On 04/12/2013 09:52 AM, Alexander Sverdlin wrote:
Octeon: fix broken plat_mem_setup()
Upstream patch abe77f90dc9c65a7c9a4d61c2cbb8db4d5566e4f (MIPS: Octeon:
Add kexec
and kdump support) seems to be untested and broken Linux 3.8 on Octeon
-- in
comparison with 3.7 Linux crashes with
[...]
[ 0.000000] Kernel panic - not syncing: Attempted to kill the idle task!
There are at least couple of issues in the patch:
1. reason for add_memory_region(memory, mem_alloc_size, BOOT_MEM_RAM)
instead of
add_memory_region(memory, size, BOOT_MEM_RAM) is unclear, especially
because it
will discard corrections performed by two preceding calls to
memory_exclude_page().
This is fixed using size again instead of mem_alloc_size, moreover,
block sizes
calculation could be simplified.
2. add_memory_region(kernel_start, kernel_size, BOOT_MEM_RAM) marks
kernel body
as RAM available for allocation, that's why the kernel later crashes
overwritting
itself. Marking it as BOOT_MEM_INIT_RAM solves the crash and still
allows to load
the same kernel with kexec (tested also).
I have a different patch I am testing that gets rid of all this crap.
The strategy we are using is to use cvmx_bootmem named blocks for all
memory in a KEXEC environment.
David Daney
Signed-off-by: Alexander Sverdlin <alexander.sverdlin.ext@xxxxxxx>
Cc: David Daney <david.daney@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
---
Changes in V2:
* corrected "end" calculation, simplified "size" calculation
* Mapped the kernel correctly as INIT RAM, instead of throwing this code
out
As a result, kernel not only boots succefully, but also able to load itself
with "kexec -l <image>".
--- linux.orig/arch/mips/cavium-octeon/setup.c
+++ linux/arch/mips/cavium-octeon/setup.c
@@ -936,14 +936,14 @@ void __init plat_mem_setup(void)
CVMX_PCIE_BAR1_PHYS_SIZE,
&memory, &size);
#ifdef CONFIG_KEXEC
- end = memory + mem_alloc_size;
+ end = memory + size;
/*
* This function automatically merges address regions
* next to each other if they are received in
* incrementing order
*/
- if (memory < crashk_base && end > crashk_end) {
+ if (memory < crashk_base && end > crashk_end) {
/* region is fully in */
add_memory_region(memory,
crashk_base - memory,
@@ -969,20 +969,20 @@ void __init plat_mem_setup(void)
* Overlap with the beginning of the region,
* reserve the beginning.
*/
- mem_alloc_size -= crashk_end - memory;
+ size = end - crashk_end;
memory = crashk_end;
} else if (memory < crashk_base && end > crashk_base &&
- end < crashk_end)
+ end < crashk_end) {
/*
* Overlap with the beginning of the region,
* chop of end.
*/
- mem_alloc_size -= end - crashk_base;
+ size = crashk_base - memory;
+ }
#endif
- add_memory_region(memory, mem_alloc_size, BOOT_MEM_RAM);
+ if (size)
+ add_memory_region(memory, size, BOOT_MEM_RAM);
total += mem_alloc_size;
- /* Recovering mem_alloc_size */
- mem_alloc_size = 4 << 20;
} else {
break;
}
@@ -994,7 +994,7 @@ void __init plat_mem_setup(void)
/* Adjust for physical offset. */
kernel_start &= ~0xffffffff80000000ULL;
- add_memory_region(kernel_start, kernel_size, BOOT_MEM_RAM);
+ add_memory_region(kernel_start, kernel_size, BOOT_MEM_INIT_RAM);
#endif /* CONFIG_CRASH_DUMP */
#ifdef CONFIG_CAVIUM_RESERVE32
