Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1044030AbdDVRf4 (ORCPT ); Sat, 22 Apr 2017 13:35:56 -0400 Received: from mail-it0-f42.google.com ([209.85.214.42]:36472 "EHLO mail-it0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1043996AbdDVRf0 (ORCPT ); Sat, 22 Apr 2017 13:35:26 -0400 From: Bjorn Andersson To: Andy Gross , David Brown , Frank Rowand , Rob Herring , Mark Rutland Cc: linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC 2/3] of: reserved_mem: Accessor for acquiring reserved_mem Date: Sat, 22 Apr 2017 10:35:18 -0700 Message-Id: <20170422173519.5782-2-bjorn.andersson@linaro.org> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170422173519.5782-1-bjorn.andersson@linaro.org> References: <20170422173519.5782-1-bjorn.andersson@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2984 Lines: 83 In some cases drivers referencing a reserved-memory region might want to remap the entire region, but when defining the reserved-memory by "size" the client driver has no means to know the associated base address of the reserved memory region. This patch adds an accessor for such drivers to acquire a handle to their associated reserved-memory for this purpose. Signed-off-by: Bjorn Andersson --- I would have preferred if we could provide a mechanism for drivers to find the reserved_mem of their own device_node, but without a phandle I have not been able to figure out a sane way to make the match. Suggestions are very welcome. drivers/of/of_reserved_mem.c | 26 ++++++++++++++++++++++++++ include/linux/of_reserved_mem.h | 8 ++++++++ 2 files changed, 34 insertions(+) diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index d507c3569a88..aa69c9590a5c 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -397,3 +397,29 @@ void of_reserved_mem_device_release(struct device *dev) rmem->ops->device_release(rmem, dev); } EXPORT_SYMBOL_GPL(of_reserved_mem_device_release); + +/** + * of_get_reserved_mem_by_idx() - acquire reserved_mem from memory-region + * @np: node pointer containing the "memory-region" + * @idx: index within memory-region + * + * This function allows drivers to acquire a reference to the reserved_mem + * struct which is referenced by their memory-region. + * + * Returns a reserved_mem reference, or NULL on error. + */ +struct reserved_mem *of_get_reserved_mem_by_idx(struct device_node *np, int idx) +{ + struct device_node *target; + struct reserved_mem *rmem; + + target = of_parse_phandle(np, "memory-region", idx); + if (!target) + return NULL; + + rmem = __find_rmem(target); + of_node_put(target); + + return rmem; +} +EXPORT_SYMBOL_GPL(of_get_reserved_mem_by_idx); diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h index f8e1992d6423..a9abbe7dd3de 100644 --- a/include/linux/of_reserved_mem.h +++ b/include/linux/of_reserved_mem.h @@ -34,6 +34,8 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, struct device_node *np, int idx); void of_reserved_mem_device_release(struct device *dev); +struct reserved_mem *of_get_reserved_mem_by_idx(struct device_node *np, int idx); + int early_init_dt_alloc_reserved_memory_arch(phys_addr_t size, phys_addr_t align, phys_addr_t start, @@ -52,6 +54,12 @@ static inline int of_reserved_mem_device_init_by_idx(struct device *dev, } static inline void of_reserved_mem_device_release(struct device *pdev) { } +static inline struct reserved_mem *of_get_reserved_mem_by_idx(struct device_node *np, + int idx); +{ + return NULL; +} + static inline void fdt_init_reserved_mem(void) { } static inline void fdt_reserved_mem_save_node(unsigned long node, const char *uname, phys_addr_t base, phys_addr_t size) { } -- 2.12.0