1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef __FIRMWARE_LOADER_H
  3#define __FIRMWARE_LOADER_H
  4
  5#include <linux/bitops.h>
  6#include <linux/firmware.h>
  7#include <linux/types.h>
  8#include <linux/kref.h>
  9#include <linux/list.h>
 10#include <linux/completion.h>
 11
 12#include <generated/utsrelease.h>
 13
 14/**
 15 * enum fw_opt - options to control firmware loading behaviour
 16 *
 17 * @FW_OPT_UEVENT: Enables the fallback mechanism to send a kobject uevent
 18 *	when the firmware is not found. Userspace is in charge to load the
 19 *	firmware using the sysfs loading facility.
 20 * @FW_OPT_NOWAIT: Used to describe the firmware request is asynchronous.
 21 * @FW_OPT_USERHELPER: Enable the fallback mechanism, in case the direct
 22 *	filesystem lookup fails at finding the firmware.  For details refer to
 23 *	firmware_fallback_sysfs().
 24 * @FW_OPT_NO_WARN: Quiet, avoid printing warning messages.
 25 * @FW_OPT_NOCACHE: Disables firmware caching. Firmware caching is used to
 26 *	cache the firmware upon suspend, so that upon resume races against the
 27 *	firmware file lookup on storage is avoided. Used for calls where the
 28 *	file may be too big, or where the driver takes charge of its own
 29 *	firmware caching mechanism.
 30 * @FW_OPT_NOFALLBACK_SYSFS: Disable the sysfs fallback mechanism. Takes
 31 *	precedence over &FW_OPT_UEVENT and &FW_OPT_USERHELPER.
 32 * @FW_OPT_FALLBACK_PLATFORM: Enable fallback to device fw copy embedded in
 33 *	the platform's main firmware. If both this fallback and the sysfs
 34 *      fallback are enabled, then this fallback will be tried first.
 35 * @FW_OPT_PARTIAL: Allow partial read of firmware instead of needing to read
 36 *	entire file.
 37 */
 38enum fw_opt {
 39	FW_OPT_UEVENT			= BIT(0),
 40	FW_OPT_NOWAIT			= BIT(1),
 41	FW_OPT_USERHELPER		= BIT(2),
 42	FW_OPT_NO_WARN			= BIT(3),
 43	FW_OPT_NOCACHE			= BIT(4),
 44	FW_OPT_NOFALLBACK_SYSFS		= BIT(5),
 45	FW_OPT_FALLBACK_PLATFORM	= BIT(6),
 46	FW_OPT_PARTIAL			= BIT(7),
 47};
 48
 49enum fw_status {
 50	FW_STATUS_UNKNOWN,
 51	FW_STATUS_LOADING,
 52	FW_STATUS_DONE,
 53	FW_STATUS_ABORTED,
 54};
 55
 56/*
 57 * Concurrent request_firmware() for the same firmware need to be
 58 * serialized.  struct fw_state is simple state machine which hold the
 59 * state of the firmware loading.
 60 */
 61struct fw_state {
 62	struct completion completion;
 63	enum fw_status status;
 64};
 65
 66struct fw_priv {
 67	struct kref ref;
 68	struct list_head list;
 69	struct firmware_cache *fwc;
 70	struct fw_state fw_st;
 71	void *data;
 72	size_t size;
 73	size_t allocated_size;
 74	size_t offset;
 75	u32 opt_flags;
 76#ifdef CONFIG_FW_LOADER_PAGED_BUF
 77	bool is_paged_buf;
 78	struct page **pages;
 79	int nr_pages;
 80	int page_array_size;
 81#endif
 82#ifdef CONFIG_FW_LOADER_USER_HELPER
 83	bool need_uevent;
 84	struct list_head pending_list;
 85#endif
 86	const char *fw_name;
 87};
 88
 89extern struct mutex fw_lock;
 90
 91static inline bool __fw_state_check(struct fw_priv *fw_priv,
 92				    enum fw_status status)
 93{
 94	struct fw_state *fw_st = &fw_priv->fw_st;
 95
 96	return fw_st->status == status;
 97}
 98
 99static inline int __fw_state_wait_common(struct fw_priv *fw_priv, long timeout)
100{
101	struct fw_state *fw_st = &fw_priv->fw_st;
102	long ret;
103
104	ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout);
105	if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
106		return -ENOENT;
107	if (!ret)
108		return -ETIMEDOUT;
109
110	return ret < 0 ? ret : 0;
111}
112
113static inline void __fw_state_set(struct fw_priv *fw_priv,
114				  enum fw_status status)
115{
116	struct fw_state *fw_st = &fw_priv->fw_st;
117
118	WRITE_ONCE(fw_st->status, status);
119
120	if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) {
121#ifdef CONFIG_FW_LOADER_USER_HELPER
122		/*
123		 * Doing this here ensures that the fw_priv is deleted from
124		 * the pending list in all abort/done paths.
125		 */
126		list_del_init(&fw_priv->pending_list);
127#endif
128		complete_all(&fw_st->completion);
129	}
130}
131
132static inline void fw_state_aborted(struct fw_priv *fw_priv)
133{
134	__fw_state_set(fw_priv, FW_STATUS_ABORTED);
135}
136
137static inline bool fw_state_is_aborted(struct fw_priv *fw_priv)
138{
139	return __fw_state_check(fw_priv, FW_STATUS_ABORTED);
140}
141
142static inline void fw_state_start(struct fw_priv *fw_priv)
143{
144	__fw_state_set(fw_priv, FW_STATUS_LOADING);
145}
146
147static inline void fw_state_done(struct fw_priv *fw_priv)
148{
149	__fw_state_set(fw_priv, FW_STATUS_DONE);
150}
151
152int assign_fw(struct firmware *fw, struct device *device);
153
154#ifdef CONFIG_FW_LOADER_PAGED_BUF
155void fw_free_paged_buf(struct fw_priv *fw_priv);
156int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
157int fw_map_paged_buf(struct fw_priv *fw_priv);
158bool fw_is_paged_buf(struct fw_priv *fw_priv);
159#else
160static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
161static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
162static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
163static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
164#endif
165
166#endif /* __FIRMWARE_LOADER_H */