Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753274AbdFVNV7 (ORCPT ); Thu, 22 Jun 2017 09:21:59 -0400 Received: from mail7.pr.hu ([87.242.0.7]:54057 "EHLO mail7.pr.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751598AbdFVNVy (ORCPT ); Thu, 22 Jun 2017 09:21:54 -0400 From: =?UTF-8?q?Zolt=C3=A1n=20B=C3=B6sz=C3=B6rm=C3=A9nyi?= To: linux-kernel@vger.kernel.org Cc: linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-i2c@vger.kernel.org, Paul Menzel , Christian Fetzer , Jean Delvare , Nehal Shah , Tim Small , Guenter Roeck , kernel@ekass.net, wim@iguana.be, jlayton@poochiereds.net, marc.2377@gmail.com, cshorler@googlemail.com, wsa@the-dreams.de, regressions@leemhuis.info, =?UTF-8?q?Zolt=C3=A1n=20B=C3=B6sz=C3=B6rm=C3=A9nyi?= Subject: [PATCH 1/5 v2] Extend the request_region() infrastructure Date: Thu, 22 Jun 2017 15:21:30 +0200 Message-Id: <20170622132134.7200-2-zboszor@pr.hu> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20170622132134.7200-1-zboszor@pr.hu> References: <20170621035349.4125-1-zboszor@pr.hu> <20170622132134.7200-1-zboszor@pr.hu> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Spam-Score: 0.3 (/) X-Scan-Signature: be3bea3309f5fb277e55bd6d8213822e X-Spam-Tracer: backend.mail.pr.hu 0.3 20170622132149Z Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5889 Lines: 167 Add a new IORESOURCE_ALLOCATED flag that is automatically used when alloc_resource() is used internally in kernel/resource.c and free_resource() now takes this flag into account. The core of __request_region() was factored out into a new function called __request_declared_region() that needs struct resource * instead of the (start, n, name) triplet. These changes allow using statically declared struct resource data coupled with the pre-existing DEFINE_RES_IO_NAMED() static initializer macro. The new macro exploiting __request_declared_region() is request_declared_muxed_region() v2: Fixed checkpatch.pl warnings and errors and extended the macro API with request_declared_region() and release_declared_region() Reversed the order of __request_declared_region and __request_region Added high level description of the muxed and declared variants of the macros. Signed-off-by: Zoltán Böszörményi --- include/linux/ioport.h | 14 ++++++++++++++ kernel/resource.c | 40 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 51 insertions(+), 3 deletions(-) diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 6230064..6ebcd39 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -52,6 +52,7 @@ struct resource { #define IORESOURCE_MEM_64 0x00100000 #define IORESOURCE_WINDOW 0x00200000 /* forwarded by bridge */ #define IORESOURCE_MUXED 0x00400000 /* Resource is software muxed */ +#define IORESOURCE_ALLOCATED 0x00800000 /* Resource was allocated */ #define IORESOURCE_EXT_TYPE_BITS 0x01000000 /* Resource extended types */ #define IORESOURCE_SYSRAM 0x01000000 /* System RAM (modifier) */ @@ -215,7 +216,14 @@ static inline bool resource_contains(struct resource *r1, struct resource *r2) /* Convenience shorthand with allocation */ #define request_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), 0) +#define request_declared_region(res) __request_region( \ + &ioport_resource, \ + (res), 0) #define request_muxed_region(start,n,name) __request_region(&ioport_resource, (start), (n), (name), IORESOURCE_MUXED) +#define request_declared_muxed_region(res) __request_declared_region( \ + &ioport_resource, \ + (res), \ + IORESOURCE_MUXED) #define __request_mem_region(start,n,name, excl) __request_region(&iomem_resource, (start), (n), (name), excl) #define request_mem_region(start,n,name) __request_region(&iomem_resource, (start), (n), (name), 0) #define request_mem_region_exclusive(start,n,name) \ @@ -227,8 +235,14 @@ extern struct resource * __request_region(struct resource *, resource_size_t n, const char *name, int flags); +extern struct resource *__request_declared_region(struct resource *parent, + struct resource *res, int flags); + /* Compatibility cruft */ #define release_region(start,n) __release_region(&ioport_resource, (start), (n)) +#define release_declared_region(res) __release_region(&ioport_resource, \ + (res)->start, \ + (res)->end - (res)->start + 1) #define release_mem_region(start,n) __release_region(&iomem_resource, (start), (n)) extern void __release_region(struct resource *, resource_size_t, diff --git a/kernel/resource.c b/kernel/resource.c index 9b5f044..2be7029 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -184,6 +184,9 @@ static void free_resource(struct resource *res) if (!res) return; + if (!(res->flags & IORESOURCE_ALLOCATED)) + return; + if (!PageSlab(virt_to_head_page(res))) { spin_lock(&bootmem_resource_lock); res->sibling = bootmem_resource_free; @@ -210,6 +213,8 @@ static struct resource *alloc_resource(gfp_t flags) else res = kzalloc(sizeof(struct resource), flags); + res->flags = IORESOURCE_ALLOCATED; + return res; } @@ -1110,8 +1115,19 @@ resource_size_t resource_alignment(struct resource *res) * the IO flag meanings (busy etc). * * request_region creates a new busy region. + * The resource descriptor is allocated by this function. + * + * request_declared_region creates a new busy region + * described in an existing resource descriptor. + * + * request_muxed_region creates a new shared busy region. + * The resource descriptor is allocated by this function. + * + * request_declared_muxed_region creates a new shared busy region + * described in an existing resource descriptor. * * release_region releases a matching busy region. + * The region is only freed if it was allocated. */ static DECLARE_WAIT_QUEUE_HEAD(muxed_resource_wait); @@ -1128,7 +1144,6 @@ struct resource * __request_region(struct resource *parent, resource_size_t start, resource_size_t n, const char *name, int flags) { - DECLARE_WAITQUEUE(wait, current); struct resource *res = alloc_resource(GFP_KERNEL); if (!res) @@ -1138,6 +1153,26 @@ struct resource * __request_region(struct resource *parent, res->start = start; res->end = start + n - 1; + if (!__request_declared_region(parent, res, flags)) { + free_resource(res); + res = NULL; + } + + return res; +} +EXPORT_SYMBOL(__request_region); + +/** + * __request_declared_region - create a new busy resource region + * @parent: parent resource descriptor + * @res: child resource descriptor + * @flags: IO resource flags + */ +struct resource *__request_declared_region(struct resource *parent, + struct resource *res, int flags) +{ + DECLARE_WAITQUEUE(wait, current); + write_lock(&resource_lock); for (;;) { @@ -1166,14 +1201,13 @@ struct resource * __request_region(struct resource *parent, continue; } /* Uhhuh, that didn't work out.. */ - free_resource(res); res = NULL; break; } write_unlock(&resource_lock); return res; } -EXPORT_SYMBOL(__request_region); +EXPORT_SYMBOL(__request_declared_region); /** * __release_region - release a previously reserved resource region -- 2.9.4