[PATCH v3 17/23] mm/memremap_pages: Support multiple ranges per invocation

In support of device-dax growing the ability to front physically dis-contiguous ranges of memory, update devm_memremap_pages() to track multiple ranges with a single reference counter and devm instance. Cc: Paul Mackerras <paulus(a)ozlabs.org&gt; Cc: Michael Ellerman <mpe(a)ellerman.id.au&gt; Cc: Benjamin Herrenschmidt <benh(a)kernel.crashing.org&gt; Cc: Dan Williams <dan.j.williams(a)intel.com&gt; Cc: Vishal Verma <vishal.l.verma(a)intel.com&gt; Cc: Dave Jiang <dave.jiang(a)intel.com&gt; Cc: Ben Skeggs <bskeggs(a)redhat.com&gt; Cc: David Airlie <airlied(a)linux.ie&gt; Cc: Daniel Vetter <daniel(a)ffwll.ch&gt; Cc: Ira Weiny <ira.weiny(a)intel.com&gt; Cc: Jason Gunthorpe <jgg(a)mellanox.com&gt; Signed-off-by: Dan Williams <dan.j.williams(a)intel.com&gt; --- arch/powerpc/kvm/book3s_hv_uvmem.c | 1 drivers/dax/device.c | 1 drivers/gpu/drm/nouveau/nouveau_dmem.c | 1 drivers/nvdimm/pfn_devs.c | 1 drivers/nvdimm/pmem.c | 1 drivers/pci/p2pdma.c | 1 include/linux/memremap.h | 10 + lib/test_hmm.c | 1 mm/memremap.c | 258 +++++++++++++++++++------------- 9 files changed, 165 insertions(+), 110 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c index 29ec555055c2..84e5a2dc8be5 100644 --- a/arch/powerpc/kvm/book3s_hv_uvmem.c +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -1172,6 +1172,7 @@ int kvmppc_uvmem_init(void) kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE; kvmppc_uvmem_pgmap.range.start = res->start; kvmppc_uvmem_pgmap.range.end = res->end; + kvmppc_uvmem_pgmap.nr_range = 1; kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops; /* just one global instance: */ kvmppc_uvmem_pgmap.owner = &kvmppc_uvmem_pgmap; diff --git a/drivers/dax/device.c b/drivers/dax/device.c index fffc54ce0911..f3755df4ae29 100644 --- a/drivers/dax/device.c +++ b/drivers/dax/device.c @@ -417,6 +417,7 @@ int dev_dax_probe(struct dev_dax *dev_dax) if (!pgmap) return -ENOMEM; pgmap->range = *range; + pgmap->nr_range = 1; } pgmap->type = MEMORY_DEVICE_DEVDAX; addr = devm_memremap_pages(dev, pgmap); diff --git a/drivers/gpu/drm/nouveau/nouveau_dmem.c b/drivers/gpu/drm/nouveau/nouveau_dmem.c index 25811ed7e274..a13c6215bba8 100644 --- a/drivers/gpu/drm/nouveau/nouveau_dmem.c +++ b/drivers/gpu/drm/nouveau/nouveau_dmem.c @@ -251,6 +251,7 @@ nouveau_dmem_chunk_alloc(struct nouveau_drm *drm, struct page **ppage) chunk->pagemap.type = MEMORY_DEVICE_PRIVATE; chunk->pagemap.range.start = res->start; chunk->pagemap.range.end = res->end; + chunk->pagemap.nr_range = 1; chunk->pagemap.ops = &nouveau_dmem_pagemap_ops; chunk->pagemap.owner = drm->dev; diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 3c4787b92a6a..b499df630d4d 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -693,6 +693,7 @@ static int __nvdimm_setup_pfn(struct nd_pfn *nd_pfn, struct dev_pagemap *pgmap) .start = nsio->res.start + start_pad, .end = nsio->res.end - end_trunc, }; + pgmap->nr_range = 1; if (nd_pfn->mode == PFN_MODE_RAM) { if (offset < reserve) return -EINVAL; diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 69cc0e783709..1f45af363a94 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -442,6 +442,7 @@ static int pmem_attach_disk(struct device *dev, } else if (pmem_should_map_pages(dev)) { pmem->pgmap.range.start = res->start; pmem->pgmap.range.end = res->end; + pmem->pgmap.nr_range = 1; pmem->pgmap.type = MEMORY_DEVICE_FS_DAX; pmem->pgmap.ops = &fsdax_pagemap_ops; addr = devm_memremap_pages(dev, &pmem->pgmap); diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index dd6b0d51a50c..403304785561 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -187,6 +187,7 @@ int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, pgmap = &p2p_pgmap->pgmap; pgmap->range.start = pci_resource_start(pdev, bar) + offset; pgmap->range.end = pgmap->range.start + size - 1; + pgmap->nr_range = 1; pgmap->type = MEMORY_DEVICE_PCI_P2PDMA; p2p_pgmap->provider = pdev; diff --git a/include/linux/memremap.h b/include/linux/memremap.h index 6c21951bdb16..4e9c738f4b31 100644 --- a/include/linux/memremap.h +++ b/include/linux/memremap.h @@ -95,7 +95,6 @@ struct dev_pagemap_ops { /** * struct dev_pagemap - metadata for ZONE_DEVICE mappings * @altmap: pre-allocated/reserved memory for vmemmap allocations - * @range: physical address range covered by @ref * @ref: reference count that pins the devm_memremap_pages() mapping * @internal_ref: internal reference if @ref is not provided by the caller * @done: completion for @internal_ref @@ -105,10 +104,12 @@ struct dev_pagemap_ops { * @owner: an opaque pointer identifying the entity that manages this * instance. Used by various helpers to make sure that no * foreign ZONE_DEVICE memory is accessed. + * @nr_range: number of ranges to be mapped + * @range: range to be mapped when nr_range == 1 + * @ranges: array of ranges to be mapped when nr_range > 1 */ struct dev_pagemap { struct vmem_altmap altmap; - struct range range; struct percpu_ref *ref; struct percpu_ref internal_ref; struct completion done; @@ -116,6 +117,11 @@ struct dev_pagemap { unsigned int flags; const struct dev_pagemap_ops *ops; void *owner; + int nr_range; + union { + struct range range; + struct range ranges[0]; + }; }; static inline struct vmem_altmap *pgmap_altmap(struct dev_pagemap *pgmap) diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 5b4521991621..e3065d6123f0 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -489,6 +489,7 @@ static bool dmirror_allocate_chunk(struct dmirror_device *mdevice, devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; devmem->pagemap.range.start = res->start; devmem->pagemap.range.end = res->end; + devmem->pagemap.nr_range = 1; devmem->pagemap.ops = &dmirror_devmem_ops; devmem->pagemap.owner = mdevice; diff --git a/mm/memremap.c b/mm/memremap.c index 9979891fec78..a7346638a09f 100644 --- a/mm/memremap.c +++ b/mm/memremap.c @@ -77,15 +77,19 @@ static void pgmap_array_delete(struct range *range) synchronize_rcu(); } -static unsigned long pfn_first(struct dev_pagemap *pgmap) +static unsigned long pfn_first(struct dev_pagemap *pgmap, int range_id) { - return PHYS_PFN(pgmap->range.start) + - vmem_altmap_offset(pgmap_altmap(pgmap)); + struct range *range = &pgmap->ranges[range_id]; + unsigned long pfn = PHYS_PFN(range->start); + + if (range_id) + return pfn; + return pfn + vmem_altmap_offset(pgmap_altmap(pgmap)); } -static unsigned long pfn_end(struct dev_pagemap *pgmap) +static unsigned long pfn_end(struct dev_pagemap *pgmap, int range_id) { - const struct range *range = &pgmap->range; + const struct range *range = &pgmap->ranges[range_id]; return (range->start + range_len(range)) >> PAGE_SHIFT; } @@ -117,8 +121,8 @@ bool pfn_zone_device_reserved(unsigned long pfn) return ret; } -#define for_each_device_pfn(pfn, map) \ - for (pfn = pfn_first(map); pfn < pfn_end(map); pfn = pfn_next(pfn)) +#define for_each_device_pfn(pfn, map, i) \ + for (pfn = pfn_first(map, i); pfn < pfn_end(map, i); pfn = pfn_next(pfn)) static void dev_pagemap_kill(struct dev_pagemap *pgmap) { @@ -144,20 +148,14 @@ static void dev_pagemap_cleanup(struct dev_pagemap *pgmap) pgmap->ref = NULL; } -void memunmap_pages(struct dev_pagemap *pgmap) +static void pageunmap_range(struct dev_pagemap *pgmap, int range_id) { - struct range *range = &pgmap->range; + struct range *range = &pgmap->ranges[range_id]; struct page *first_page; - unsigned long pfn; int nid; - dev_pagemap_kill(pgmap); - for_each_device_pfn(pfn, pgmap) - put_page(pfn_to_page(pfn)); - dev_pagemap_cleanup(pgmap); - /* make sure to access a memmap that was actually initialized */ - first_page = pfn_to_page(pfn_first(pgmap)); + first_page = pfn_to_page(pfn_first(pgmap, range_id)); /* pages are dead and unused, undo the arch mapping */ nid = page_to_nid(first_page); @@ -177,6 +175,22 @@ void memunmap_pages(struct dev_pagemap *pgmap) untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range)); pgmap_array_delete(range); +} + +void memunmap_pages(struct dev_pagemap *pgmap) +{ + unsigned long pfn; + int i; + + dev_pagemap_kill(pgmap); + for (i = 0; i < pgmap->nr_range; i++) + for_each_device_pfn(pfn, pgmap, i) + put_page(pfn_to_page(pfn)); + dev_pagemap_cleanup(pgmap); + + for (i = 0; i < pgmap->nr_range; i++) + pageunmap_range(pgmap, i); + WARN_ONCE(pgmap->altmap.alloc, "failed to free all reserved pages\n"); devmap_managed_enable_put(); } @@ -195,96 +209,29 @@ static void dev_pagemap_percpu_release(struct percpu_ref *ref) complete(&pgmap->done); } -/* - * Not device managed version of dev_memremap_pages, undone by - * memunmap_pages(). Please use dev_memremap_pages if you have a struct - * device available. - */ -void *memremap_pages(struct dev_pagemap *pgmap, int nid) +static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params, + int range_id, int nid) { - struct range *range = &pgmap->range; + struct range *range = &pgmap->ranges[range_id]; struct dev_pagemap *conflict_pgmap; - struct mhp_params params = { - /* - * We do not want any optional features only our own memmap - */ - .altmap = pgmap_altmap(pgmap), - .pgprot = PAGE_KERNEL, - }; int error, is_ram; - bool need_devmap_managed = true; - switch (pgmap->type) { - case MEMORY_DEVICE_PRIVATE: - if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) { - 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); - } - if (!pgmap->owner) { - WARN(1, "Missing owner\n"); - return ERR_PTR(-EINVAL); - } - break; - case MEMORY_DEVICE_FS_DAX: - if (!IS_ENABLED(CONFIG_ZONE_DEVICE) || - IS_ENABLED(CONFIG_FS_DAX_LIMITED)) { - WARN(1, "File system DAX not supported\n"); - return ERR_PTR(-EINVAL); - } - break; - case MEMORY_DEVICE_DEVDAX: - need_devmap_managed = false; - break; - case MEMORY_DEVICE_PCI_P2PDMA: - params.pgprot = pgprot_noncached(params.pgprot); - need_devmap_managed = false; - break; - default: - WARN(1, "Invalid pgmap type %d\n", pgmap->type); - break; - } - - if (!pgmap->ref) { - if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup)) - return ERR_PTR(-EINVAL); - - init_completion(&pgmap->done); - error = percpu_ref_init(&pgmap->internal_ref, - dev_pagemap_percpu_release, 0, GFP_KERNEL); - if (error) - return ERR_PTR(error); - pgmap->ref = &pgmap->internal_ref; - } else { - if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) { - WARN(1, "Missing reference count teardown definition\n"); - return ERR_PTR(-EINVAL); - } - } - - if (need_devmap_managed) { - error = devmap_managed_enable_get(pgmap); - if (error) - return ERR_PTR(error); - } + if (WARN_ONCE(pgmap_altmap(pgmap) && range_id > 0, + "altmap not supported for multiple ranges\n")) + return -EINVAL; conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->start), NULL); if (conflict_pgmap) { WARN(1, "Conflicting mapping in same section\n"); put_dev_pagemap(conflict_pgmap); - error = -ENOMEM; - goto err_array; + return -ENOMEM; } conflict_pgmap = get_dev_pagemap(PHYS_PFN(range->end), NULL); if (conflict_pgmap) { WARN(1, "Conflicting mapping in same section\n"); put_dev_pagemap(conflict_pgmap); - error = -ENOMEM; - goto err_array; + return -ENOMEM; } is_ram = region_intersects(range->start, range_len(range), @@ -294,19 +241,18 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) WARN_ONCE(1, "attempted on %s region %#llx-%#llx\n", is_ram == REGION_MIXED ? "mixed" : "ram", range->start, range->end); - error = -ENXIO; - goto err_array; + return -ENXIO; } error = xa_err(xa_store_range(&pgmap_array, PHYS_PFN(range->start), PHYS_PFN(range->end), pgmap, GFP_KERNEL)); if (error) - goto err_array; + return error; if (nid < 0) nid = numa_mem_id(); - error = track_pfn_remap(NULL, &params.pgprot, PHYS_PFN(range->start), 0, + error = track_pfn_remap(NULL, &params->pgprot, PHYS_PFN(range->start), 0, range_len(range)); if (error) goto err_pfn_remap; @@ -326,7 +272,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) */ if (pgmap->type == MEMORY_DEVICE_PRIVATE) { error = add_pages(nid, PHYS_PFN(range->start), - PHYS_PFN(range_len(range)), &params); + PHYS_PFN(range_len(range)), params); } else { error = kasan_add_zero_shadow(__va(range->start), range_len(range)); if (error) { @@ -335,7 +281,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) } error = arch_add_memory(nid, range->start, range_len(range), - &params); + params); } if (!error) { @@ -343,7 +289,7 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE]; move_pfn_range_to_zone(zone, PHYS_PFN(range->start), - PHYS_PFN(range_len(range)), params.altmap); + PHYS_PFN(range_len(range)), params->altmap); } mem_hotplug_done(); @@ -357,20 +303,116 @@ void *memremap_pages(struct dev_pagemap *pgmap, int nid) memmap_init_zone_device(&NODE_DATA(nid)->node_zones[ZONE_DEVICE], PHYS_PFN(range->start), PHYS_PFN(range_len(range)), pgmap); - percpu_ref_get_many(pgmap->ref, pfn_end(pgmap) - pfn_first(pgmap)); - return __va(range->start); + percpu_ref_get_many(pgmap->ref, pfn_end(pgmap, range_id) + - pfn_first(pgmap, range_id)); + return 0; - err_add_memory: +err_add_memory: kasan_remove_zero_shadow(__va(range->start), range_len(range)); - err_kasan: +err_kasan: untrack_pfn(NULL, PHYS_PFN(range->start), range_len(range)); - err_pfn_remap: +err_pfn_remap: pgmap_array_delete(range); - err_array: - dev_pagemap_kill(pgmap); - dev_pagemap_cleanup(pgmap); - devmap_managed_enable_put(); - return ERR_PTR(error); + return error; +} + + +/* + * Not device managed version of dev_memremap_pages, undone by + * memunmap_pages(). Please use dev_memremap_pages if you have a struct + * device available. + */ +void *memremap_pages(struct dev_pagemap *pgmap, int nid) +{ + struct mhp_params params = { + .altmap = pgmap_altmap(pgmap), + .pgprot = PAGE_KERNEL, + }; + const int nr_range = pgmap->nr_range; + bool need_devmap_managed = true; + int error, i; + + if (WARN_ONCE(!nr_range, "nr_range must be specified\n")) + return ERR_PTR(-EINVAL); + + switch (pgmap->type) { + case MEMORY_DEVICE_PRIVATE: + if (!IS_ENABLED(CONFIG_DEVICE_PRIVATE)) { + 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); + } + if (!pgmap->owner) { + WARN(1, "Missing owner\n"); + return ERR_PTR(-EINVAL); + } + break; + case MEMORY_DEVICE_FS_DAX: + if (!IS_ENABLED(CONFIG_ZONE_DEVICE) || + IS_ENABLED(CONFIG_FS_DAX_LIMITED)) { + WARN(1, "File system DAX not supported\n"); + return ERR_PTR(-EINVAL); + } + break; + case MEMORY_DEVICE_DEVDAX: + need_devmap_managed = false; + break; + case MEMORY_DEVICE_PCI_P2PDMA: + params.pgprot = pgprot_noncached(params.pgprot); + need_devmap_managed = false; + break; + default: + WARN(1, "Invalid pgmap type %d\n", pgmap->type); + break; + } + + if (!pgmap->ref) { + if (pgmap->ops && (pgmap->ops->kill || pgmap->ops->cleanup)) + return ERR_PTR(-EINVAL); + + init_completion(&pgmap->done); + error = percpu_ref_init(&pgmap->internal_ref, + dev_pagemap_percpu_release, 0, GFP_KERNEL); + if (error) + return ERR_PTR(error); + pgmap->ref = &pgmap->internal_ref; + } else { + if (!pgmap->ops || !pgmap->ops->kill || !pgmap->ops->cleanup) { + WARN(1, "Missing reference count teardown definition\n"); + return ERR_PTR(-EINVAL); + } + } + + if (need_devmap_managed) { + error = devmap_managed_enable_get(pgmap); + if (error) + return ERR_PTR(error); + } + + /* + * Clear the pgmap nr_range as it will be incremented for each + * successfully processed range. This communicates how many + * regions to unwind in the abort case. + */ + pgmap->nr_range = 0; + error = 0; + for (i = 0; i < nr_range; i++) { + error = pagemap_range(pgmap, &params, i, nid); + if (error) + break; + pgmap->nr_range++; + } + + if (i < nr_range) { + memunmap_pages(pgmap); + pgmap->nr_range = nr_range; + return ERR_PTR(error); + } + + return __va(pgmap->ranges[0].start); } EXPORT_SYMBOL_GPL(memremap_pages);