In order to eject a memory device object represented as "PNP0C80:%d" in sysfs, its associated memblocks (system/memory/memory%d) need to be off-lined. However, there is no user friendly way to correlate between a memory device object and its memblocks in sysfs.
This patch creates sysfs links to memblocks under a memory device object so that a user can easily checks and manipulates its memblocks in sysfs. For example, when PNP0C80:05 is associated with memory8 and memory9, the following two links are created under PNP0C80:05. This allows a user to access memory8/9 directly from PNP0C80:05. # ll /sys/devices/LNXSYSTM:00/LNXSYBUS:00/PNP0C80:05 lrwxrwxrwx. memory8 -> ../../../system/memory/memory8 lrwxrwxrwx. memory9 -> ../../../system/memory/memory9 Signed-off-by: Toshi Kani <toshi.k...@hp.com> --- This patch applies on top of the Rafael's patch below. https://patchwork.kernel.org/patch/2153261/ v2: Added a NULL return check for find_memory_block_hinted() as pointed by Yasuaki Ishimatsu. --- drivers/acpi/acpi_memhotplug.c | 56 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 3b3abbc..98477a5 100644 --- a/drivers/acpi/acpi_memhotplug.c +++ b/drivers/acpi/acpi_memhotplug.c @@ -28,6 +28,7 @@ */ #include <linux/acpi.h> +#include <linux/memory.h> #include <linux/memory_hotplug.h> #include "internal.h" @@ -168,6 +169,55 @@ static int acpi_memory_check_device(struct acpi_memory_device *mem_device) return 0; } +static void acpi_setup_mem_blk_links(struct acpi_memory_device *mem_device, + struct acpi_memory_info *info, bool add_links) +{ + struct memory_block *mem_blk = NULL; + struct mem_section *mem_sect; + unsigned long start_pfn, end_pfn, pfn; + unsigned long section_nr; + int ret; + + start_pfn = PFN_DOWN(info->start_addr); + end_pfn = PFN_UP(info->start_addr + info->length-1); + + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + section_nr = pfn_to_section_nr(pfn); + + if (!present_section_nr(section_nr)) + continue; + + mem_sect = __nr_to_section(section_nr); + + /* skip if the same memblock */ + if (mem_blk) + if ((section_nr >= mem_blk->start_section_nr) && + (section_nr <= mem_blk->end_section_nr)) + continue; + + mem_blk = find_memory_block_hinted(mem_sect, mem_blk); + if (!mem_blk) + continue; + + if (add_links) { + ret = sysfs_create_link_nowarn( + &mem_device->device->dev.kobj, + &mem_blk->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + if (ret && ret != -EEXIST) + dev_err(&mem_device->device->dev, + "Failed to create sysfs link %s\n", + kobject_name(&mem_blk->dev.kobj)); + } else { + sysfs_remove_link(&mem_device->device->dev.kobj, + kobject_name(&mem_blk->dev.kobj)); + } + } + + if (mem_blk) + kobject_put(&mem_blk->dev.kobj); +} + static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) { int result, num_enabled = 0; @@ -207,6 +257,9 @@ static int acpi_memory_enable_device(struct acpi_memory_device *mem_device) continue; } + /* Create sysfs links to its mem_blk devices */ + acpi_setup_mem_blk_links(mem_device, info, true); + if (!result) info->enabled = 1; /* @@ -241,6 +294,9 @@ static int acpi_memory_remove_memory(struct acpi_memory_device *mem_device) /* The kernel does not use this memory block */ continue; + /* Remove sysfs links to its mem_blk devices */ + acpi_setup_mem_blk_links(mem_device, info, false); + if (!info->enabled) /* * The kernel uses this memory block, but it may be not -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
