From: "mike.travis@hpe.com" Date: Thu, 24 May 2018 15:17:14 -0500 Subject: x86/platform/UV: Add kernel parameter to set memory block size Git-commit: d7609f4210cb716c11abfe2bfb5997191095d00b Patch-mainline: v4.18-rc2 References: bsc#1108243 Add a kernel parameter that allows setting UV memory block size. This is to provide an adjustment for new forms of PMEM and other DIMM memory that might require alignment restrictions other than scanning the global address table for the required minimum alignment. The value set will be further adjusted by both the GAM range table scan as well as restrictions imposed by set_memory_block_size_order(). Signed-off-by: Mike Travis Reviewed-by: Andrew Banman Cc: Andrew Morton Cc: Dimitri Sivanich Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Russ Anderson Cc: Thomas Gleixner Cc: dan.j.williams@intel.com Cc: jgross@suse.com Cc: kirill.shutemov@linux.intel.com Cc: mhocko@suse.com Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/lkml/20180524201711.854849120@stormcage.americas.sgi.com Signed-off-by: Ingo Molnar Acked-by: Joerg Roedel --- arch/x86/kernel/apic/x2apic_uv_x.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c index 2270a777d647..d492752f79e1 100644 --- a/arch/x86/kernel/apic/x2apic_uv_x.c +++ b/arch/x86/kernel/apic/x2apic_uv_x.c @@ -396,6 +396,17 @@ EXPORT_SYMBOL(uv_hub_info_version); /* Default UV memory block size is 2GB */ static unsigned long mem_block_size = (2UL << 30); +/* Kernel parameter to specify UV mem block size */ +static int parse_mem_block_size(char *ptr) +{ + unsigned long size = memparse(ptr, NULL); + + /* Size will be rounded down by set_block_size() below */ + mem_block_size = size; + return 0; +} +early_param("uv_memblksize", parse_mem_block_size); + static __init int adj_blksize(u32 lgre) { unsigned long base = (unsigned long)lgre << UV_GAM_RANGE_SHFT;