MIPS: kdump: Add support

[ralf@linux-mips.org: Original patch by Maxim Uvarov <muvarov@gmail.com>
with plenty of further shining, polishing, debugging and testing by me.]

Signed-off-by: Maxim Uvarov <muvarov@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: kexec@lists.infradead.org
Cc: horms@verge.net.au
Patchwork: https://patchwork.linux-mips.org/patch/1025/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 462f9c4fe2e5..c97fc030fdac 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2379,6 +2379,29 @@ config KEXEC
           support.  As of this writing the exact hardware interface is
           strongly in flux, so no good recommendation can be made.
 
+config CRASH_DUMP
+          bool "Kernel crash dumps"
+          help
+          Generate crash dump after being started by kexec.
+          This should be normally only set in special crash dump kernels
+          which are loaded in the main kernel with kexec-tools into
+          a specially reserved region and then later executed after
+          a crash by kdump/kexec. The crash dump kernel must be compiled
+          to a memory address not used by the main kernel or firmware using
+          PHYSICAL_START.
+
+config PHYSICAL_START
+          hex "Physical address where the kernel is loaded"
+          default "0xffffffff84000000" if 64BIT
+          default "0x84000000" if 32BIT
+          depends on CRASH_DUMP
+          help
+          This gives the CKSEG0 or KSEG0 address where the kernel is loaded.
+          If you plan to use kernel for capturing the crash dump change
+          this value to start of the reserved region (the "X" value as
+          specified in the "crashkernel=YM@XM" command line boot parameter
+          passed to the panic-ed kernel).
+
 config SECCOMP
         bool "Enable seccomp to safely compute untrusted bytecode"
         depends on PROC_FS