From mboxrd@z Thu Jan 1 00:00:00 1970 From: takahiro.akashi@linaro.org (AKASHI Takahiro) Date: Thu, 14 Jul 2016 00:42:26 +0900 Subject: [PATCH v22 1/8] arm64: kdump: reserve memory for crash dump kernel In-Reply-To: References: <20160712050514.22307-1-takahiro.akashi@linaro.org> <20160712050514.22307-2-takahiro.akashi@linaro.org> Message-ID: <20160713154225.GA25403@porco> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi, On Wed, Jul 13, 2016 at 10:12:12AM +0100, Suzuki K Poulose wrote: > On 12/07/16 06:05, AKASHI Takahiro wrote: > >On the startup of primary kernel, the memory region used by crash dump > >kernel must be specified by "crashkernel=" kernel parameter. > >reserve_crashkernel() will allocate and reserve the region for later use. > > > >User space tools, like kexec-tools, will be able to find that region as > > - "Crash kernel" in /proc/iomem, or > > - "linux,crashkernel-base" and "linux,crashkernel-size" under > > /sys/firmware/devicetree/base/chosen > > > >Signed-off-by: AKASHI Takahiro > >Signed-off-by: Mark Salter > >Signed-off-by: Pratyush Anand > >Reviewed-by: James Morse > > Minor nits below. > > >--- > > arch/arm64/kernel/setup.c | 7 ++- > > arch/arm64/mm/init.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 121 insertions(+), 1 deletion(-) > > > >diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > >index c1509e6..cb5eee0 100644 > >--- a/arch/arm64/kernel/setup.c > >+++ b/arch/arm64/kernel/setup.c > >@@ -31,7 +31,6 @@ > > #include > > #include > > #include > >-#include > > #include > > #include > > #include > >@@ -222,6 +221,12 @@ static void __init request_standard_resources(void) > > kernel_data.end <= res->end) > > request_resource(res, &kernel_data); > > } > >+ > >+#ifdef CONFIG_KEXEC_CORE > >+ /* User space tools will find "Crash kernel" region in /proc/iomem. */ > >+ if (crashk_res.end) > >+ insert_resource(&iomem_resource, &crashk_res); > >+#endif > > nit: Could we not do this from reserve_crashkernel() ? Reserve_crashkernel() should be called before arm64_memblock_init(). If the code above is put in reserve_crashkernel(), the inserted resource will be gone later by calling request_resource() in request_standard_resource() because the crashkernel memory is part of System RAM. > > > > #include > > #include > >@@ -76,6 +78,117 @@ static int __init early_initrd(char *p) > > early_param("initrd", early_initrd); > > #endif > > > >+#ifdef CONFIG_KEXEC_CORE > >+static unsigned long long crash_size, crash_base; > >+static struct property crash_base_prop = { > >+ .name = "linux,crashkernel-base", > >+ .length = sizeof(u64), > >+ .value = &crash_base > >+}; > >+static struct property crash_size_prop = { > >+ .name = "linux,crashkernel-size", > >+ .length = sizeof(u64), > >+ .value = &crash_size, > >+}; > >+ > > >+ > >+/* > >+ * reserve_crashkernel() - reserves memory for crash kernel > >+ * > >+ * This function reserves memory area given in "crashkernel=" kernel command > >+ * line parameter. The memory reserved is used by dump capture kernel when > >+ * primary kernel is crashing. > >+ */ > >+static void __init reserve_crashkernel(void) > >+{ > >+ int ret; > >+ > >+ ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > >+ &crash_size, &crash_base); > >+ /* no crashkernel= or invalid value specified */ > >+ if (ret || !crash_size) > >+ return; > >+ > >+ if (crash_base == 0) { > > ... > > >+ memblock_reserve(crash_base, crash_size); > >+ > >+ } else { > > ... > > >+ > >+ memblock_reserve(crash_base, crash_size); > > >+ } > > Nit: you could move the memblock_reserve() here to a single place. Sure. Thanks, -Takahiro AKASHI > >+ > >+ pr_info("Reserving %lldMB of memory at %lldMB for crashkernel\n", > >+ crash_size >> 20, crash_base >> 20); > >+ > >+ crashk_res.start = crash_base; > >+ crashk_res.end = crash_base + crash_size - 1; > > As mentioned above, may be we could move the insert_resource() here, which > would keep the generic setup.c code cleaner and is a bit more reader friendly. > > >+} > >+#else > > Suzuki > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf0-x230.google.com ([2607:f8b0:400e:c00::230]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bNMJQ-0008Tv-VY for kexec@lists.infradead.org; Wed, 13 Jul 2016 15:43:02 +0000 Received: by mail-pf0-x230.google.com with SMTP id t190so19801366pfb.3 for ; Wed, 13 Jul 2016 08:42:40 -0700 (PDT) Date: Thu, 14 Jul 2016 00:42:26 +0900 From: AKASHI Takahiro Subject: Re: [PATCH v22 1/8] arm64: kdump: reserve memory for crash dump kernel Message-ID: <20160713154225.GA25403@porco> References: <20160712050514.22307-1-takahiro.akashi@linaro.org> <20160712050514.22307-2-takahiro.akashi@linaro.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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: Suzuki K Poulose Cc: mark.rutland@arm.com, Pratyush Anand , geoff@infradead.org, catalin.marinas@arm.com, will.deacon@arm.com, robh+dt@kernel.org, james.morse@arm.com, Mark Salter , bauerman@linux.vnet.ibm.com, dyoung@redhat.com, kexec@lists.infradead.org, linux-arm-kernel@lists.infradead.org Hi, On Wed, Jul 13, 2016 at 10:12:12AM +0100, Suzuki K Poulose wrote: > On 12/07/16 06:05, AKASHI Takahiro wrote: > >On the startup of primary kernel, the memory region used by crash dump > >kernel must be specified by "crashkernel=" kernel parameter. > >reserve_crashkernel() will allocate and reserve the region for later use. > > > >User space tools, like kexec-tools, will be able to find that region as > > - "Crash kernel" in /proc/iomem, or > > - "linux,crashkernel-base" and "linux,crashkernel-size" under > > /sys/firmware/devicetree/base/chosen > > > >Signed-off-by: AKASHI Takahiro > >Signed-off-by: Mark Salter > >Signed-off-by: Pratyush Anand > >Reviewed-by: James Morse > > Minor nits below. > > >--- > > arch/arm64/kernel/setup.c | 7 ++- > > arch/arm64/mm/init.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 121 insertions(+), 1 deletion(-) > > > >diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > >index c1509e6..cb5eee0 100644 > >--- a/arch/arm64/kernel/setup.c > >+++ b/arch/arm64/kernel/setup.c > >@@ -31,7 +31,6 @@ > > #include > > #include > > #include > >-#include > > #include > > #include > > #include > >@@ -222,6 +221,12 @@ static void __init request_standard_resources(void) > > kernel_data.end <= res->end) > > request_resource(res, &kernel_data); > > } > >+ > >+#ifdef CONFIG_KEXEC_CORE > >+ /* User space tools will find "Crash kernel" region in /proc/iomem. */ > >+ if (crashk_res.end) > >+ insert_resource(&iomem_resource, &crashk_res); > >+#endif > > nit: Could we not do this from reserve_crashkernel() ? Reserve_crashkernel() should be called before arm64_memblock_init(). If the code above is put in reserve_crashkernel(), the inserted resource will be gone later by calling request_resource() in request_standard_resource() because the crashkernel memory is part of System RAM. > > > > #include > > #include > >@@ -76,6 +78,117 @@ static int __init early_initrd(char *p) > > early_param("initrd", early_initrd); > > #endif > > > >+#ifdef CONFIG_KEXEC_CORE > >+static unsigned long long crash_size, crash_base; > >+static struct property crash_base_prop = { > >+ .name = "linux,crashkernel-base", > >+ .length = sizeof(u64), > >+ .value = &crash_base > >+}; > >+static struct property crash_size_prop = { > >+ .name = "linux,crashkernel-size", > >+ .length = sizeof(u64), > >+ .value = &crash_size, > >+}; > >+ > > >+ > >+/* > >+ * reserve_crashkernel() - reserves memory for crash kernel > >+ * > >+ * This function reserves memory area given in "crashkernel=" kernel command > >+ * line parameter. The memory reserved is used by dump capture kernel when > >+ * primary kernel is crashing. > >+ */ > >+static void __init reserve_crashkernel(void) > >+{ > >+ int ret; > >+ > >+ ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), > >+ &crash_size, &crash_base); > >+ /* no crashkernel= or invalid value specified */ > >+ if (ret || !crash_size) > >+ return; > >+ > >+ if (crash_base == 0) { > > ... > > >+ memblock_reserve(crash_base, crash_size); > >+ > >+ } else { > > ... > > >+ > >+ memblock_reserve(crash_base, crash_size); > > >+ } > > Nit: you could move the memblock_reserve() here to a single place. Sure. Thanks, -Takahiro AKASHI > >+ > >+ pr_info("Reserving %lldMB of memory at %lldMB for crashkernel\n", > >+ crash_size >> 20, crash_base >> 20); > >+ > >+ crashk_res.start = crash_base; > >+ crashk_res.end = crash_base + crash_size - 1; > > As mentioned above, may be we could move the insert_resource() here, which > would keep the generic setup.c code cleaner and is a bit more reader friendly. > > >+} > >+#else > > Suzuki > _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec