x86: implement crashkernel cma reservation

Implement the crashkernel CMA reservation for x86:
- enable parsing of the cma suffix by parse_crashkernel()
- reserve memory with reserve_crashkernel_cma()
- add the CMA-reserved ranges to the e820 map for the crash kernel
- exclude the CMA-reserved ranges from vmcore

Link: https://lkml.kernel.org/r/aEqp1LD2og4QeBw9@dwarf.suse.cz
Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Cc: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Donald Dutile <ddutile@redhat.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Pingfan Liu <piliu@redhat.com>
Cc: Tao Liu <ltao@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index bcb534688dfe760ced9d6e5caaa0f58c901c90fa..c6b12bed173df534256a1866fa4d7031d6cb2a53 100644 (file)
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -163,10 +163,10 @@ static struct crash_mem *fill_up_crash_elf_data(void)
                return NULL;
 
        /*
-        * Exclusion of crash region and/or crashk_low_res may cause
-        * another range split. So add extra two slots here.
+        * Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
+        * may cause range splits. So add extra slots here.
         */
-       nr_ranges += 2;
+       nr_ranges += 2 + crashk_cma_cnt;
        cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
        if (!cmem)
                return NULL;
@@ -184,6 +184,7 @@ static struct crash_mem *fill_up_crash_elf_data(void)
 static int elf_header_exclude_ranges(struct crash_mem *cmem)
 {
        int ret = 0;
+       int i;
 
        /* Exclude the low 1M because it is always reserved */
        ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
@@ -198,8 +199,17 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem)
        if (crashk_low_res.end)
                ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
                                              crashk_low_res.end);
+       if (ret)
+               return ret;
 
-       return ret;
+       for (i = 0; i < crashk_cma_cnt; ++i) {
+               ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+                                             crashk_cma_ranges[i].end);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
 }
 
 static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
@@ -374,6 +384,14 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params)
                add_e820_entry(params, &ei);
        }
 
+       for (i = 0; i < crashk_cma_cnt; ++i) {
+               ei.addr = crashk_cma_ranges[i].start;
+               ei.size = crashk_cma_ranges[i].end -
+                         crashk_cma_ranges[i].start + 1;
+               ei.type = E820_TYPE_RAM;
+               add_e820_entry(params, &ei);
+       }
+
 out:
        vfree(cmem);
        return ret;

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c22dc630c2974ca75e123f34b5fa768f173cd682..680d1b6dfea4139f75581f32caac59493b66ba8f 100644 (file)
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -599,7 +599,7 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 
 static void __init arch_reserve_crashkernel(void)
 {
-       unsigned long long crash_base, crash_size, low_size = 0;
+       unsigned long long crash_base, crash_size, low_size = 0, cma_size = 0;
        bool high = false;
        int ret;
 
@@ -608,7 +608,7 @@ static void __init arch_reserve_crashkernel(void)
 
        ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
                                &crash_size, &crash_base,
-                               &low_size, NULL, &high);
+                               &low_size, &cma_size, &high);
        if (ret)
                return;
 
@@ -618,6 +618,7 @@ static void __init arch_reserve_crashkernel(void)
        }
 
        reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+       reserve_crashkernel_cma(cma_size);
 }
 
 static struct resource standard_io_resources[] = {