// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_address.h>
#include <linux/of_iommu.h>
#include <linux/of_reserved_mem.h>
#include <linux/dma-direct.h> /* for bus_dma_region */
#include <linux/dma-map-ops.h>
#include <linux/init.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <asm/errno.h>
#include "of_private.h"
/**
* of_match_device - Tell if a struct device matches an of_device_id list
* @matches: array of of device match structures to search in
* @dev: the of device structure to match against
*
* Used by a driver to check whether an platform_device present in the
* system is in its list of supported devices.
*/
const struct of_device_id *of_match_device(const struct of_device_id *matches,
const struct device *dev)
{
if (!matches || !dev->of_node || dev->of_node_reused)
return NULL;
return of_match_node(matches, dev->of_node);
}
EXPORT_SYMBOL(of_match_device);
static void
of_dma_set_restricted_buffer(struct device *dev, struct device_node *np)
{
struct device_node *node, *of_node = dev->of_node;
int count, i;
if (!IS_ENABLED(CONFIG_DMA_RESTRICTED_POOL))
return;
count = of_property_count_elems_of_size(of_node, "memory-region",
sizeof(u32));
/*
* If dev->of_node doesn't exist or doesn't contain memory-region, try
* the OF node having DMA configuration.
*/
if (count <= 0) {
of_node = np;
count = of_property_count_elems_of_size(
of_node, "memory-region", sizeof(u32));
}
for (i = 0; i < count; i++) {
node = of_parse_phandle(of_node, "memory-region", i);
/*
* There might be multiple memory regions, but only one
* restricted-dma-pool region is allowed.
*/
if (of_device_is_compatible(node, "restricted-dma-pool") &&
of_device_is_available(node)) {
of_node_put(node);
break;
}
of_node_put(node);
}
/*
* Attempt to initialize a restricted-dma-pool region if one was found.
* Note that count can hold a negative error code.
*/
if (i < count && of_reserved_mem_device_init_by_idx(dev, of_node, i))
dev_warn(dev, "failed to initialise \"restricted-dma-pool\" memory node\n");
}
/**
* of_dma_configure_id - Setup DMA configuration
* @dev: Device to apply DMA configuration
* @np: Pointer to OF node having DMA configuration
* @force_dma: Whether device is to be set up by of_dma_configure() even if
* DMA capability is not explicitly described by firmware.
* @id: Optional const pointer value input id
*
* Try to get devices's DMA configuration from DT and update it
* accordingly.
*
* If platform code needs to use its own special DMA configuration, it
* can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
* to fix up DMA configuration.
*/
int of_dma_configure_id(struct device *dev, struct device_node *np,
bool force_dma, const u32 *id)
{
const struct bus_dma_region *map = NULL;
struct device_node *bus_np;
u64 mask, end = 0;
bool coherent, set_map = false;
int ret;
if (np == dev->of_node)
bus_np = __of_get_dma_parent(np);
else
bus_np = of_node_get(np);
ret = of_dma_get_range(bus_np, &map);
of_node_put(bus_np);
if (ret < 0) {
/*
* For legacy reasons, we have to assume some devices need
* DMA configuration regardless of whether "dma-ranges" is
* correctly specified or not.
*/
if (!force_dma)
return ret == -ENODEV ? 0 : ret;
} else {
/* Determine the overall bounds of all DMA regions */
end = dma_range_map_max(map);
set_map = true;
}
/*
* If @dev is expected to be DMA-capable then the bus code that created
* it should have initialised its dma_mask pointer by this point. For
* now, we'll continue the legacy behaviour of coercing it to the
* coherent mask if not, but we'll no longer do so quietly.
*/
if (!dev->dma_mask) {
dev_warn(dev, "DMA mask not set\n");
dev->dma_mask = &dev->coherent_dma_mask;
}
if (!end && dev->coherent_dma_mask)
end = dev->coherent_dma_mask;
else if (!end)
end = (1ULL << 32) - 1;
/*
* Limit coherent and dma mask based on size and default mask
* set by the driver.
*/
mask = DMA_BIT_MASK(ilog2(end) + 1);
dev->coherent_dma_mask &= mask;
*dev->dma_mask &= mask;
/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
if (set_map) {
dev->bus_dma_limit = end;
dev->dma_range_map = map;
}
coherent = of_dma_is_coherent(np);
dev_dbg(dev, "device is%sdma coherent\n",
coherent ? " " : " not ");
ret = of_iommu_configure(dev, np, id);
if (ret == -EPROBE_DEFER) {
/* Don't touch range map if it wasn't set from a valid dma-ranges */
if (set_map)
dev->dma_range_map = NULL;
kfree(map);
return -EPROBE_DEFER;
}
/* Take all other IOMMU errors to mean we'll just carry on without it */
dev_dbg(dev, "device is%sbehind an iommu\n",
!ret ? " " : " not ");
arch_setup_dma_ops(dev, coherent);
if (ret)
of_dma_set_restricted_buffer(dev, np);
return 0;
}
EXPORT_SYMBOL_GPL(of_dma_configure_id);
const void *of_device_get_match_data(const struct device *dev)
{
const struct of_device_id *match;
match = of_match_device(dev->driver->of_match_table, dev);
if (!match)
return NULL;
return match->data;
}
EXPORT_SYMBOL(of_device_get_match_data);
/**
* of_device_modalias - Fill buffer with newline terminated modalias string
* @dev: Calling device
* @str: Modalias string
* @len: Size of @str
*/
ssize_t of_device_modalias(struct device *dev, char *str, ssize_t len)
{
ssize_t sl;
if (!dev || !dev->of_node || dev->of_node_reused)
return -ENODEV;
sl = of_modalias(dev->of_node, str, len - 2);
if (sl < 0)
return sl;
if (sl > len - 2)
return -ENOMEM;
str[sl++] = '\n';
str[sl] = 0;
return sl;
}
EXPORT_SYMBOL_GPL(of_device_modalias);
/**
* of_device_uevent - Display OF related uevent information
* @dev: Device to display the uevent information for
* @env: Kernel object's userspace event reference to fill up
*/
void of_device_uevent(const struct device *dev, struct kobj_uevent_env *env)
{
const char *compat, *type;
struct alias_prop *app;
struct property *p;
int seen = 0;
if ((!dev) || (!dev->of_node))
return;
add_uevent_var(env, "OF_NAME=%pOFn", dev->of_node);
add_uevent_var(env, "OF_FULLNAME=%pOF", dev->of_node);
type = of_node_get_device_type(dev->of_node);
if (type)
add_uevent_var(env, "OF_TYPE=%s", type);
/* Since the compatible field can contain pretty much anything
* it's not really legal to split it out with commas. We split it
* up using a number of environment variables instead. */
of_property_for_each_string(dev->of_node, "compatible", p, compat) {
add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
seen++;
}
add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
seen = 0;
mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (dev->of_node == app->np) {
add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
app->alias);
seen++;
}
}
mutex_unlock(&of_mutex);
}
EXPORT_SYMBOL_GPL(of_device_uevent);
int of_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
{
int sl;
if ((!dev) || (!dev->of_node) || dev->of_node_reused)
return -ENODEV;
/* Devicetree modalias is tricky, we add it in 2 steps */
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
sl = of_modalias(dev->of_node, &env->buf[env->buflen-1],
sizeof(env->buf) - env->buflen);
if (sl < 0)
return sl;
if (sl >= (sizeof(env->buf) - env->buflen))
return -ENOMEM;
env->buflen += sl;
return 0;
}
EXPORT_SYMBOL_GPL(of_device_uevent_modalias);
/**
* of_device_make_bus_id - Use the device node data to assign a unique name
* @dev: pointer to device structure that is linked to a device tree node
*
* This routine will first try using the translated bus address to
* derive a unique name. If it cannot, then it will prepend names from
* parent nodes until a unique name can be derived.
*/
void of_device_make_bus_id(struct device *dev)
{
struct device_node *node = dev->of_node;
const __be32 *reg;
u64 addr;
u32 mask;
/* Construct the name, using parent nodes if necessary to ensure uniqueness */
while (node->parent) {
/*
* If the address can be translated, then that is as much
* uniqueness as we need. Make it the first component and return
*/
reg = of_get_property(node, "reg", NULL);
if (reg && (addr = of_translate_address(node, reg)) != OF_BAD_ADDR) {
if (!of_property_read_u32(node, "mask", &mask))
dev_set_name(dev, dev_name(dev) ? "%llx.%x.%pOFn:%s" : "%llx.%x.%pOFn",
addr, ffs(mask) - 1, node, dev_name(dev));
else
dev_set_name(dev, dev_name(dev) ? "%llx.%pOFn:%s" : "%llx.%pOFn",
addr, node, dev_name(dev));
return;
}
/* format arguments only used if dev_name() resolves to NULL */
dev_set_name(dev, dev_name(dev) ? "%s:%s" : "%s",
kbasename(node->full_name), dev_name(dev));
node = node->parent;
}
}
EXPORT_SYMBOL_GPL(of_device_make_bus_id);
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