From: Joao Martins <joao.m.martins@xxxxxxxxxx> Subject: dax/hmem: introduce dax_hmem.region_idle parameter Introduce a new module parameter for dax_hmem which initializes all region devices as free, rather than allocating a pagemap for the region by default. All hmem devices created with dax_hmem.region_idle=1 will have full available size for creating dynamic dax devices. Link: https://lkml.kernel.org/r/159643106460.4062302.5868522341307530091.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Link: https://lore.kernel.org/r/20200716172913.19658-4-joao.m.martins@xxxxxxxxxx Link: https://lkml.kernel.org/r/160106119033.30709.11249962152222193448.stgit@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Joao Martins <joao.m.martins@xxxxxxxxxx> Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx> 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: Brice Goglin <Brice.Goglin@xxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Daniel Vetter <daniel@xxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: Dave Jiang <dave.jiang@xxxxxxxxx> Cc: David Airlie <airlied@xxxxxxxx> Cc: David Hildenbrand <david@xxxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Hulk Robot <hulkci@xxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Ira Weiny <ira.weiny@xxxxxxxxx> Cc: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Cc: Jason Yan <yanaijie@xxxxxxxxxx> Cc: Jeff Moyer <jmoyer@xxxxxxxxxx> Cc: "Jérôme Glisse" <jglisse@xxxxxxxxxx> Cc: Jia He <justin.he@xxxxxxx> Cc: Jonathan Cameron <Jonathan.Cameron@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: Pavel Tatashin <pasha.tatashin@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: Vishal Verma <vishal.l.verma@xxxxxxxxx> 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/hmem/hmem.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/drivers/dax/hmem/hmem.c~dax-hmem-introduce-dax_hmemregion_idle-parameter +++ a/drivers/dax/hmem/hmem.c @@ -5,6 +5,9 @@ #include <linux/pfn_t.h> #include "../bus.h" +static bool region_idle; +module_param_named(region_idle, region_idle, bool, 0644); + static int dax_hmem_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -30,7 +33,7 @@ static int dax_hmem_probe(struct platfor data = (struct dev_dax_data) { .dax_region = dax_region, .id = -1, - .size = resource_size(res), + .size = region_idle ? 0 : resource_size(res), }; dev_dax = devm_create_dev_dax(&data); if (IS_ERR(dev_dax)) _
