From 296a7624f5b292af610d728e7e347fda341a985e Mon Sep 17 00:00:00 2001 From: Miodrag Dinic Date: Mon, 19 Jun 2017 17:50:08 +0200 Subject: [PATCH] MIPS: cmdline: Add support for 'memmap' parameter Implement support for parsing 'memmap' kernel command line parameter. This patch covers parsing of the following two formats for 'memmap' parameter values: - nn[KMG]@ss[KMG] - nn[KMG]$ss[KMG] ([KMG] = K M or G (kilo, mega, giga)) These two allowed formats for parameter value are already documented in file kernel-parameters.txt in Documentation/admin-guide folder. Some architectures already support them, but Mips did not prior to this patch. Excerpt from Documentation/admin-guide/kernel-parameters.txt: memmap=nn[KMG]@ss[KMG] [KNL] Force usage of a specific region of memory. Region of memory to be used is from ss to ss+nn. memmap=nn[KMG]$ss[KMG] Mark specific memory as reserved. Region of memory to be reserved is from ss to ss+nn. Example: Exclude memory from 0x18690000-0x1869ffff memmap=64K$0x18690000 or memmap=0x10000$0x18690000 There is no need to update this documentation file with respect to this patch. Signed-off-by: Miodrag Dinic Signed-off-by: Goran Ferenc Signed-off-by: Aleksandar Markovic Cc: James.Hogan@imgtec.com Cc: Paul.Burton@imgtec.com Cc: Raghu.Gandham@imgtec.com Cc: Leonid.Yegoshin@imgtec.com Cc: Douglas.Leung@imgtec.com Cc: Petar.Jovanovic@imgtec.com Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/16508/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/setup.c | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 01d1dbde5fbf1..fe39397267651 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -670,6 +670,46 @@ static int __init early_parse_mem(char *p) } early_param("mem", early_parse_mem); +static int __init early_parse_memmap(char *p) +{ + char *oldp; + u64 start_at, mem_size; + + if (!p) + return -EINVAL; + + if (!strncmp(p, "exactmap", 8)) { + pr_err("\"memmap=exactmap\" invalid on MIPS\n"); + return 0; + } + + oldp = p; + mem_size = memparse(p, &p); + if (p == oldp) + return -EINVAL; + + if (*p == '@') { + start_at = memparse(p+1, &p); + add_memory_region(start_at, mem_size, BOOT_MEM_RAM); + } else if (*p == '#') { + pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n"); + return -EINVAL; + } else if (*p == '$') { + start_at = memparse(p+1, &p); + add_memory_region(start_at, mem_size, BOOT_MEM_RESERVED); + } else { + pr_err("\"memmap\" invalid format!\n"); + return -EINVAL; + } + + if (*p == '\0') { + usermem = 1; + return 0; + } else + return -EINVAL; +} +early_param("memmap", early_parse_memmap); + #ifdef CONFIG_PROC_VMCORE unsigned long setup_elfcorehdr, setup_elfcorehdr_size; static int __init early_parse_elfcorehdr(char *p) -- 2.39.5