From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751422AbdHXJGa (ORCPT ); Thu, 24 Aug 2017 05:06:30 -0400 Received: from mail-it0-f44.google.com ([209.85.214.44]:37636 "EHLO mail-it0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255AbdHXJG3 (ORCPT ); Thu, 24 Aug 2017 05:06:29 -0400 MIME-Version: 1.0 In-Reply-To: <20170824081811.19299-4-takahiro.akashi@linaro.org> References: <20170824081811.19299-1-takahiro.akashi@linaro.org> <20170824081811.19299-4-takahiro.akashi@linaro.org> From: Ard Biesheuvel Date: Thu, 24 Aug 2017 10:06:28 +0100 Message-ID: Subject: Re: [PATCH 03/14] resource: add walk_system_ram_res_rev() To: AKASHI Takahiro Cc: Catalin Marinas , Will Deacon , Thiago Jung Bauermann , David Howells , Vivek Goyal , Herbert Xu , "David S. Miller" , Andrew Morton , Michael Ellerman , Dave Young , Baoquan He , Arnd Bergmann , "kexec@lists.infradead.org" , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , Linus Torvalds Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 24 August 2017 at 09:18, AKASHI Takahiro wrote: > This function, being a variant of walk_system_ram_res() introduced in > commit 8c86e70acead ("resource: provide new functions to walk through > resources"), walks through a list of all the resources of System RAM > in reversed order, i.e., from higher to lower. > > It will be used in kexec_file implementation on arm64. > > Signed-off-by: AKASHI Takahiro > Cc: Vivek Goyal > Cc: Andrew Morton > Cc: Linus Torvalds > --- > include/linux/ioport.h | 3 +++ > kernel/resource.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index 6230064d7f95..9a212266299f 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -271,6 +271,9 @@ extern int > walk_system_ram_res(u64 start, u64 end, void *arg, > int (*func)(u64, u64, void *)); > extern int > +walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)); > +extern int > walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, > void *arg, int (*func)(u64, u64, void *)); > > diff --git a/kernel/resource.c b/kernel/resource.c > index 9b5f04404152..1d6d734c75ac 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > #include > > > @@ -469,6 +470,53 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, > return ret; > } > > +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)) > +{ > + struct resource res, *rams; > + u64 orig_end; > + int count, i; > + int ret = -1; > + > + count = 16; /* initial */ > +again: > + /* create a list */ > + rams = vmalloc(sizeof(struct resource) * count); > + if (!rams) > + return ret; > + > + res.start = start; > + res.end = end; > + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > + orig_end = res.end; > + i = 0; > + while ((res.start < res.end) && > + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { > + if (i >= count) { > + /* unlikely but */ > + vfree(rams); > + count += 16; If the count is likely to be < 16, why are we using vmalloc() here? > + goto again; > + } > + > + rams[i].start = res.start; > + rams[i++].end = res.end; > + > + res.start = res.end + 1; > + res.end = orig_end; > + } > + > + /* go reverse */ > + for (i--; i >= 0; i--) { > + ret = (*func)(rams[i].start, rams[i].end, arg); > + if (ret) > + break; > + } > + > + vfree(rams); > + return ret; > +} > + > #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) > > /* > -- > 2.14.1 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: ard.biesheuvel@linaro.org (Ard Biesheuvel) Date: Thu, 24 Aug 2017 10:06:28 +0100 Subject: [PATCH 03/14] resource: add walk_system_ram_res_rev() In-Reply-To: <20170824081811.19299-4-takahiro.akashi@linaro.org> References: <20170824081811.19299-1-takahiro.akashi@linaro.org> <20170824081811.19299-4-takahiro.akashi@linaro.org> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 24 August 2017 at 09:18, AKASHI Takahiro wrote: > This function, being a variant of walk_system_ram_res() introduced in > commit 8c86e70acead ("resource: provide new functions to walk through > resources"), walks through a list of all the resources of System RAM > in reversed order, i.e., from higher to lower. > > It will be used in kexec_file implementation on arm64. > > Signed-off-by: AKASHI Takahiro > Cc: Vivek Goyal > Cc: Andrew Morton > Cc: Linus Torvalds > --- > include/linux/ioport.h | 3 +++ > kernel/resource.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index 6230064d7f95..9a212266299f 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -271,6 +271,9 @@ extern int > walk_system_ram_res(u64 start, u64 end, void *arg, > int (*func)(u64, u64, void *)); > extern int > +walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)); > +extern int > walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, > void *arg, int (*func)(u64, u64, void *)); > > diff --git a/kernel/resource.c b/kernel/resource.c > index 9b5f04404152..1d6d734c75ac 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > #include > > > @@ -469,6 +470,53 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, > return ret; > } > > +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)) > +{ > + struct resource res, *rams; > + u64 orig_end; > + int count, i; > + int ret = -1; > + > + count = 16; /* initial */ > +again: > + /* create a list */ > + rams = vmalloc(sizeof(struct resource) * count); > + if (!rams) > + return ret; > + > + res.start = start; > + res.end = end; > + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > + orig_end = res.end; > + i = 0; > + while ((res.start < res.end) && > + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { > + if (i >= count) { > + /* unlikely but */ > + vfree(rams); > + count += 16; If the count is likely to be < 16, why are we using vmalloc() here? > + goto again; > + } > + > + rams[i].start = res.start; > + rams[i++].end = res.end; > + > + res.start = res.end + 1; > + res.end = orig_end; > + } > + > + /* go reverse */ > + for (i--; i >= 0; i--) { > + ret = (*func)(rams[i].start, rams[i].end, arg); > + if (ret) > + break; > + } > + > + vfree(rams); > + return ret; > +} > + > #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) > > /* > -- > 2.14.1 > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-it0-x232.google.com ([2607:f8b0:4001:c0b::232]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dko6D-0004B4-TB for kexec@lists.infradead.org; Thu, 24 Aug 2017 09:06:51 +0000 Received: by mail-it0-x232.google.com with SMTP id a73so127649itd.1 for ; Thu, 24 Aug 2017 02:06:29 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20170824081811.19299-4-takahiro.akashi@linaro.org> References: <20170824081811.19299-1-takahiro.akashi@linaro.org> <20170824081811.19299-4-takahiro.akashi@linaro.org> From: Ard Biesheuvel Date: Thu, 24 Aug 2017 10:06:28 +0100 Message-ID: Subject: Re: [PATCH 03/14] resource: add walk_system_ram_res_rev() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: AKASHI Takahiro Cc: Herbert Xu , Baoquan He , Catalin Marinas , Will Deacon , "linux-kernel@vger.kernel.org" , "kexec@lists.infradead.org" , David Howells , Linus Torvalds , Arnd Bergmann , "linux-arm-kernel@lists.infradead.org" , Michael Ellerman , Thiago Jung Bauermann , Andrew Morton , Dave Young , "David S. Miller" , Vivek Goyal On 24 August 2017 at 09:18, AKASHI Takahiro wrote: > This function, being a variant of walk_system_ram_res() introduced in > commit 8c86e70acead ("resource: provide new functions to walk through > resources"), walks through a list of all the resources of System RAM > in reversed order, i.e., from higher to lower. > > It will be used in kexec_file implementation on arm64. > > Signed-off-by: AKASHI Takahiro > Cc: Vivek Goyal > Cc: Andrew Morton > Cc: Linus Torvalds > --- > include/linux/ioport.h | 3 +++ > kernel/resource.c | 48 ++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 51 insertions(+) > > diff --git a/include/linux/ioport.h b/include/linux/ioport.h > index 6230064d7f95..9a212266299f 100644 > --- a/include/linux/ioport.h > +++ b/include/linux/ioport.h > @@ -271,6 +271,9 @@ extern int > walk_system_ram_res(u64 start, u64 end, void *arg, > int (*func)(u64, u64, void *)); > extern int > +walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)); > +extern int > walk_iomem_res_desc(unsigned long desc, unsigned long flags, u64 start, u64 end, > void *arg, int (*func)(u64, u64, void *)); > > diff --git a/kernel/resource.c b/kernel/resource.c > index 9b5f04404152..1d6d734c75ac 100644 > --- a/kernel/resource.c > +++ b/kernel/resource.c > @@ -23,6 +23,7 @@ > #include > #include > #include > +#include > #include > > > @@ -469,6 +470,53 @@ int walk_system_ram_res(u64 start, u64 end, void *arg, > return ret; > } > > +int walk_system_ram_res_rev(u64 start, u64 end, void *arg, > + int (*func)(u64, u64, void *)) > +{ > + struct resource res, *rams; > + u64 orig_end; > + int count, i; > + int ret = -1; > + > + count = 16; /* initial */ > +again: > + /* create a list */ > + rams = vmalloc(sizeof(struct resource) * count); > + if (!rams) > + return ret; > + > + res.start = start; > + res.end = end; > + res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; > + orig_end = res.end; > + i = 0; > + while ((res.start < res.end) && > + (!find_next_iomem_res(&res, IORES_DESC_NONE, true))) { > + if (i >= count) { > + /* unlikely but */ > + vfree(rams); > + count += 16; If the count is likely to be < 16, why are we using vmalloc() here? > + goto again; > + } > + > + rams[i].start = res.start; > + rams[i++].end = res.end; > + > + res.start = res.end + 1; > + res.end = orig_end; > + } > + > + /* go reverse */ > + for (i--; i >= 0; i--) { > + ret = (*func)(rams[i].start, rams[i].end, arg); > + if (ret) > + break; > + } > + > + vfree(rams); > + return ret; > +} > + > #if !defined(CONFIG_ARCH_HAS_WALK_MEMORY) > > /* > -- > 2.14.1 > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec