From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: "Dan Williams"
<dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>,
"Jérôme Glisse" <jglisse-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
"Jason Gunthorpe" <jgg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
"Ben Skeggs" <bskeggs-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Cc: Ralph Campbell
<rcampbell-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org,
linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org,
linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org,
nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org
Subject: [PATCH 11/25] memremap: add a migrate_to_ram method to struct dev_pagemap_ops
Date: Mon, 17 Jun 2019 14:27:19 +0200 [thread overview]
Message-ID: <20190617122733.22432-12-hch@lst.de> (raw)
In-Reply-To: <20190617122733.22432-1-hch-jcswGhMUV9g@public.gmane.org>
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>
---
include/linux/hmm.h | 6 ------
include/linux/memremap.h | 6 ++++++
include/linux/swapops.h | 15 ---------------
kernel/memremap.c | 35 ++++-------------------------------
mm/hmm.c | 13 +++++--------
mm/memory.c | 9 ++-------
6 files changed, 17 insertions(+), 67 deletions(-)
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 31e1c5347331..e64824334b85 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -694,11 +694,6 @@ 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;
@@ -709,7 +704,6 @@ struct hmm_devmem {
struct dev_pagemap pagemap;
const struct hmm_devmem_ops *ops;
struct percpu_ref ref;
- dev_page_fault_t page_fault;
};
/*
diff --git a/include/linux/memremap.h b/include/linux/memremap.h
index cec02d5400f1..72a8a1a9303b 100644
--- a/include/linux/memremap.h
+++ b/include/linux/memremap.h
@@ -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);
};
/**
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index 4d961668e5fc..15bdb6fe71e5 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -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
diff --git a/kernel/memremap.c b/kernel/memremap.c
index 7272027fbdd7..5245c25b10e3 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 dev_pagemap_get_ops(struct device *dev, struct dev_pagemap *pgmap)
}
#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),
@@ -192,6 +161,10 @@ 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_PUBLIC:
if (!IS_ENABLED(CONFIG_DEVICE_PUBLIC)) {
diff --git a/mm/hmm.c b/mm/hmm.c
index 0add50944d64..2e5642dc6b04 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -1363,15 +1363,12 @@ 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)
@@ -1385,6 +1382,7 @@ 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,
};
/*
@@ -1435,7 +1433,6 @@ 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;
diff --git a/mm/memory.c b/mm/memory.c
index ddf20bd0c317..e8d0012032d7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2782,13 +2782,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf)
migration_entry_wait(vma->vm_mm, vmf->pmd,
vmf->address);
} else if (is_device_private_entry(entry)) {
- /*
- * For un-addressable device memory we call the pgmap
- * fault handler callback. The callback must migrate
- * the page back to some CPU accessible page.
- */
- ret = device_private_entry_fault(vma, vmf->address, entry,
- vmf->flags, vmf->pmd);
+ vmf->page = device_private_entry_to_page(entry);
+ ret = vmf->page->pgmap->ops->migrate_to_ram(vmf);
} else if (is_hwpoison_entry(entry)) {
ret = VM_FAULT_HWPOISON;
} else {
--
2.20.1
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next prev parent reply other threads:[~2019-06-17 12:27 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-17 12:27 dev_pagemap related cleanups v2 Christoph Hellwig
2019-06-17 12:27 ` [PATCH 01/25] mm: remove the unused ARCH_HAS_HMM_DEVICE Kconfig option Christoph Hellwig
2019-06-17 12:27 ` [PATCH 05/25] mm: export alloc_pages_vma Christoph Hellwig
[not found] ` <20190617122733.22432-1-hch-jcswGhMUV9g@public.gmane.org>
2019-06-17 12:27 ` [PATCH 02/25] mm: remove the struct hmm_device infrastructure Christoph Hellwig
2019-06-17 12:27 ` [PATCH 03/25] mm: remove hmm_devmem_add_resource Christoph Hellwig
2019-06-17 12:27 ` [PATCH 04/25] mm: don't clear ->mapping in hmm_devmem_free Christoph Hellwig
2019-06-17 12:27 ` [PATCH 06/25] mm: factor out a devm_request_free_mem_region helper Christoph Hellwig
[not found] ` <20190617122733.22432-7-hch-jcswGhMUV9g@public.gmane.org>
2019-06-17 17:37 ` Dan Williams
2019-06-17 17:40 ` Christoph Hellwig
[not found] ` <20190617174018.GA18185-jcswGhMUV9g@public.gmane.org>
2019-06-17 17:42 ` Christoph Hellwig
2019-06-17 12:27 ` [PATCH 07/25] memremap: validate the pagemap type passed to devm_memremap_pages Christoph Hellwig
[not found] ` <20190617122733.22432-8-hch-jcswGhMUV9g@public.gmane.org>
2019-06-17 19:02 ` Dan Williams
[not found] ` <CAPcyv4hbGfOawfafqQ-L1CMr6OMFGmnDtdgLTXrgQuPxYNHA2w-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-06-17 19:54 ` Christoph Hellwig
[not found] ` <20190617195404.GA20275-jcswGhMUV9g@public.gmane.org>
2019-06-17 20:36 ` Dan Williams
2019-06-17 12:27 ` [PATCH 08/25] memremap: move dev_pagemap callbacks into a separate structure Christoph Hellwig
2019-06-17 17:51 ` Dan Williams
[not found] ` <CAPcyv4i_0wUJHDqY91R=x5M2o_De+_QKZxPyob5=E9CCv8rM7A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2019-06-17 19:55 ` Christoph Hellwig
[not found] ` <20190617195526.GB20275-jcswGhMUV9g@public.gmane.org>
2019-06-17 21:09 ` Dan Williams
2019-06-17 20:08 ` Logan Gunthorpe
[not found] ` <d68c5e4c-b2de-95c3-0b75-1f2391b25a34-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2019-06-17 20:09 ` Christoph Hellwig
2019-06-17 12:27 ` [PATCH 09/25] memremap: pass a struct dev_pagemap to ->kill and ->cleanup Christoph Hellwig
2019-06-17 12:27 ` [PATCH 10/25] memremap: lift the devmap_enable manipulation into devm_memremap_pages Christoph Hellwig
[not found] ` <20190617122733.22432-11-hch-jcswGhMUV9g@public.gmane.org>
2019-06-17 19:25 ` Dan Williams
2019-06-17 12:27 ` Christoph Hellwig [this message]
2019-06-17 12:27 ` [PATCH 12/25] memremap: remove the data field in struct dev_pagemap Christoph Hellwig
2019-06-17 12:27 ` [PATCH 13/25] memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag Christoph Hellwig
2019-06-17 12:27 ` [PATCH 14/25] memremap: provide an optional internal refcount in struct dev_pagemap Christoph Hellwig
2019-06-17 12:27 ` [PATCH 15/25] device-dax: use the dev_pagemap internal refcount Christoph Hellwig
[not found] ` <20190617122733.22432-16-hch-jcswGhMUV9g@public.gmane.org>
2019-06-18 19:43 ` Dan Williams
2019-06-17 12:27 ` [PATCH 16/25] PCI/P2PDMA: " Christoph Hellwig
[not found] ` <20190617122733.22432-17-hch-jcswGhMUV9g@public.gmane.org>
2019-06-17 20:10 ` Logan Gunthorpe
2019-06-17 12:27 ` [PATCH 17/25] nouveau: use alloc_page_vma directly Christoph Hellwig
2019-06-17 12:27 ` [PATCH 18/25] nouveau: use devm_memremap_pages directly Christoph Hellwig
2019-06-17 12:27 ` [PATCH 19/25] mm: remove hmm_vma_alloc_locked_page Christoph Hellwig
2019-06-17 12:27 ` [PATCH 20/25] mm: remove hmm_devmem_add Christoph Hellwig
2019-06-17 12:27 ` [PATCH 21/25] mm: mark DEVICE_PUBLIC as broken Christoph Hellwig
2019-06-17 12:27 ` [PATCH 23/25] mm: sort out the DEVICE_PRIVATE Kconfig mess Christoph Hellwig
2019-06-17 12:27 ` [PATCH 24/25] mm: remove the HMM config option Christoph Hellwig
2019-06-17 12:27 ` [PATCH 25/25] mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR Christoph Hellwig
2019-06-17 12:27 ` [PATCH 22/25] mm: simplify ZONE_DEVICE page private data Christoph Hellwig
2019-06-18 19:47 ` dev_pagemap related cleanups v2 Dan Williams
2019-06-19 9:40 ` Christoph Hellwig
2019-06-19 16:36 ` Jason Gunthorpe
2019-06-19 16:46 ` Dan Williams
2019-06-19 18:19 ` Jason Gunthorpe
2019-06-20 6:32 ` Christoph Hellwig
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