From: Bartosz Golaszewski <brgl@bgdev.pl> To: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>, "David S . Miller" <davem@davemloft.net>, Mauro Carvalho Chehab <mchehab+samsung@kernel.org>, Greg Kroah-Hartman <gregkh@linuxfoundation.org>, Andrew Morton <akpm@linux-foundation.org>, Arnd Bergmann <arnd@arndb.de>, Jonathan Corbet <corbet@lwn.net>, Sekhar Nori <nsekhar@ti.com>, Kevin Hilman <khilman@kernel.org>, David Lechner <david@lechnology.com>, Boris Brezillon <boris.brezillon@bootlin.com>, Andrew Lunn <andrew@lunn.ch>, Alban Bedel <albeu@free.fr>, Maxime Ripard <maxime.ripard@bootlin.com>, Chen-Yu Tsai <wens@csie.org> Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Bartosz Golaszewski <bgolaszewski@baylibre.com> Subject: [PATCH v3 11/21] nvmem: remove the global cell list Date: Wed, 12 Sep 2018 09:51:19 +0200 [thread overview] Message-ID: <20180912075129.25185-12-brgl@bgdev.pl> (raw) In-Reply-To: <20180912075129.25185-1-brgl@bgdev.pl> From: Bartosz Golaszewski <bgolaszewski@baylibre.com> Nvmem subsystem keeps a global list of cells that, for non-DT systems, can only be referenced by cell name, which makes it impossible to have more than one nvmem device with cells named the same. This patch makes every nvmem device the owner of the list of its cells. This effectively removes the support for non-DT systems, but it will be reintroduced following a different approach in subsequent patches. This isn't a problem as support for board files in nvmem is currently broken anyway: any user that would try to get an nvmem cell from the global cell list would remove the cell after the calling nvmem_cell_put(). This can cause anything from a subsequent user not being able to get the cell to double free errors if more users hold reference to the same cell at the same time. Fortunately there are no such users which allows us to rework this part. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> --- drivers/nvmem/core.c | 64 +++++++++++--------------------------------- 1 file changed, 15 insertions(+), 49 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index c950d54bb69d..585688ea2152 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -38,6 +38,7 @@ struct nvmem_device { int flags; struct bin_attribute eeprom; struct device *base_dev; + struct list_head cells; nvmem_reg_read_t reg_read; nvmem_reg_write_t reg_write; void *priv; @@ -58,9 +59,6 @@ struct nvmem_cell { static DEFINE_MUTEX(nvmem_mutex); static DEFINE_IDA(nvmem_ida); -static LIST_HEAD(nvmem_cells); -static DEFINE_MUTEX(nvmem_cells_mutex); - #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key eeprom_lock_key; #endif @@ -282,28 +280,11 @@ static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) return to_nvmem_device(d); } -static struct nvmem_cell *nvmem_find_cell(const char *cell_id) -{ - struct nvmem_cell *p; - - mutex_lock(&nvmem_cells_mutex); - - list_for_each_entry(p, &nvmem_cells, node) - if (!strcmp(p->name, cell_id)) { - mutex_unlock(&nvmem_cells_mutex); - return p; - } - - mutex_unlock(&nvmem_cells_mutex); - - return NULL; -} - static void nvmem_cell_drop(struct nvmem_cell *cell) { - mutex_lock(&nvmem_cells_mutex); + mutex_lock(&nvmem_mutex); list_del(&cell->node); - mutex_unlock(&nvmem_cells_mutex); + mutex_unlock(&nvmem_mutex); kfree(cell); } @@ -311,16 +292,15 @@ static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) { struct nvmem_cell *cell, *p; - list_for_each_entry_safe(cell, p, &nvmem_cells, node) - if (cell->nvmem == nvmem) - nvmem_cell_drop(cell); + list_for_each_entry_safe(cell, p, &nvmem->cells, node) + nvmem_cell_drop(cell); } static void nvmem_cell_add(struct nvmem_cell *cell) { - mutex_lock(&nvmem_cells_mutex); - list_add_tail(&cell->node, &nvmem_cells); - mutex_unlock(&nvmem_cells_mutex); + mutex_lock(&nvmem_mutex); + list_add_tail(&cell->node, &cell->nvmem->cells); + mutex_unlock(&nvmem_mutex); } static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, @@ -465,6 +445,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) } kref_init(&nvmem->refcnt); + INIT_LIST_HEAD(&nvmem->cells); nvmem->id = rval; nvmem->owner = config->owner; @@ -626,29 +607,14 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np, { struct nvmem_device *nvmem = NULL; - mutex_lock(&nvmem_mutex); - - if (np) { - nvmem = of_nvmem_find(np); - if (!nvmem) { - mutex_unlock(&nvmem_mutex); - return ERR_PTR(-EPROBE_DEFER); - } - } else { - struct nvmem_cell *cell = nvmem_find_cell(cell_id); - - if (cell) { - nvmem = cell->nvmem; - *cellp = cell; - } - - if (!nvmem) { - mutex_unlock(&nvmem_mutex); - return ERR_PTR(-ENOENT); - } - } + if (!np) + return ERR_PTR(-ENOENT); + mutex_lock(&nvmem_mutex); + nvmem = of_nvmem_find(np); mutex_unlock(&nvmem_mutex); + if (!nvmem) + return ERR_PTR(-EPROBE_DEFER); if (!try_module_get(nvmem->owner)) { dev_err(&nvmem->dev, -- 2.18.0
WARNING: multiple messages have this Message-ID (diff)
From: brgl@bgdev.pl (Bartosz Golaszewski) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 11/21] nvmem: remove the global cell list Date: Wed, 12 Sep 2018 09:51:19 +0200 [thread overview] Message-ID: <20180912075129.25185-12-brgl@bgdev.pl> (raw) In-Reply-To: <20180912075129.25185-1-brgl@bgdev.pl> From: Bartosz Golaszewski <bgolaszewski@baylibre.com> Nvmem subsystem keeps a global list of cells that, for non-DT systems, can only be referenced by cell name, which makes it impossible to have more than one nvmem device with cells named the same. This patch makes every nvmem device the owner of the list of its cells. This effectively removes the support for non-DT systems, but it will be reintroduced following a different approach in subsequent patches. This isn't a problem as support for board files in nvmem is currently broken anyway: any user that would try to get an nvmem cell from the global cell list would remove the cell after the calling nvmem_cell_put(). This can cause anything from a subsequent user not being able to get the cell to double free errors if more users hold reference to the same cell at the same time. Fortunately there are no such users which allows us to rework this part. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> --- drivers/nvmem/core.c | 64 +++++++++++--------------------------------- 1 file changed, 15 insertions(+), 49 deletions(-) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index c950d54bb69d..585688ea2152 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -38,6 +38,7 @@ struct nvmem_device { int flags; struct bin_attribute eeprom; struct device *base_dev; + struct list_head cells; nvmem_reg_read_t reg_read; nvmem_reg_write_t reg_write; void *priv; @@ -58,9 +59,6 @@ struct nvmem_cell { static DEFINE_MUTEX(nvmem_mutex); static DEFINE_IDA(nvmem_ida); -static LIST_HEAD(nvmem_cells); -static DEFINE_MUTEX(nvmem_cells_mutex); - #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key eeprom_lock_key; #endif @@ -282,28 +280,11 @@ static struct nvmem_device *of_nvmem_find(struct device_node *nvmem_np) return to_nvmem_device(d); } -static struct nvmem_cell *nvmem_find_cell(const char *cell_id) -{ - struct nvmem_cell *p; - - mutex_lock(&nvmem_cells_mutex); - - list_for_each_entry(p, &nvmem_cells, node) - if (!strcmp(p->name, cell_id)) { - mutex_unlock(&nvmem_cells_mutex); - return p; - } - - mutex_unlock(&nvmem_cells_mutex); - - return NULL; -} - static void nvmem_cell_drop(struct nvmem_cell *cell) { - mutex_lock(&nvmem_cells_mutex); + mutex_lock(&nvmem_mutex); list_del(&cell->node); - mutex_unlock(&nvmem_cells_mutex); + mutex_unlock(&nvmem_mutex); kfree(cell); } @@ -311,16 +292,15 @@ static void nvmem_device_remove_all_cells(const struct nvmem_device *nvmem) { struct nvmem_cell *cell, *p; - list_for_each_entry_safe(cell, p, &nvmem_cells, node) - if (cell->nvmem == nvmem) - nvmem_cell_drop(cell); + list_for_each_entry_safe(cell, p, &nvmem->cells, node) + nvmem_cell_drop(cell); } static void nvmem_cell_add(struct nvmem_cell *cell) { - mutex_lock(&nvmem_cells_mutex); - list_add_tail(&cell->node, &nvmem_cells); - mutex_unlock(&nvmem_cells_mutex); + mutex_lock(&nvmem_mutex); + list_add_tail(&cell->node, &cell->nvmem->cells); + mutex_unlock(&nvmem_mutex); } static int nvmem_cell_info_to_nvmem_cell(struct nvmem_device *nvmem, @@ -465,6 +445,7 @@ struct nvmem_device *nvmem_register(const struct nvmem_config *config) } kref_init(&nvmem->refcnt); + INIT_LIST_HEAD(&nvmem->cells); nvmem->id = rval; nvmem->owner = config->owner; @@ -626,29 +607,14 @@ static struct nvmem_device *__nvmem_device_get(struct device_node *np, { struct nvmem_device *nvmem = NULL; - mutex_lock(&nvmem_mutex); - - if (np) { - nvmem = of_nvmem_find(np); - if (!nvmem) { - mutex_unlock(&nvmem_mutex); - return ERR_PTR(-EPROBE_DEFER); - } - } else { - struct nvmem_cell *cell = nvmem_find_cell(cell_id); - - if (cell) { - nvmem = cell->nvmem; - *cellp = cell; - } - - if (!nvmem) { - mutex_unlock(&nvmem_mutex); - return ERR_PTR(-ENOENT); - } - } + if (!np) + return ERR_PTR(-ENOENT); + mutex_lock(&nvmem_mutex); + nvmem = of_nvmem_find(np); mutex_unlock(&nvmem_mutex); + if (!nvmem) + return ERR_PTR(-EPROBE_DEFER); if (!try_module_get(nvmem->owner)) { dev_err(&nvmem->dev, -- 2.18.0
next prev parent reply other threads:[~2018-09-12 7:52 UTC|newest] Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top 2018-09-12 7:51 [PATCH v3 00/21] nvmem: rework of the subsystem for non-DT users Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 01/21] nvmem: provide nvmem_dev_name() Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 02/21] nvmem: remove the name field from struct nvmem_device Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 03/21] nvmem: use list_for_each_entry_safe in nvmem_device_remove_all_cells() Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 04/21] nvmem: remove a stray newline Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 05/21] nvmem: check the return value of nvmem_add_cells() Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 06/21] nvmem: use kref Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 07/21] nvmem: lpc18xx_eeprom: use devm_nvmem_register() Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 08/21] nvmem: sunxi_sid: " Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-13 1:38 ` kbuild test robot 2018-09-13 1:38 ` kbuild test robot 2018-09-13 8:39 ` Bartosz Golaszewski 2018-09-13 8:39 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 09/21] nvmem: mxs-ocotp: " Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 10/21] nvmem: change the signature of nvmem_unregister() Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-13 0:34 ` kbuild test robot 2018-09-13 0:34 ` kbuild test robot 2018-09-13 1:46 ` kbuild test robot 2018-09-13 1:46 ` kbuild test robot 2018-09-12 7:51 ` Bartosz Golaszewski [this message] 2018-09-12 7:51 ` [PATCH v3 11/21] nvmem: remove the global cell list Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 12/21] nvmem: add support for cell info Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 13/21] nvmem: resolve cells from DT at registration time Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 14/21] nvmem: add support for cell lookups from machine code Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 15/21] Documentation: nvmem: document cell tables and lookup entries Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 16/21] nvmem: add a notifier chain Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 9:33 ` Bartosz Golaszewski 2018-09-12 9:33 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 17/21] nvmem: use SPDX license identifiers Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 18/21] nvmem: make the naming of arguments in nvmem_cell_get() consistent Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 19/21] nvmem: use EOPNOTSUPP instead of ENOSYS Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 20/21] nvmem: fix commenting style Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-12 7:51 ` [PATCH v3 21/21] nvmem: use octal permissions instead of constants Bartosz Golaszewski 2018-09-12 7:51 ` Bartosz Golaszewski 2018-09-14 14:43 ` [PATCH v3 00/21] nvmem: rework of the subsystem for non-DT users Bartosz Golaszewski 2018-09-14 14:43 ` Bartosz Golaszewski
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