[PATCH] Limit E820 map and /proc/iomem for mem parameter on x86-64
Bernhard Walle
bwalle at suse.de
Tue Jun 10 17:53:25 EDT 2008
This patch tries to unify the behaviour of i386 and x86-64 when parsing
the memory (mem/memmap) parameter of the kernel command line:
On i386, the view was limited (i.e. the actual view was presented).
On x86-64, the view was full (i.e. the BIOS view was presented).
This patch moves the limit_regions() function and the print_memory_map()
function to a new file e820.c, shared between the two x86 flavours. Then
it adds calls to limit_regions() in 64 bit code.
I gave the patch a bit testing. However, it's not for merging, it's just
to get early feedback to see if that goes into the right direction.
Signed-off-by: Bernhard Walle <bwalle at suse.de>
---
arch/x86/kernel/Makefile | 2 -
arch/x86/kernel/e820.c | 75 +++++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/e820_32.c | 60 +-----------------------------------
arch/x86/kernel/e820_64.c | 4 ++
arch/x86/kernel/setup_32.c | 4 +-
include/asm-x86/e820.h | 4 ++
6 files changed, 88 insertions(+), 61 deletions(-)
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -22,7 +22,7 @@ obj-y += setup_$(BITS).o i8259_$(BITS)
obj-$(CONFIG_X86_32) += sys_i386_32.o i386_ksyms_32.o
obj-$(CONFIG_X86_64) += sys_x86_64.o x8664_ksyms_64.o
obj-$(CONFIG_X86_64) += syscall_64.o vsyscall_64.o setup64.o
-obj-y += bootflag.o e820_$(BITS).o
+obj-y += bootflag.o e820_$(BITS).o e820.o
obj-y += pci-dma.o quirks.o i8237.o topology.o kdebugfs.o
obj-y += alternative.o i8253.o pci-nommu.o
obj-$(CONFIG_X86_64) += bugs_64.o
--- /dev/null
+++ b/arch/x86/kernel/e820.c
@@ -0,0 +1,75 @@
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/ioport.h>
+#include <linux/string.h>
+#include <linux/kexec.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/pfn.h>
+#include <linux/uaccess.h>
+#include <linux/suspend.h>
+
+#include <asm/pgtable.h>
+#include <asm/page.h>
+#include <asm/e820.h>
+#include <asm/setup.h>
+
+void __init limit_regions(struct e820map *e820, unsigned long long size)
+{
+ unsigned long long current_addr;
+ int i;
+
+ print_memory_map(e820, "limit_regions start");
+ for (i = 0; i < e820->nr_map; i++) {
+ current_addr = e820->map[i].addr + e820->map[i].size;
+ if (current_addr < size)
+ continue;
+
+ if (e820->map[i].type != E820_RAM)
+ continue;
+
+ if (e820->map[i].addr >= size) {
+ /*
+ * This region starts past the end of the
+ * requested size, skip it completely.
+ */
+ e820->nr_map = i;
+ } else {
+ e820->nr_map = i + 1;
+ e820->map[i].size -= current_addr - size;
+ }
+ print_memory_map(e820, "limit_regions endfor");
+ return;
+ }
+ print_memory_map(e820, "limit_regions endfunc");
+}
+
+void __init print_memory_map(struct e820map *e820, char *who)
+{
+ int i;
+
+ for (i = 0; i < e820->nr_map; i++) {
+ printk(" %s: %016Lx - %016Lx ", who,
+ e820->map[i].addr,
+ e820->map[i].addr + e820->map[i].size);
+ switch (e820->map[i].type) {
+ case E820_RAM: printk("(usable)\n");
+ break;
+ case E820_RESERVED:
+ printk("(reserved)\n");
+ break;
+ case E820_ACPI:
+ printk("(ACPI data)\n");
+ break;
+ case E820_NVS:
+ printk("(ACPI NVS)\n");
+ break;
+ default: printk("type %u\n", e820->map[i].type);
+ break;
+ }
+ }
+}
+
+
--- a/arch/x86/kernel/e820_32.c
+++ b/arch/x86/kernel/e820_32.c
@@ -584,62 +584,6 @@ void __init e820_register_memory(void)
pci_mem_start, gapstart, gapsize);
}
-void __init print_memory_map(char *who)
-{
- int i;
-
- for (i = 0; i < e820.nr_map; i++) {
- printk(" %s: %016Lx - %016Lx ", who,
- e820.map[i].addr,
- e820.map[i].addr + e820.map[i].size);
- switch (e820.map[i].type) {
- case E820_RAM: printk("(usable)\n");
- break;
- case E820_RESERVED:
- printk("(reserved)\n");
- break;
- case E820_ACPI:
- printk("(ACPI data)\n");
- break;
- case E820_NVS:
- printk("(ACPI NVS)\n");
- break;
- default: printk("type %u\n", e820.map[i].type);
- break;
- }
- }
-}
-
-void __init limit_regions(unsigned long long size)
-{
- unsigned long long current_addr;
- int i;
-
- print_memory_map("limit_regions start");
- for (i = 0; i < e820.nr_map; i++) {
- current_addr = e820.map[i].addr + e820.map[i].size;
- if (current_addr < size)
- continue;
-
- if (e820.map[i].type != E820_RAM)
- continue;
-
- if (e820.map[i].addr >= size) {
- /*
- * This region starts past the end of the
- * requested size, skip it completely.
- */
- e820.nr_map = i;
- } else {
- e820.nr_map = i + 1;
- e820.map[i].size -= current_addr - size;
- }
- print_memory_map("limit_regions endfor");
- return;
- }
- print_memory_map("limit_regions endfunc");
-}
-
/*
* This function checks if any part of the range <start,end> is mapped
* with type.
@@ -729,7 +673,7 @@ static int __init parse_memmap(char *arg
start_at = memparse(arg+1, &arg);
add_memory_region(start_at, mem_size, E820_RESERVED);
} else {
- limit_regions(mem_size);
+ limit_regions(&e820, mem_size);
user_defined_memmap = 1;
}
}
@@ -771,5 +715,5 @@ void __init update_e820(void)
return;
e820.nr_map = nr_map;
printk(KERN_INFO "modified physical RAM map:\n");
- print_memory_map("modified");
+ print_memory_map(&e820, "modified");
}
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -761,9 +761,12 @@ char * __init machine_specific_memory_se
static int __init parse_memopt(char *p)
{
+ printk(KERN_INFO "parse_memopt\n");
if (!p)
return -EINVAL;
end_user_pfn = memparse(p, &p);
+ limit_regions(&e820, end_user_pfn);
+
end_user_pfn >>= PAGE_SHIFT;
return 0;
}
@@ -809,6 +812,7 @@ static int __init parse_memmap_opt(char
start_at = memparse(p+1, &p);
add_memory_region(start_at, mem_size, E820_RESERVED);
} else {
+ limit_regions(&e820, mem_size);
end_user_pfn = (mem_size >> PAGE_SHIFT);
}
return *p == '\0' ? 0 : -EINVAL;
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -787,7 +787,7 @@ void __init setup_arch(char **cmdline_p)
ARCH_SETUP
printk(KERN_INFO "BIOS-provided physical RAM map:\n");
- print_memory_map(memory_setup());
+ print_memory_map(&e820, memory_setup());
copy_edd();
@@ -809,7 +809,7 @@ void __init setup_arch(char **cmdline_p)
if (user_defined_memmap) {
printk(KERN_INFO "user-defined physical RAM map:\n");
- print_memory_map("user");
+ print_memory_map(&e820, "user");
}
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
--- a/include/asm-x86/e820.h
+++ b/include/asm-x86/e820.h
@@ -20,6 +20,10 @@ struct e820map {
__u32 nr_map;
struct e820entry map[E820MAX];
};
+
+void limit_regions(struct e820map *e820, unsigned long long size);
+void print_memory_map(struct e820map *e820, char *who);
+
#endif /* __ASSEMBLY__ */
#define ISA_START_ADDRESS 0xa0000
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