On 05/24/2012 11:39 AM, Suzuki K. Poulose wrote:
> As of now, the kexec reserves the spin-table for all the CPUs
> on an SMP machine. The spin-table is pointed to by the
> cpu-release-addr property in the device-tree. Reserving the
> spin-table in the crash kernel will cause a BUG(), if the table
> lies outside the memory reserved for the crashkernel.
>
> Disable reserving the spin-table regions and use maxcpus=1 to
> use only the crashing CPU to boot the crash kernel.
>
> Signed-off-by: Suzuki K. Poulose<suzuki at in.ibm.com>
Simon,
Any response on this one ?
I have tested this on a Currituck board (476, SMP) with a UP kernel.
Without this patch, the secondary kernel hits 'PANIC' in boot while
trying to reserve a memory(the spin table), outside the memory
range(crash reserve).
Thanks
Suzuki
> ---
>
> kexec/arch/ppc/crashdump-powerpc.c | 19 +++++++++++++------
> kexec/arch/ppc/fixup_dtb.c | 4 ++++
> 2 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/kexec/arch/ppc/crashdump-powerpc.c b/kexec/arch/ppc/crashdump-powerpc.c
> index 1bef69b..4c8c75d 100644
> --- a/kexec/arch/ppc/crashdump-powerpc.c
> +++ b/kexec/arch/ppc/crashdump-powerpc.c
> @@ -262,10 +262,19 @@ static void ulltoa(unsigned long long i, char *str)
> }
> }
>
> +/* Append str to cmdline */
> +static void add_cmdline(char *cmdline, char *str)
> +{
> + int cmdlen = strlen(cmdline) + strlen(str);
> + if (cmdlen> (COMMAND_LINE_SIZE - 1))
> + die("Command line overflow\n");
> + strcat(cmdline, str);
> +}
> +
> static int add_cmdline_param(char *cmdline, unsigned long long addr,
> char *cmdstr, char *byte)
> {
> - int cmdlen, len, align = 1024;
> + int align = 1024;
> char str[COMMAND_LINE_SIZE], *ptr;
>
> /* Passing in =xxxK / =xxxM format. Saves space required in cmdline.*/
> @@ -284,11 +293,8 @@ static int add_cmdline_param(char *cmdline, unsigned long long addr,
> ptr += strlen(str);
> ulltoa(addr, ptr);
> strcat(str, byte);
> - len = strlen(str);
> - cmdlen = strlen(cmdline) + len;
> - if (cmdlen> (COMMAND_LINE_SIZE - 1))
> - die("Command line overflow\n");
> - strcat(cmdline, str);
> +
> + add_cmdline(cmdline, str);
>
> dbgprintf("Command line after adding elfcorehdr: %s\n", cmdline);
>
> @@ -365,6 +371,7 @@ int load_crashdump_segments(struct kexec_info *info, char *mod_cmdline,
> */
> add_cmdline_param(mod_cmdline, elfcorehdr, " elfcorehdr=", "K");
> add_cmdline_param(mod_cmdline, saved_max_mem, " savemaxmem=", "M");
> + add_cmdline(mod_cmdline, " maxcpus=1");
> return 0;
> }
>
> diff --git a/kexec/arch/ppc/fixup_dtb.c b/kexec/arch/ppc/fixup_dtb.c
> index e9890a4..f832026 100644
> --- a/kexec/arch/ppc/fixup_dtb.c
> +++ b/kexec/arch/ppc/fixup_dtb.c
> @@ -172,6 +172,9 @@ static void fixup_reserve_regions(struct kexec_info *info, char *blob_buf)
> }
> }
>
> +#if 0
> + /* XXX: Do not reserve spin-table for CPUs. */
> +
> /* Add reserve regions for cpu-release-addr */
> nodeoffset = fdt_node_offset_by_prop_value(blob_buf, -1, "device_type", "cpu", 4);
> while (nodeoffset != -FDT_ERR_NOTFOUND) {
> @@ -201,6 +204,7 @@ static void fixup_reserve_regions(struct kexec_info *info, char *blob_buf)
> nodeoffset = fdt_node_offset_by_prop_value(blob_buf, nodeoffset,
> "device_type", "cpu", 4);
> }
> +#endif
>
> out:
> print_fdt_reserve_regions(blob_buf);
>
>
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>
