Re: [PATCH 1/2] x86 boot: add E820_RESVD_KERN

From: Yinghai Lu
Date: Mon Jun 30 2008 - 19:21:09 EST

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On Mon, Jun 30, 2008 at 3:53 PM, Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:
> On Mon, Jun 30, 2008 at 12:16 PM, Ingo Molnar <mingo@xxxxxxx> wrote:
>>
>> * Yinghai Lu <yhlu.kernel@xxxxxxxxx> wrote:
>>
>>> > For find_e820_area, this is safe enough. But what about conflict
>>> > between setup_data and ebda or ramdisk?
>>>
>>> can you have setup_data and ebda at the same time?
>>>
>>> setup_data and ramdisk should be ok, because bootloader is supposed to
>>> make them not to be conflicts.
>>
>> the more sanity checks we do before relying on some crutial data, the
>> better. It's easier to panic or sanitize data in some structured way and
>> complain about it in the syslog than to let things get corrupted. Boot
>> loaders are ... not unknown to be have bugs too, at times.
>
> to address Ying's concern, we could let reserve_setup_data
> call reserve_early in addition to e820_update_range...
>
> reserve_early will panic if RAMDISK overlap efi setup_data...
>

Ying,
please check the attached patch

YH
[PATCH] x86: move reserve_setup_data to setup.c

Ying Huang want to setup_data to be reserved, but not included in no save
range.

here try to modify e820 table to reserve that range as early.
also add that in early_res in case bootloader mess up it with ramdisk.

other solution would be
1. add early_res_to_highmem...
2. early_res_to_e820...
but they could reserve wrongly other type memory, if early_res has some resource reserved early,
and not need later, but it is not removed from early_res in time.
like the RAMDISK (already handled).

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

---
arch/x86/kernel/e820.c | 4 +++-
arch/x86/kernel/head.c | 18 ------------------
arch/x86/kernel/head64.c | 1 -
arch/x86/kernel/setup.c | 34 ++++++++++++++++++++++++++++------
include/asm-x86/bootparam.h | 2 --
include/asm-x86/e820.h | 3 +++
6 files changed, 34 insertions(+), 28 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -120,6 +120,7 @@ void __init e820_print_map(char *who)
(e820.map[i].addr + e820.map[i].size));
switch (e820.map[i].type) {
case E820_RAM:
+ case E820_RESERVED_KERN:
printk(KERN_CONT "(usable)\n");
break;
case E820_RESERVED:
@@ -611,7 +612,7 @@ void __init e820_mark_nosave_regions(uns
register_nosave_region(pfn, PFN_UP(ei->addr));

pfn = PFN_DOWN(ei->addr + ei->size);
- if (ei->type != E820_RAM)
+ if (ei->type != E820_RAM && ei->type != E820_RESERVED_KERN)
register_nosave_region(PFN_UP(ei->addr), pfn);

if (pfn >= limit_pfn)
@@ -1207,6 +1208,7 @@ void __init e820_reserve_resources(void)
res = alloc_bootmem_low(sizeof(struct resource) * e820.nr_map);
for (i = 0; i < e820.nr_map; i++) {
switch (e820.map[i].type) {
+ case E820_RESERVED_KERN:
case E820_RAM: res->name = "System RAM"; break;
case E820_ACPI: res->name = "ACPI Tables"; break;
case E820_NVS: res->name = "ACPI Non-volatile Storage"; break;
Index: linux-2.6/arch/x86/kernel/head.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/head.c
+++ linux-2.6/arch/x86/kernel/head.c
@@ -53,21 +53,3 @@ void __init reserve_ebda_region(void)
/* reserve all memory between lowmem and the 1MB mark */
reserve_early_overlap_ok(lowmem, 0x100000, "BIOS reserved");
}
-
-void __init reserve_setup_data(void)
-{
- struct setup_data *data;
- u64 pa_data;
- char buf[32];
-
- if (boot_params.hdr.version < 0x0209)
- return;
- pa_data = boot_params.hdr.setup_data;
- while (pa_data) {
- data = early_ioremap(pa_data, sizeof(*data));
- sprintf(buf, "setup data %x", data->type);
- reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
- pa_data = data->next;
- early_iounmap(data, sizeof(*data));
- }
-}
Index: linux-2.6/arch/x86/kernel/head64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/head64.c
+++ linux-2.6/arch/x86/kernel/head64.c
@@ -123,7 +123,6 @@ void __init x86_64_start_kernel(char * r
#endif

reserve_ebda_region();
- reserve_setup_data();

/*
* At this point everything still needed from the boot loader
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -389,14 +389,34 @@ static void __init parse_setup_data(void
default:
break;
}
-#ifndef CONFIG_DEBUG_BOOT_PARAMS
- free_early(pa_data, pa_data+sizeof(*data)+data->len);
-#endif
pa_data = data->next;
early_iounmap(data, PAGE_SIZE);
}
}

+static void __init reserve_setup_data(void)
+{
+ struct setup_data *data;
+ u64 pa_data;
+ char buf[32];
+
+ if (boot_params.hdr.version < 0x0209)
+ return;
+ pa_data = boot_params.hdr.setup_data;
+ while (pa_data) {
+ data = early_ioremap(pa_data, sizeof(*data));
+ sprintf(buf, "setup data %x", data->type);
+ reserve_early(pa_data, pa_data+sizeof(*data)+data->len, buf);
+ e820_update_range(pa_data, sizeof(*data)+data->len,
+ E820_RAM, E820_RESERVED_KERN);
+ pa_data = data->next;
+ early_iounmap(data, sizeof(*data));
+ }
+ sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map);
+ printk(KERN_INFO "extended physical RAM map:\n");
+ e820_print_map("reserve setup_data");
+}
+
/*
* --------- Crashkernel reservation ------------------------------
*/
@@ -524,7 +544,6 @@ void __init setup_arch(char **cmdline_p)
pre_setup_arch_hook();
early_cpu_init();
early_ioremap_init();
- reserve_setup_data();
#else
printk(KERN_INFO "Command line: %s\n", boot_command_line);
#endif
@@ -566,6 +585,8 @@ void __init setup_arch(char **cmdline_p)
ARCH_SETUP

setup_memory_map();
+ parse_setup_data();
+
copy_edd();

if (!boot_params.hdr.root_flags)
@@ -592,10 +613,11 @@ void __init setup_arch(char **cmdline_p)
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;

- parse_setup_data();
-
parse_early_param();

+ /* after early param, so could get panic from serial */
+ reserve_setup_data();
+
if (acpi_mps_check()) {
#ifdef CONFIG_X86_LOCAL_APIC
disable_apic = 1;
Index: linux-2.6/include/asm-x86/bootparam.h
===================================================================
--- linux-2.6.orig/include/asm-x86/bootparam.h
+++ linux-2.6/include/asm-x86/bootparam.h
@@ -108,6 +108,4 @@ struct boot_params {
__u8 _pad9[276]; /* 0xeec */
} __attribute__((packed));

-void reserve_setup_data(void);
-
#endif /* _ASM_BOOTPARAM_H */
Index: linux-2.6/include/asm-x86/e820.h
===================================================================
--- linux-2.6.orig/include/asm-x86/e820.h
+++ linux-2.6/include/asm-x86/e820.h
@@ -44,6 +44,9 @@
#define E820_ACPI 3
#define E820_NVS 4

+/* reserved RAM used by kernel itself */
+#define E820_RESERVED_KERN 128
+
#ifndef __ASSEMBLY__
struct e820entry {
__u64 addr; /* start of memory segment */

Next message: Peter Palfrader: "2.6.25.6: warn_on_slowpath in tcp_input.c"
Previous message: Andrew Morton: "Re: [PATCH 2/2] MN10300: Provide __ucmpdi2() for MN10300"
In reply to: Yinghai Lu: "Re: [PATCH 1/2] x86 boot: add E820_RESVD_KERN"
Next in thread: Huang, Ying: "Re: [PATCH 1/2] x86 boot: add E820_RESVD_KERN"
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