[PATCH 03/12] device-dax: Make pgmap optional for instance creation

From: Dan Williams
Date: Mon Mar 23 2020 - 20:10:57 EST

The passed in dev_pagemap is only required in the pmem case as the
libnvdimm core may have reserved a vmem_altmap for dev_memremap_pages()
to place the memmap in pmem directly. In the hmem case there is no
agent reserving an altmap so it can all be handled by a core internal
default.

Pass the resource range via a new @range property of 'struct
dev_dax_data'.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/dax/bus.c | 29 +++++++++++++++--------------
drivers/dax/bus.h | 2 ++
drivers/dax/dax-private.h | 9 ++++++++-
drivers/dax/device.c | 28 +++++++++++++++++++---------
drivers/dax/hmem/hmem.c | 8 ++++----
drivers/dax/kmem.c | 12 ++++++------
drivers/dax/pmem/core.c | 4 ++++
tools/testing/nvdimm/dax-dev.c | 8 ++++----
8 files changed, 62 insertions(+), 38 deletions(-)

diff --git a/drivers/dax/bus.c b/drivers/dax/bus.c
index a5b1b7a82a87..79e7514480b7 100644
--- a/drivers/dax/bus.c
+++ b/drivers/dax/bus.c
@@ -271,7 +271,7 @@ static ssize_t size_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dev_dax *dev_dax = to_dev_dax(dev);
- unsigned long long size = resource_size(&dev_dax->region->res);
+ unsigned long long size = range_len(&dev_dax->range);

return sprintf(buf, "%llu\n", size);
}
@@ -293,19 +293,12 @@ static ssize_t target_node_show(struct device *dev,
}
static DEVICE_ATTR_RO(target_node);

-static unsigned long long dev_dax_resource(struct dev_dax *dev_dax)
-{
- struct dax_region *dax_region = dev_dax->region;
-
- return dax_region->res.start;
-}
-
static ssize_t resource_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct dev_dax *dev_dax = to_dev_dax(dev);

- return sprintf(buf, "%#llx\n", dev_dax_resource(dev_dax));
+ return sprintf(buf, "%#llx\n", dev_dax->range.start);
}
static DEVICE_ATTR(resource, 0400, resource_show, NULL);

@@ -376,6 +369,7 @@ static void dev_dax_release(struct device *dev)

dax_region_put(dax_region);
put_dax(dax_dev);
+ kfree(dev_dax->pgmap);
kfree(dev_dax);
}

@@ -412,7 +406,12 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
if (!dev_dax)
return ERR_PTR(-ENOMEM);

- memcpy(&dev_dax->pgmap, data->pgmap, sizeof(struct dev_pagemap));
+ if (data->pgmap) {
+ dev_dax->pgmap = kmemdup(data->pgmap,
+ sizeof(struct dev_pagemap), GFP_KERNEL);
+ if (!dev_dax->pgmap)
+ goto err_pgmap;
+ }

/*
* No 'host' or dax_operations since there is no access to this
@@ -420,17 +419,18 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
*/
dax_dev = alloc_dax(dev_dax, NULL, NULL, DAXDEV_F_SYNC);
if (!dax_dev)
- goto err;
+ goto err_alloc_dax;

/* a device_dax instance is dead while the driver is not attached */
kill_dax(dax_dev);

- /* from here on we're committed to teardown via dax_dev_release() */
+ /* from here on we're committed to teardown via dev_dax_release() */
dev = &dev_dax->dev;
device_initialize(dev);

dev_dax->dax_dev = dax_dev;
dev_dax->region = dax_region;
+ dev_dax->range = data->range;
dev_dax->target_node = dax_region->target_node;
kref_get(&dax_region->kref);

@@ -456,8 +456,9 @@ struct dev_dax *devm_create_dev_dax(struct dev_dax_data *data)
return ERR_PTR(rc);

return dev_dax;
-
- err:
+err_alloc_dax:
+ kfree(dev_dax->pgmap);
+err_pgmap:
kfree(dev_dax);

return ERR_PTR(rc);
diff --git a/drivers/dax/bus.h b/drivers/dax/bus.h
index 299c2e7fac09..4aeb36da83a4 100644
--- a/drivers/dax/bus.h
+++ b/drivers/dax/bus.h
@@ -3,6 +3,7 @@
#ifndef __DAX_BUS_H__
#define __DAX_BUS_H__
#include <linux/device.h>
+#include <linux/range.h>

struct dev_dax;
struct resource;
@@ -21,6 +22,7 @@ struct dev_dax_data {
struct dax_region *dax_region;
struct dev_pagemap *pgmap;
enum dev_dax_subsys subsys;
+ struct range range;
int id;
};

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 28767dc3ec13..22d43095559a 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -41,6 +41,7 @@ struct dax_region {
* @target_node: effective numa node if dev_dax memory range is onlined
* @dev - device core
* @pgmap - pgmap for memmap setup / lifetime (driver owned)
+ * @range: resource range for the instance
* @dax_mem_res: physical address range of hotadded DAX memory
*/
struct dev_dax {
@@ -48,10 +49,16 @@ struct dev_dax {
struct dax_device *dax_dev;
int target_node;
struct device dev;
- struct dev_pagemap pgmap;
+ struct dev_pagemap *pgmap;
+ struct range range;
struct resource *dax_kmem_res;
};

+static inline u64 range_len(struct range *range)
+{
+ return range->end - range->start + 1;
+}
+
static inline struct dev_dax *to_dev_dax(struct device *dev)
{
return container_of(dev, struct dev_dax, dev);
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index eaa651ddeccd..d631344fdadb 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -55,12 +55,12 @@ static int check_vma(struct dev_dax *dev_dax, struct vm_area_struct *vma,
__weak phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
unsigned long size)
{
- struct resource *res = &dev_dax->region->res;
+ struct range *range = &dev_dax->range;
phys_addr_t phys;

- phys = pgoff * PAGE_SIZE + res->start;
- if (phys >= res->start && phys <= res->end) {
- if (phys + size - 1 <= res->end)
+ phys = pgoff * PAGE_SIZE + range->start;
+ if (phys >= range->start && phys <= range->end) {
+ if (phys + size - 1 <= range->end)
return phys;
}

@@ -395,21 +395,31 @@ int dev_dax_probe(struct device *dev)
{
struct dev_dax *dev_dax = to_dev_dax(dev);
struct dax_device *dax_dev = dev_dax->dax_dev;
- struct resource *res = &dev_dax->region->res;
+ struct range *range = &dev_dax->range;
+ struct dev_pagemap *pgmap;
struct inode *inode;
struct cdev *cdev;
void *addr;
int rc;

/* 1:1 map region resource range to device-dax instance range */
- if (!devm_request_mem_region(dev, res->start, resource_size(res),
+ if (!devm_request_mem_region(dev, range->start, range_len(range),
dev_name(dev))) {
- dev_warn(dev, "could not reserve region %pR\n", res);
+ dev_warn(dev, "could not reserve range: %#llx - %#llx\n",
+ range->start, range->end);
return -EBUSY;
}

- dev_dax->pgmap.type = MEMORY_DEVICE_DEVDAX;
- addr = devm_memremap_pages(dev, &dev_dax->pgmap);
+ pgmap = dev_dax->pgmap;
+ if (!pgmap) {
+ pgmap = devm_kzalloc(dev, sizeof(*pgmap), GFP_KERNEL);
+ if (!pgmap)
+ return -ENOMEM;
+ pgmap->res.start = range->start;
+ pgmap->res.end = range->end;
+ }
+ pgmap->type = MEMORY_DEVICE_DEVDAX;
+ addr = devm_memremap_pages(dev, pgmap);
if (IS_ERR(addr))
return PTR_ERR(addr);

diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
index b84fe17178d8..af82d6ba820a 100644
--- a/drivers/dax/hmem/hmem.c
+++ b/drivers/dax/hmem/hmem.c
@@ -8,7 +8,6 @@
static int dax_hmem_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
- struct dev_pagemap pgmap = { };
struct dax_region *dax_region;
struct memregion_info *mri;
struct dev_dax_data data;
@@ -20,8 +19,6 @@ static int dax_hmem_probe(struct platform_device *pdev)
return -ENOMEM;

mri = dev->platform_data;
- memcpy(&pgmap.res, res, sizeof(*res));
-
dax_region = alloc_dax_region(dev, pdev->id, res, mri->target_node,
PMD_SIZE);
if (!dax_region)
@@ -30,7 +27,10 @@ static int dax_hmem_probe(struct platform_device *pdev)
data = (struct dev_dax_data) {
.dax_region = dax_region,
.id = 0,
- .pgmap = &pgmap,
+ .range = {
+ .start = res->start,
+ .end = res->end,
+ },
};
dev_dax = devm_create_dev_dax(&data);
if (IS_ERR(dev_dax))
diff --git a/drivers/dax/kmem.c b/drivers/dax/kmem.c
index 3d0a7e702c94..111e4c06ff49 100644
--- a/drivers/dax/kmem.c
+++ b/drivers/dax/kmem.c
@@ -17,7 +17,7 @@
int dev_dax_kmem_probe(struct device *dev)
{
struct dev_dax *dev_dax = to_dev_dax(dev);
- struct resource *res = &dev_dax->region->res;
+ struct range *range = &dev_dax->range;
resource_size_t kmem_start;
resource_size_t kmem_size;
resource_size_t kmem_end;
@@ -33,17 +33,17 @@ int dev_dax_kmem_probe(struct device *dev)
*/
numa_node = dev_dax->target_node;
if (numa_node < 0) {
- dev_warn(dev, "rejecting DAX region %pR with invalid node: %d\n",
- res, numa_node);
+ dev_warn(dev, "rejecting DAX region with invalid node: %d\n",
+ numa_node);
return -EINVAL;
}

/* Hotplug starting at the beginning of the next block: */
- kmem_start = ALIGN(res->start, memory_block_size_bytes());
+ kmem_start = ALIGN(range->start, memory_block_size_bytes());

- kmem_size = resource_size(res);
+ kmem_size = range_len(range);
/* Adjust the size down to compensate for moving up kmem_start: */
- kmem_size -= kmem_start - res->start;
+ kmem_size -= kmem_start - range->start;
/* Align the size down to cover only complete blocks: */
kmem_size &= ~(memory_block_size_bytes() - 1);
kmem_end = kmem_start + kmem_size;
diff --git a/drivers/dax/pmem/core.c b/drivers/dax/pmem/core.c
index 08ee5947a49c..4fa81d3d2f65 100644
--- a/drivers/dax/pmem/core.c
+++ b/drivers/dax/pmem/core.c
@@ -63,6 +63,10 @@ struct dev_dax *__dax_pmem_probe(struct device *dev, enum dev_dax_subsys subsys)
.id = id,
.pgmap = &pgmap,
.subsys = subsys,
+ .range = {
+ .start = res.start,
+ .end = res.end,
+ },
};
dev_dax = devm_create_dev_dax(&data);

diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c
index 7e5d979e73cb..38d8e55c4a0d 100644
--- a/tools/testing/nvdimm/dax-dev.c
+++ b/tools/testing/nvdimm/dax-dev.c
@@ -9,12 +9,12 @@
phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
unsigned long size)
{
- struct resource *res = &dev_dax->region->res;
+ struct range *range = &dev_dax->range;
phys_addr_t addr;

- addr = pgoff * PAGE_SIZE + res->start;
- if (addr >= res->start && addr <= res->end) {
- if (addr + size - 1 <= res->end) {
+ addr = pgoff * PAGE_SIZE + range->start;
+ if (addr >= range->start && addr <= range->end) {
+ if (addr + size - 1 <= range->end) {
if (get_nfit_res(addr)) {
struct page *page;