diff options
| author | Christoph Hellwig <hch@lst.de> | 2019-06-26 14:27:11 +0200 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@mellanox.com> | 2019-07-02 19:32:44 +0200 |
| commit | 897e6365cda6ba6356e83a3aaa68dec82ef4c548 (patch) | |
| tree | 91a2776f8a994aa78d9eb1f91fce9debc51b1727 /kernel | |
| parent | memremap: lift the devmap_enable manipulation into devm_memremap_pages (diff) | |
| download | linux-897e6365cda6ba6356e83a3aaa68dec82ef4c548.tar.xz linux-897e6365cda6ba6356e83a3aaa68dec82ef4c548.zip | |
memremap: add a migrate_to_ram method to struct dev_pagemap_ops
This replaces the hacky ->fault callback, which is currently directly
called from common code through a hmm specific data structure as an
exercise in layering violations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ralph Campbell <rcampbell@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/memremap.c | 35 |
1 files changed, 4 insertions, 31 deletions
diff --git a/kernel/memremap.c b/kernel/memremap.c index 3219a4c91d07..c06a5487dda7 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -11,7 +11,6 @@ #include <linux/types.h> #include <linux/wait_bit.h> #include <linux/xarray.h> -#include <linux/hmm.h> static DEFINE_XARRAY(pgmap_array); #define SECTION_MASK ~((1UL << PA_SECTION_SHIFT) - 1) @@ -46,36 +45,6 @@ static int devmap_managed_enable_get(struct device *dev, struct dev_pagemap *pgm } #endif /* CONFIG_DEV_PAGEMAP_OPS */ -#if IS_ENABLED(CONFIG_DEVICE_PRIVATE) -vm_fault_t device_private_entry_fault(struct vm_area_struct *vma, - unsigned long addr, - swp_entry_t entry, - unsigned int flags, - pmd_t *pmdp) -{ - struct page *page = device_private_entry_to_page(entry); - struct hmm_devmem *devmem; - - devmem = container_of(page->pgmap, typeof(*devmem), pagemap); - - /* - * The page_fault() callback must migrate page back to system memory - * so that CPU can access it. This might fail for various reasons - * (device issue, device was unsafely unplugged, ...). When such - * error conditions happen, the callback must return VM_FAULT_SIGBUS. - * - * Note that because memory cgroup charges are accounted to the device - * memory, this should never fail because of memory restrictions (but - * allocation of regular system page might still fail because we are - * out of memory). - * - * There is a more in-depth description of what that callback can and - * cannot do, in include/linux/memremap.h - */ - return devmem->page_fault(vma, addr, page, flags, pmdp); -} -#endif /* CONFIG_DEVICE_PRIVATE */ - static void pgmap_array_delete(struct resource *res) { xa_store_range(&pgmap_array, PHYS_PFN(res->start), PHYS_PFN(res->end), @@ -193,6 +162,10 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) WARN(1, "Device private memory not supported\n"); return ERR_PTR(-EINVAL); } + if (!pgmap->ops || !pgmap->ops->migrate_to_ram) { + WARN(1, "Missing migrate_to_ram method\n"); + return ERR_PTR(-EINVAL); + } break; case MEMORY_DEVICE_FS_DAX: if (!IS_ENABLED(CONFIG_ZONE_DEVICE) || |