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linux/drivers/of/of_private.h

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of: Use SPDX license tag for DT files Convert remaining DT files to use SPDX-License-Identifier tags. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-28 02:55:14 +08:00
/* SPDX-License-Identifier: GPL-2.0+ */
of: Output devicetree alias names in uevent In some situations, userspace may want to resolve a device by function and logical number (ie, "serial0") rather than by the base address or full device path. Being able to resolve a device by alias frees userspace from the burden of otherwise having to maintain a mapping between device addresses and their logical assignments on each platform when multiple instances of the same hardware block are present in the system. Although the uevent device attribute contains devicetree compatible information and the full device path, the uevent does not list the alises that may have been defined for the device. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [grant.likely: Removed OF_ALIAS_N field; I don't think it's needed] [grant.likely: Added #ifndef _LINUX_OF_PRIVATE_H wrapper] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 06:55:41 +08:00
#ifndef _LINUX_OF_PRIVATE_H
#define _LINUX_OF_PRIVATE_H
/*
* Private symbols used by OF support code
*
* Paul Mackerras August 1996.
* Copyright (C) 1996-2005 Paul Mackerras.
*/
of: unittest: overlay: ensure proper alignment of copied FDT The Devicetree standard specifies an 8 byte alignment of the FDT. Code in libfdt expects this alignment for an FDT image in memory. kmemdup() returns 4 byte alignment on openrisc. Replace kmemdup() with kmalloc(), align pointer, memcpy() to get proper alignment. The 4 byte alignment exposed a related bug which triggered a crash on openrisc with: commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9") as reported in: https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/ Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Link: https://lore.kernel.org/r/20210408204508.2276230-1-frowand.list@gmail.com Signed-off-by: Rob Herring <robh@kernel.org>
2021-04-09 04:45:08 +08:00
#define FDT_ALIGN_SIZE 8
of: Output devicetree alias names in uevent In some situations, userspace may want to resolve a device by function and logical number (ie, "serial0") rather than by the base address or full device path. Being able to resolve a device by alias frees userspace from the burden of otherwise having to maintain a mapping between device addresses and their logical assignments on each platform when multiple instances of the same hardware block are present in the system. Although the uevent device attribute contains devicetree compatible information and the full device path, the uevent does not list the alises that may have been defined for the device. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [grant.likely: Removed OF_ALIAS_N field; I don't think it's needed] [grant.likely: Added #ifndef _LINUX_OF_PRIVATE_H wrapper] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 06:55:41 +08:00
/**
* struct alias_prop - Alias property in 'aliases' node
* @link: List node to link the structure in aliases_lookup list
* @alias: Alias property name
* @np: Pointer to device_node that the alias stands for
* @id: Index value from end of alias name
* @stem: Alias string without the index
*
* The structure represents one alias property of 'aliases' node as
* an entry in aliases_lookup list.
*/
struct alias_prop {
struct list_head link;
const char *alias;
struct device_node *np;
int id;
of: of_private.h: Replace zero-length array with flexible-array member The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Rob Herring <robh@kernel.org>
2020-03-20 07:10:58 +08:00
char stem[];
of: Output devicetree alias names in uevent In some situations, userspace may want to resolve a device by function and logical number (ie, "serial0") rather than by the base address or full device path. Being able to resolve a device by alias frees userspace from the burden of otherwise having to maintain a mapping between device addresses and their logical assignments on each platform when multiple instances of the same hardware block are present in the system. Although the uevent device attribute contains devicetree compatible information and the full device path, the uevent does not list the alises that may have been defined for the device. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [grant.likely: Removed OF_ALIAS_N field; I don't think it's needed] [grant.likely: Added #ifndef _LINUX_OF_PRIVATE_H wrapper] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 06:55:41 +08:00
};
of: make default address and size cells sizes private Only some old OpenFirmware implementations rely on default sizes. Any FDT and modern implementation should have explicit properties. Make the OF_ROOT_NODE_*_CELLS_DEFAULT defines private so we don't get any outside users. This also gets us one step closer to removing the asm/prom.h dependency on Sparc. Cc: "David S. Miller" <davem@davemloft.net> Cc: Frank Rowand <frowand.list@gmail.com> Cc: sparclinux@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2018-08-30 06:21:45 +08:00
#if defined(CONFIG_SPARC)
#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 2
#else
#define OF_ROOT_NODE_ADDR_CELLS_DEFAULT 1
#endif
#define OF_ROOT_NODE_SIZE_CELLS_DEFAULT 1
of: rename of_aliases_mutex to just of_mutex We're overloading usage of of_aliases_mutex for sysfs changes, so rename to something that is more generic. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:03 +08:00
extern struct mutex of_mutex;
of: Output devicetree alias names in uevent In some situations, userspace may want to resolve a device by function and logical number (ie, "serial0") rather than by the base address or full device path. Being able to resolve a device by alias frees userspace from the burden of otherwise having to maintain a mapping between device addresses and their logical assignments on each platform when multiple instances of the same hardware block are present in the system. Although the uevent device attribute contains devicetree compatible information and the full device path, the uevent does not list the alises that may have been defined for the device. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [grant.likely: Removed OF_ALIAS_N field; I don't think it's needed] [grant.likely: Added #ifndef _LINUX_OF_PRIVATE_H wrapper] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 06:55:41 +08:00
extern struct list_head aliases_lookup;
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern struct kset *of_kset;
of: Move CONFIG_OF_DYNAMIC code into a separate file Split the dynamic device tree code into a separate file to make it really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not get sent. Enabling it turns on reference counting, notifiers and the ability to add and remove nodes. v2: Moved of_node_release() into dynamic.c Signed-off-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh+dt@kernel.org>
2014-06-26 22:40:48 +08:00
#if defined(CONFIG_OF_DYNAMIC)
extern int of_property_notify(int action, struct device_node *np,
of: Reorder device tree changes and notifiers Currently, devicetree reconfig notifiers get emitted before the change is applied to the tree, but that behaviour is problematic if the receiver wants the determine the new state of the tree. The current users don't care, but the changeset code to follow will be making multiple changes at once. Reorder notifiers to get emitted after the change has been applied to the tree so that callbacks see the new tree state. At the same time, fixup the existing callbacks to expect the new order. There are a few callbacks that compare the old and new values of a changed property. Put both property pointers into the of_prop_reconfig structure. The current notifiers also allow the notifier callback to fail and cancel the change to the tree, but that feature isn't actually used. It really isn't valid to ignore a tree modification provided by firmware anyway, so remove the ability to cancel a change to the tree. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com>
2014-07-17 02:48:23 +08:00
struct property *prop, struct property *old_prop);
of: Move CONFIG_OF_DYNAMIC code into a separate file Split the dynamic device tree code into a separate file to make it really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not get sent. Enabling it turns on reference counting, notifiers and the ability to add and remove nodes. v2: Moved of_node_release() into dynamic.c Signed-off-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh+dt@kernel.org>
2014-06-26 22:40:48 +08:00
extern void of_node_release(struct kobject *kobj);
of: overlay: detect cases where device tree may become corrupt When an attempt to apply an overlay changeset fails, an effort is made to revert any partial application of the changeset. When an attempt to remove an overlay changeset fails, an effort is made to re-apply any partial reversion of the changeset. The existing code does not check for failure to recover a failed overlay changeset application or overlay changeset revert. Add the missing checks and flag the devicetree as corrupt if the state of the devicetree can not be determined. Improve and expand the returned errors to more fully reflect the result of the effort to undo the partial effects of a failed attempt to apply or remove an overlay changeset. If the device tree might be corrupt, do not allow further attempts to apply or remove an overlay changeset. When creating an overlay changeset from an overlay device tree, add some additional warnings if the state of the overlay device tree is not as expected. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-18 07:36:26 +08:00
extern int __of_changeset_apply_entries(struct of_changeset *ocs,
int *ret_revert);
extern int __of_changeset_apply_notify(struct of_changeset *ocs);
extern int __of_changeset_revert_entries(struct of_changeset *ocs,
int *ret_apply);
extern int __of_changeset_revert_notify(struct of_changeset *ocs);
of: Move CONFIG_OF_DYNAMIC code into a separate file Split the dynamic device tree code into a separate file to make it really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not get sent. Enabling it turns on reference counting, notifiers and the ability to add and remove nodes. v2: Moved of_node_release() into dynamic.c Signed-off-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh+dt@kernel.org>
2014-06-26 22:40:48 +08:00
#else /* CONFIG_OF_DYNAMIC */
static inline int of_property_notify(int action, struct device_node *np,
of: Reorder device tree changes and notifiers Currently, devicetree reconfig notifiers get emitted before the change is applied to the tree, but that behaviour is problematic if the receiver wants the determine the new state of the tree. The current users don't care, but the changeset code to follow will be making multiple changes at once. Reorder notifiers to get emitted after the change has been applied to the tree so that callbacks see the new tree state. At the same time, fixup the existing callbacks to expect the new order. There are a few callbacks that compare the old and new values of a changed property. Put both property pointers into the of_prop_reconfig structure. The current notifiers also allow the notifier callback to fail and cancel the change to the tree, but that feature isn't actually used. It really isn't valid to ignore a tree modification provided by firmware anyway, so remove the ability to cancel a change to the tree. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com>
2014-07-17 02:48:23 +08:00
struct property *prop, struct property *old_prop)
of: Move CONFIG_OF_DYNAMIC code into a separate file Split the dynamic device tree code into a separate file to make it really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not get sent. Enabling it turns on reference counting, notifiers and the ability to add and remove nodes. v2: Moved of_node_release() into dynamic.c Signed-off-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh+dt@kernel.org>
2014-06-26 22:40:48 +08:00
{
return 0;
}
#endif /* CONFIG_OF_DYNAMIC */
of: make kobject and bin_attribute support configurable Having device_nodes be kobjects is only needed if sysfs or OF_DYNAMIC is enabled. Otherwise, having a kobject in struct device_node is unnecessary bloat in minimal kernel configurations. Likewise, bin_attribute is only needed in struct property when sysfs is enabled, so we can make it configurable too. Tested-by: Nicolas Pitre <nico@linaro.org> Reviewed-by: Frank Rowand <frowand.list@gmail.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-05 03:09:40 +08:00
#if defined(CONFIG_OF_KOBJ)
int of_node_is_attached(struct device_node *node);
int __of_add_property_sysfs(struct device_node *np, struct property *pp);
void __of_remove_property_sysfs(struct device_node *np, struct property *prop);
void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
struct property *oldprop);
int __of_attach_node_sysfs(struct device_node *np);
void __of_detach_node_sysfs(struct device_node *np);
#else
static inline int __of_add_property_sysfs(struct device_node *np, struct property *pp)
{
return 0;
}
static inline void __of_remove_property_sysfs(struct device_node *np, struct property *prop) {}
static inline void __of_update_property_sysfs(struct device_node *np,
struct property *newprop, struct property *oldprop) {}
static inline int __of_attach_node_sysfs(struct device_node *np)
{
return 0;
}
static inline void __of_detach_node_sysfs(struct device_node *np) {}
#endif
of: overlay: avoid race condition between applying multiple overlays The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously. Move of_resolve_phandles() into of_overlay_apply() so that it does not have to be duplicated by each caller of of_overlay_apply(). The test in of_resolve_phandles() that the overlay tree is detached is temporarily disabled so that old style overlay unittests do not fail. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-18 07:36:29 +08:00
#if defined(CONFIG_OF_RESOLVE)
int of_resolve_phandles(struct device_node *tree);
#endif
of: Rework and simplify phandle cache to use a fixed size The phandle cache was added to speed up of_find_node_by_phandle() by avoiding walking the whole DT to find a matching phandle. The implementation has several shortcomings: - The cache is designed to work on a linear set of phandle values. This is true for dtc generated DTs, but not for other cases such as Power. - The cache isn't enabled until of_core_init() and a typical system may see hundreds of calls to of_find_node_by_phandle() before that point. - The cache is freed and re-allocated when the number of phandles changes. - It takes a raw spinlock around a memory allocation which breaks on RT. Change the implementation to a fixed size and use hash_32() as the cache index. This greatly simplifies the implementation. It avoids the need for any re-alloc of the cache and taking a reference on nodes in the cache. We only have a single source of removing cache entries which is of_detach_node(). Using hash_32() removes any assumption on phandle values improving the hit rate for non-linear phandle values. The effect on linear values using hash_32() is about a 10% collision. The chances of thrashing on colliding values seems to be low. To compare performance, I used a RK3399 board which is a pretty typical system. I found that just measuring boot time as done previously is noisy and may be impacted by other things. Also bringing up secondary cores causes some issues with measuring, so I booted with 'nr_cpus=1'. With no caching, calls to of_find_node_by_phandle() take about 20124 us for 1248 calls. There's an additional 288 calls before time keeping is up. Using the average time per hit/miss with the cache, we can calculate these calls to take 690 us (277 hit / 11 miss) with a 128 entry cache and 13319 us with no cache or an uninitialized cache. Comparing the 3 implementations the time spent in of_find_node_by_phandle() is: no cache: 20124 us (+ 13319 us) 128 entry cache: 5134 us (+ 690 us) current cache: 819 us (+ 13319 us) We could move the allocation of the cache earlier to improve the current cache, but that just further complicates the situation as it needs to be after slab is up, so we can't do it when unflattening (which uses memblock). Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Segher Boessenkool <segher@kernel.crashing.org> Cc: Frank Rowand <frowand.list@gmail.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Frank Rowand <frowand.list@gmail.com> Tested-by: Frank Rowand <frowand.list@gmail.com> Signed-off-by: Rob Herring <robh@kernel.org>
2019-12-07 06:27:41 +08:00
void __of_phandle_cache_inv_entry(phandle handle);
of: __of_detach_node() - remove node from phandle cache Non-overlay dynamic devicetree node removal may leave the node in the phandle cache. Subsequent calls to of_find_node_by_phandle() will incorrectly find the stale entry. Remove the node from the cache. Add paranoia checks in of_find_node_by_phandle() as a second level of defense (do not return cached node if detached, do not add node to cache if detached). Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Michael Bringmann <mwb@linux.vnet.ibm.com> Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-12-19 03:40:03 +08:00
of: overlay: avoid race condition between applying multiple overlays The process of applying an overlay consists of: - unflatten an overlay FDT (flattened device tree) into an EDT (expanded device tree) - fixup the phandle values in the overlay EDT to fit in a range above the phandle values in the live device tree - create the overlay changeset to reflect the contents of the overlay EDT - apply the overlay changeset, to modify the live device tree, potentially changing the maximum phandle value in the live device tree There is currently no protection against two overlay applies concurrently determining what range of phandle values are in use in the live device tree, and subsequently changing that range. Add a mutex to prevent multiple overlay applies from occurring simultaneously. Move of_resolve_phandles() into of_overlay_apply() so that it does not have to be duplicated by each caller of of_overlay_apply(). The test in of_resolve_phandles() that the overlay tree is detached is temporarily disabled so that old style overlay unittests do not fail. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-18 07:36:29 +08:00
#if defined(CONFIG_OF_OVERLAY)
void of_overlay_mutex_lock(void);
void of_overlay_mutex_unlock(void);
#else
static inline void of_overlay_mutex_lock(void) {};
static inline void of_overlay_mutex_unlock(void) {};
#endif
of: fix unittest build without CONFIG_OF_OVERLAY We get a link error when the new tests are used by overlays are not: drivers/of/built-in.o: In function `unflatten_device_tree': (.init.text+0x967): undefined reference to `unittest_unflatten_overlay_base' This makes the #ifdef check match the symbols that lead to building the unittest_unflatten_overlay_base function. Fixes: 81d0848fc8d2 ("of: Add unit tests for applying overlays") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Tested-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-04-28 17:44:12 +08:00
#if defined(CONFIG_OF_UNITTEST) && defined(CONFIG_OF_OVERLAY)
of: Add unit tests for applying overlays Existing overlay unit tests examine individual pieces of the overlay code. The new tests target the entire process of applying an overlay. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-04-26 08:09:54 +08:00
extern void __init unittest_unflatten_overlay_base(void);
#else
static inline void unittest_unflatten_overlay_base(void) {};
#endif
extern void *__unflatten_device_tree(const void *blob,
struct device_node *dad,
struct device_node **mynodes,
void *(*dt_alloc)(u64 size, u64 align),
bool detached);
OF: Utility helper functions for dynamic nodes Introduce helper functions for working with the live DT tree, all of them related to dynamically adding/removing nodes and properties. __of_prop_dup() copies a property dynamically __of_node_alloc() creates an empty node Bug fix about prop->len == 0 by Ionut Nicu <ioan.nicu.ext@nsn.com> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [glikely: Added unittest for of_copy_property and dropped fine-grained allocations] [glikely: removed name, type and phandle arguments from __of_node_alloc] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:47 +08:00
/**
* General utilities for working with live trees.
*
* All functions with two leading underscores operate
* without taking node references, so you either have to
* own the devtree lock or work on detached trees only.
*/
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
of: overlay: do not include path in full_name of added nodes Struct device_node full_name no longer includes the full path name when the devicetree is created from a flattened device tree (FDT). The overlay node creation code was not modified to reflect this change. Fix the node full_name generated by overlay code to contain only the basename. Unittests call an overlay internal function to create new nodes. Fix up these calls to provide basename only instead of the full path. Fixes: a7e4cfb0a7ca ("of/fdt: only store the device node basename in full_name") Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-02-27 06:01:23 +08:00
struct device_node *__of_node_dup(const struct device_node *np,
const char *full_name);
OF: Utility helper functions for dynamic nodes Introduce helper functions for working with the live DT tree, all of them related to dynamically adding/removing nodes and properties. __of_prop_dup() copies a property dynamically __of_node_alloc() creates an empty node Bug fix about prop->len == 0 by Ionut Nicu <ioan.nicu.ext@nsn.com> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [glikely: Added unittest for of_copy_property and dropped fine-grained allocations] [glikely: removed name, type and phandle arguments from __of_node_alloc] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:47 +08:00
of: overlay: remove a dependency on device node full_name The "%pOF" printf format was recently added to print the full name of a device tree node, with the intent of changing the node full_name field to contain only the node name instead of the full path of the node. dup_and_fixup_symbol_prop() duplicates a property from the "/__symbols__" node of an overlay device tree. The value of each duplicated property must be fixed up to include the full path of a node in the live device tree. The current code uses the node's full_name for that purpose. Update the code to use the "%pOF" printf format to determine the node's full path. Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2017-10-18 07:36:31 +08:00
struct device_node *__of_find_node_by_path(struct device_node *parent,
const char *path);
of: find_node_by_full_name rewrite to compare each level find_node_by_full_name() does the same thing as of_find_node_by_path(), but takes no locks and doesn't work on aliases. Refactor of_find_node_opts_by_path() into __of_find_node_by_full_path() and replace find_node_by_full_name() with it. Signed-off-by: Rob Herring <robh@kernel.org>
2017-06-03 01:43:18 +08:00
struct device_node *__of_find_node_by_full_path(struct device_node *node,
const char *path);
of: Move dynamic node fixups out of powerpc and into common code PowerPC does an odd thing with dynamic nodes. It uses a notifier to catch new node additions and set some of the values like name and type. This makes no sense since that same code can be put directly into of_attach_node(). Besides, all dynamic node users need this, not just powerpc. Fix this problem by moving the logic out of arch/powerpc and into drivers/of/dynamic.c. It is also important to remove this notifier because we want to move the firing of notifiers from before the tree is modified to after so that the receiver gets a consistent view of the tree, but that is incompatible with notifiers that modify the node. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-07-16 13:25:43 +08:00
extern const void *__of_get_property(const struct device_node *np,
const char *name, int *lenp);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
extern int __of_add_property(struct device_node *np, struct property *prop);
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern int __of_add_property_sysfs(struct device_node *np,
struct property *prop);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
extern int __of_remove_property(struct device_node *np, struct property *prop);
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern void __of_remove_property_sysfs(struct device_node *np,
struct property *prop);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
extern int __of_update_property(struct device_node *np,
struct property *newprop, struct property **oldprop);
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern void __of_update_property_sysfs(struct device_node *np,
struct property *newprop, struct property *oldprop);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern int __of_attach_node_sysfs(struct device_node *np);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
extern void __of_detach_node(struct device_node *np);
of: Make devicetree sysfs update functions consistent. All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-24 07:05:06 +08:00
extern void __of_detach_node_sysfs(struct device_node *np);
of: Create unlocked versions of node and property add/remove functions The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:46 +08:00
of: fix memory leak related to safe_name() Fix a memory leak resulting from memory allocation in safe_name(). This patch fixes all call sites of safe_name(). Mathieu Malaterre reported the memory leak on boot: On my PowerMac device-tree would generate a duplicate name: [ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1" in this case a newly allocated name is generated by `safe_name`. However in this case it is never deallocated. The bug was found using kmemleak reported as: unreferenced object 0xdf532e60 (size 32): comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s) hex dump (first 32 bytes): 6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1...... ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................ backtrace: [<c02d3350>] kvasprintf+0x64/0xc8 [<c02d3400>] kasprintf+0x4c/0x5c [<c0453814>] safe_name.isra.1+0x80/0xc4 [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c [<c075f21c>] of_core_init+0x8c/0xf8 [<c0729594>] kernel_init_freeable+0xd4/0x208 [<c00047e8>] kernel_init+0x24/0x11c [<c00158ec>] ret_from_kernel_thread+0x5c/0x64 Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331 Signed-off-by: Frank Rowand <frank.rowand@am.sony.com> Reported-by: mathieu.malaterre@gmail.com Tested-by: Mathieu Malaterre <mathieu.malaterre@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Rob Herring <robh@kernel.org>
2016-06-17 01:51:46 +08:00
extern void __of_sysfs_remove_bin_file(struct device_node *np,
struct property *prop);
of: cache phandle nodes to reduce cost of of_find_node_by_phandle() Create a cache of the nodes that contain a phandle property. Use this cache to find the node for a given phandle value instead of scanning the devicetree to find the node. If the phandle value is not found in the cache, of_find_node_by_phandle() will fall back to the tree scan algorithm. The cache is initialized in of_core_init(). The cache is freed via a late_initcall_sync() if modules are not enabled. If the devicetree is created by the dtc compiler, with all phandle property values auto generated, then the size required by the cache could be 4 * (1 + number of phandles) bytes. This results in an O(1) node lookup cost for a given phandle value. Due to a concern that the phandle property values might not be consistent with what is generated by the dtc compiler, a mask has been added to the cache lookup algorithm. To maintain the O(1) node lookup cost, the size of the cache has been increased by rounding the number of entries up to the next power of two. The overhead of finding the devicetree node containing a given phandle value has been noted by several people in the recent past, in some cases with a patch to add a hashed index of devicetree nodes, based on the phandle value of the node. One concern with this approach is the extra space added to each node. This patch takes advantage of the phandle property values auto generated by the dtc compiler, which begin with one and monotonically increase by one, resulting in a range of 1..n for n phandle values. This implementation should also provide a good reduction of overhead for any range of phandle values that are mostly in a monotonic range. Performance measurements by Chintan Pandya <cpandya@codeaurora.org> of several implementations of patches that are similar to this one suggest an expected reduction of boot time by ~400ms for his test system. If the cache size was decreased to 64 entries, the boot time was reduced by ~340 ms. The measurements were on a 4.9.73 kernel for arch/arm64/boot/dts/qcom/sda670-mtp.dts, contains 2371 nodes and 814 phandle values. Reported-by: Chintan Pandya <cpandya@codeaurora.org> Signed-off-by: Frank Rowand <frank.rowand@sony.com> Signed-off-by: Rob Herring <robh@kernel.org>
2018-03-05 08:14:47 +08:00
/* illegal phandle value (set when unresolved) */
#define OF_PHANDLE_ILLEGAL 0xdeadbeef
of: Transactional DT support. Introducing DT transactional support. A DT transaction is a method which allows one to apply changes in the live tree, in such a way that either the full set of changes take effect, or the state of the tree can be rolled-back to the state it was before it was attempted. An applied transaction can be rolled-back at any time. Documentation is in Documentation/devicetree/changesets.txt Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [glikely: Removed device notifiers and reworked to be more consistent] Signed-off-by: Grant Likely <grant.likely@linaro.org>
2014-07-05 00:58:49 +08:00
/* iterators for transactions, used for overlays */
/* forward iterator */
#define for_each_transaction_entry(_oft, _te) \
list_for_each_entry(_te, &(_oft)->te_list, node)
/* reverse iterator */
#define for_each_transaction_entry_reverse(_oft, _te) \
list_for_each_entry_reverse(_te, &(_oft)->te_list, node)
of: Factor out #{addr,size}-cells parsing In some cases such as PCI host controllers, we may have a "parent bus" which is an OF leaf node, but still need to correctly parse ranges from the point of view of that bus. For that, factor out variants of the "#addr-cells" and "#size-cells" parsers which do not assume they have a device node and thus immediately traverse upwards before reading the relevant property. Signed-off-by: Robin Murphy <robin.murphy@arm.com> [robh: don't make of_bus_n_{addr,size}_cells() public] Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Rob Herring <robh@kernel.org>
2019-07-03 01:42:39 +08:00
extern int of_bus_n_addr_cells(struct device_node *np);
extern int of_bus_n_size_cells(struct device_node *np);
dma-mapping: introduce DMA range map, supplanting dma_pfn_offset The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> [hch: various interface cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-09-18 00:43:40 +08:00
struct bus_dma_region;
#if defined(CONFIG_OF_ADDRESS) && defined(CONFIG_HAS_DMA)
int of_dma_get_range(struct device_node *np,
const struct bus_dma_region **map);
of: Make of_dma_get_range() private of_dma_get_range() is only used within the DT core code, so remove the export and move the header declaration to the private header. Cc: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rob Herring <robh@kernel.org>
2019-09-05 18:53:27 +08:00
#else
dma-mapping: introduce DMA range map, supplanting dma_pfn_offset The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com> [hch: various interface cleanups] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org> Tested-by: Nathan Chancellor <natechancellor@gmail.com>
2020-09-18 00:43:40 +08:00
static inline int of_dma_get_range(struct device_node *np,
const struct bus_dma_region **map)
of: Make of_dma_get_range() private of_dma_get_range() is only used within the DT core code, so remove the export and move the header declaration to the private header. Cc: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Rob Herring <robh@kernel.org>
2019-09-05 18:53:27 +08:00
{
return -ENODEV;
}
#endif
of: Output devicetree alias names in uevent In some situations, userspace may want to resolve a device by function and logical number (ie, "serial0") rather than by the base address or full device path. Being able to resolve a device by alias frees userspace from the burden of otherwise having to maintain a mapping between device addresses and their logical assignments on each platform when multiple instances of the same hardware block are present in the system. Although the uevent device attribute contains devicetree compatible information and the full device path, the uevent does not list the alises that may have been defined for the device. Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org> [grant.likely: Removed OF_ALIAS_N field; I don't think it's needed] [grant.likely: Added #ifndef _LINUX_OF_PRIVATE_H wrapper] Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-12-07 06:55:41 +08:00
#endif /* _LINUX_OF_PRIVATE_H */