On 08/10/16 at 03:35pm, Hari Bathini wrote:
> When fadump is enabled, by default 5% of system RAM is reserved for
> fadump kernel. While that works for most cases, it is not good enough
> for every case.
>
> Currently, to override the default value, fadump supports specifying
> memory to reserve with fadump_reserve_mem=size, where only a fixed size
> can be specified. This patch adds support to specify memory size to
> reserve for different memory ranges as below:
>
> fadump_reserve_mem=<range1>:<size1>[,<range2>:<size2>,...]
Hi, Hari
I do not understand why you need introduce the new cmdline param, what's
the difference between the "fadump reserved" memory and the memory
reserved by "crashkernel="? Can fadump just use crashkernel= to reserve
memory?
Thanks
Dave
>
> Supporting range based input for "fadump_reserve_mem" parameter helps
> using the same commandline parameter for different system memory sizes.
>
> Signed-off-by: Hari Bathini <hbath...@linux.vnet.ibm.com>
> Reviewed-by: Mahesh J Salgaonkar <mah...@linux.vnet.ibm.com>
> ---
>
> Changes from v2:
> 1. Updated changelog
>
>
> arch/powerpc/kernel/fadump.c | 63
> ++++++++++++++++++++++++++++++++++++------
> 1 file changed, 54 insertions(+), 9 deletions(-)
>
> diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c
> index b3a6633..7c01b5b 100644
> --- a/arch/powerpc/kernel/fadump.c
> +++ b/arch/powerpc/kernel/fadump.c
> @@ -193,6 +193,55 @@ static unsigned long init_fadump_mem_struct(struct
> fadump_mem_struct *fdm,
> return addr;
> }
>
> +/*
> + * This function parses command line for fadump_reserve_mem=
> + *
> + * Supports the below two syntaxes:
> + * 1. fadump_reserve_mem=size
> + * 2. fadump_reserve_mem=ramsize-range:size[,...]
> + *
> + * Sets fw_dump.reserve_bootvar with the memory size
> + * provided, 0 otherwise
> + *
> + * The function returns -EINVAL on failure, 0 otherwise.
> + */
> +static int __init parse_fadump_reserve_mem(void)
> +{
> + char *name = "fadump_reserve_mem=";
> + char *fadump_cmdline = NULL, *cur;
> +
> + fw_dump.reserve_bootvar = 0;
> +
> + /* find fadump_reserve_mem and use the last one if there are many */
> + cur = strstr(boot_command_line, name);
> + while (cur) {
> + fadump_cmdline = cur;
> + cur = strstr(cur+1, name);
> + }
> +
> + /* when no fadump_reserve_mem= cmdline option is provided */
> + if (!fadump_cmdline)
> + return 0;
> +
> + fadump_cmdline += strlen(name);
> +
> + /* for fadump_reserve_mem=size cmdline syntax */
> + if (!is_colon_in_param(fadump_cmdline)) {
> + fw_dump.reserve_bootvar = memparse(fadump_cmdline, NULL);
> + return 0;
> + }
> +
> + /* for fadump_reserve_mem=ramsize-range:size[,...] cmdline syntax */
> + cur = fadump_cmdline;
> + fw_dump.reserve_bootvar = parse_mem_range_size("fadump_reserve_mem",
> + &cur, memblock_phys_mem_size());
> + if (cur == fadump_cmdline) {
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> /**
> * fadump_calculate_reserve_size(): reserve variable boot area 5% of System
> RAM
> *
> @@ -212,12 +261,17 @@ static inline unsigned long
> fadump_calculate_reserve_size(void)
> {
> unsigned long size;
>
> + /* sets fw_dump.reserve_bootvar */
> + parse_fadump_reserve_mem();
> +
> /*
> * Check if the size is specified through fadump_reserve_mem= cmdline
> * option. If yes, then use that.
> */
> if (fw_dump.reserve_bootvar)
> return fw_dump.reserve_bootvar;
> + else
> + printk(KERN_INFO "fadump: calculating default boot size\n");
>
> /* divide by 20 to get 5% of value */
> size = memblock_end_of_DRAM() / 20;
> @@ -348,15 +402,6 @@ static int __init early_fadump_param(char *p)
> }
> early_param("fadump", early_fadump_param);
>
> -/* Look for fadump_reserve_mem= cmdline option */
> -static int __init early_fadump_reserve_mem(char *p)
> -{
> - if (p)
> - fw_dump.reserve_bootvar = memparse(p, &p);
> - return 0;
> -}
> -early_param("fadump_reserve_mem", early_fadump_reserve_mem);
> -
> static void register_fw_dump(struct fadump_mem_struct *fdm)
> {
> int rc;
>
