linux/drivers/of/of_pci.c
Shawn Lin 9a1dc38912 of/pci: Add of_pci_get_max_link_speed() to parse max-link-speed from DT
This new helper function could be used by host drivers to get the limitaion
of max link speed provided by DT.  If the property isn't assigned or is
invalid, it will return -EINVAL to the caller.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Rob Herring <robh@kernel.org>
2016-11-14 15:21:14 -06:00

434 lines
12 KiB
C

#define pr_fmt(fmt) "OF: PCI: " fmt
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_device.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
static inline int __of_pci_pci_compare(struct device_node *node,
unsigned int data)
{
int devfn;
devfn = of_pci_get_devfn(node);
if (devfn < 0)
return 0;
return devfn == data;
}
struct device_node *of_pci_find_child_device(struct device_node *parent,
unsigned int devfn)
{
struct device_node *node, *node2;
for_each_child_of_node(parent, node) {
if (__of_pci_pci_compare(node, devfn))
return node;
/*
* Some OFs create a parent node "multifunc-device" as
* a fake root for all functions of a multi-function
* device we go down them as well.
*/
if (!strcmp(node->name, "multifunc-device")) {
for_each_child_of_node(node, node2) {
if (__of_pci_pci_compare(node2, devfn)) {
of_node_put(node);
return node2;
}
}
}
}
return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_child_device);
/**
* of_pci_get_devfn() - Get device and function numbers for a device node
* @np: device node
*
* Parses a standard 5-cell PCI resource and returns an 8-bit value that can
* be passed to the PCI_SLOT() and PCI_FUNC() macros to extract the device
* and function numbers respectively. On error a negative error code is
* returned.
*/
int of_pci_get_devfn(struct device_node *np)
{
unsigned int size;
const __be32 *reg;
reg = of_get_property(np, "reg", &size);
if (!reg || size < 5 * sizeof(__be32))
return -EINVAL;
return (be32_to_cpup(reg) >> 8) & 0xff;
}
EXPORT_SYMBOL_GPL(of_pci_get_devfn);
/**
* of_pci_parse_bus_range() - parse the bus-range property of a PCI device
* @node: device node
* @res: address to a struct resource to return the bus-range
*
* Returns 0 on success or a negative error-code on failure.
*/
int of_pci_parse_bus_range(struct device_node *node, struct resource *res)
{
const __be32 *values;
int len;
values = of_get_property(node, "bus-range", &len);
if (!values || len < sizeof(*values) * 2)
return -EINVAL;
res->name = node->name;
res->start = be32_to_cpup(values++);
res->end = be32_to_cpup(values);
res->flags = IORESOURCE_BUS;
return 0;
}
EXPORT_SYMBOL_GPL(of_pci_parse_bus_range);
/**
* This function will try to obtain the host bridge domain number by
* finding a property called "linux,pci-domain" of the given device node.
*
* @node: device tree node with the domain information
*
* Returns the associated domain number from DT in the range [0-0xffff], or
* a negative value if the required property is not found.
*/
int of_get_pci_domain_nr(struct device_node *node)
{
const __be32 *value;
int len;
u16 domain;
value = of_get_property(node, "linux,pci-domain", &len);
if (!value || len < sizeof(*value))
return -EINVAL;
domain = (u16)be32_to_cpup(value);
return domain;
}
EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
/**
* This function will try to find the limitation of link speed by finding
* a property called "max-link-speed" of the given device node.
*
* @node: device tree node with the max link speed information
*
* Returns the associated max link speed from DT, or a negative value if the
* required property is not found or is invalid.
*/
int of_pci_get_max_link_speed(struct device_node *node)
{
u32 max_link_speed;
if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
max_link_speed > 4)
return -EINVAL;
return max_link_speed;
}
EXPORT_SYMBOL_GPL(of_pci_get_max_link_speed);
/**
* of_pci_check_probe_only - Setup probe only mode if linux,pci-probe-only
* is present and valid
*/
void of_pci_check_probe_only(void)
{
u32 val;
int ret;
ret = of_property_read_u32(of_chosen, "linux,pci-probe-only", &val);
if (ret) {
if (ret == -ENODATA || ret == -EOVERFLOW)
pr_warn("linux,pci-probe-only without valid value, ignoring\n");
return;
}
if (val)
pci_add_flags(PCI_PROBE_ONLY);
else
pci_clear_flags(PCI_PROBE_ONLY);
pr_info("PROBE_ONLY %sabled\n", val ? "en" : "dis");
}
EXPORT_SYMBOL_GPL(of_pci_check_probe_only);
#if defined(CONFIG_OF_ADDRESS)
/**
* of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
* @dev: device node of the host bridge having the range property
* @busno: bus number associated with the bridge root bus
* @bus_max: maximum number of buses for this bridge
* @resources: list where the range of resources will be added after DT parsing
* @io_base: pointer to a variable that will contain on return the physical
* address for the start of the I/O range. Can be NULL if the caller doesn't
* expect IO ranges to be present in the device tree.
*
* It is the caller's job to free the @resources list.
*
* This function will parse the "ranges" property of a PCI host bridge device
* node and setup the resource mapping based on its content. It is expected
* that the property conforms with the Power ePAPR document.
*
* It returns zero if the range parsing has been successful or a standard error
* value if it failed.
*/
int of_pci_get_host_bridge_resources(struct device_node *dev,
unsigned char busno, unsigned char bus_max,
struct list_head *resources, resource_size_t *io_base)
{
struct resource_entry *window;
struct resource *res;
struct resource *bus_range;
struct of_pci_range range;
struct of_pci_range_parser parser;
char range_type[4];
int err;
if (io_base)
*io_base = (resource_size_t)OF_BAD_ADDR;
bus_range = kzalloc(sizeof(*bus_range), GFP_KERNEL);
if (!bus_range)
return -ENOMEM;
pr_info("host bridge %s ranges:\n", dev->full_name);
err = of_pci_parse_bus_range(dev, bus_range);
if (err) {
bus_range->start = busno;
bus_range->end = bus_max;
bus_range->flags = IORESOURCE_BUS;
pr_info(" No bus range found for %s, using %pR\n",
dev->full_name, bus_range);
} else {
if (bus_range->end > bus_range->start + bus_max)
bus_range->end = bus_range->start + bus_max;
}
pci_add_resource(resources, bus_range);
/* Check for ranges property */
err = of_pci_range_parser_init(&parser, dev);
if (err)
goto parse_failed;
pr_debug("Parsing ranges property...\n");
for_each_of_pci_range(&parser, &range) {
/* Read next ranges element */
if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_IO)
snprintf(range_type, 4, " IO");
else if ((range.flags & IORESOURCE_TYPE_BITS) == IORESOURCE_MEM)
snprintf(range_type, 4, "MEM");
else
snprintf(range_type, 4, "err");
pr_info(" %s %#010llx..%#010llx -> %#010llx\n", range_type,
range.cpu_addr, range.cpu_addr + range.size - 1,
range.pci_addr);
/*
* If we failed translation or got a zero-sized region
* then skip this range
*/
if (range.cpu_addr == OF_BAD_ADDR || range.size == 0)
continue;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
if (!res) {
err = -ENOMEM;
goto parse_failed;
}
err = of_pci_range_to_resource(&range, dev, res);
if (err) {
kfree(res);
continue;
}
if (resource_type(res) == IORESOURCE_IO) {
if (!io_base) {
pr_err("I/O range found for %s. Please provide an io_base pointer to save CPU base address\n",
dev->full_name);
err = -EINVAL;
goto conversion_failed;
}
if (*io_base != (resource_size_t)OF_BAD_ADDR)
pr_warn("More than one I/O resource converted for %s. CPU base address for old range lost!\n",
dev->full_name);
*io_base = range.cpu_addr;
}
pci_add_resource_offset(resources, res, res->start - range.pci_addr);
}
return 0;
conversion_failed:
kfree(res);
parse_failed:
resource_list_for_each_entry(window, resources)
kfree(window->res);
pci_free_resource_list(resources);
return err;
}
EXPORT_SYMBOL_GPL(of_pci_get_host_bridge_resources);
#endif /* CONFIG_OF_ADDRESS */
#ifdef CONFIG_PCI_MSI
static LIST_HEAD(of_pci_msi_chip_list);
static DEFINE_MUTEX(of_pci_msi_chip_mutex);
int of_pci_msi_chip_add(struct msi_controller *chip)
{
if (!of_property_read_bool(chip->of_node, "msi-controller"))
return -EINVAL;
mutex_lock(&of_pci_msi_chip_mutex);
list_add(&chip->list, &of_pci_msi_chip_list);
mutex_unlock(&of_pci_msi_chip_mutex);
return 0;
}
EXPORT_SYMBOL_GPL(of_pci_msi_chip_add);
void of_pci_msi_chip_remove(struct msi_controller *chip)
{
mutex_lock(&of_pci_msi_chip_mutex);
list_del(&chip->list);
mutex_unlock(&of_pci_msi_chip_mutex);
}
EXPORT_SYMBOL_GPL(of_pci_msi_chip_remove);
struct msi_controller *of_pci_find_msi_chip_by_node(struct device_node *of_node)
{
struct msi_controller *c;
mutex_lock(&of_pci_msi_chip_mutex);
list_for_each_entry(c, &of_pci_msi_chip_list, list) {
if (c->of_node == of_node) {
mutex_unlock(&of_pci_msi_chip_mutex);
return c;
}
}
mutex_unlock(&of_pci_msi_chip_mutex);
return NULL;
}
EXPORT_SYMBOL_GPL(of_pci_find_msi_chip_by_node);
#endif /* CONFIG_PCI_MSI */
/**
* of_pci_map_rid - Translate a requester ID through a downstream mapping.
* @np: root complex device node.
* @rid: PCI requester ID to map.
* @map_name: property name of the map to use.
* @map_mask_name: optional property name of the mask to use.
* @target: optional pointer to a target device node.
* @id_out: optional pointer to receive the translated ID.
*
* Given a PCI requester ID, look up the appropriate implementation-defined
* platform ID and/or the target device which receives transactions on that
* ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
* @id_out may be NULL if only the other is required. If @target points to
* a non-NULL device node pointer, only entries targeting that node will be
* matched; if it points to a NULL value, it will receive the device node of
* the first matching target phandle, with a reference held.
*
* Return: 0 on success or a standard error code on failure.
*/
int of_pci_map_rid(struct device_node *np, u32 rid,
const char *map_name, const char *map_mask_name,
struct device_node **target, u32 *id_out)
{
u32 map_mask, masked_rid;
int map_len;
const __be32 *map = NULL;
if (!np || !map_name || (!target && !id_out))
return -EINVAL;
map = of_get_property(np, map_name, &map_len);
if (!map) {
if (target)
return -ENODEV;
/* Otherwise, no map implies no translation */
*id_out = rid;
return 0;
}
if (!map_len || map_len % (4 * sizeof(*map))) {
pr_err("%s: Error: Bad %s length: %d\n", np->full_name,
map_name, map_len);
return -EINVAL;
}
/* The default is to select all bits. */
map_mask = 0xffffffff;
/*
* Can be overridden by "{iommu,msi}-map-mask" property.
* If of_property_read_u32() fails, the default is used.
*/
if (map_mask_name)
of_property_read_u32(np, map_mask_name, &map_mask);
masked_rid = map_mask & rid;
for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
struct device_node *phandle_node;
u32 rid_base = be32_to_cpup(map + 0);
u32 phandle = be32_to_cpup(map + 1);
u32 out_base = be32_to_cpup(map + 2);
u32 rid_len = be32_to_cpup(map + 3);
if (rid_base & ~map_mask) {
pr_err("%s: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
np->full_name, map_name, map_name,
map_mask, rid_base);
return -EFAULT;
}
if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
continue;
phandle_node = of_find_node_by_phandle(phandle);
if (!phandle_node)
return -ENODEV;
if (target) {
if (*target)
of_node_put(phandle_node);
else
*target = phandle_node;
if (*target != phandle_node)
continue;
}
if (id_out)
*id_out = masked_rid - rid_base + out_base;
pr_debug("%s: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
np->full_name, map_name, map_mask, rid_base, out_base,
rid_len, rid, *id_out);
return 0;
}
pr_err("%s: Invalid %s translation - no match for rid 0x%x on %s\n",
np->full_name, map_name, rid,
target && *target ? (*target)->full_name : "any target");
return -EFAULT;
}