Commit 296a7624 authored by Miodrag Dinic's avatar Miodrag Dinic Committed by Ralf Baechle
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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: default avatarMiodrag Dinic <miodrag.dinic@imgtec.com>
Signed-off-by: default avatarGoran Ferenc <goran.ferenc@imgtec.com>
Signed-off-by: default avatarAleksandar Markovic <aleksandar.markovic@imgtec.com>
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: default avatarRalf Baechle <ralf@linux-mips.org>
parent b9c4dc2c
......@@ -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)
......
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