In sometimes users specify the memory region in immovable node in some kernel commandline, such as "kernel_core" or the "immovable_mem=" in the patchset that I have send. But users don't know the memory region. So add this interface to print it.
It will show like this: "nn@ss,nn@ss,...". "nn" means the size of memory region, "ss" means the start position of this region. Signed-off-by: Chao Fan <[email protected]> --- drivers/base/memory.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 1d60b58a8c19..9cadf1a9dccb 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -25,6 +25,7 @@ #include <linux/atomic.h> #include <linux/uaccess.h> +#include <linux/acpi.h> static DEFINE_MUTEX(mem_sysfs_mutex); @@ -389,6 +390,52 @@ static ssize_t show_phys_device(struct device *dev, } #ifdef CONFIG_MEMORY_HOTREMOVE +/* + * Immovable memory region + */ + +static ssize_t +show_immovable_mem(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct acpi_table_header *table_header = NULL; + struct acpi_srat_mem_affinity *ma; + struct acpi_subtable_header *th; + unsigned long long table_size; + unsigned long long table_end; + char pbuf[35], *p = buf; + int len; + + acpi_get_table(ACPI_SIG_SRAT, 0, &table_header); + + table_size = sizeof(struct acpi_table_srat); + table_end = (unsigned long)table_header + table_header->length; + th = (struct acpi_subtable_header *)((unsigned long) + table_header + table_size); + + while (((unsigned long)th) + + sizeof(struct acpi_subtable_header) < table_end) { + if (th->type == 1) { + ma = (struct acpi_srat_mem_affinity *)th; + if (ma->flags & ACPI_SRAT_MEM_HOT_PLUGGABLE) + continue; + len = sprintf(pbuf, "%llx@%llx", + ma->length, ma->base_address); + if (p != buf) { + *p = ','; + p++; + } + memcpy(p, pbuf, len); + p = p + len; + } + th = (struct acpi_subtable_header *)((unsigned long) + th + th->length); + } + return sprintf(buf, "%s\n", buf); +} + +static DEVICE_ATTR(immovable_mem, 0444, show_immovable_mem, NULL); + static void print_allowed_zone(char *buf, int nid, unsigned long start_pfn, unsigned long nr_pages, int online_type, struct zone *default_zone) @@ -798,6 +845,9 @@ static struct attribute *memory_root_attrs[] = { #endif &dev_attr_block_size_bytes.attr, +#ifdef CONFIG_MEMORY_HOTREMOVE + &dev_attr_immovable_mem.attr, +#endif &dev_attr_auto_online_blocks.attr, NULL }; -- 2.14.3
