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From: Yinghai Lu <yinghai@kernel.org>
To: Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
	"H. Peter Anvin" <hpa@zytor.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Jan Kiszka <jan.kiszka@web.de>,
	Jason Wessel <jason.wessel@windriver.com>,
	Borislav Petkov <bp@alien8.de>,
	linux-kernel@vger.kernel.org, Yinghai Lu <yinghai@kernel.org>,
	Rob Landley <rob@landley.net>
Subject: [PATCH 30/35] x86: Add Crash kernel low reservation
Date: Thu, 24 Jan 2013 12:20:11 -0800	[thread overview]
Message-ID: <1359058816-7615-31-git-send-email-yinghai@kernel.org> (raw)
In-Reply-To: <1359058816-7615-1-git-send-email-yinghai@kernel.org>

During kdump kernel's booting stage, it need to find low ram for
swiotlb buffer when system does not support intel iommu/dmar remapping.

kexed-tools is appending memmap=exactmap and range from /proc/iomem
with "Crash kernel", and that range is above 4G for 64bit after boot
protocol 2.12.

We need to add another range in /proc/iomem like "Crash kernel low",
so kexec-tools could find that info and append to kdump kernel
command line.

Try to reserve some under 4G if the normal "Crash kernel" is above 4G.

User could specify the size with crashkernel_low=XX[KMG].

-v2: fix warning that is found by Fengguang's test robot.
-v3: move out get_mem_size change to another patch, to solve compiling
     warning that is found by Borislav Petkov <bp@alien8.de>
-v4: user must specify crashkernel_low if system does not support
     intel or amd iommu.

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Rob Landley <rob@landley.net>
---
 Documentation/kernel-parameters.txt |    3 +++
 arch/x86/kernel/setup.c             |   42 +++++++++++++++++++++++++++++++++--
 include/linux/kexec.h               |    3 +++
 kernel/kexec.c                      |   34 +++++++++++++++++++++++-----
 4 files changed, 75 insertions(+), 7 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348..da0e077 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -594,6 +594,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 			is selected automatically. Check
 			Documentation/kdump/kdump.txt for further details.
 
+	crashkernel_low=size[KMG]
+			[KNL, x86] parts under 4G.
+
 	crashkernel=range1:size1[,range2:size2,...][@offset]
 			[KNL] Same as above, but depends on the memory
 			in the running system. The syntax of range is
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 563c99d..4d6179f 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -508,8 +508,44 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 # define CRASH_KERNEL_ADDR_MAX	MAXMEM
 #endif
 
+static void __init reserve_crashkernel_low(void)
+{
+#ifdef CONFIG_X86_64
+	const unsigned long long alignment = 16<<20;	/* 16M */
+	unsigned long long low_base = 0, low_size = 0;
+	unsigned long total_low_mem;
+	unsigned long long base;
+	int ret;
+
+	total_low_mem = memblock_mem_size(1UL<<(32-PAGE_SHIFT));
+	ret = parse_crashkernel_low(boot_command_line, total_low_mem,
+						&low_size, &base);
+	if (ret != 0 || low_size <= 0)
+		return;
+
+	low_base = memblock_find_in_range(low_size, (1ULL<<32),
+					low_size, alignment);
+
+	if (!low_base) {
+		pr_info("crashkernel low reservation failed - No suitable area found.\n");
+
+		return;
+	}
+
+	memblock_reserve(low_base, low_size);
+	pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (System low RAM: %ldMB)\n",
+			(unsigned long)(low_size >> 20),
+			(unsigned long)(low_base >> 20),
+			(unsigned long)(total_low_mem >> 20));
+	crashk_low_res.start = low_base;
+	crashk_low_res.end   = low_base + low_size - 1;
+	insert_resource(&iomem_resource, &crashk_low_res);
+#endif
+}
+
 static void __init reserve_crashkernel(void)
 {
+	const unsigned long long alignment = 16<<20;	/* 16M */
 	unsigned long long total_mem;
 	unsigned long long crash_size, crash_base;
 	int ret;
@@ -523,8 +559,6 @@ static void __init reserve_crashkernel(void)
 
 	/* 0 means: find the address automatically */
 	if (crash_base <= 0) {
-		const unsigned long long alignment = 16<<20;	/* 16M */
-
 		/*
 		 *  kexec want bzImage is below CRASH_KERNEL_ADDR_MAX
 		 */
@@ -535,6 +569,7 @@ static void __init reserve_crashkernel(void)
 			pr_info("crashkernel reservation failed - No suitable area found.\n");
 			return;
 		}
+
 	} else {
 		unsigned long long start;
 
@@ -556,6 +591,9 @@ static void __init reserve_crashkernel(void)
 	crashk_res.start = crash_base;
 	crashk_res.end   = crash_base + crash_size - 1;
 	insert_resource(&iomem_resource, &crashk_res);
+
+	if (crash_base >= (1ULL<<32))
+		reserve_crashkernel_low();
 }
 #else
 static void __init reserve_crashkernel(void)
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index d0b8458..d2e6927 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -191,6 +191,7 @@ extern struct kimage *kexec_crash_image;
 /* Location of a reserved region to hold the crash kernel.
  */
 extern struct resource crashk_res;
+extern struct resource crashk_low_res;
 typedef u32 note_buf_t[KEXEC_NOTE_BYTES/4];
 extern note_buf_t __percpu *crash_notes;
 extern u32 vmcoreinfo_note[VMCOREINFO_NOTE_SIZE/4];
@@ -199,6 +200,8 @@ extern size_t vmcoreinfo_max_size;
 
 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
 		unsigned long long *crash_size, unsigned long long *crash_base);
+int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
+		unsigned long long *crash_size, unsigned long long *crash_base);
 int crash_shrink_memory(unsigned long new_size);
 size_t crash_get_memory_size(void);
 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 5e4bd78..2436ffc 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -54,6 +54,12 @@ struct resource crashk_res = {
 	.end   = 0,
 	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
 };
+struct resource crashk_low_res = {
+	.name  = "Crash kernel low",
+	.start = 0,
+	.end   = 0,
+	.flags = IORESOURCE_BUSY | IORESOURCE_MEM
+};
 
 int kexec_should_crash(struct task_struct *p)
 {
@@ -1369,10 +1375,11 @@ static int __init parse_crashkernel_simple(char 		*cmdline,
  * That function is the entry point for command line parsing and should be
  * called from the arch-specific code.
  */
-int __init parse_crashkernel(char 		 *cmdline,
+static int __init __parse_crashkernel(char *cmdline,
 			     unsigned long long system_ram,
 			     unsigned long long *crash_size,
-			     unsigned long long *crash_base)
+			     unsigned long long *crash_base,
+				const char *name)
 {
 	char 	*p = cmdline, *ck_cmdline = NULL;
 	char	*first_colon, *first_space;
@@ -1382,16 +1389,16 @@ int __init parse_crashkernel(char 		 *cmdline,
 	*crash_base = 0;
 
 	/* find crashkernel and use the last one if there are more */
-	p = strstr(p, "crashkernel=");
+	p = strstr(p, name);
 	while (p) {
 		ck_cmdline = p;
-		p = strstr(p+1, "crashkernel=");
+		p = strstr(p+1, name);
 	}
 
 	if (!ck_cmdline)
 		return -EINVAL;
 
-	ck_cmdline += 12; /* strlen("crashkernel=") */
+	ck_cmdline += strlen(name);
 
 	/*
 	 * if the commandline contains a ':', then that's the extended
@@ -1409,6 +1416,23 @@ int __init parse_crashkernel(char 		 *cmdline,
 	return 0;
 }
 
+int __init parse_crashkernel(char *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+					"crashkernel=");
+}
+
+int __init parse_crashkernel_low(char *cmdline,
+			     unsigned long long system_ram,
+			     unsigned long long *crash_size,
+			     unsigned long long *crash_base)
+{
+	return __parse_crashkernel(cmdline, system_ram, crash_size, crash_base,
+					"crashkernel_low=");
+}
 
 static void update_vmcoreinfo_note(void)
 {
-- 
1.7.10.4


  parent reply	other threads:[~2013-01-24 20:25 UTC|newest]

Thread overview: 89+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-24 20:19 [PATCH 00/35] x86, boot, 64bit: Add support for loading ramdisk and bzImage above 4G Yinghai Lu
2013-01-24 20:19 ` [PATCH 01/35] x86, mm: Fix page table early allocation offset checking Yinghai Lu
2013-01-30  1:20   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 02/35] x86: Handle multiple exactmaps and out of order exactmap Yinghai Lu
2013-01-24 20:19 ` [PATCH 03/35] x86, mm: Introduce memmap=reserveram Yinghai Lu
2013-01-24 20:19 ` [PATCH 04/35] x86: Clean up e820 add kernel range Yinghai Lu
2013-01-24 23:21   ` Jacob Shin
2013-01-30  1:21   ` [tip:x86/mm2] x86: Factor out e820_add_kernel_range() tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 05/35] x86, 64bit, mm: Make pgd next calculation consistent with pud/pmd Yinghai Lu
2013-01-30  1:22   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 06/35] x86, realmode: Set real_mode permissions early Yinghai Lu
2013-01-30  1:23   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 07/35] x86, 64bit, mm: Add generic kernel/ident mapping helper Yinghai Lu
2013-01-30  1:24   ` [tip:x86/mm2] x86, 64bit, mm: Add generic kernel/ ident " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 08/35] x86, 64bit: Copy zero-page early Yinghai Lu
2013-01-30  1:25   ` [tip:x86/mm2] x86, 64bit: Copy struct boot_params early tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 09/35] x86, 64bit, realmode: Use init_level4_pgt to set trapmoline_pgd directly Yinghai Lu
2013-01-30  1:27   ` [tip:x86/mm2] x86, 64bit, realmode: Use init_level4_pgt to set trampoline_pgd directly tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 10/35] x86, realmode: Separate real_mode reserve and setup Yinghai Lu
2013-01-30  1:28   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 11/35] x86, 64bit: early #PF handler set page table Yinghai Lu
2013-01-30  1:29   ` [tip:x86/mm2] x86, 64bit: Use a #PF handler to materialize early mappings on demand tip-bot for H. Peter Anvin
2013-01-24 20:19 ` [PATCH 12/35] x86, 64bit: #PF handler set page to cover only 2M per #PF Yinghai Lu
2013-01-30  1:30   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 13/35] x86, 64bit: Don't set max_pfn_mapped wrong value early on native path Yinghai Lu
2013-01-30  1:31   ` [tip:x86/mm2] x86, 64bit: Don' t " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 14/35] x86: Merge early_reserve_initrd for 32bit and 64bit Yinghai Lu
2013-01-30  1:32   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 15/35] x86: Add get_ramdisk_image/size() Yinghai Lu
2013-01-30  1:34   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 16/35] x86, boot: Add get_cmd_line_ptr() Yinghai Lu
2013-01-30  1:35   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 17/35] x86, boot: Move checking of cmd_line_ptr out of common path Yinghai Lu
2013-01-30  1:36   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:19 ` [PATCH 18/35] x86, boot: Pass cmd_line_ptr with unsigned long instead Yinghai Lu
2013-01-30  1:37   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 19/35] x86, boot: Move verify_cpu.S and no_longmode down Yinghai Lu
2013-01-30  1:38   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 20/35] x86, boot: Move lldt/ltr out of 64bit code section Yinghai Lu
2013-01-30  1:39   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 21/35] x86, kexec: Remove 1024G limitation for kexec buffer on 64bit Yinghai Lu
2013-01-30  1:40   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 22/35] x86, kexec: Set ident mapping for kernel that is above max_pfn Yinghai Lu
2013-01-30  1:42   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 23/35] x86, kexec: Replace ident_mapping_init and init_level4_page Yinghai Lu
2013-01-30  1:43   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 24/35] x86, kexec, 64bit: Only set ident mapping for ram Yinghai Lu
2013-01-30  1:44   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 25/35] x86, boot: Add fields to support load bzImage and ramdisk above 4G Yinghai Lu
2013-01-28  0:07   ` [tip:x86/boot] x86, boot: Define the 2.12 bzImage boot protocol tip-bot for H. Peter Anvin
2013-01-29  9:48   ` [tip:x86/boot] x86, boot: Sanitize boot_params if not zeroed on creation tip-bot for H. Peter Anvin
2013-01-30  1:45   ` [tip:x86/mm2] x86, boot: enable support load bzImage and ramdisk above 4G tip-bot for Yinghai Lu
2013-01-30  1:54     ` Yinghai Lu
2013-01-30  2:18       ` H. Peter Anvin
2013-01-30  3:47   ` [tip:x86/mm2] x86, boot: Support loading bzImage, boot_params " tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 26/35] x86, boot: Update comments about entries for 64bit image Yinghai Lu
2013-01-30  1:46   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:48   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 27/35] x86, boot: Not need to check setup_header version for setup_data Yinghai Lu
2013-01-30  1:47   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:49   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 28/35] memblock: Add memblock_mem_size() Yinghai Lu
2013-01-30  1:49   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:50   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 29/35] x86, kdump: Remove crashkernel range find limit for 64bit Yinghai Lu
2013-01-30  1:50   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:51   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` Yinghai Lu [this message]
2013-01-30  1:51   ` [tip:x86/mm2] x86: Add Crash kernel low reservation tip-bot for Yinghai Lu
2013-02-07  5:14     ` Rob Landley
2013-02-07  6:39       ` Yinghai Lu
2013-01-30  3:52   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 31/35] x86: Merge early kernel reserve for 32bit and 64bit Yinghai Lu
2013-01-30  1:52   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:53   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 32/35] x86, 64bit, mm: Mark data/bss/brk to nx Yinghai Lu
2013-01-30  1:53   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:55   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 33/35] x86, 64bit, mm: hibernate use generic mapping_init Yinghai Lu
2013-01-24 22:50   ` Rafael J. Wysocki
2013-01-30  1:54   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:56   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 34/35] mm: Add alloc_bootmem_low_pages_nopanic() Yinghai Lu
2013-01-30  1:56   ` [tip:x86/mm2] " tip-bot for Yinghai Lu
2013-01-30  3:57   ` tip-bot for Yinghai Lu
2013-01-24 20:20 ` [PATCH 35/35] x86: Don't panic if can not alloc buffer for swiotlb Yinghai Lu
2013-01-25 16:47   ` Konrad Rzeszutek Wilk
2013-01-30  1:57   ` [tip:x86/mm2] x86: Don' t " tip-bot for Yinghai Lu
2013-01-30  3:58   ` tip-bot for Yinghai Lu

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