Hi Toshi, 2013/02/23 4:42, Toshi Kani wrote: > 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.kani@xxxxxx> > --- > This patch applies on top of the Rafael's patch below. > https://patchwork.kernel.org/patch/2153261/ > > --- > drivers/acpi/acpi_memhotplug.c | 54 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 54 insertions(+) > > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c > index 3b3abbc..d6226b3 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 +169,53 @@ 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); NULL pointer check is needed. Thank, Yasuaki Ishimatsu > + > + 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 +255,9 @@ 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 +292,9 @@ 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-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
