From: "Jérôme Glisse" <jglisse@redhat.com>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: "John Hubbard" <jhubbard@nvidia.com>,
"Anshuman Khandual" <khandual@linux.vnet.ibm.com>,
"Balbir Singh" <balbir@au1.ibm.com>,
"Benjamin Herrenschmidt" <benh@kernel.crashing.org>,
"Aneesh Kumar" <aneesh.kumar@linux.vnet.ibm.com>,
"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
"Srikar Dronamraju" <srikar@linux.vnet.ibm.com>,
"Haren Myneni" <haren@linux.vnet.ibm.com>,
"Dan Williams" <dan.j.williams@intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>
Subject: [RFC HMM CDM 2/3] mm/hmm: add new helper to hotplug CDM memory region
Date: Fri, 7 Apr 2017 16:28:52 -0400 [thread overview]
Message-ID: <1491596933-21669-3-git-send-email-jglisse@redhat.com> (raw)
In-Reply-To: <1491596933-21669-1-git-send-email-jglisse@redhat.com>
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.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
include/linux/hmm.h | 3 +++
mm/hmm.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
2 files changed, 64 insertions(+), 1 deletion(-)
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index 374e5fd..e4fda18 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -392,6 +392,9 @@ 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);
int hmm_devmem_fault_range(struct hmm_devmem *devmem,
diff --git a/mm/hmm.c b/mm/hmm.c
index ff8ec59..28c7fcb 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -1038,6 +1038,63 @@ struct hmm_devmem *hmm_devmem_add(const struct hmm_devmem_ops *ops,
}
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;
+
+ 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->resource->desc = MEMORY_DEVICE_CACHE_COHERENT;
+ 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)
*
@@ -1051,6 +1108,7 @@ void hmm_devmem_remove(struct hmm_devmem *devmem)
{
resource_size_t start, size;
struct device *device;
+ bool cdm = false;
if (!devmem)
return;
@@ -1059,11 +1117,13 @@ void hmm_devmem_remove(struct hmm_devmem *devmem)
start = devmem->resource->start;
size = resource_size(devmem->resource);
+ cdm = devmem->resource->desc == MEMORY_DEVICE_CACHE_COHERENT;
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);
--
2.7.4
next prev parent reply other threads:[~2017-04-07 20:29 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-07 20:28 [RFC HMM CDM 0/3] Coherent Device Memory (CDM) on top of HMM Jérôme Glisse
2017-04-07 20:28 ` [RFC HMM CDM 1/3] mm/cache-coherent-device-memory: new type of ZONE_DEVICE Jérôme Glisse
2017-04-07 20:28 ` Jérôme Glisse [this message]
2017-04-07 20:28 ` [RFC HMM CDM 3/3] mm/migrate: memory migration using a device DMA engine Jérôme Glisse
2017-04-10 18:11 ` Reza Arbab
2017-04-09 0:31 ` [RFC HMM CDM 0/3] Coherent Device Memory (CDM) on top of HMM Balbir Singh
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