[PATCH v2 5/5] x86: implement crashkernel cma reservation

[Jiri Bohac]

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

Signed-off-by: Jiri Bohac <jbo...@suse.cz>
---
 arch/x86/kernel/crash.c | 26 ++++++++++++++++++++++----
 arch/x86/kernel/setup.c |  5 +++--
 2 files changed, 25 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 340af8155658..70823fa9abea 100644
--- 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)
@@ -352,6 +362,14 @@ 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 853afde761a7..90e10a18f0c9 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -471,7 +471,7 @@ 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;
        char *cmdline = boot_command_line;
        bool high = false;
        int ret;
@@ -481,7 +481,7 @@ static void __init arch_reserve_crashkernel(void)
 
        ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
                                &crash_size, &crash_base,
-                               &low_size, NULL, &high);
+                               &low_size, &cma_size, &high);
        if (ret)
                return;
 
@@ -492,6 +492,7 @@ static void __init arch_reserve_crashkernel(void)
 
        reserve_crashkernel_generic(cmdline, crash_size, crash_base,
                                    low_size, high);
+       reserve_crashkernel_cma(cma_size);
 }
 
 static struct resource standard_io_resources[] = {

-- 
Jiri Bohac <jbo...@suse.cz>
SUSE Labs, Prague, Czechia