From mboxrd@z Thu Jan 1 00:00:00 1970 From: panand@redhat.com (Pratyush Anand) Date: Tue, 7 Jun 2016 10:25:15 +0530 Subject: [PATCH kexec-tools v2 12/32] kexec: add helper to exlude a region from a set of memory ranges In-Reply-To: References: <20160606164129.GM1041@n2100.armlinux.org.uk> Message-ID: <20160607045515.GA13643@dhcppc6> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 06/06/2016:05:59:44 PM, Russell King wrote: > Add a helper to exclude a region from a set of memory ranges. > > Signed-off-by: Russell King Reviewed-by: Pratyush Anand > --- > kexec/mem_regions.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > kexec/mem_regions.h | 4 +++ > 2 files changed, 75 insertions(+) > > diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c > index 804984a..b01a5c8 100644 > --- a/kexec/mem_regions.c > +++ b/kexec/mem_regions.c > @@ -55,3 +55,74 @@ int mem_regions_add(struct memory_ranges *ranges, unsigned long long base, > return 0; > } > > +static void mem_regions_remove(struct memory_ranges *ranges, int index) > +{ > + int tail_entries; > + > + /* we are assured to have at least one entry */ > + ranges->size -= 1; > + > + /* if we have following entries, shuffle them down one place */ > + tail_entries = ranges->size - index; > + if (tail_entries) > + memmove(ranges->ranges + index, ranges->ranges + index + 1, > + tail_entries * sizeof(*ranges->ranges)); > + > + /* zero the new tail entry */ > + memset(ranges->ranges + ranges->size, 0, sizeof(*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, ret; > + > + 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) { > + if (r->end == range->end) > + /* Remove this entry */ > + mem_regions_remove(ranges, i); > + else > + /* 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 { > + /* > + * Split this area into 2 smaller ones and > + * remove excluded range from between. First > + * create new entry for the remaining area. > + */ > + ret = mem_regions_add(ranges, range->end + 1, > + r->end - range->end, 0); > + if (ret < 0) > + return ret; > + > + /* > + * Update this area to end before excluded > + * range. > + */ > + r->end = range->start - 1; > + break; > + } > + } > + } > + return 0; > +} > 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-qk0-f171.google.com ([209.85.220.171]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bA93F-0003En-Su for kexec@lists.infradead.org; Tue, 07 Jun 2016 04:55:44 +0000 Received: by mail-qk0-f171.google.com with SMTP id p22so35737019qka.2 for ; Mon, 06 Jun 2016 21:55:21 -0700 (PDT) Date: Tue, 7 Jun 2016 10:25:15 +0530 From: Pratyush Anand Subject: Re: [PATCH kexec-tools v2 12/32] kexec: add helper to exlude a region from a set of memory ranges Message-ID: <20160607045515.GA13643@dhcppc6> References: <20160606164129.GM1041@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Russell King Cc: kexec@lists.infradead.org, Baoquan He , linux-arm-kernel@lists.infradead.org On 06/06/2016:05:59:44 PM, Russell King wrote: > Add a helper to exclude a region from a set of memory ranges. > > Signed-off-by: Russell King Reviewed-by: Pratyush Anand > --- > kexec/mem_regions.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++ > kexec/mem_regions.h | 4 +++ > 2 files changed, 75 insertions(+) > > diff --git a/kexec/mem_regions.c b/kexec/mem_regions.c > index 804984a..b01a5c8 100644 > --- a/kexec/mem_regions.c > +++ b/kexec/mem_regions.c > @@ -55,3 +55,74 @@ int mem_regions_add(struct memory_ranges *ranges, unsigned long long base, > return 0; > } > > +static void mem_regions_remove(struct memory_ranges *ranges, int index) > +{ > + int tail_entries; > + > + /* we are assured to have at least one entry */ > + ranges->size -= 1; > + > + /* if we have following entries, shuffle them down one place */ > + tail_entries = ranges->size - index; > + if (tail_entries) > + memmove(ranges->ranges + index, ranges->ranges + index + 1, > + tail_entries * sizeof(*ranges->ranges)); > + > + /* zero the new tail entry */ > + memset(ranges->ranges + ranges->size, 0, sizeof(*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, ret; > + > + 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) { > + if (r->end == range->end) > + /* Remove this entry */ > + mem_regions_remove(ranges, i); > + else > + /* 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 { > + /* > + * Split this area into 2 smaller ones and > + * remove excluded range from between. First > + * create new entry for the remaining area. > + */ > + ret = mem_regions_add(ranges, range->end + 1, > + r->end - range->end, 0); > + if (ret < 0) > + return ret; > + > + /* > + * Update this area to end before excluded > + * range. > + */ > + r->end = range->start - 1; > + break; > + } > + } > + } > + return 0; > +} > 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 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec