From 37ddd5d053c57fee798d72fa9c18660f59a9299b Mon Sep 17 00:00:00 2001 From: Manish Ahuja Date: Sat, 12 Apr 2008 09:31:52 +1000 Subject: [PATCH] [POWERPC] pseries/phyp dump: Reserve a variable amount of space at boot This changes the way we calculate how much space to reserve for the pHyp dump. Currently we reserve 256MB only. With this change, the code first checks to see if an amount has been specified on the boot command line with the "phyp_dump_reserve_size" option, and if so, uses that much. Otherwise it computes 5% of total ram and rounds it down to a multiple of 256MB, and uses the larger of that or 256MB. This is for large systems with a lot of memory (10GB or more). The aim is to have more space available for the kernel on reboot on machines with more resources. Although the dump will be collected pretty fast and the memory released really early on allowing the machine to have the full memory available, this alleviates any issues that can be caused by having way too little memory on very very large systems during those few minutes. Signed-off-by: Manish Ahuja Signed-off-by: Paul Mackerras --- arch/powerpc/kernel/prom.c | 35 ++++++++++++++++++++-- arch/powerpc/platforms/pseries/phyp_dump.c | 9 ++++++ include/asm-powerpc/phyp_dump.h | 4 ++- 3 files changed, 45 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index 31d5b22c59a2..8a9359ae4718 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -1042,6 +1042,33 @@ static void __init early_reserve_mem(void) } #ifdef CONFIG_PHYP_DUMP +/** + * phyp_dump_calculate_reserve_size() - reserve variable boot area 5% or arg + * + * Function to find the largest size we need to reserve + * during early boot process. + * + * It either looks for boot param and returns that OR + * returns larger of 256 or 5% rounded down to multiples of 256MB. + * + */ +static inline unsigned long phyp_dump_calculate_reserve_size(void) +{ + unsigned long tmp; + + if (phyp_dump_info->reserve_bootvar) + return phyp_dump_info->reserve_bootvar; + + /* divide by 20 to get 5% of value */ + tmp = lmb_end_of_DRAM(); + do_div(tmp, 20); + + /* round it down in multiples of 256 */ + tmp = tmp & ~0x0FFFFFFFUL; + + return (tmp > PHYP_DUMP_RMR_END ? tmp : PHYP_DUMP_RMR_END); +} + /** * phyp_dump_reserve_mem() - reserve all not-yet-dumped mmemory * @@ -1055,6 +1082,8 @@ static void __init early_reserve_mem(void) static void __init phyp_dump_reserve_mem(void) { unsigned long base, size; + unsigned long variable_reserve_size; + if (!phyp_dump_info->phyp_dump_configured) { printk(KERN_ERR "Phyp-dump not supported on this hardware\n"); return; @@ -1065,9 +1094,11 @@ static void __init phyp_dump_reserve_mem(void) return; } + variable_reserve_size = phyp_dump_calculate_reserve_size(); + if (phyp_dump_info->phyp_dump_is_active) { /* Reserve *everything* above RMR.Area freed by userland tools*/ - base = PHYP_DUMP_RMR_END; + base = variable_reserve_size; size = lmb_end_of_DRAM() - base; /* XXX crashed_ram_end is wrong, since it may be beyond @@ -1079,7 +1110,7 @@ static void __init phyp_dump_reserve_mem(void) } else { size = phyp_dump_info->cpu_state_size + phyp_dump_info->hpte_region_size + - PHYP_DUMP_RMR_END; + variable_reserve_size; base = lmb_end_of_DRAM() - size; lmb_reserve(base, size); phyp_dump_info->init_reserve_start = base; diff --git a/arch/powerpc/platforms/pseries/phyp_dump.c b/arch/powerpc/platforms/pseries/phyp_dump.c index 7ddd10526cea..edbc012c2ebc 100644 --- a/arch/powerpc/platforms/pseries/phyp_dump.c +++ b/arch/powerpc/platforms/pseries/phyp_dump.c @@ -496,3 +496,12 @@ static int __init early_phyp_dump_enabled(char *p) } early_param("phyp_dump", early_phyp_dump_enabled); +/* Look for phyp_dump_reserve_size= cmdline option */ +static int __init early_phyp_dump_reserve_size(char *p) +{ + if (p) + phyp_dump_info->reserve_bootvar = memparse(p, &p); + + return 0; +} +early_param("phyp_dump_reserve_size", early_phyp_dump_reserve_size); diff --git a/include/asm-powerpc/phyp_dump.h b/include/asm-powerpc/phyp_dump.h index 209a98913d9d..fa74c6c3e106 100644 --- a/include/asm-powerpc/phyp_dump.h +++ b/include/asm-powerpc/phyp_dump.h @@ -24,8 +24,10 @@ struct phyp_dump { /* Memory that is reserved during very early boot. */ unsigned long init_reserve_start; unsigned long init_reserve_size; - /* Check status during boot if dump supported, active & present*/ + /* cmd line options during boot */ + unsigned long reserve_bootvar; unsigned long phyp_dump_at_boot; + /* Check status during boot if dump supported, active & present*/ unsigned long phyp_dump_configured; unsigned long phyp_dump_is_active; /* store cpu & hpte size */ -- 2.34.1