From: Dan Williams <dan.j.williams@xxxxxxxxx> Subject: device-dax/kmem: introduce dax_kmem_range() Towards removing the mode specific @dax_kmem_res attribute from the generic 'struct dev_dax', and preparing for multi-range support, teach the driver to calculate the hotplug range from the device range. The hotplug range is the trivially calculated memory-block-size aligned version of the device range. Link: https://lkml.kernel.org/r/160106111109.30709.3173462396758431559.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Vishal Verma <vishal.l.verma@xxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx> Cc: Brice Goglin <Brice.Goglin@xxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Ira Weiny <ira.weiny@xxxxxxxxx> Cc: Jia He <justin.he@xxxxxxx> Cc: Joao Martins <joao.m.martins@xxxxxxxxxx> Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> Cc: Ard Biesheuvel <ardb@xxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Ben Skeggs <bskeggs@xxxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Hulk Robot <hulkci@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Cc: Jason Yan <yanaijie@xxxxxxxxxx> Cc: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: kernel test robot <lkp@xxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@xxxxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Tom Lendacky <thomas.lendacky@xxxxxxx> Cc: Vivek Goyal <vgoyal@xxxxxxxxxx> Cc: Wei Yang <richard.weiyang@xxxxxxxxxxxxxxxxx> Cc: Will Deacon <will@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/dax/kmem.c | 40 +++++++++++++++++----------------------- 1 file changed, 17 insertions(+), 23 deletions(-) --- a/drivers/dax/kmem.c~device-dax-kmem-introduce-dax_kmem_range +++ a/drivers/dax/kmem.c @@ -19,13 +19,20 @@ static const char *kmem_name; /* Set if any memory will remain added when the driver will be unloaded. */ static bool any_hotremove_failed; +static struct range dax_kmem_range(struct dev_dax *dev_dax) +{ + struct range range; + + /* memory-block align the hotplug range */ + range.start = ALIGN(dev_dax->range.start, memory_block_size_bytes()); + range.end = ALIGN_DOWN(dev_dax->range.end + 1, memory_block_size_bytes()) - 1; + return range; +} + int dev_dax_kmem_probe(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); - struct range *range = &dev_dax->range; - resource_size_t kmem_start; - resource_size_t kmem_size; - resource_size_t kmem_end; + struct range range = dax_kmem_range(dev_dax); struct resource *new_res; const char *new_res_name; int numa_node; @@ -44,25 +51,14 @@ int dev_dax_kmem_probe(struct device *de return -EINVAL; } - /* Hotplug starting at the beginning of the next block: */ - kmem_start = ALIGN(range->start, memory_block_size_bytes()); - - kmem_size = range_len(range); - /* Adjust the size down to compensate for moving up kmem_start: */ - kmem_size -= kmem_start - range->start; - /* Align the size down to cover only complete blocks: */ - kmem_size &= ~(memory_block_size_bytes() - 1); - kmem_end = kmem_start + kmem_size; - new_res_name = kstrdup(dev_name(dev), GFP_KERNEL); if (!new_res_name) return -ENOMEM; /* Region is permanently reserved if hotremove fails. */ - new_res = request_mem_region(kmem_start, kmem_size, new_res_name); + new_res = request_mem_region(range.start, range_len(&range), new_res_name); if (!new_res) { - dev_warn(dev, "could not reserve region [%pa-%pa]\n", - &kmem_start, &kmem_end); + dev_warn(dev, "could not reserve region [%#llx-%#llx]\n", range.start, range.end); kfree(new_res_name); return -EBUSY; } @@ -96,9 +92,8 @@ int dev_dax_kmem_probe(struct device *de static int dev_dax_kmem_remove(struct device *dev) { struct dev_dax *dev_dax = to_dev_dax(dev); + struct range range = dax_kmem_range(dev_dax); struct resource *res = dev_dax->dax_kmem_res; - resource_size_t kmem_start = res->start; - resource_size_t kmem_size = resource_size(res); const char *res_name = res->name; int rc; @@ -108,12 +103,11 @@ static int dev_dax_kmem_remove(struct de * there is no way to hotremove this memory until reboot because device * unbind will succeed even if we return failure. */ - rc = remove_memory(dev_dax->target_node, kmem_start, kmem_size); + rc = remove_memory(dev_dax->target_node, range.start, range_len(&range)); if (rc) { any_hotremove_failed = true; - dev_err(dev, - "DAX region %pR cannot be hotremoved until the next reboot\n", - res); + dev_err(dev, "%#llx-%#llx cannot be hotremoved until the next reboot\n", + range.start, range.end); return rc; } _
