From ab7d88549e2f7ae116afd303f32e1950cb790a1d Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Wed, 12 Jan 2022 15:05:03 +0100 Subject: hwrng: cavium - HW_RANDOM_CAVIUM should depend on ARCH_THUNDER The Cavium ThunderX Random Number Generator is only present on Cavium ThunderX SoCs, and not available as an independent PCIe endpoint. Hence add a dependency on ARCH_THUNDER, to prevent asking the user about this driver when configuring a kernel without Cavium Thunder SoC support. Fixes: cc2f1908c6b8f625 ("hwrng: cavium - Add Cavium HWRNG driver for ThunderX SoC.") Signed-off-by: Geert Uytterhoeven Signed-off-by: Herbert Xu --- drivers/char/hw_random/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index 9704963f9d50..a087156a5818 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -401,7 +401,7 @@ config HW_RANDOM_MESON config HW_RANDOM_CAVIUM tristate "Cavium ThunderX Random Number Generator support" - depends on HW_RANDOM && PCI && ARM64 + depends on HW_RANDOM && PCI && ARCH_THUNDER default HW_RANDOM help This driver provides kernel-side support for the Random Number -- cgit v1.2.3 From 26a03981318d2e0f12456a1041fe3bf8af5416cf Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 24 Jan 2022 21:29:46 +0100 Subject: hwrng: core - explicit ordering of initcalls hw-random device drivers depend on the hw-random core being initialized. Make this ordering explicit, also for the case these drivers are built-in. As the core itself depends on misc_register() which is set up at subsys_initcall time, advance the initialization of the core (only) to the fs_initcall() level. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index a3db27916256..e860e044b19e 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -638,7 +638,7 @@ static void __exit hwrng_modexit(void) unregister_miscdev(); } -module_init(hwrng_modinit); +fs_initcall(hwrng_modinit); /* depends on misc_register() */ module_exit(hwrng_modexit); MODULE_DESCRIPTION("H/W Random Number Generator (RNG) driver"); -- cgit v1.2.3 From 6ff6304497c900a0284e3aa89ad86f0ed01f86d8 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 24 Jan 2022 21:29:47 +0100 Subject: hwrng: core - read() callback must be called for size of 32 or more bytes According to , the @max parameter of the ->read callback "is a multiple of 4 and >= 32 bytes". That promise was not kept by add_early_randomness(), which only asked for 16 bytes. As rng_buffer_size() is at least 32, we can simply ask for 32 bytes. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index e860e044b19e..c2d260b5dd92 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -64,10 +64,9 @@ static size_t rng_buffer_size(void) static void add_early_randomness(struct hwrng *rng) { int bytes_read; - size_t size = min_t(size_t, 16, rng_buffer_size()); mutex_lock(&reading_mutex); - bytes_read = rng_get_data(rng, rng_buffer, size, 0); + bytes_read = rng_get_data(rng, rng_buffer, 32, 0); mutex_unlock(&reading_mutex); if (bytes_read > 0) add_device_randomness(rng_buffer, bytes_read); -- cgit v1.2.3 From c05ac449442dd214e262057a3a49c368e224c384 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 24 Jan 2022 21:29:48 +0100 Subject: hwrng: core - use rng_fillbuf in add_early_randomness() Using rng_buffer in add_early_randomness() may race with rng_dev_read(). Use rng_fillbuf instead, as it is otherwise only used within the kernel by hwrng_fillfn() and therefore never exposed to userspace. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index c2d260b5dd92..89891ac87af0 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -66,10 +66,10 @@ static void add_early_randomness(struct hwrng *rng) int bytes_read; mutex_lock(&reading_mutex); - bytes_read = rng_get_data(rng, rng_buffer, 32, 0); + bytes_read = rng_get_data(rng, rng_fillbuf, 32, 0); mutex_unlock(&reading_mutex); if (bytes_read > 0) - add_device_randomness(rng_buffer, bytes_read); + add_device_randomness(rng_fillbuf, bytes_read); } static inline void cleanup_rng(struct kref *kref) -- cgit v1.2.3 From f41aa47c8bb40bcbad51fc368fe15f96406897cb Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 24 Jan 2022 21:29:49 +0100 Subject: hwrng: core - only set cur_rng_set_by_user if it is working In case the user-specified rng device is not working, it is not used; therefore cur_rng_set_by_user must not be set to 1. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 89891ac87af0..9405fcdace38 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -335,8 +335,9 @@ static ssize_t rng_current_store(struct device *dev, } else { list_for_each_entry(rng, &rng_list, list) { if (sysfs_streq(rng->name, buf)) { - cur_rng_set_by_user = 1; err = set_current_rng(rng); + if (!err) + cur_rng_set_by_user = 1; break; } } -- cgit v1.2.3 From f4f7c153a61782f3fb259d0f39aab91444e555d9 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Mon, 24 Jan 2022 21:29:50 +0100 Subject: hwrng: core - break out of hwrng_fillfn if current rng is not trusted For two reasons, current_quality may become zero within the rngd kernel thread: (1) The user lowers current_quality to 0 by writing to the sysfs module parameter file (note that increasing the quality from zero is without effect at the moment), or (2) there are two or more hwrng devices registered, and those which provide quality>0 are unregistered, but one with quality==0 remains. If current_quality is 0, the randomness is not trusted and cannot help to increase the entropy count. That will lead to continuous calls to the hwrngd thread and continuous stirring of the input pool with untrusted bits. Cc: Matt Mackall Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 9405fcdace38..bc9f95cbac92 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -429,6 +429,9 @@ static int hwrng_fillfn(void *unused) while (!kthread_should_stop()) { struct hwrng *rng; + if (!current_quality) + break; + rng = get_current_rng(); if (IS_ERR(rng) || !rng) break; -- cgit v1.2.3 From a43bed8220f26178f0f63bf4c0fc23b7b8b76763 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Fri, 28 Jan 2022 08:02:54 +0100 Subject: hwrng: core - credit entropy for low quality sources of randomness In case the entropy quality is low, there may be less than one bit to credit in the call to add_hwgenerator_randomness(): The number of bytes returned by rng_get_data() multiplied by the current quality (in entropy bits per 1024 bits of input) must be larger than 128 to credit at least one bit. However, imx-rngc.c sets the quality to 19, but may return less than 32 bytes; hid_u2fzero.c sets the quality to 1; and users may override the quality setting manually. In case there is less than one bit to credit, keep track of it and add that credit to the next iteration. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index bc9f95cbac92..f327f7493585 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -424,6 +424,7 @@ static int __init register_miscdev(void) static int hwrng_fillfn(void *unused) { + size_t entropy, entropy_credit = 0; /* in 1/1024 of a bit */ long rc; while (!kthread_should_stop()) { @@ -445,9 +446,17 @@ static int hwrng_fillfn(void *unused) msleep_interruptible(10000); continue; } + + /* If we cannot credit at least one bit of entropy, + * keep track of the remainder for the next iteration + */ + entropy = rc * current_quality * 8 + entropy_credit; + if ((entropy >> 10) == 0) + entropy_credit = entropy; + /* Outside lock, sure, but y'know: randomness. */ add_hwgenerator_randomness((void *)rng_fillbuf, rc, - rc * current_quality * 8 >> 10); + entropy >> 10); } hwrng_fill = NULL; return 0; -- cgit v1.2.3 From c90e453916bd4d74297303d000f011cdb47a7d94 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 13 Feb 2022 21:46:28 +0100 Subject: hwrng: core - do not bother to order list of devices by quality There is no real reason why this list needs to be kept ordered by the driver-provided quality value -- a value which is set only by a handful of hw_random devices anyway. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 36 ++++++++++++++++-------------------- 1 file changed, 16 insertions(+), 20 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index f327f7493585..6f09f4e5af20 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -31,7 +31,7 @@ static struct hwrng *current_rng; /* the current rng has been explicitly chosen by user via sysfs */ static int cur_rng_set_by_user; static struct task_struct *hwrng_fill; -/* list of registered rngs, sorted decending by quality */ +/* list of registered rngs */ static LIST_HEAD(rng_list); /* Protects rng_list and current_rng */ static DEFINE_MUTEX(rng_mutex); @@ -297,24 +297,28 @@ static struct miscdevice rng_miscdev = { static int enable_best_rng(void) { + struct hwrng *rng, *new_rng = NULL; int ret = -ENODEV; BUG_ON(!mutex_is_locked(&rng_mutex)); - /* rng_list is sorted by quality, use the best (=first) one */ - if (!list_empty(&rng_list)) { - struct hwrng *new_rng; - - new_rng = list_entry(rng_list.next, struct hwrng, list); - ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng)); - if (!ret) - cur_rng_set_by_user = 0; - } else { + /* no rng to use? */ + if (list_empty(&rng_list)) { drop_current_rng(); cur_rng_set_by_user = 0; - ret = 0; + return 0; } + /* use the rng which offers the best quality */ + list_for_each_entry(rng, &rng_list, list) { + if (!new_rng || rng->quality > new_rng->quality) + new_rng = rng; + } + + ret = ((new_rng == current_rng) ? 0 : set_current_rng(new_rng)); + if (!ret) + cur_rng_set_by_user = 0; + return ret; } @@ -475,7 +479,6 @@ int hwrng_register(struct hwrng *rng) { int err = -EINVAL; struct hwrng *tmp; - struct list_head *rng_list_ptr; bool is_new_current = false; if (!rng->name || (!rng->data_read && !rng->read)) @@ -489,18 +492,11 @@ int hwrng_register(struct hwrng *rng) if (strcmp(tmp->name, rng->name) == 0) goto out_unlock; } + list_add_tail(&rng->list, &rng_list); init_completion(&rng->cleanup_done); complete(&rng->cleanup_done); - /* rng_list is sorted by decreasing quality */ - list_for_each(rng_list_ptr, &rng_list) { - tmp = list_entry(rng_list_ptr, struct hwrng, list); - if (tmp->quality < rng->quality) - break; - } - list_add_tail(&rng->list, rng_list_ptr); - if (!current_rng || (!cur_rng_set_by_user && rng->quality > current_rng->quality)) { /* -- cgit v1.2.3 From 077bb7a1baec75bd2d7d08e2cbdeb5b72344a4ad Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 13 Feb 2022 21:46:29 +0100 Subject: hwrng: core - start and stop in-kernel rngd in separate function Extract the start/stop logic for the in-kernel rngd thread to a separate function. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 6f09f4e5af20..29febf55b0d4 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -51,7 +51,7 @@ MODULE_PARM_DESC(default_quality, static void drop_current_rng(void); static int hwrng_init(struct hwrng *rng); -static void start_khwrngd(void); +static void hwrng_manage_rngd(void); static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, int wait); @@ -164,10 +164,7 @@ skip_init: if (current_quality > 1024) current_quality = 1024; - if (current_quality == 0 && hwrng_fill) - kthread_stop(hwrng_fill); - if (current_quality > 0 && !hwrng_fill) - start_khwrngd(); + hwrng_manage_rngd(); return 0; } @@ -466,12 +463,19 @@ static int hwrng_fillfn(void *unused) return 0; } -static void start_khwrngd(void) +static void hwrng_manage_rngd(void) { - hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); - if (IS_ERR(hwrng_fill)) { - pr_err("hwrng_fill thread creation failed\n"); - hwrng_fill = NULL; + if (WARN_ON(!mutex_is_locked(&rng_mutex))) + return; + + if (current_quality == 0 && hwrng_fill) + kthread_stop(hwrng_fill); + if (current_quality > 0 && !hwrng_fill) { + hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); + if (IS_ERR(hwrng_fill)) { + pr_err("hwrng_fill thread creation failed\n"); + hwrng_fill = NULL; + } } } -- cgit v1.2.3 From f0fb6953b39e015acfecb8b5158642614e6ce364 Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 13 Feb 2022 21:46:30 +0100 Subject: hwrng: core - use per-rng quality value instead of global setting The current_quality variable exposed as a module parameter is fundamentally broken: If it is set at boot time, it is overwritten once the first hw rng device is loaded; if it is set at runtime, it is without effect if the hw rng device had its quality value set to 0 (and no default_quality was set); and if a new rng is selected, it gets overwritten. Therefore, mark it as obsolete, and replace it by the per-rng quality setting. Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 29febf55b0d4..8df102b39b35 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -44,14 +44,14 @@ static unsigned short default_quality; /* = 0; default to "off" */ module_param(current_quality, ushort, 0644); MODULE_PARM_DESC(current_quality, - "current hwrng entropy estimation per 1024 bits of input"); + "current hwrng entropy estimation per 1024 bits of input -- obsolete"); module_param(default_quality, ushort, 0644); MODULE_PARM_DESC(default_quality, "default entropy content of hwrng per 1024 bits of input"); static void drop_current_rng(void); static int hwrng_init(struct hwrng *rng); -static void hwrng_manage_rngd(void); +static void hwrng_manage_rngd(struct hwrng *rng); static inline int rng_get_data(struct hwrng *rng, u8 *buffer, size_t size, int wait); @@ -160,11 +160,13 @@ static int hwrng_init(struct hwrng *rng) reinit_completion(&rng->cleanup_done); skip_init: - current_quality = rng->quality ? : default_quality; - if (current_quality > 1024) - current_quality = 1024; + if (!rng->quality) + rng->quality = default_quality; + if (rng->quality > 1024) + rng->quality = 1024; + current_quality = rng->quality; /* obsolete */ - hwrng_manage_rngd(); + hwrng_manage_rngd(rng); return 0; } @@ -429,19 +431,24 @@ static int hwrng_fillfn(void *unused) long rc; while (!kthread_should_stop()) { + unsigned short quality; struct hwrng *rng; - if (!current_quality) - break; - rng = get_current_rng(); if (IS_ERR(rng) || !rng) break; mutex_lock(&reading_mutex); rc = rng_get_data(rng, rng_fillbuf, rng_buffer_size(), 1); + if (current_quality != rng->quality) + rng->quality = current_quality; /* obsolete */ + quality = rng->quality; mutex_unlock(&reading_mutex); put_rng(rng); + + if (!quality) + break; + if (rc <= 0) { pr_warn("hwrng: no data available\n"); msleep_interruptible(10000); @@ -451,7 +458,7 @@ static int hwrng_fillfn(void *unused) /* If we cannot credit at least one bit of entropy, * keep track of the remainder for the next iteration */ - entropy = rc * current_quality * 8 + entropy_credit; + entropy = rc * quality * 8 + entropy_credit; if ((entropy >> 10) == 0) entropy_credit = entropy; @@ -463,14 +470,14 @@ static int hwrng_fillfn(void *unused) return 0; } -static void hwrng_manage_rngd(void) +static void hwrng_manage_rngd(struct hwrng *rng) { if (WARN_ON(!mutex_is_locked(&rng_mutex))) return; - if (current_quality == 0 && hwrng_fill) + if (rng->quality == 0 && hwrng_fill) kthread_stop(hwrng_fill); - if (current_quality > 0 && !hwrng_fill) { + if (rng->quality > 0 && !hwrng_fill) { hwrng_fill = kthread_run(hwrng_fillfn, NULL, "hwrng"); if (IS_ERR(hwrng_fill)) { pr_err("hwrng_fill thread creation failed\n"); -- cgit v1.2.3 From 8208285632f950d2bfd489b10148e05134b7119e Mon Sep 17 00:00:00 2001 From: Dominik Brodowski Date: Sun, 13 Feb 2022 21:46:31 +0100 Subject: hwrng: core - introduce rng_quality sysfs attribute The rng_quality sysfs attribute returns the quality setting for the currently active hw_random device, in entropy bits per 1024 bits of input. Storing a value between 0 and 1024 to this file updates this estimate accordingly. Based on the updates to the quality setting, the rngd kernel thread may be stopped (if no hw_random device is trusted to return entropy), may be started (if the quality setting is increased from zero), or may use a different hw_random source (if that has higher quality output). Cc: Herbert Xu Cc: Jason A. Donenfeld Signed-off-by: Dominik Brodowski Signed-off-by: Herbert Xu --- drivers/char/hw_random/core.c | 64 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 63 insertions(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index 8df102b39b35..71eafcc451e1 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -44,7 +44,7 @@ static unsigned short default_quality; /* = 0; default to "off" */ module_param(current_quality, ushort, 0644); MODULE_PARM_DESC(current_quality, - "current hwrng entropy estimation per 1024 bits of input -- obsolete"); + "current hwrng entropy estimation per 1024 bits of input -- obsolete, use rng_quality instead"); module_param(default_quality, ushort, 0644); MODULE_PARM_DESC(default_quality, "default entropy content of hwrng per 1024 bits of input"); @@ -402,14 +402,76 @@ static ssize_t rng_selected_show(struct device *dev, return sysfs_emit(buf, "%d\n", cur_rng_set_by_user); } +static ssize_t rng_quality_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + ssize_t ret; + struct hwrng *rng; + + rng = get_current_rng(); + if (IS_ERR(rng)) + return PTR_ERR(rng); + + if (!rng) /* no need to put_rng */ + return -ENODEV; + + ret = sysfs_emit(buf, "%hu\n", rng->quality); + put_rng(rng); + + return ret; +} + +static ssize_t rng_quality_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t len) +{ + u16 quality; + int ret = -EINVAL; + + if (len < 2) + return -EINVAL; + + ret = mutex_lock_interruptible(&rng_mutex); + if (ret) + return -ERESTARTSYS; + + ret = kstrtou16(buf, 0, &quality); + if (ret || quality > 1024) { + ret = -EINVAL; + goto out; + } + + if (!current_rng) { + ret = -ENODEV; + goto out; + } + + current_rng->quality = quality; + current_quality = quality; /* obsolete */ + + /* the best available RNG may have changed */ + ret = enable_best_rng(); + + /* start/stop rngd if necessary */ + if (current_rng) + hwrng_manage_rngd(current_rng); + +out: + mutex_unlock(&rng_mutex); + return ret ? ret : len; +} + static DEVICE_ATTR_RW(rng_current); static DEVICE_ATTR_RO(rng_available); static DEVICE_ATTR_RO(rng_selected); +static DEVICE_ATTR_RW(rng_quality); static struct attribute *rng_dev_attrs[] = { &dev_attr_rng_current.attr, &dev_attr_rng_available.attr, &dev_attr_rng_selected.attr, + &dev_attr_rng_quality.attr, NULL }; -- cgit v1.2.3 From 0934683dd1c7d307cac29902ee5e0ab50aa279f9 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:22 +0200 Subject: hwrng: atmel - add wait for ready support on read Add wait for ready support on read. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 43 ++++++++++++++++++++++++++------------ 1 file changed, 30 insertions(+), 13 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index ecb71c4317a5..1a4874668c04 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -20,6 +21,7 @@ #define TRNG_CR 0x00 #define TRNG_MR 0x04 #define TRNG_ISR 0x1c +#define TRNG_ISR_DATRDY BIT(0) #define TRNG_ODATA 0x50 #define TRNG_KEY 0x524e4700 /* RNG */ @@ -36,25 +38,40 @@ struct atmel_trng { struct hwrng rng; }; +static bool atmel_trng_wait_ready(struct atmel_trng *trng, bool wait) +{ + int ready; + + ready = readl(trng->base + TRNG_ISR) & TRNG_ISR_DATRDY; + if (!ready && wait) + readl_poll_timeout(trng->base + TRNG_ISR, ready, + ready & TRNG_ISR_DATRDY, 1000, 20000); + + return !!ready; +} + static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max, bool wait) { struct atmel_trng *trng = container_of(rng, struct atmel_trng, rng); u32 *data = buf; + int ret; + + ret = atmel_trng_wait_ready(trng, wait); + if (!ret) + goto out; - /* data ready? */ - if (readl(trng->base + TRNG_ISR) & 1) { - *data = readl(trng->base + TRNG_ODATA); - /* - ensure data ready is only set again AFTER the next data - word is ready in case it got set between checking ISR - and reading ODATA, so we don't risk re-reading the - same word - */ - readl(trng->base + TRNG_ISR); - return 4; - } else - return 0; + *data = readl(trng->base + TRNG_ODATA); + /* + * ensure data ready is only set again AFTER the next data word is ready + * in case it got set between checking ISR and reading ODATA, so we + * don't risk re-reading the same word + */ + readl(trng->base + TRNG_ISR); + ret = 4; + +out: + return ret; } static void atmel_trng_enable(struct atmel_trng *trng) -- cgit v1.2.3 From a223ea9f89ab960eb254ba78429efd42eaf845eb Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:23 +0200 Subject: hwrng: atmel - disable trng on failure path Call atmel_trng_disable() on failure path of probe. Fixes: a1fa98d8116f ("hwrng: atmel - disable TRNG during suspend") Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index 1a4874668c04..b7ef951927fb 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -131,6 +131,7 @@ static int atmel_trng_probe(struct platform_device *pdev) err_register: clk_disable_unprepare(trng->clk); + atmel_trng_disable(trng); return ret; } -- cgit v1.2.3 From f14b02088fb8b6633bc32b052e0d66308f191cc8 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:24 +0200 Subject: hwrng: atmel - rename enable/disable functions to init/cleanup s/atmel_trng_disable/atmel_trng_cleanup/g and s/atmel_trng_enable/atmel_trng_init/g to cope with struct hwrng::{init, cleanup} members. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index b7ef951927fb..17f02049c112 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -74,12 +74,12 @@ out: return ret; } -static void atmel_trng_enable(struct atmel_trng *trng) +static void atmel_trng_init(struct atmel_trng *trng) { writel(TRNG_KEY | 1, trng->base + TRNG_CR); } -static void atmel_trng_disable(struct atmel_trng *trng) +static void atmel_trng_cleanup(struct atmel_trng *trng) { writel(TRNG_KEY, trng->base + TRNG_CR); } @@ -117,7 +117,7 @@ static int atmel_trng_probe(struct platform_device *pdev) if (ret) return ret; - atmel_trng_enable(trng); + atmel_trng_init(trng); trng->rng.name = pdev->name; trng->rng.read = atmel_trng_read; @@ -131,7 +131,7 @@ static int atmel_trng_probe(struct platform_device *pdev) err_register: clk_disable_unprepare(trng->clk); - atmel_trng_disable(trng); + atmel_trng_cleanup(trng); return ret; } @@ -140,7 +140,7 @@ static int atmel_trng_remove(struct platform_device *pdev) struct atmel_trng *trng = platform_get_drvdata(pdev); - atmel_trng_disable(trng); + atmel_trng_cleanup(trng); clk_disable_unprepare(trng->clk); return 0; @@ -151,7 +151,7 @@ static int atmel_trng_suspend(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); - atmel_trng_disable(trng); + atmel_trng_cleanup(trng); clk_disable_unprepare(trng->clk); return 0; @@ -166,7 +166,7 @@ static int atmel_trng_resume(struct device *dev) if (ret) return ret; - atmel_trng_enable(trng); + atmel_trng_init(trng); return 0; } -- cgit v1.2.3 From 9fbd8b306fcb8d1f1294972f26a3e4d57134c4ad Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:25 +0200 Subject: hwrng: atmel - move set of TRNG_HALFR in atmel_trng_init() Move set of TRNG_HALFR in atmel_trng_init() as this function is also called on resume path. In case of SAMA7G5 where backup and self-refresh PM mode is available most of the SoC parts are powered of (including TRNG) when entering suspend. In that case on resuming path TRNG_HALFR should also be re-configured. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 49 +++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 24 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index 17f02049c112..ef49dbe681cf 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -36,6 +36,7 @@ struct atmel_trng { struct clk *clk; void __iomem *base; struct hwrng rng; + bool has_half_rate; }; static bool atmel_trng_wait_ready(struct atmel_trng *trng, bool wait) @@ -74,14 +75,32 @@ out: return ret; } -static void atmel_trng_init(struct atmel_trng *trng) +static int atmel_trng_init(struct atmel_trng *trng) { + unsigned long rate; + int ret; + + ret = clk_prepare_enable(trng->clk); + if (ret) + return ret; + + if (trng->has_half_rate) { + rate = clk_get_rate(trng->clk); + + /* if peripheral clk is above 100MHz, set HALFR */ + if (rate > 100000000) + writel(TRNG_HALFR, trng->base + TRNG_MR); + } + writel(TRNG_KEY | 1, trng->base + TRNG_CR); + + return 0; } static void atmel_trng_cleanup(struct atmel_trng *trng) { writel(TRNG_KEY, trng->base + TRNG_CR); + clk_disable_unprepare(trng->clk); } static int atmel_trng_probe(struct platform_device *pdev) @@ -105,22 +124,14 @@ static int atmel_trng_probe(struct platform_device *pdev) if (!data) return -ENODEV; - if (data->has_half_rate) { - unsigned long rate = clk_get_rate(trng->clk); - - /* if peripheral clk is above 100MHz, set HALFR */ - if (rate > 100000000) - writel(TRNG_HALFR, trng->base + TRNG_MR); - } + trng->has_half_rate = data->has_half_rate; + trng->rng.name = pdev->name; + trng->rng.read = atmel_trng_read; - ret = clk_prepare_enable(trng->clk); + ret = atmel_trng_init(trng); if (ret) return ret; - atmel_trng_init(trng); - trng->rng.name = pdev->name; - trng->rng.read = atmel_trng_read; - ret = devm_hwrng_register(&pdev->dev, &trng->rng); if (ret) goto err_register; @@ -130,7 +141,6 @@ static int atmel_trng_probe(struct platform_device *pdev) return 0; err_register: - clk_disable_unprepare(trng->clk); atmel_trng_cleanup(trng); return ret; } @@ -141,7 +151,6 @@ static int atmel_trng_remove(struct platform_device *pdev) atmel_trng_cleanup(trng); - clk_disable_unprepare(trng->clk); return 0; } @@ -152,7 +161,6 @@ static int atmel_trng_suspend(struct device *dev) struct atmel_trng *trng = dev_get_drvdata(dev); atmel_trng_cleanup(trng); - clk_disable_unprepare(trng->clk); return 0; } @@ -160,15 +168,8 @@ static int atmel_trng_suspend(struct device *dev) static int atmel_trng_resume(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); - int ret; - ret = clk_prepare_enable(trng->clk); - if (ret) - return ret; - - atmel_trng_init(trng); - - return 0; + return atmel_trng_init(trng); } static const struct dev_pm_ops atmel_trng_pm_ops = { -- cgit v1.2.3 From b953188525973314e32586e45bbd3d4768891c27 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:26 +0200 Subject: hwrng: atmel - use __maybe_unused and pm_ptr() for pm ops Use __maybe_unused and pm_ptr() for pm ops. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index ef49dbe681cf..0fff74808472 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -155,8 +155,7 @@ static int atmel_trng_remove(struct platform_device *pdev) return 0; } -#ifdef CONFIG_PM -static int atmel_trng_suspend(struct device *dev) +static int __maybe_unused atmel_trng_suspend(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); @@ -165,18 +164,17 @@ static int atmel_trng_suspend(struct device *dev) return 0; } -static int atmel_trng_resume(struct device *dev) +static int __maybe_unused atmel_trng_resume(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); return atmel_trng_init(trng); } -static const struct dev_pm_ops atmel_trng_pm_ops = { +static const struct dev_pm_ops __maybe_unused atmel_trng_pm_ops = { .suspend = atmel_trng_suspend, .resume = atmel_trng_resume, }; -#endif /* CONFIG_PM */ static const struct atmel_trng_data at91sam9g45_config = { .has_half_rate = false, @@ -204,9 +202,7 @@ static struct platform_driver atmel_trng_driver = { .remove = atmel_trng_remove, .driver = { .name = "atmel-trng", -#ifdef CONFIG_PM - .pm = &atmel_trng_pm_ops, -#endif /* CONFIG_PM */ + .pm = pm_ptr(&atmel_trng_pm_ops), .of_match_table = atmel_trng_dt_ids, }, }; -- cgit v1.2.3 From c4f51eab6ce0b7138f375673dbb2789e49b6d028 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:27 +0200 Subject: hwrng: atmel - add runtime pm support Add runtime PM support. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 44 +++++++++++++++++++++++++++----------- 1 file changed, 32 insertions(+), 12 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index 0fff74808472..b662d44a09a6 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -17,6 +17,7 @@ #include #include #include +#include #define TRNG_CR 0x00 #define TRNG_MR 0x04 @@ -58,6 +59,12 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max, u32 *data = buf; int ret; + ret = pm_runtime_get_sync((struct device *)trng->rng.priv); + if (ret < 0) { + pm_runtime_put_sync((struct device *)trng->rng.priv); + return ret; + } + ret = atmel_trng_wait_ready(trng, wait); if (!ret) goto out; @@ -72,6 +79,8 @@ static int atmel_trng_read(struct hwrng *rng, void *buf, size_t max, ret = 4; out: + pm_runtime_mark_last_busy((struct device *)trng->rng.priv); + pm_runtime_put_sync_autosuspend((struct device *)trng->rng.priv); return ret; } @@ -127,21 +136,28 @@ static int atmel_trng_probe(struct platform_device *pdev) trng->has_half_rate = data->has_half_rate; trng->rng.name = pdev->name; trng->rng.read = atmel_trng_read; + trng->rng.priv = (unsigned long)&pdev->dev; + platform_set_drvdata(pdev, trng); +#ifndef CONFIG_PM ret = atmel_trng_init(trng); if (ret) return ret; +#endif - ret = devm_hwrng_register(&pdev->dev, &trng->rng); - if (ret) - goto err_register; - - platform_set_drvdata(pdev, trng); + pm_runtime_set_autosuspend_delay(&pdev->dev, 100); + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_enable(&pdev->dev); - return 0; + ret = devm_hwrng_register(&pdev->dev, &trng->rng); + if (ret) { + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); +#ifndef CONFIG_PM + atmel_trng_cleanup(trng); +#endif + } -err_register: - atmel_trng_cleanup(trng); return ret; } @@ -151,11 +167,13 @@ static int atmel_trng_remove(struct platform_device *pdev) atmel_trng_cleanup(trng); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); return 0; } -static int __maybe_unused atmel_trng_suspend(struct device *dev) +static int __maybe_unused atmel_trng_runtime_suspend(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); @@ -164,7 +182,7 @@ static int __maybe_unused atmel_trng_suspend(struct device *dev) return 0; } -static int __maybe_unused atmel_trng_resume(struct device *dev) +static int __maybe_unused atmel_trng_runtime_resume(struct device *dev) { struct atmel_trng *trng = dev_get_drvdata(dev); @@ -172,8 +190,10 @@ static int __maybe_unused atmel_trng_resume(struct device *dev) } static const struct dev_pm_ops __maybe_unused atmel_trng_pm_ops = { - .suspend = atmel_trng_suspend, - .resume = atmel_trng_resume, + SET_RUNTIME_PM_OPS(atmel_trng_runtime_suspend, + atmel_trng_runtime_resume, NULL) + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) }; static const struct atmel_trng_data at91sam9g45_config = { -- cgit v1.2.3 From 53e748c2758ca24854b6ce89fb08a93a36772dc0 Mon Sep 17 00:00:00 2001 From: Claudiu Beznea Date: Mon, 21 Feb 2022 09:59:28 +0200 Subject: hwrng: atmel - remove extra line Remove extra line. Signed-off-by: Claudiu Beznea Signed-off-by: Herbert Xu --- drivers/char/hw_random/atmel-rng.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/atmel-rng.c b/drivers/char/hw_random/atmel-rng.c index b662d44a09a6..b8effe77d80f 100644 --- a/drivers/char/hw_random/atmel-rng.c +++ b/drivers/char/hw_random/atmel-rng.c @@ -165,7 +165,6 @@ static int atmel_trng_remove(struct platform_device *pdev) { struct atmel_trng *trng = platform_get_drvdata(pdev); - atmel_trng_cleanup(trng); pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); -- cgit v1.2.3 From e6205ad58a7ac194abfb33897585b38687d797fa Mon Sep 17 00:00:00 2001 From: Wan Jiabing Date: Fri, 25 Feb 2022 14:38:59 +0800 Subject: hwrng: cavium - fix NULL but dereferenced coccicheck error Fix following coccicheck warning: ./drivers/char/hw_random/cavium-rng-vf.c:182:17-20: ERROR: pdev is NULL but dereferenced. Signed-off-by: Wan Jiabing Reviewed-by: Sunil Goutham Signed-off-by: Herbert Xu --- drivers/char/hw_random/cavium-rng-vf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/cavium-rng-vf.c b/drivers/char/hw_random/cavium-rng-vf.c index 6f66919652bf..7c55f4cf4a8b 100644 --- a/drivers/char/hw_random/cavium-rng-vf.c +++ b/drivers/char/hw_random/cavium-rng-vf.c @@ -179,7 +179,7 @@ static int cavium_map_pf_regs(struct cavium_rng *rng) pdev = pci_get_device(PCI_VENDOR_ID_CAVIUM, PCI_DEVID_CAVIUM_RNG_PF, NULL); if (!pdev) { - dev_err(&pdev->dev, "Cannot find RNG PF device\n"); + pr_err("Cannot find RNG PF device\n"); return -EIO; } -- cgit v1.2.3 From 7f0f1f3ef62ed7a40e30aff28115bd94c4211d1d Mon Sep 17 00:00:00 2001 From: Miaoqian Lin Date: Mon, 7 Mar 2022 11:07:24 +0000 Subject: hwrng: nomadik - Change clk_disable to clk_disable_unprepare The corresponding API for clk_prepare_enable is clk_disable_unprepare, other than clk_disable_unprepare. Fix this by changing clk_disable to clk_disable_unprepare. Fixes: beca35d05cc2 ("hwrng: nomadik - use clk_prepare_enable()") Signed-off-by: Miaoqian Lin Reviewed-by: Linus Walleij Signed-off-by: Herbert Xu --- drivers/char/hw_random/nomadik-rng.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/hw_random/nomadik-rng.c b/drivers/char/hw_random/nomadik-rng.c index 67947a19aa22..e8f9621e7954 100644 --- a/drivers/char/hw_random/nomadik-rng.c +++ b/drivers/char/hw_random/nomadik-rng.c @@ -65,14 +65,14 @@ static int nmk_rng_probe(struct amba_device *dev, const struct amba_id *id) out_release: amba_release_regions(dev); out_clk: - clk_disable(rng_clk); + clk_disable_unprepare(rng_clk); return ret; } static void nmk_rng_remove(struct amba_device *dev) { amba_release_regions(dev); - clk_disable(rng_clk); + clk_disable_unprepare(rng_clk); } static const struct amba_id nmk_rng_ids[] = { -- cgit v1.2.3