->handle);
+ struct acpi_pci_generic_root_info *ri;
+ struct pci_bus *bus, *child;
+ int err;
+
+ ri = kzalloc_node(sizeof(*ri), GFP_KERNEL, node);
+ if (!ri)
+ return NULL;
+
+ err = pci_acpi_setup_ecam_mapping(root, ri);
+ if (err)
+ return NULL;
+
+ acpi_pci_root_ops.pci_ops = &ri->cfg->ops->pci_ops;
+ bus = acpi_pci_root_create(root, &acpi_pci_root_ops, &ri->common,
+ ri->cfg);
+ if (!bus)
+ return NULL;
+
+ pci_bus_size_bridges(bus);
+ pci_bus_assign_resources(bus);
+
+ list_for_each_entry(child, &bus->children, node)
+ pcie_bus_configure_settings(child);
+
+ return bus;
}
void pcibios_add_bus(struct pci_bus *bus)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9661c8572d21..f66d1881c2d9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1390,7 +1390,12 @@ static inline int pci_domain_nr(struct pci_bus *bus)
{
return bus->domain_nr;
}
+/* Arch specific ACPI hook to set-up domain number */
+#ifdef CONFIG_ACPI
+int acpi_pci_bus_domain_nr(struct pci_bus *bus);
+#else
static inline int acpi_pci_bus_domain_nr(struct pci_bus *bus) { return -1; }
+#endif
void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent);
#else
static inline void pci_bus_assign_domain_nr(struct pci_bus *bus,