Code inspired by arch/x86/pci/acpi.c and arch/ia64/pci/pci.c files.
The main reasons why we need this:
- parse and manage resources (BUS, IO and MEM)
- create pci root bus and enumerate its children
- provide PCI config space accessors (via MMCONFIG)
Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
---
arch/arm64/include/asm/pci.h | 8 +
arch/arm64/kernel/pci.c | 401 +++++++++++++++++++++++++++++++++++++++++--
2 files changed, 391 insertions(+), 18 deletions(-)
diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h
index fded096..ecd940f 100644
--- a/arch/arm64/include/asm/pci.h
+++ b/arch/arm64/include/asm/pci.h
@@ -33,6 +33,14 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
extern int isa_dma_bridge_buggy;
#ifdef CONFIG_PCI
+struct pci_controller {
+ struct acpi_device *companion;
+ int segment;
+ int node; /* nearest node with memory or NUMA_NO_NODE for global allocation */
+};
+
+#define PCI_CONTROLLER(busdev) ((struct pci_controller *) busdev->sysdata)
+
static inline int pci_proc_domain(struct pci_bus *bus)
{
return 1;
diff --git a/arch/arm64/kernel/pci.c b/arch/arm64/kernel/pci.c
index 42fb195..cc34ded 100644
--- a/arch/arm64/kernel/pci.c
+++ b/arch/arm64/kernel/pci.c
@@ -1,6 +1,10 @@
/*
- * Code borrowed from powerpc/kernel/pci-common.c
+ * Code borrowed from powerpc/kernel/pci-common.c and arch/ia64/pci/pci.c
*
+ * Copyright (c) 2002, 2005 Hewlett-Packard Development Company, L.P.
+ * David Mosberger-Tang <davidm@xxxxxxxxxx>
+ * Bjorn Helgaas <bjorn.helgaas@xxxxxx>
+ * Copyright (C) 2004 Silicon Graphics, Inc.
* Copyright (C) 2003 Anton Blanchard <anton@xxxxxxxxxx>, IBM
* Copyright (C) 2014 ARM Ltd.
*
@@ -17,10 +21,16 @@
#include <linux/mm.h>
#include <linux/of_pci.h>
#include <linux/of_platform.h>
+#include <linux/of_address.h>
#include <linux/slab.h>
+#include <linux/pci.h>
+#include <linux/acpi.h>
+#include <linux/mmconfig.h>
#include <asm/pci-bridge.h>
+#define PREFIX "PCI: "
+
/*
* Called after each bus is probed, but before its children are examined
*/
@@ -43,7 +53,8 @@ resource_size_t pcibios_align_resource(void *data, const struct resource *res,
*/
int pcibios_add_device(struct pci_dev *dev)
{
- dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
+ if (acpi_disabled)
+ dev->irq = of_irq_parse_and_map_pci(dev, 0, 0);
return 0;
}
@@ -54,45 +65,399 @@ static bool dt_domain_found = false;
void pci_bus_assign_domain_nr(struct pci_bus *bus, struct device *parent)
{
- int domain = of_get_pci_domain_nr(parent->of_node);
+ int domain = -1;
- if (domain >= 0) {
- dt_domain_found = true;
- } else if (dt_domain_found == true) {
- dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n",
- parent->of_node->full_name);
- return;
+ if (acpi_disabled) {
+ domain = of_get_pci_domain_nr(parent->of_node);
+
+ if (domain >= 0) {
+ dt_domain_found = true;
+ } else if (dt_domain_found == true) {
+ dev_err(parent, "Node %s is missing \"linux,pci-domain\" property in DT\n",
+ parent->of_node->full_name);
+ return;
+ } else {
+ domain = pci_get_new_domain_nr();
+ }
} else {
- domain = pci_get_new_domain_nr();
+ /*
+ * Take the domain nr from associated private data.
+ * Case where bus has parent is covered in pci_alloc_bus()
+ */
+ if (!parent)
+ domain = PCI_CONTROLLER(bus)->segment;
}
bus->domain_nr = domain;
}
#endif
+static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus,
+ unsigned int devfn)
+{
+ struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
+
+ if (cfg && cfg->virt)
+ return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
+ return NULL;
+}
+
/*
* raw_pci_read/write - Platform-specific PCI config space access.
- *
- * Default empty implementation. Replace with an architecture-specific setup
- * routine, if necessary.
*/
int raw_pci_read(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 *val)
{
- return -EINVAL;
+ char __iomem *addr;
+
+ if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
+err: *val = -1;
+ return -EINVAL;
+ }
+
+ rcu_read_lock();
+ addr = pci_dev_base(domain, bus, devfn);
+ if (!addr) {
+ rcu_read_unlock();
+ goto err;
+ }
+
+ switch (len) {
+ case 1:
+ *val = readb(addr + reg);
+ break;
+ case 2:
+ *val = readw(addr + reg);
+ break;
+ case 4:
+ *val = readl(addr + reg);
+ break;
+ }
+ rcu_read_unlock();
+
+ return 0;
}
int raw_pci_write(unsigned int domain, unsigned int bus,
unsigned int devfn, int reg, int len, u32 val)
{
- return -EINVAL;
+ char __iomem *addr;
+
+ if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
+ return -EINVAL;
+
+ rcu_read_lock();
+ addr = pci_dev_base(domain, bus, devfn);
+ if (!addr) {
+ rcu_read_unlock();
+ return -EINVAL;
+ }
+
+ switch (len) {
+ case 1:
+ writeb(val, addr + reg);
+ break;
+ case 2:
+ writew(val, addr + reg);
+ break;
+ case 4:
+ writel(val, addr + reg);
+ break;
+ }
+ rcu_read_unlock();
+
+ return 0;
}
#ifdef CONFIG_ACPI
+static int pci_read(struct pci_bus *bus, unsigned int devfn, int where,
+ int size, u32 *value)
+{
+ return raw_pci_read(pci_domain_nr(bus), bus->number,
+ devfn, where, size, value);
+}
+
+static int pci_write(struct pci_bus *bus, unsigned int devfn, int where,
+ int size, u32 value)
+{
+ return raw_pci_write(pci_domain_nr(bus), bus->number,
+ devfn, where, size, value);
+}
+
+struct pci_ops pci_root_ops = {
+ .read = pci_read,
+ .write = pci_write,
+};
+
+static struct pci_controller *alloc_pci_controller(int seg)
+{
+ struct pci_controller *controller;
+
+ controller = kzalloc(sizeof(*controller), GFP_KERNEL);
+ if (!controller)
+ return NULL;
+
+ controller->segment = seg;
+ return controller;
+}
+
+struct pci_root_info {
+ struct acpi_device *bridge;
+ struct pci_controller *controller;
+ struct list_head resources;
+ struct resource *res;
+ resource_size_t *res_offset;
+ unsigned int res_num;
+ char *name;
+};
+
+static acpi_status resource_to_window(struct acpi_resource *resource,
+ struct acpi_resource_address64 *addr)
+{
+ acpi_status status;
+
+ /*
+ * We're only interested in _CRS descriptors that are
+ * - address space descriptors for memory
+ * - non-zero size
+ * - producers, i.e., the address space is routed downstream,
+ * not consumed by the bridge itself
+ */
+ status = acpi_resource_to_address64(resource, addr);
+ if (ACPI_SUCCESS(status) &&
+ (addr->resource_type == ACPI_MEMORY_RANGE ||
+ addr->resource_type == ACPI_IO_RANGE) &&
+ addr->address_length &&
+ addr->producer_consumer == ACPI_PRODUCER)
+ return AE_OK;
+
+ return AE_ERROR;
+}
+
+static acpi_status count_window(struct acpi_resource *resource, void *data)
+{
+ unsigned int *windows = (unsigned int *) data;
+ struct acpi_resource_address64 addr;
+ acpi_status status;
+
+ status = resource_to_window(resource, &addr);
+ if (ACPI_SUCCESS(status))
+ (*windows)++;
+
+ return AE_OK;
+}
+
+static acpi_status add_window(struct acpi_resource *res, void *data)
+{
+ struct pci_root_info *info = data;
+ struct resource *resource;
+ struct acpi_resource_address64 addr;
+ acpi_status status;
+ unsigned long flags;
+ struct resource *root;
+ u64 start;
+
+ /* Return AE_OK for non-window resources to keep scanning for more */
+ status = resource_to_window(res, &addr);
+ if (!ACPI_SUCCESS(status))
+ return AE_OK;
+
+ if (addr.resource_type == ACPI_MEMORY_RANGE) {
+ flags = IORESOURCE_MEM;
+ root = &iomem_resource;
+ } else if (addr.resource_type == ACPI_IO_RANGE) {
+ flags = IORESOURCE_IO;
+ root = &ioport_resource;
+ } else
+ return AE_OK;
+
+ start = addr.minimum + addr.translation_offset;
+
+ resource = &info->res[info->res_num];
+ resource->name = info->name;
+ resource->flags = flags;
+ resource->start = start;
+ resource->end = resource->start + addr.address_length - 1;
+
+ if (flags & IORESOURCE_IO) {
+ unsigned long port;
+ int err;
+
+ err = pci_register_io_range(start, addr.address_length);
+ if (err)
+ return AE_OK;
+
+ port = pci_address_to_pio(start);
+ if (port == (unsigned long)-1)
+ return AE_OK;
+
+ resource->start = port;
+ resource->end = port + addr.address_length - 1;
+
+ if (pci_remap_iospace(resource, start) < 0)
+ return AE_OK;
+
+ info->res_offset[info->res_num] = 0;
+ } else
+ info->res_offset[info->res_num] = addr.translation_offset;
+
+ if (insert_resource(root, resource)) {
+ dev_err(&info->bridge->dev,
+ "can't allocate host bridge window %pR\n",
+ resource);
+ } else {
+ if (addr.translation_offset)
+ dev_info(&info->bridge->dev, "host bridge window %pR "
+ "(PCI address [%#llx-%#llx])\n",
+ resource,
+ resource->start - addr.translation_offset,
+ resource->end - addr.translation_offset);
+ else
+ dev_info(&info->bridge->dev,
+ "host bridge window %pR\n", resource);
+ }
+
+ pci_add_resource_offset(&info->resources, resource,
+ info->res_offset[info->res_num]);
+ info->res_num++;
+ return AE_OK;
+}
+
+static void free_pci_root_info_res(struct pci_root_info *info)
+{
+ kfree(info->name);
+ kfree(info->res);
+ info->res = NULL;
+ kfree(info->res_offset);
+ info->res_offset = NULL;
+ info->res_num = 0;
+ kfree(info->controller);
+ info->controller = NULL;
+}
+
+static void __release_pci_root_info(struct pci_root_info *info)
+{
+ int i;
+ struct resource *res;
+
+ for (i = 0; i < info->res_num; i++) {
+ res = &info->res[i];
+
+ if (!res->parent)
+ continue;
+
+ if (!(res->flags & (IORESOURCE_MEM | IORESOURCE_IO)))
+ continue;
+
+ release_resource(res);
+ }
+
+ free_pci_root_info_res(info);
+ kfree(info);
+}
+
+static void release_pci_root_info(struct pci_host_bridge *bridge)
+{
+ struct pci_root_info *info = bridge->release_data;
+
+ __release_pci_root_info(info);
+}
+
+static int
+probe_pci_root_info(struct pci_root_info *info, struct acpi_device *device,
+ int busnum, int domain)
+{
+ char *name;
+
+ name = kmalloc(16, GFP_KERNEL);
+ if (!name)
+ return -ENOMEM;
+
+ sprintf(name, "PCI Bus %04x:%02x", domain, busnum);
+ info->bridge = device;
+ info->name = name;
+
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS, count_window,
+ &info->res_num);
+ if (info->res_num) {
+ info->res =
+ kzalloc_node(sizeof(*info->res) * info->res_num,
+ GFP_KERNEL, info->controller->node);
+ if (!info->res) {
+ kfree(name);
+ return -ENOMEM;
+ }
+
+ info->res_offset =
+ kzalloc_node(sizeof(*info->res_offset) * info->res_num,
+ GFP_KERNEL, info->controller->node);
+ if (!info->res_offset) {
+ kfree(name);
+ kfree(info->res);
+ info->res = NULL;
+ return -ENOMEM;
+ }
+
+ info->res_num = 0;
+ acpi_walk_resources(device->handle, METHOD_NAME__CRS,
+ add_window, info);
+ } else
+ kfree(name);
+
+ return 0;
+}
+
/* Root bridge scanning */
struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root)
{
- /* TODO: Should be revisited when implementing PCI on ACPI */
- return NULL;
+ struct acpi_device *device = root->device;
+ int domain = root->segment;
+ int bus = root->secondary.start;
+ struct pci_controller *controller;
+ struct pci_root_info *info = NULL;
+ int busnum = root->secondary.start;
+ struct pci_bus *pbus;
+ int ret;
+
+ controller = alloc_pci_controller(domain);
+ if (!controller)
+ return NULL;
+
+ controller->companion = device;
+ controller->node = acpi_get_node(device->handle);
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info) {
+ dev_err(&device->dev,
+ "pci_bus %04x:%02x: ignored (out of memory)\n",
+ domain, busnum);
+ kfree(controller);
+ return NULL;
+ }
+
+ info->controller = controller;
+ INIT_LIST_HEAD(&info->resources);
+
+ ret = probe_pci_root_info(info, device, busnum, domain);
+ if (ret) {
+ kfree(info->controller);
+ kfree(info);
+ return NULL;
+ }
+ /* insert busn resource at first */
+ pci_add_resource(&info->resources, &root->secondary);
+
+ pbus = pci_create_root_bus(NULL, bus, &pci_root_ops, controller,
+ &info->resources);
+ if (!pbus) {
+ pci_free_resource_list(&info->resources);
+ __release_pci_root_info(info);
+ return NULL;
+ }
+
+ pci_set_host_bridge_release(to_pci_host_bridge(pbus->bridge),
+ release_pci_root_info, info);
+ pci_scan_child_bus(pbus);
+ return pbus;
}
-#endif
+#endif /* CONFIG_ACPI */
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
