Re: [patch 4/5] Use extended crashkernel command line on IA64

Bernhard Walle
2007-09-09T19:08:48Z

* Matthew Wilcox <matthew@wil.cx> [2007-09-09 15:01]:
> On Sun, Sep 09, 2007 at 10:39:18AM +0200, Bernhard Walle wrote:
> > Because the total amount of System RAM must be known when calling this
> > function, efi_memmap_init() is modified to return its comulated
>
> accumulated?

Yes, sorry.

> > total_memory variable in a pointer value. IMO that's better than making the
> > variable global.
>
> Why not make efi_memmap_init() return total_memory instead of void?

Good idea:

-----

From: Bernhard Walle <bwalle@suse.de>
Subject: Use extended crashkernel command line on IA64
Cc: linux-ia64@vger.kernel.org

This patch adapts IA64 to use the generic parse_crashkernel() function
instead of its own parsing for the crashkernel command line.

Because the total amount of System RAM must be known when calling this
function, efi_memmap_init() is modified to return its accumulated
total_memory variable in a pointer value. IMO that's better than making the
variable global.

Also, the crashkernel handling is moved in an own function in
arch/ia64/kernel/setup.c to make the code more readable.

Signed-off-by: Bernhard Walle <bwalle@suse.de>

---
arch/ia64/kernel/efi.c | 4 +-
arch/ia64/kernel/setup.c | 88 +++++++++++++++++++++++----------------------
include/asm-ia64/meminit.h | 2 -
3 files changed, 50 insertions(+), 44 deletions(-)

--- a/arch/ia64/kernel/efi.c
+++ b/arch/ia64/kernel/efi.c
@@ -967,7 +967,7 @@ find_memmap_space (void)
* to use. We can allocate partial granules only if the unavailable
* parts exist, and are WB.
*/
-void
+unsigned long
efi_memmap_init(unsigned long *s, unsigned long *e)
{
struct kern_memdesc *k, *prev = NULL;
@@ -1084,6 +1084,8 @@ efi_memmap_init(unsigned long *s, unsign
/* reserve the memory we are using for kern_memmap */
*s = (u64)kern_memmap;
*e = (u64)++k;
+
+ return total_memory;
}

void
--- a/arch/ia64/kernel/setup.c
+++ b/arch/ia64/kernel/setup.c
@@ -208,6 +208,48 @@ static int __init register_memory(void)

__initcall(register_memory);

+
+#ifdef CONFIG_KEXEC
+static void setup_crashkernel(unsigned long total, int *n)
+{
+ unsigned long long base = 0, size = 0;
+ int ret;
+
+ ret = parse_crashkernel(boot_command_line, total,
+ &size, &base);
+ if (ret == 0 && size > 0) {
+ if (!base) {
+ sort_regions(rsvd_region, *n);
+ base = kdump_find_rsvd_region(size,
+ rsvd_region, *n);
+ }
+ if (base != ~0UL) {
+ printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
+ "for crashkernel (System RAM: %ldMB)\n",
+ (unsigned long)(size >> 20),
+ (unsigned long)(base >> 20),
+ (unsigned long)(total >> 20));
+ rsvd_region[*n].start =
+ (unsigned long)__va(base);
+ rsvd_region[*n].end =
+ (unsigned long)__va(base + size);
+ (*n)++;
+ crashk_res.start = base;
+ crashk_res.end = base + size - 1;
+ }
+ }
+ efi_memmap_res.start = ia64_boot_param->efi_memmap;
+ efi_memmap_res.end = efi_memmap_res.start +
+ ia64_boot_param->efi_memmap_size;
+ boot_param_res.start = __pa(ia64_boot_param);
+ boot_param_res.end = boot_param_res.start +
+ sizeof(*ia64_boot_param);
+}
+#else
+static inline void setup_crashkernel(unsigned long total, int *n)
+{}
+#endif
+
/**
* reserve_memory - setup reserved memory areas
*
@@ -219,6 +261,7 @@ void __init
reserve_memory (void)
{
int n = 0;
+ unsigned long total_memory = 0;

/*
* none of the entries in this table overlap
@@ -254,50 +297,11 @@ reserve_memory (void)
n++;
#endif

- efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
+ total_memory = efi_memmap_init(&rsvd_region[n].start, &rsvd_region[n].end);
n++;

-#ifdef CONFIG_KEXEC
- /* crashkernel=size@offset specifies the size to reserve for a crash
- * kernel. If offset is 0, then it is determined automatically.
- * By reserving this memory we guarantee that linux never set's it
- * up as a DMA target.Useful for holding code to do something
- * appropriate after a kernel panic.
- */
- {
- char *from = strstr(boot_command_line, "crashkernel=");
- unsigned long base, size;
- if (from) {
- size = memparse(from + 12, &from);
- if (*from == '@')
- base = memparse(from+1, &from);
- else
- base = 0;
- if (size) {
- if (!base) {
- sort_regions(rsvd_region, n);
- base = kdump_find_rsvd_region(size,
- rsvd_region, n);
- }
- if (base != ~0UL) {
- rsvd_region[n].start =
- (unsigned long)__va(base);
- rsvd_region[n].end =
- (unsigned long)__va(base + size);
- n++;
- crashk_res.start = base;
- crashk_res.end = base + size - 1;
- }
- }
- }
- efi_memmap_res.start = ia64_boot_param->efi_memmap;
- efi_memmap_res.end = efi_memmap_res.start +
- ia64_boot_param->efi_memmap_size;
- boot_param_res.start = __pa(ia64_boot_param);
- boot_param_res.end = boot_param_res.start +
- sizeof(*ia64_boot_param);
- }
-#endif
+ setup_crashkernel(total_memory, &n);
+
/* end of memory marker */
rsvd_region[n].start = ~0UL;
rsvd_region[n].end = ~0UL;
--- a/include/asm-ia64/meminit.h
+++ b/include/asm-ia64/meminit.h
@@ -35,7 +35,7 @@ extern void find_memory (void);
extern void reserve_memory (void);
extern void find_initrd (void);
extern int filter_rsvd_memory (unsigned long start, unsigned long end, void *arg);
-extern void efi_memmap_init(unsigned long *, unsigned long *);
+extern unsigned long efi_memmap_init(unsigned long *s, unsigned long *e);
extern int find_max_min_low_pfn (unsigned long , unsigned long, void *);

extern unsigned long vmcore_find_descriptor_size(unsigned long address);