[PATCH v4 2/4] x86: Store memory ranges globally used for crash kernel to boot into
WANG Chao
chaowang at redhat.com
Fri Mar 28 01:23:49 EDT 2014
On 03/27/14 at 06:32pm, Vivek Goyal wrote:
> On Wed, Mar 19, 2014 at 04:03:59PM +0800, WANG Chao wrote:
> > Use these two variables to store the memory ranges and the number of
> > memory ranges for crash kernel to boot into:
> >
> > struct memory_range crash_memory_range;
> > int crash_memory_range;
>
> I know it is my fault but I now feel that "nr_crash_ranges" is much
> more intutive to represent number of crash ranges.
>
> >
> > These two variables are not static now, so can be used in other file
> > later.
>
> So one could access these arrays with the help of pointers.
> get_crash_memory_ranges() returns pointer to crash_memory_range
> array. So why do we need to remove static cast.
get_crash_memory_ranges() is static, but we want to use
crash_memory_range in x86-linux-setup.c. So we have to make
crash_memory_range and crash_memory_ranges global variables.
But as you pointed out it might be good to store crash_memory_range and
crash_memory_ranges in the global kexec_info structure as we did for
memory_range and memory_ranges, we could get rid of these two global
variables.
>
> And even if we have to, then why do we need to return pointer to
> crash_memory_range array?
For historical reason, get_crash_memory_ranges() is not only set
crash_memory_range but also return the pointer of another copy of
crash_memory_range:
static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
int kexec_flags, unsigned long lowmem_limit)
{
[..]
crash_memory_range = xxx;
[..]
*range = crash_memory_range;
*ranges = memory_range;
}
I was just trying to keep the change as minimal as possible, so that the
reviewers can be more clear of what the patch does instead of something
looks messed up. But if you have no problem review it, I can do some
clean up within this patch. However I think it's better to be addressed
the cleanup in the future, or at least as a separated patch in this
series.
Thanks
WANG Chao
>
> Thanks
> Vivek
>
> >
> > Signed-off-by: WANG Chao <chaowang at redhat.com>
> > Tested-by: Linn Crosetto <linn at hp.com>
> > ---
> > kexec/arch/i386/crashdump-x86.c | 134 ++++++++++++++++++++++------------------
> > kexec/arch/i386/crashdump-x86.h | 5 +-
> > 2 files changed, 77 insertions(+), 62 deletions(-)
> >
> > diff --git a/kexec/arch/i386/crashdump-x86.c b/kexec/arch/i386/crashdump-x86.c
> > index 979c2bd..c55a6b1 100644
> > --- a/kexec/arch/i386/crashdump-x86.c
> > +++ b/kexec/arch/i386/crashdump-x86.c
> > @@ -179,7 +179,8 @@ static int exclude_region(int *nr_ranges, uint64_t start, uint64_t end);
> >
> > /* Stores a sorted list of RAM memory ranges for which to create elf headers.
> > * A separate program header is created for backup region */
> > -static struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
> > +struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
> > +int crash_memory_ranges;
> >
> > /* Memory region reserved for storing panic kernel and other data. */
> > #define CRASH_RESERVED_MEM_NR 8
> > @@ -201,7 +202,7 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
> > int kexec_flags, unsigned long lowmem_limit)
> > {
> > const char *iomem = proc_iomem();
> > - int memory_ranges = 0, gart = 0, i;
> > + int gart = 0, i;
> > char line[MAX_LINE];
> > FILE *fp;
> > unsigned long long start, end;
> > @@ -218,7 +219,7 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
> > char *str;
> > int type, consumed, count;
> >
> > - if (memory_ranges >= CRASH_MAX_MEMORY_RANGES)
> > + if (crash_memory_ranges >= CRASH_MAX_MEMORY_RANGES)
> > break;
> > count = sscanf(line, "%Lx-%Lx : %n",
> > &start, &end, &consumed);
> > @@ -250,17 +251,17 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
> > continue;
> > }
> >
> > - crash_memory_range[memory_ranges].start = start;
> > - crash_memory_range[memory_ranges].end = end;
> > - crash_memory_range[memory_ranges].type = type;
> > + crash_memory_range[crash_memory_ranges].start = start;
> > + crash_memory_range[crash_memory_ranges].end = end;
> > + crash_memory_range[crash_memory_ranges].type = type;
> >
> > - segregate_lowmem_region(&memory_ranges, lowmem_limit);
> > + segregate_lowmem_region(&crash_memory_ranges, lowmem_limit);
> >
> > - memory_ranges++;
> > + crash_memory_ranges++;
> > }
> > fclose(fp);
> > if (kexec_flags & KEXEC_PRESERVE_CONTEXT) {
> > - for (i = 0; i < memory_ranges; i++) {
> > + for (i = 0; i < crash_memory_ranges; i++) {
> > if (crash_memory_range[i].end > 0x0009ffff) {
> > crash_reserved_mem[0].start = \
> > crash_memory_range[i].start;
> > @@ -278,17 +279,17 @@ static int get_crash_memory_ranges(struct memory_range **range, int *ranges,
> > }
> >
> > for (i = 0; i < crash_reserved_mem_nr; i++)
> > - if (exclude_region(&memory_ranges, crash_reserved_mem[i].start,
> > + if (exclude_region(&crash_memory_ranges, crash_reserved_mem[i].start,
> > crash_reserved_mem[i].end) < 0)
> > return -1;
> >
> > if (gart) {
> > /* exclude GART region if the system has one */
> > - if (exclude_region(&memory_ranges, gart_start, gart_end) < 0)
> > + if (exclude_region(&crash_memory_ranges, gart_start, gart_end) < 0)
> > return -1;
> > }
> > *range = crash_memory_range;
> > - *ranges = memory_ranges;
> > + *ranges = crash_memory_ranges;
> >
> > return 0;
> > }
> > @@ -324,7 +325,7 @@ static int get_crash_memory_ranges_xen(struct memory_range **range,
> > }
> >
> > *range = crash_memory_range;
> > - *ranges = j;
> > + *ranges = crash_memory_ranges = j;
> >
> > qsort(*range, *ranges, sizeof(struct memory_range), compare_ranges);
> >
> > @@ -417,8 +418,8 @@ static int exclude_region(int *nr_ranges, uint64_t start, uint64_t end)
> >
> > /* Adds a segment from list of memory regions which new kernel can use to
> > * boot. Segment start and end should be aligned to 1K boundary. */
> > -static int add_memmap(struct memory_range *memmap_p, unsigned long long addr,
> > - size_t size)
> > +static int add_memmap(struct memory_range *memmap_p, int *nr_range,
> > + unsigned long long addr, size_t size)
> > {
> > int i, j, nr_entries = 0, tidx = 0, align = 1024;
> > unsigned long long mstart, mend;
> > @@ -450,29 +451,23 @@ static int add_memmap(struct memory_range *memmap_p, unsigned long long addr,
> > else if (addr > mend)
> > tidx = i+1;
> > }
> > - /* Insert the memory region. */
> > - for (j = nr_entries-1; j >= tidx; j--)
> > - memmap_p[j+1] = memmap_p[j];
> > - memmap_p[tidx].start = addr;
> > - memmap_p[tidx].end = addr + size - 1;
> > + /* Insert the memory region. */
> > + for (j = nr_entries-1; j >= tidx; j--)
> > + memmap_p[j+1] = memmap_p[j];
> > + memmap_p[tidx].start = addr;
> > + memmap_p[tidx].end = addr + size - 1;
> > + memmap_p[tidx].type = RANGE_RAM;
> > + *nr_range = nr_entries + 1;
> >
> > - dbgprintf("Memmap after adding segment\n");
> > - for (i = 0; i < CRASH_MAX_MEMMAP_NR; i++) {
> > - mstart = memmap_p[i].start;
> > - mend = memmap_p[i].end;
> > - if (mstart == 0 && mend == 0)
> > - break;
> > - dbgprintf("%016llx - %016llx\n",
> > - mstart, mend);
> > - }
> > + dbgprint_mem_range("Memmap after adding segment", memmap_p, *nr_range);
> >
> > return 0;
> > }
> >
> > /* Removes a segment from list of memory regions which new kernel can use to
> > * boot. Segment start and end should be aligned to 1K boundary. */
> > -static int delete_memmap(struct memory_range *memmap_p, unsigned long long addr,
> > - size_t size)
> > +static int delete_memmap(struct memory_range *memmap_p, int *nr_range,
> > + unsigned long long addr, size_t size)
> > {
> > int i, j, nr_entries = 0, tidx = -1, operation = 0, align = 1024;
> > unsigned long long mstart, mend;
> > @@ -534,24 +529,17 @@ static int delete_memmap(struct memory_range *memmap_p, unsigned long long addr,
> > for (j = nr_entries-1; j > tidx; j--)
> > memmap_p[j+1] = memmap_p[j];
> > memmap_p[tidx+1] = temp_region;
> > + *nr_range = nr_entries + 1;
> > }
> > if ((operation == -1) && tidx >=0) {
> > /* Delete the exact match memory region. */
> > for (j = i+1; j < CRASH_MAX_MEMMAP_NR; j++)
> > memmap_p[j-1] = memmap_p[j];
> > memmap_p[j-1].start = memmap_p[j-1].end = 0;
> > + *nr_range = nr_entries - 1;
> > }
> >
> > - dbgprintf("Memmap after deleting segment\n");
> > - for (i = 0; i < CRASH_MAX_MEMMAP_NR; i++) {
> > - mstart = memmap_p[i].start;
> > - mend = memmap_p[i].end;
> > - if (mstart == 0 && mend == 0) {
> > - break;
> > - }
> > - dbgprintf("%016llx - %016llx\n",
> > - mstart, mend);
> > - }
> > + dbgprint_mem_range("Memmap after deleting segment", memmap_p, *nr_range);
> >
> > return 0;
> > }
> > @@ -626,6 +614,9 @@ static int cmdline_add_memmap(char *cmdline, struct memory_range *memmap_p)
> > /* All regions traversed. */
> > break;
> >
> > + if (memmap_p[i].type != RANGE_RAM)
> > + continue;
> > +
> > /* A region is not worth adding if region size < 100K. It eats
> > * up precious command line length. */
> > if ((endk - startk) < min_sizek)
> > @@ -797,6 +788,25 @@ static void get_backup_area(struct kexec_info *info,
> > info->backup_src_size = BACKUP_SRC_END - BACKUP_SRC_START + 1;
> > }
> >
> > +static void exclude_ram(struct memory_range *mr, int *nr_mr)
> > +{
> > + int ranges, i, j, m;
> > +
> > + ranges = *nr_mr;
> > + for (i = 0, j = 0; i < ranges; i++) {
> > + if (mr[j].type == RANGE_RAM) {
> > + dbgprintf("Remove RAM %016llx-%016llxx: (%d)\n", mr[j].start, mr[j].end, mr[j].type);
> > + for (m = j; m < *nr_mr; m++)
> > + mr[m] = mr[m+1];
> > + (*nr_mr)--;
> > + } else {
> > + j++;
> > + }
> > + }
> > +
> > + dbgprint_mem_range("After remove RAM", mr, *nr_mr);
> > +}
> > +
> > /* Loads additional segments in case of a panic kernel is being loaded.
> > * One segment for backup region, another segment for storing elf headers
> > * for crash memory image.
> > @@ -807,7 +817,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > void *tmp;
> > unsigned long sz, bufsz, memsz, elfcorehdr;
> > int nr_ranges = 0, align = 1024, i;
> > - struct memory_range *mem_range, *memmap_p;
> > + struct memory_range *mem_range;
> > struct crash_elf_info elf_info;
> > unsigned kexec_arch;
> >
> > @@ -850,10 +860,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> >
> > get_backup_area(info, mem_range, nr_ranges);
> >
> > - dbgprintf("CRASH MEMORY RANGES\n");
> > -
> > - for(i = 0; i < nr_ranges; ++i)
> > - dbgprintf("%016Lx-%016Lx\n", mem_range[i].start, mem_range[i].end);
> > + dbgprint_mem_range("CRASH MEMORY RANGES", mem_range, nr_ranges);
> >
> > /*
> > * if the core type has not been set on command line, set it here
> > @@ -878,17 +885,6 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > if (get_kernel_vaddr_and_size(info, &elf_info))
> > return -1;
> >
> > - /* Memory regions which panic kernel can safely use to boot into */
> > - sz = (sizeof(struct memory_range) * CRASH_MAX_MEMMAP_NR);
> > - memmap_p = xmalloc(sz);
> > - memset(memmap_p, 0, sz);
> > - add_memmap(memmap_p, info->backup_src_start, info->backup_src_size);
> > - for (i = 0; i < crash_reserved_mem_nr; i++) {
> > - sz = crash_reserved_mem[i].end - crash_reserved_mem[i].start +1;
> > - if (add_memmap(memmap_p, crash_reserved_mem[i].start, sz) < 0)
> > - return ENOCRASHKERNEL;
> > - }
> > -
> > /* Create a backup region segment to store backup data*/
> > if (!(info->kexec_flags & KEXEC_PRESERVE_CONTEXT)) {
> > sz = _ALIGN(info->backup_src_size, align);
> > @@ -898,8 +894,6 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > 0, max_addr, -1);
> > dbgprintf("Created backup segment at 0x%lx\n",
> > info->backup_start);
> > - if (delete_memmap(memmap_p, info->backup_start, sz) < 0)
> > - return EFAILED;
> > }
> >
> > /* Create elf header segment and store crash image data. */
> > @@ -915,6 +909,23 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > ELF_CORE_HEADER_ALIGN) < 0)
> > return EFAILED;
> > }
> > +
> > + /* Memory regions which panic kernel can safely use to boot into */
> > + exclude_ram(crash_memory_range, &crash_memory_ranges);
> > +
> > + add_memmap(crash_memory_range, &crash_memory_ranges, info->backup_src_start, info->backup_src_size);
> > + for (i = 0; i < crash_reserved_mem_nr; i++) {
> > + sz = crash_reserved_mem[i].end - crash_reserved_mem[i].start +1;
> > + if (add_memmap(crash_memory_range, &crash_memory_ranges, crash_reserved_mem[i].start, sz) < 0)
> > + return ENOCRASHKERNEL;
> > + }
> > +
> > + /* exclude backup region from crash dump memory range */
> > + sz = _ALIGN(info->backup_src_size, align);
> > + if (delete_memmap(crash_memory_range, &crash_memory_ranges, info->backup_start, sz) < 0) {
> > + return EFAILED;
> > + }
> > +
> > /* the size of the elf headers allocated is returned in 'bufsz' */
> >
> > /* Hack: With some ld versions (GNU ld version 2.14.90.0.4 20030523),
> > @@ -934,9 +945,9 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > elfcorehdr = add_buffer(info, tmp, bufsz, memsz, align, min_base,
> > max_addr, -1);
> > dbgprintf("Created elf header segment at 0x%lx\n", elfcorehdr);
> > - if (delete_memmap(memmap_p, elfcorehdr, memsz) < 0)
> > + if (delete_memmap(crash_memory_range, &crash_memory_ranges, elfcorehdr, memsz) < 0)
> > return -1;
> > - cmdline_add_memmap(mod_cmdline, memmap_p);
> > + cmdline_add_memmap(mod_cmdline, crash_memory_range);
> > if (!bzImage_support_efi_boot)
> > cmdline_add_efi(mod_cmdline);
> > cmdline_add_elfcorehdr(mod_cmdline, elfcorehdr);
> > @@ -951,6 +962,7 @@ int load_crashdump_segments(struct kexec_info *info, char* mod_cmdline,
> > end = mem_range[i].end;
> > cmdline_add_memmap_acpi(mod_cmdline, start, end);
> > }
> > +
> > return 0;
> > }
> >
> > diff --git a/kexec/arch/i386/crashdump-x86.h b/kexec/arch/i386/crashdump-x86.h
> > index b61cf0a..633ee0e 100644
> > --- a/kexec/arch/i386/crashdump-x86.h
> > +++ b/kexec/arch/i386/crashdump-x86.h
> > @@ -20,7 +20,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
> > /* Kernel text size */
> > #define X86_64_KERNEL_TEXT_SIZE (512UL*1024*1024)
> >
> > -#define CRASH_MAX_MEMMAP_NR (KEXEC_MAX_SEGMENTS + 1)
> > +#define CRASH_MAX_MEMMAP_NR CRASH_MAX_MEMORY_RANGES
> > #define CRASH_MAX_MEMORY_RANGES (MAX_MEMORY_RANGES + 2)
> >
> > /* Backup Region, First 640K of System RAM. */
> > @@ -28,4 +28,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
> > #define BACKUP_SRC_END 0x0009ffff
> > #define BACKUP_SRC_SIZE (BACKUP_SRC_END - BACKUP_SRC_START + 1)
> >
> > +extern struct memory_range crash_memory_range[CRASH_MAX_MEMORY_RANGES];
> > +extern int crash_memory_ranges;
> > +
> > #endif /* CRASHDUMP_X86_H */
> > --
> > 1.8.5.3
> >
> >
> > _______________________________________________
> > kexec mailing list
> > kexec at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/kexec
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