| Message ID | E1axXSv-0004i3-Gi@e0050434b2927.dyn.arm.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, May 3, 2016 at 3:52 PM, Russell King <rmk@arm.linux.org.uk> wrote: > Add a helper to exclude a region from a set of memory ranges. > > Signed-off-by: Russell King <rmk@arm.linux.org.uk> > --- > kexec/mem_regions.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > kexec/mem_regions.h | 4 ++++ > 2 files changed, 59 insertions(+) > > diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c > index 804984a..c6ba942 100644 > --- a/kexec/mem_regions.c > +++ b/kexec/mem_regions.c > @@ -29,6 +29,61 @@ void mem_regions_sort(struct memory_ranges *ranges) > } > > /** > + * mem_regions_exclude() - excludes a memory region from a set of memory ranges > + * @ranges: memory ranges to exclude the region from > + * @range: memory range to exclude > + * > + * Exclude a memory region from a set of memory ranges. We assume that > + * the region to be excluded is either wholely located within one of the > + * memory ranges, or not at all. > + */ > +int mem_regions_exclude(struct memory_ranges *ranges, > + const struct memory_range *range) > +{ > + int i; > + > + for (i = 0; i < ranges->size; i++) { > + struct memory_range *r = ranges->ranges + i; > + > + /* > + * We assume that crash area is fully contained in > + * some larger memory area. > + */ > + if (r->start <= range->start && r->end >= range->end) { > + if (r->start == range->start) { > + /* Shrink the start of this memory range */ > + r->start = range->end + 1; > + } else if (r->end == range->end) { > + /* Shrink the end of this memory range */ > + r->end = range->start - 1; What if r->start == range->start) && (r->end == range->end)? > + } else { > + struct memory_range *new; > + > + /* > + * Split this area into 2 smaller ones and > + * remove excluded range from between. First > + * create new entry for the remaining area. > + */ > + if (ranges->size >= ranges->max_size) > + return -1; > + > + new = ranges->ranges + ranges->size++; > + new->start = range->end + 1; > + new->end = r->end; > + > + /* > + * Update this area to end before excluded > + * range. > + */ > + r->end = range->start - 1; > + break; > + } > + } > + } > + return 0; > +} > + > +/** > * mem_regions_add() - add a memory region to a set of ranges > * @ranges: ranges to add the memory region to > * @max: maximum number of entries in memory region > diff --git a/kexec/mem_regions.h b/kexec/mem_regions.h > index da7b5e8..ae9e972 100644 > --- a/kexec/mem_regions.h > +++ b/kexec/mem_regions.h > @@ -2,9 +2,13 @@ > #define MEM_REGIONS_H > > struct memory_ranges; > +struct memory_range; > > void mem_regions_sort(struct memory_ranges *ranges); > > +int mem_regions_exclude(struct memory_ranges *ranges, > + const struct memory_range *range); > + > int mem_regions_add(struct memory_ranges *ranges, unsigned long long base, > unsigned long long length, int type); > > -- > 1.9.1 >
diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c index 804984a..c6ba942 100644 --- a/kexec/mem_regions.c +++ b/kexec/mem_regions.c @@ -29,6 +29,61 @@ void mem_regions_sort(struct memory_ranges *ranges) } /** + * mem_regions_exclude() - excludes a memory region from a set of memory ranges + * @ranges: memory ranges to exclude the region from + * @range: memory range to exclude + * + * Exclude a memory region from a set of memory ranges. We assume that + * the region to be excluded is either wholely located within one of the + * memory ranges, or not at all. + */ +int mem_regions_exclude(struct memory_ranges *ranges, + const struct memory_range *range) +{ + int i; + + for (i = 0; i < ranges->size; i++) { + struct memory_range *r = ranges->ranges + i; + + /* + * We assume that crash area is fully contained in + * some larger memory area. + */ + if (r->start <= range->start && r->end >= range->end) { + if (r->start == range->start) { + /* Shrink the start of this memory range */ + r->start = range->end + 1; + } else if (r->end == range->end) { + /* Shrink the end of this memory range */ + r->end = range->start - 1; + } else { + struct memory_range *new; + + /* + * Split this area into 2 smaller ones and + * remove excluded range from between. First + * create new entry for the remaining area. + */ + if (ranges->size >= ranges->max_size) + return -1; + + new = ranges->ranges + ranges->size++; + new->start = range->end + 1; + new->end = r->end; + + /* + * Update this area to end before excluded + * range. + */ + r->end = range->start - 1; + break; + } + } + } + return 0; +} + +/** * mem_regions_add() - add a memory region to a set of ranges * @ranges: ranges to add the memory region to * @max: maximum number of entries in memory region diff --git a/kexec/mem_regions.h b/kexec/mem_regions.h index da7b5e8..ae9e972 100644 --- a/kexec/mem_regions.h +++ b/kexec/mem_regions.h @@ -2,9 +2,13 @@ #define MEM_REGIONS_H struct memory_ranges; +struct memory_range; void mem_regions_sort(struct memory_ranges *ranges); +int mem_regions_exclude(struct memory_ranges *ranges, + const struct memory_range *range); + int mem_regions_add(struct memory_ranges *ranges, unsigned long long base, unsigned long long length, int type);
Add a helper to exclude a region from a set of memory ranges. Signed-off-by: Russell King <rmk@arm.linux.org.uk> --- kexec/mem_regions.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++ kexec/mem_regions.h | 4 ++++ 2 files changed, 59 insertions(+)