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authorHari Bathini <hbathini@linux.ibm.com>2019-09-11 17:56:03 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2019-09-13 17:04:45 +0300
commitbec53196adf4791d466adf0e339b61186c7b5283 (patch)
treed21c6ffd50038faa23011ca14fddeecaabdb6fbc /arch/powerpc/kernel/fadump.c
parentb2a815a554a34f0e6fab4526ae762d5528783600 (diff)
downloadlinux-bec53196adf4791d466adf0e339b61186c7b5283.tar.xz
powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel
Add a new kernel config option, CONFIG_PRESERVE_FA_DUMP that ensures that crash data, from previously crash'ed kernel, is preserved. This helps in cases where FADump is not enabled but the subsequent memory preserving kernel boot is likely to process this crash data. One typical usecase for this config option is petitboot kernel. As OPAL allows registering address with it in the first kernel and retrieving it after MPIPL, use it to store the top of boot memory. A kernel that intends to preserve crash data retrieves it and avoids using memory beyond this address. Move arch_reserved_kernel_pages() function as it is needed for both FA_DUMP and PRESERVE_FA_DUMP configurations. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/156821375751.5656.11459483669542541602.stgit@hbathini.in.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/fadump.c')
-rw-r--r--arch/powerpc/kernel/fadump.c44
1 files changed, 39 insertions, 5 deletions
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
index 6f52a60bc212..645d9d4d9332 100644
--- a/arch/powerpc/kernel/fadump.c
+++ b/arch/powerpc/kernel/fadump.c
@@ -36,6 +36,7 @@ static struct fw_dump fw_dump;
static void __init fadump_reserve_crash_area(u64 base);
+#ifndef CONFIG_PRESERVE_FA_DUMP
static DEFINE_MUTEX(fadump_mutex);
struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 };
struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 };
@@ -439,11 +440,6 @@ error_out:
return 0;
}
-unsigned long __init arch_reserved_kernel_pages(void)
-{
- return memblock_reserved_size() / PAGE_SIZE;
-}
-
/* Look for fadump= cmdline option. */
static int __init early_fadump_param(char *p)
{
@@ -1358,6 +1354,39 @@ int __init setup_fadump(void)
return 1;
}
subsys_initcall(setup_fadump);
+#else /* !CONFIG_PRESERVE_FA_DUMP */
+
+/* Scan the Firmware Assisted dump configuration details. */
+int __init early_init_dt_scan_fw_dump(unsigned long node, const char *uname,
+ int depth, void *data)
+{
+ if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0))
+ return 0;
+
+ opal_fadump_dt_scan(&fw_dump, node);
+ return 1;
+}
+
+/*
+ * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel,
+ * preserve crash data. The subsequent memory preserving kernel boot
+ * is likely to process this crash data.
+ */
+int __init fadump_reserve_mem(void)
+{
+ if (fw_dump.dump_active) {
+ /*
+ * If last boot has crashed then reserve all the memory
+ * above boot memory to preserve crash data.
+ */
+ pr_info("Preserving crash data for processing in next boot.\n");
+ fadump_reserve_crash_area(fw_dump.boot_mem_top);
+ } else
+ pr_debug("FADump-aware kernel..\n");
+
+ return 1;
+}
+#endif /* CONFIG_PRESERVE_FA_DUMP */
/* Preserve everything above the base address */
static void __init fadump_reserve_crash_area(u64 base)
@@ -1382,3 +1411,8 @@ static void __init fadump_reserve_crash_area(u64 base)
memblock_reserve(mstart, msize);
}
}
+
+unsigned long __init arch_reserved_kernel_pages(void)
+{
+ return memblock_reserved_size() / PAGE_SIZE;
+}