[PATCH 3/8] device-dax: Remove multi-resource infrastructure

From: Dan Williams
Date: Tue Oct 30 2018 - 23:24:55 EST


The multi-resource implementation anticipated discontiguous sub-division
support. That has not yet materialized, delete the infrastructure and
related code.

Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/dax/dax-private.h | 4 ---
drivers/dax/device-dax.h | 3 +-
drivers/dax/device.c | 49 +++++++---------------------------------
drivers/dax/pmem.c | 3 +-
tools/testing/nvdimm/dax-dev.c | 16 ++-----------
5 files changed, 13 insertions(+), 62 deletions(-)

diff --git a/drivers/dax/dax-private.h b/drivers/dax/dax-private.h
index 9b393c218fe4..dbd077653b5c 100644
--- a/drivers/dax/dax-private.h
+++ b/drivers/dax/dax-private.h
@@ -39,14 +39,10 @@ struct dax_region {
* @region - parent region
* @dax_dev - core dax functionality
* @dev - device core
- * @num_resources - number of physical address extents in this device
- * @res - array of physical address ranges
*/
struct dev_dax {
struct dax_region *region;
struct dax_device *dax_dev;
struct device dev;
- int num_resources;
- struct resource res[0];
};
#endif
diff --git a/drivers/dax/device-dax.h b/drivers/dax/device-dax.h
index 4f1c69e1b3a2..e9be99584b92 100644
--- a/drivers/dax/device-dax.h
+++ b/drivers/dax/device-dax.h
@@ -19,6 +19,5 @@ struct dax_region;
void dax_region_put(struct dax_region *dax_region);
struct dax_region *alloc_dax_region(struct device *parent, int region_id,
struct resource *res, unsigned int align, unsigned long flags);
-struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
- int id, struct resource *res, int count);
+struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id);
#endif /* __DEVICE_DAX_H__ */
diff --git a/drivers/dax/device.c b/drivers/dax/device.c
index 811c1015194c..db12e24b8005 100644
--- a/drivers/dax/device.c
+++ b/drivers/dax/device.c
@@ -151,11 +151,7 @@ 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 = 0;
- int i;
-
- for (i = 0; i < dev_dax->num_resources; i++)
- size += resource_size(&dev_dax->res[i]);
+ unsigned long long size = resource_size(&dev_dax->region->res);

return sprintf(buf, "%llu\n", size);
}
@@ -224,21 +220,11 @@ 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;
- /* gcc-4.6.3-nolibc for i386 complains that this is uninitialized */
- phys_addr_t uninitialized_var(phys);
- int i;
-
- for (i = 0; i < dev_dax->num_resources; i++) {
- res = &dev_dax->res[i];
- phys = pgoff * PAGE_SIZE + res->start;
- if (phys >= res->start && phys <= res->end)
- break;
- pgoff -= PHYS_PFN(resource_size(res));
- }
+ struct resource *res = &dev_dax->region->res;
+ phys_addr_t phys;

- if (i < dev_dax->num_resources) {
- res = &dev_dax->res[i];
+ phys = pgoff * PAGE_SIZE + res->start;
+ if (phys >= res->start && phys <= res->end) {
if (phys + size - 1 <= res->end)
return phys;
}
@@ -608,8 +594,7 @@ static void unregister_dev_dax(void *dev)
put_device(dev);
}

-struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
- int id, struct resource *res, int count)
+struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region, int id)
{
struct device *parent = dax_region->dev;
struct dax_device *dax_dev;
@@ -617,29 +602,12 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
struct inode *inode;
struct device *dev;
struct cdev *cdev;
- int rc, i;
+ int rc;

- if (!count)
- return ERR_PTR(-EINVAL);
-
- dev_dax = kzalloc(struct_size(dev_dax, res, count), GFP_KERNEL);
+ dev_dax = kzalloc(sizeof(*dev_dax), GFP_KERNEL);
if (!dev_dax)
return ERR_PTR(-ENOMEM);

- for (i = 0; i < count; i++) {
- if (!IS_ALIGNED(res[i].start, dax_region->align)
- || !IS_ALIGNED(resource_size(&res[i]),
- dax_region->align)) {
- rc = -EINVAL;
- break;
- }
- dev_dax->res[i].start = res[i].start;
- dev_dax->res[i].end = res[i].end;
- }
-
- if (i < count)
- goto err;
-
/*
* No 'host' or dax_operations since there is no access to this
* device outside of mmap of the resulting character device.
@@ -659,7 +627,6 @@ struct dev_dax *devm_create_dev_dax(struct dax_region *dax_region,
cdev_init(cdev, &dax_fops);
cdev->owner = parent->driver->owner;

- dev_dax->num_resources = count;
dev_dax->dax_dev = dax_dev;
dev_dax->region = dax_region;
kref_get(&dax_region->kref);
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c
index 3afae503fc42..23bc8ed40e84 100644
--- a/drivers/dax/pmem.c
+++ b/drivers/dax/pmem.c
@@ -137,8 +137,7 @@ static int dax_pmem_probe(struct device *dev)
if (!dax_region)
return -ENOMEM;

- /* TODO: support for subdividing a dax region... */
- dev_dax = devm_create_dev_dax(dax_region, id, &res, 1);
+ dev_dax = devm_create_dev_dax(dax_region, id);

/* child dev_dax instances now own the lifetime of the dax_region */
dax_region_put(dax_region);
diff --git a/tools/testing/nvdimm/dax-dev.c b/tools/testing/nvdimm/dax-dev.c
index 36ee3d8797c3..f36e708265b8 100644
--- a/tools/testing/nvdimm/dax-dev.c
+++ b/tools/testing/nvdimm/dax-dev.c
@@ -17,20 +17,11 @@
phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
unsigned long size)
{
- struct resource *res;
+ struct resource *res = &dev_dax->region->res;
phys_addr_t addr;
- int i;

- for (i = 0; i < dev_dax->num_resources; i++) {
- res = &dev_dax->res[i];
- addr = pgoff * PAGE_SIZE + res->start;
- if (addr >= res->start && addr <= res->end)
- break;
- pgoff -= PHYS_PFN(resource_size(res));
- }
-
- if (i < dev_dax->num_resources) {
- res = &dev_dax->res[i];
+ addr = pgoff * PAGE_SIZE + res->start;
+ if (addr >= res->start && addr <= res->end) {
if (addr + size - 1 <= res->end) {
if (get_nfit_res(addr)) {
struct page *page;
@@ -44,6 +35,5 @@ phys_addr_t dax_pgoff_to_phys(struct dev_dax *dev_dax, pgoff_t pgoff,
return addr;
}
}
-
return -1;
}