memremap: add a migrate_to_ram method to struct dev_pagemap_ops (897e6365) · Commits · 戴 / test

include/linux/hmm.h

+0 −6

Original line number	Diff line number	Diff line
		@@ -692,11 +692,6 @@ struct hmm_devmem_ops {
		* chunk, as an optimization. It must, however, prioritize the faulting address
		* over all the others.
		*/
		typedef vm_fault_t (dev_page_fault_t)(struct vm_area_struct vma,
		unsigned long addr,
		const struct page *page,
		unsigned int flags,
		pmd_t *pmdp);

		struct hmm_devmem {
		struct completion completion;
		@@ -707,7 +702,6 @@ struct hmm_devmem {
		struct dev_pagemap pagemap;
		const struct hmm_devmem_ops *ops;
		struct percpu_ref ref;
		dev_page_fault_t page_fault;
		};

		/*

include/linux/memremap.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -80,6 +80,12 @@ struct dev_pagemap_ops {
		* Wait for refcount in struct dev_pagemap to be idle and reap it.
		*/
		void (cleanup)(struct dev_pagemap pgmap);

		/*
		* Used for private (un-addressable) device memory only. Must migrate
		* the page back to a CPU accessible page.
		*/
		vm_fault_t (migrate_to_ram)(struct vm_fault vmf);
		};

		/**

include/linux/swapops.h

+0 −15

Original line number	Diff line number	Diff line
		@@ -129,12 +129,6 @@ static inline struct page *device_private_entry_to_page(swp_entry_t entry)
		{
		return pfn_to_page(swp_offset(entry));
		}

		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);
		#else /* CONFIG_DEVICE_PRIVATE */
		static inline swp_entry_t make_device_private_entry(struct page *page, bool write)
		{
		@@ -164,15 +158,6 @@ static inline struct page *device_private_entry_to_page(swp_entry_t entry)
		{
		return NULL;
		}

		static inline 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)
		{
		return VM_FAULT_SIGBUS;
		}
		#endif /* CONFIG_DEVICE_PRIVATE */

		#ifdef CONFIG_MIGRATION

kernel/memremap.c

+4 −31

Original line number	Diff line number	Diff line
		@@ -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) \|\|

mm/hmm.c

+5 −8

Original line number	Diff line number	Diff line
		@@ -1366,15 +1366,12 @@ static void hmm_devmem_ref_kill(struct dev_pagemap *pgmap)
		percpu_ref_kill(pgmap->ref);
		}

		static vm_fault_t hmm_devmem_fault(struct vm_area_struct *vma,
		unsigned long addr,
		const struct page *page,
		unsigned int flags,
		pmd_t *pmdp)
		static vm_fault_t hmm_devmem_migrate_to_ram(struct vm_fault *vmf)
		{
		struct hmm_devmem *devmem = page->pgmap->data;
		struct hmm_devmem *devmem = vmf->page->pgmap->data;

		return devmem->ops->fault(devmem, vma, addr, page, flags, pmdp);
		return devmem->ops->fault(devmem, vmf->vma, vmf->address, vmf->page,
		vmf->flags, vmf->pmd);
		}

		static void hmm_devmem_free(struct page page, void data)
		@@ -1388,6 +1385,7 @@ static const struct dev_pagemap_ops hmm_pagemap_ops = {
		.page_free = hmm_devmem_free,
		.kill = hmm_devmem_ref_kill,
		.cleanup = hmm_devmem_ref_exit,
		.migrate_to_ram = hmm_devmem_migrate_to_ram,
		};

		/*
		@@ -1438,7 +1436,6 @@ struct hmm_devmem hmm_devmem_add(const struct hmm_devmem_ops ops,
		devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT;
		devmem->pfn_last = devmem->pfn_first +
		(resource_size(devmem->resource) >> PAGE_SHIFT);
		devmem->page_fault = hmm_devmem_fault;

		devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
		devmem->pagemap.res = *devmem->resource;

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