From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751386AbdHaCfB (ORCPT ); Wed, 30 Aug 2017 22:35:01 -0400 Received: from mail-pg0-f53.google.com ([74.125.83.53]:32908 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750802AbdHaCe7 (ORCPT ); Wed, 30 Aug 2017 22:34:59 -0400 X-Google-Smtp-Source: ADKCNb5h0AuoAEV9Ao86CVMc7EDrMEbLZmNiRmn4bCr9oLV7XlVxpLM6kJR5TvUv3kxAlx3Rmv4ivQ== Subject: Re: [PATCH 03/14] resource: add walk_system_ram_res_rev() To: AKASHI Takahiro , catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org Cc: Linus Torvalds , kexec@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20170824081811.19299-1-takahiro.akashi@linaro.org> <20170824081811.19299-4-takahiro.akashi@linaro.org> From: Pratyush Anand Message-ID: <5b6a0f9a-839a-ed57-e78e-88dbc9a7361c@redhat.com> Date: Thu, 31 Aug 2017 08:04:51 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170824081811.19299-4-takahiro.akashi@linaro.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 24 August 2017 01:48 PM, 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; > + goto again; Wounld't it be better to re-alloc a bigger space,copy previous values and free the previous pointer, instead of going *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) > > /* > -- Regards Pratyush From mboxrd@z Thu Jan 1 00:00:00 1970 From: panand@redhat.com (Pratyush Anand) Date: Thu, 31 Aug 2017 08:04:51 +0530 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: <5b6a0f9a-839a-ed57-e78e-88dbc9a7361c@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thursday 24 August 2017 01:48 PM, 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; > + goto again; Wounld't it be better to re-alloc a bigger space,copy previous values and free the previous pointer, instead of going *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) > > /* > -- Regards Pratyush From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pg0-f49.google.com ([74.125.83.49]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1dnFKE-0005KL-QR for kexec@lists.infradead.org; Thu, 31 Aug 2017 02:35:25 +0000 Received: by mail-pg0-f49.google.com with SMTP id 83so24928285pgb.4 for ; Wed, 30 Aug 2017 19:34:59 -0700 (PDT) Subject: Re: [PATCH 03/14] resource: add walk_system_ram_res_rev() References: <20170824081811.19299-1-takahiro.akashi@linaro.org> <20170824081811.19299-4-takahiro.akashi@linaro.org> From: Pratyush Anand Message-ID: <5b6a0f9a-839a-ed57-e78e-88dbc9a7361c@redhat.com> Date: Thu, 31 Aug 2017 08:04:51 +0530 MIME-Version: 1.0 In-Reply-To: <20170824081811.19299-4-takahiro.akashi@linaro.org> Content-Language: en-US List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: AKASHI Takahiro , catalin.marinas@arm.com, will.deacon@arm.com, bauerman@linux.vnet.ibm.com, dhowells@redhat.com, vgoyal@redhat.com, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, mpe@ellerman.id.au, dyoung@redhat.com, bhe@redhat.com, arnd@arndb.de, ard.biesheuvel@linaro.org Cc: kexec@lists.infradead.org, Linus Torvalds , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Thursday 24 August 2017 01:48 PM, 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; > + goto again; Wounld't it be better to re-alloc a bigger space,copy previous values and free the previous pointer, instead of going *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) > > /* > -- Regards Pratyush _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec