The patch titled
Subject: mm/hmm: add new helper to hotplug CDM memory region
has been added to the -mm tree. Its filename is
mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3.patch
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*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
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------------------------------------------------------
From: Jérôme Glisse <jglisse@xxxxxxxxxx>
Subject: mm/hmm: add new helper to hotplug CDM memory region
Unlike unaddressable memory, coherent device memory has a real resource
associated with it on the system (as CPU can address it). Add a new
helper to hotplug such memory within the HMM framework.
Link: http://lkml.kernel.org/r/20170817000548.32038-20-jglisse@xxxxxxxxxx
Signed-off-by: Jérôme Glisse <jglisse@xxxxxxxxxx>
Reviewed-by: Balbir Singh <bsingharora@xxxxxxxxx>
Cc: Aneesh Kumar <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: David Nellans <dnellans@xxxxxxxxxx>
Cc: Evgeny Baskakov <ebaskakov@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: John Hubbard <jhubbard@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Mark Hairgrove <mhairgrove@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Ross Zwisler <ross.zwisler@xxxxxxxxxxxxxxx>
Cc: Sherry Cheung <SCheung@xxxxxxxxxx>
Cc: Subhash Gutti <sgutti@xxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/hmm.h | 3 +
mm/hmm.c | 88 +++++++++++++++++++++++++++++++++++++++---
2 files changed, 86 insertions(+), 5 deletions(-)
diff -puN include/linux/hmm.h~mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3 include/linux/hmm.h
--- a/include/linux/hmm.h~mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3
+++ a/include/linux/hmm.h
@@ -443,6 +443,9 @@ struct hmm_devmem {
struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
struct device *device,
unsigned long size);
+struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
+ struct device *device,
+ struct resource *res);
void hmm_devmem_remove(struct hmm_devmem *devmem);
/*
diff -puN mm/hmm.c~mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3 mm/hmm.c
--- a/mm/hmm.c~mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3
+++ a/mm/hmm.c
@@ -854,7 +854,11 @@ static void hmm_devmem_release(struct de
zone = page_zone(page);
mem_hotplug_begin();
- __remove_pages(zone, start_pfn, npages);
+ if (resource->desc == IORES_DESC_DEVICE_PRIVATE_MEMORY)
+ __remove_pages(zone, start_pfn, npages);
+ else
+ arch_remove_memory(start_pfn << PAGE_SHIFT,
+ npages << PAGE_SHIFT);
mem_hotplug_done();
hmm_devmem_radix_release(resource);
@@ -890,7 +894,11 @@ static int hmm_devmem_pages_create(struc
if (is_ram == REGION_INTERSECTS)
return -ENXIO;
- devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
+ if (devmem->resource->desc == IORES_DESC_DEVICE_PUBLIC_MEMORY)
+ devmem->pagemap.type = MEMORY_DEVICE_PUBLIC;
+ else
+ devmem->pagemap.type = MEMORY_DEVICE_PRIVATE;
+
devmem->pagemap.res = devmem->resource;
devmem->pagemap.page_fault = hmm_devmem_fault;
devmem->pagemap.page_free = hmm_devmem_free;
@@ -935,9 +943,15 @@ static int hmm_devmem_pages_create(struc
* over the device memory is un-accessible thus we do not want to
* create a linear mapping for the memory like arch_add_memory()
* would do.
+ *
+ * For device public memory, which is accesible by the CPU, we do
+ * want the linear mapping and thus use arch_add_memory().
*/
- ret = add_pages(nid, align_start >> PAGE_SHIFT,
- align_size >> PAGE_SHIFT, false);
+ if (devmem->pagemap.type == MEMORY_DEVICE_PUBLIC)
+ ret = arch_add_memory(nid, align_start, align_size, false);
+ else
+ ret = add_pages(nid, align_start >> PAGE_SHIFT,
+ align_size >> PAGE_SHIFT, false);
if (ret) {
mem_hotplug_done();
goto error_add_memory;
@@ -1084,6 +1098,67 @@ error_percpu_ref:
}
EXPORT_SYMBOL(hmm_devmem_add);
+struct hmm_devmem *hmm_devmem_add_resource(const struct hmm_devmem_ops *ops,
+ struct device *device,
+ struct resource *res)
+{
+ struct hmm_devmem *devmem;
+ int ret;
+
+ if (res->desc != IORES_DESC_DEVICE_PUBLIC_MEMORY)
+ return ERR_PTR(-EINVAL);
+
+ static_branch_enable(&device_private_key);
+
+ devmem = devres_alloc_node(&hmm_devmem_release, sizeof(*devmem),
+ GFP_KERNEL, dev_to_node(device));
+ if (!devmem)
+ return ERR_PTR(-ENOMEM);
+
+ init_completion(&devmem->completion);
+ devmem->pfn_first = -1UL;
+ devmem->pfn_last = -1UL;
+ devmem->resource = res;
+ devmem->device = device;
+ devmem->ops = ops;
+
+ ret = percpu_ref_init(&devmem->ref, &hmm_devmem_ref_release,
+ 0, GFP_KERNEL);
+ if (ret)
+ goto error_percpu_ref;
+
+ ret = devm_add_action(device, hmm_devmem_ref_exit, &devmem->ref);
+ if (ret)
+ goto error_devm_add_action;
+
+
+ devmem->pfn_first = devmem->resource->start >> PAGE_SHIFT;
+ devmem->pfn_last = devmem->pfn_first +
+ (resource_size(devmem->resource) >> PAGE_SHIFT);
+
+ ret = hmm_devmem_pages_create(devmem);
+ if (ret)
+ goto error_devm_add_action;
+
+ devres_add(device, devmem);
+
+ ret = devm_add_action(device, hmm_devmem_ref_kill, &devmem->ref);
+ if (ret) {
+ hmm_devmem_remove(devmem);
+ return ERR_PTR(ret);
+ }
+
+ return devmem;
+
+error_devm_add_action:
+ hmm_devmem_ref_kill(&devmem->ref);
+ hmm_devmem_ref_exit(&devmem->ref);
+error_percpu_ref:
+ devres_free(devmem);
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(hmm_devmem_add_resource);
+
/*
* hmm_devmem_remove() - remove device memory (kill and free ZONE_DEVICE)
*
@@ -1097,6 +1172,7 @@ void hmm_devmem_remove(struct hmm_devmem
{
resource_size_t start, size;
struct device *device;
+ bool cdm = false;
if (!devmem)
return;
@@ -1105,11 +1181,13 @@ void hmm_devmem_remove(struct hmm_devmem
start = devmem->resource->start;
size = resource_size(devmem->resource);
+ cdm = devmem->resource->desc == IORES_DESC_DEVICE_PUBLIC_MEMORY;
hmm_devmem_ref_kill(&devmem->ref);
hmm_devmem_ref_exit(&devmem->ref);
hmm_devmem_pages_remove(devmem);
- devm_release_mem_region(device, start, size);
+ if (!cdm)
+ devm_release_mem_region(device, start, size);
}
EXPORT_SYMBOL(hmm_devmem_remove);
_
Patches currently in -mm which might be from jglisse@xxxxxxxxxx are
hmm-heterogeneous-memory-management-documentation-v3.patch
mm-hmm-heterogeneous-memory-management-hmm-for-short-v5.patch
mm-hmm-mirror-mirror-process-address-space-on-device-with-hmm-helpers-v3.patch
mm-hmm-mirror-helper-to-snapshot-cpu-page-table-v4.patch
mm-hmm-mirror-device-page-fault-handler.patch
mm-zone_device-new-type-of-zone_device-for-unaddressable-memory-v5.patch
mm-zone_device-special-case-put_page-for-device-private-pages-v4.patch
mm-memcontrol-allow-to-uncharge-page-without-using-page-lru-field.patch
mm-memcontrol-support-memory_device_private-v4.patch
mm-hmm-devmem-device-memory-hotplug-using-zone_device-v7.patch
mm-hmm-devmem-dummy-hmm-device-for-zone_device-memory-v3.patch
mm-migrate-new-migrate-mode-migrate_sync_no_copy.patch
mm-migrate-new-memory-migration-helper-for-use-with-device-memory-v5.patch
mm-migrate-migrate_vma-unmap-page-from-vma-while-collecting-pages.patch
mm-migrate-support-un-addressable-zone_device-page-in-migration-v3.patch
mm-migrate-allow-migrate_vma-to-alloc-new-page-on-empty-entry-v4.patch
mm-device-public-memory-device-memory-cache-coherent-with-cpu-v5.patch
mm-hmm-add-new-helper-to-hotplug-cdm-memory-region-v3.patch
lib-interval_tree-fast-overlap-detection-fix.patch
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