From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on archive.lwn.net X-Spam-Level: X-Spam-Status: No, score=-5.8 required=5.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=unavailable autolearn_force=no version=3.4.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by archive.lwn.net (Postfix) with ESMTP id 85BC37D584 for ; Fri, 14 Sep 2018 14:42:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728633AbeINT46 (ORCPT ); Fri, 14 Sep 2018 15:56:58 -0400 Received: from mail-wr1-f66.google.com ([209.85.221.66]:36627 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728342AbeINTz2 (ORCPT ); Fri, 14 Sep 2018 15:55:28 -0400 Received: by mail-wr1-f66.google.com with SMTP id e1-v6so10901837wrt.3 for ; Fri, 14 Sep 2018 07:40:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=iacN5A7LU/wkiibiq8lC1h7AfXkWsMWEAz/JdUQ5Jmo=; b=A+PagJ5alGzsVmfKrww5yuuAB6Pcn4SGpA91HCgqbvU1U9nSTVpk+XzKJ7LG/8Jx+e acc/IFWZWDF2nM86ugfSp+QR6KPe/D84tX2YoNpluCYpihWTpWVI85PTvuEuN7a89A2n 6zS493ccqYefWmoyKOcpx4NJQ4D6C7hjWz26Zlw2gVzSjCY7f9ZBbsTcuHjuNYAgDxJi W+VgAdR0S8ONWFeacyPy/8ReWYFz4U7y9Ln8wTTf76pxHjhyBIiUg7CjVn6FNe8u5hEo gmtMJeOKTjK21+o/5OVkmLczbQM0SeJNLxwcOvQs6RLk3kZZS3JAE2orW+ytONqCWIOv nevw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=iacN5A7LU/wkiibiq8lC1h7AfXkWsMWEAz/JdUQ5Jmo=; b=AUi5znf4XC6qrC03yow52L3M8zUH5gYoptTidN/zSWSP/eHR80SyZJMT8KJ20dfz5V 0rj6rfKUJ3spgtWNu+/y698UdTbzEhDhi9QY2ZCFYPFpC5DmA0VnUzMhVwF/b6+mAjbn k1D5dabF3mBcUb+/+OASg5R5lsKqgPcllzpZwvZW7PNC0DbIIlP+6BTOTKPGPeo43wwE aKgMyoIO7p/KHJ6+nGsW74XPDqEOhSkpK/wsYfL//7lL90UFE5G6NidIxV23r0FXunbV L1ZIYqQF26l0/bixzLI+yY9bHEV+9qHrTxlE5YkjxyxaD4vRJzCtsm/a9UaLy9p42V/4 jlEw== X-Gm-Message-State: APzg51BsFA8kRfP1KHhawkhlI0U3Q42Ntr0sYWK8eox4/x2i3LBHhQOf OviE+acn2magU4B++HXkWJIMZA== X-Google-Smtp-Source: ANB0VdblS+NZxH8ZB/fLWY+GavsC2hZ/aBLIrCWzkE/zRigEXO09s2nspcwqwru6QNdqjHcIsi0dTA== X-Received: by 2002:a5d:6aca:: with SMTP id u10-v6mr10240281wrw.44.1536936039380; Fri, 14 Sep 2018 07:40:39 -0700 (PDT) Received: from brgl-bgdev.home ([2a01:cb1d:af:5b00:e837:b8d5:48c1:571b]) by smtp.gmail.com with ESMTPSA id v46-v6sm10313526wrc.63.2018.09.14.07.40.38 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 14 Sep 2018 07:40:38 -0700 (PDT) From: Bartosz Golaszewski To: Srinivas Kandagatla , "David S . Miller" , Mauro Carvalho Chehab , Greg Kroah-Hartman , Andrew Morton , Arnd Bergmann , Jonathan Corbet , Sekhar Nori , Kevin Hilman , David Lechner , Boris Brezillon , Andrew Lunn , Alban Bedel , Maxime Ripard , Chen-Yu Tsai Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Bartosz Golaszewski Subject: [PATCH v4 12/22] nvmem: remove the global cell list Date: Fri, 14 Sep 2018 16:40:01 +0200 Message-Id: <20180914144011.27614-13-brgl@bgdev.pl> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20180914144011.27614-1-brgl@bgdev.pl> References: <20180914144011.27614-1-brgl@bgdev.pl> Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Bartosz Golaszewski 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 --- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: brgl@bgdev.pl (Bartosz Golaszewski) Date: Fri, 14 Sep 2018 16:40:01 +0200 Subject: [PATCH v4 12/22] nvmem: remove the global cell list In-Reply-To: <20180914144011.27614-1-brgl@bgdev.pl> References: <20180914144011.27614-1-brgl@bgdev.pl> Message-ID: <20180914144011.27614-13-brgl@bgdev.pl> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Bartosz Golaszewski 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 --- 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