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From: Dan Williams <dan.j.williams@intel.com>
To: akpm@linux-foundation.org
Cc: Joao Martins <joao.m.martins@oracle.com>,
	peterz@infradead.org, vishal.l.verma@intel.com,
	dave.hansen@linux.intel.com, ard.biesheuvel@linaro.org,
	vishal.l.verma@intel.com, linux-mm@kvack.org,
	linux-nvdimm@lists.01.org, joao.m.martins@oracle.com,
	linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org,
	dri-devel@lists.freedesktop.org
Subject: [PATCH v3 21/23] device-dax: Add an 'align' attribute
Date: Fri, 31 Jul 2020 20:26:56 -0700
Message-ID: <159625241660.3040297.3801913809845542130.stgit@dwillia2-desk3.amr.corp.intel.com> (raw)
In-Reply-To: <159625229779.3040297.11363509688097221416.stgit@dwillia2-desk3.amr.corp.intel.com>

From: Joao Martins <joao.m.martins@oracle.com>

Introduce a device align attribute. While doing so,
rename the region align attribute to be more explicitly
named as so, but keep it named as @align to retain the API
for tools like daxctl.

Changes on align may not always be valid, when say certain
mappings were created with 2M and then we switch to 1G. So, we
validate all ranges against the new value being attempted,
post resizing.

Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Link: https://lore.kernel.org/r/20200716172913.19658-3-joao.m.martins@oracle.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
 drivers/dax/bus.c |  102 ++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 92 insertions(+), 10 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index feca1413481c..7a9439132573 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -230,14 +230,15 @@ static ssize_t region_size_show(struct device *dev,
 static struct device_attribute dev_attr_region_size = __ATTR(size, 0444,
 		region_size_show, NULL);
 
-static ssize_t align_show(struct device *dev,
+static ssize_t region_align_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
 {
 	struct dax_region *dax_region = dev_get_drvdata(dev);
 
 	return sprintf(buf, "%u\n", dax_region->align);
 }
-static DEVICE_ATTR_RO(align);
+static struct device_attribute dev_attr_region_align =
+		__ATTR(align, 0400, region_align_show, NULL);
 
 #define for_each_dax_region_resource(dax_region, res) \
 	for (res = (dax_region)->res.child; res; res = res->sibling)
@@ -488,7 +489,7 @@ static umode_t dax_region_visible(struct kobject *kobj, struct attribute *a,
 static struct attribute *dax_region_attributes[] = {
 	&dev_attr_available_size.attr,
 	&dev_attr_region_size.attr,
-	&dev_attr_align.attr,
+	&dev_attr_region_align.attr,
 	&dev_attr_create.attr,
 	&dev_attr_seed.attr,
 	&dev_attr_delete.attr,
@@ -855,15 +856,13 @@ static ssize_t size_show(struct device *dev,
 	return sprintf(buf, "%llu\n", size);
 }
 
-static bool alloc_is_aligned(struct dax_region *dax_region,
-		resource_size_t size)
+static bool alloc_is_aligned(struct dev_dax *dev_dax, resource_size_t size)
 {
 	/*
 	 * The minimum mapping granularity for a device instance is a
 	 * single subsection, unless the arch says otherwise.
 	 */
-	return IS_ALIGNED(size, max_t(unsigned long, dax_region->align,
-				memremap_compat_align()));
+	return IS_ALIGNED(size, max_t(unsigned long, dev_dax->align, memremap_compat_align()));
 }
 
 static int dev_dax_shrink(struct dev_dax *dev_dax, resource_size_t size)
@@ -958,7 +957,7 @@ static ssize_t dev_dax_resize(struct dax_region *dax_region,
 		return dev_dax_shrink(dev_dax, size);
 
 	to_alloc = size - dev_size;
-	if (dev_WARN_ONCE(dev, !alloc_is_aligned(dax_region, to_alloc),
+	if (dev_WARN_ONCE(dev, !alloc_is_aligned(dev_dax, to_alloc),
 			"resize of %pa misaligned\n", &to_alloc))
 		return -ENXIO;
 
@@ -1022,7 +1021,7 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 	if (rc)
 		return rc;
 
-	if (!alloc_is_aligned(dax_region, val)) {
+	if (!alloc_is_aligned(dev_dax, val)) {
 		dev_dbg(dev, "%s: size: %lld misaligned\n", __func__, val);
 		return -EINVAL;
 	}
@@ -1041,6 +1040,87 @@ static ssize_t size_store(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RW(size);
 
+static ssize_t align_show(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+
+	return sprintf(buf, "%d\n", dev_dax->align);
+}
+
+static ssize_t dev_dax_validate_align(struct dev_dax *dev_dax)
+{
+	resource_size_t dev_size = dev_dax_size(dev_dax);
+	struct device *dev = &dev_dax->dev;
+	ssize_t rc, i;
+
+	if (dev->driver)
+		return -EBUSY;
+
+	rc = -EINVAL;
+	if (dev_size > 0 && !alloc_is_aligned(dev_dax, dev_size)) {
+		dev_dbg(dev, "%s: align %u invalid for size %llu\n",
+			__func__, dev_dax->align, dev_size);
+		return rc;
+	}
+
+	for (i = 0; i < dev_dax->nr_range; i++) {
+		size_t len = range_len(&dev_dax->ranges[i].range);
+
+		if (!alloc_is_aligned(dev_dax, len)) {
+			dev_dbg(dev, "%s: align %u invalid for range %ld\n",
+				__func__, dev_dax->align, i);
+			return rc;
+		}
+	}
+
+	switch (dev_dax->align) {
+	case PUD_SIZE:
+		if (!IS_ENABLED(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
+			break;
+		fallthrough;
+	case PMD_SIZE:
+		if (!has_transparent_hugepage())
+			break;
+		fallthrough;
+	case PAGE_SIZE:
+		rc = 0;
+		break;
+	}
+
+	return rc;
+}
+
+static ssize_t align_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t len)
+{
+	struct dev_dax *dev_dax = to_dev_dax(dev);
+	struct dax_region *dax_region = dev_dax->region;
+	unsigned long long val, align_save;
+	ssize_t rc;
+
+	rc = kstrtoull(buf, 0, &val);
+	if (rc)
+		return -ENXIO;
+
+	device_lock(dax_region->dev);
+	if (!dax_region->dev->driver) {
+		device_unlock(dax_region->dev);
+		return -ENXIO;
+	}
+
+	device_lock(dev);
+	align_save = dev_dax->align;
+	dev_dax->align = val;
+	rc = dev_dax_validate_align(dev_dax);
+	if (rc)
+		dev_dax->align = align_save;
+	device_unlock(dev);
+	device_unlock(dax_region->dev);
+	return rc == 0 ? len : rc;
+}
+static DEVICE_ATTR_RW(align);
+
 static int dev_dax_target_node(struct dev_dax *dev_dax)
 {
 	struct dax_region *dax_region = dev_dax->region;
@@ -1101,7 +1181,8 @@ static umode_t dev_dax_visible(struct kobject *kobj, struct attribute *a, int n)
 		return 0;
 	if (a == &dev_attr_numa_node.attr && !IS_ENABLED(CONFIG_NUMA))
 		return 0;
-	if (a == &dev_attr_size.attr && is_static(dax_region))
+	if ((a == &dev_attr_align.attr ||
+	     a == &dev_attr_size.attr) && is_static(dax_region))
 		return 0444;
 	return a->mode;
 }
@@ -1110,6 +1191,7 @@ static struct attribute *dev_dax_attributes[] = {
 	&dev_attr_modalias.attr,
 	&dev_attr_size.attr,
 	&dev_attr_target_node.attr,
+	&dev_attr_align.attr,
 	&dev_attr_resource.attr,
 	&dev_attr_numa_node.attr,
 	NULL,



  parent reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-08-01  3:24 [PATCH v3 00/23] device-dax: Support sub-dividing soft-reserved ranges Dan Williams
2020-08-01  3:25 ` [PATCH v3 01/23] x86/numa: Cleanup configuration dependent command-line options Dan Williams
2020-08-01  3:25 ` [PATCH v3 02/23] x86/numa: Add 'nohmat' option Dan Williams
2020-08-01  3:51   ` Randy Dunlap
2020-08-01 16:36     ` Dan Williams
2020-08-01  3:25 ` [PATCH v3 03/23] efi/fake_mem: Arrange for a resource entry per efi_fake_mem instance Dan Williams
2020-08-01  3:25 ` [PATCH v3 04/23] ACPI: HMAT: Refactor hmat_register_target_device to hmem_register_device Dan Williams
2020-08-01  3:25 ` [PATCH v3 05/23] resource: Report parent to walk_iomem_res_desc() callback Dan Williams
2020-08-01  3:25 ` [PATCH v3 06/23] mm/memory_hotplug: Introduce default phys_to_target_node() implementation Dan Williams
2020-08-01  6:24   ` kernel test robot
2020-08-01 16:39   ` kernel test robot
2020-08-01  3:25 ` [PATCH v3 07/23] ACPI: HMAT: Attach a device for each soft-reserved range Dan Williams
2020-08-01  3:25 ` [PATCH v3 08/23] device-dax: Drop the dax_region.pfn_flags attribute Dan Williams
2020-08-01  3:25 ` [PATCH v3 09/23] device-dax: Move instance creation parameters to 'struct dev_dax_data' Dan Williams
2020-08-01  3:25 ` [PATCH v3 10/23] device-dax: Make pgmap optional for instance creation Dan Williams
2020-08-01  3:26 ` [PATCH v3 11/23] device-dax: Kill dax_kmem_res Dan Williams
2020-08-01  3:26 ` [PATCH v3 12/23] device-dax: Add an allocation interface for device-dax instances Dan Williams
2020-08-01  3:26 ` [PATCH v3 13/23] device-dax: Introduce 'seed' devices Dan Williams
2020-08-01  3:26 ` [PATCH v3 14/23] drivers/base: Make device_find_child_by_name() compatible with sysfs inputs Dan Williams
2020-08-01  3:26 ` [PATCH v3 15/23] device-dax: Add resize support Dan Williams
2020-08-01  3:26 ` [PATCH v3 16/23] mm/memremap_pages: Convert to 'struct range' Dan Williams
2020-08-01  3:26 ` [PATCH v3 17/23] mm/memremap_pages: Support multiple ranges per invocation Dan Williams
2020-08-01  3:26 ` [PATCH v3 18/23] device-dax: Add dis-contiguous resource support Dan Williams
2020-08-01  3:26 ` [PATCH v3 19/23] device-dax: Introduce 'mapping' devices Dan Williams
2020-08-01  3:26 ` [PATCH v3 20/23] device-dax: Make align a per-device property Dan Williams
2020-08-01  7:23   ` kernel test robot
2020-08-01  3:26 ` Dan Williams [this message]
2020-08-01  6:14   ` [PATCH v3 21/23] device-dax: Add an 'align' attribute kernel test robot
2020-08-01  6:18   ` kernel test robot
2020-08-01  3:27 ` [PATCH v3 22/23] dax/hmem: Introduce dax_hmem.region_idle parameter Dan Williams
2020-08-01  3:27 ` [PATCH v3 23/23] device-dax: Add a range mapping allocation attribute Dan Williams
2020-08-04 17:02 ` [PATCH v3 00/23] device-dax: Support sub-dividing soft-reserved ranges Jason Gunthorpe

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