Changes since v2: [1]
- switch from non-idiomatic srcu synchronization of the device
registration state to rwsem protection of the cxlmd->cxlm pointer.
(Jason)
[1]: http://lore.kernel.org/r/161707245893.2072157.6743322596719518693.stgit@dwillia2-desk3.amr.corp.intel.com
---
A collection of fixes initially inspired by Jason's recognition of
dev_set_name() error handling mistakes on other driver review, but also
from a deeper discussion of idiomatic device operation shutdown flows.
The end result is easier to reason about and validate. Thank you, Jason.
The sysfs_emit() fixup and unpublishing of device power management files
are independent sanity cleanups.
---
Dan Williams (4):
cxl/mem: Use sysfs_emit() for attribute show routines
cxl/mem: Fix synchronization mechanism for device removal vs ioctl operations
cxl/mem: Do not rely on device_add() side effects for dev_set_name() failures
cxl/mem: Disable cxl device power management
drivers/cxl/mem.c | 141 +++++++++++++++++++++++++++++++----------------------
1 file changed, 83 insertions(+), 58 deletions(-)
base-commit: a38fd8748464831584a19438cbb3082b5a2dab15
While none the CXL sysfs attributes are threatening to overrun a
PAGE_SIZE of output, it is good form to use the recommended helpers.
Fixes: b39cb1052a5c ("cxl/mem: Register CXL memX devices")
Reported-by: Jason Gunthorpe <[email protected]>
Reviewed-by: Ben Widawsky <[email protected]>
Reviewed-by: Jason Gunthorpe <[email protected]>
Link: https://lore.kernel.org/r/161661971101.1721612.16412318662284948582.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <[email protected]>
---
drivers/cxl/mem.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index ecfc9ccdba8d..30bf4f0f3c17 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -1066,7 +1066,7 @@ static ssize_t firmware_version_show(struct device *dev,
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_mem *cxlm = cxlmd->cxlm;
- return sprintf(buf, "%.16s\n", cxlm->firmware_version);
+ return sysfs_emit(buf, "%.16s\n", cxlm->firmware_version);
}
static DEVICE_ATTR_RO(firmware_version);
@@ -1076,7 +1076,7 @@ static ssize_t payload_max_show(struct device *dev,
struct cxl_memdev *cxlmd = to_cxl_memdev(dev);
struct cxl_mem *cxlm = cxlmd->cxlm;
- return sprintf(buf, "%zu\n", cxlm->payload_size);
+ return sysfs_emit(buf, "%zu\n", cxlm->payload_size);
}
static DEVICE_ATTR_RO(payload_max);
@@ -1087,7 +1087,7 @@ static ssize_t ram_size_show(struct device *dev, struct device_attribute *attr,
struct cxl_mem *cxlm = cxlmd->cxlm;
unsigned long long len = range_len(&cxlm->ram_range);
- return sprintf(buf, "%#llx\n", len);
+ return sysfs_emit(buf, "%#llx\n", len);
}
static struct device_attribute dev_attr_ram_size =
@@ -1100,7 +1100,7 @@ static ssize_t pmem_size_show(struct device *dev, struct device_attribute *attr,
struct cxl_mem *cxlm = cxlmd->cxlm;
unsigned long long len = range_len(&cxlm->pmem_range);
- return sprintf(buf, "%#llx\n", len);
+ return sysfs_emit(buf, "%#llx\n", len);
}
static struct device_attribute dev_attr_pmem_size =
There is no power management of cxl virtual devices, disable
device-power-management and runtime-power-management to prevent
userspace from growing expectations of those attributes appearing. They
can be added back in the future if needed.
Reviewed-by: Ben Widawsky <[email protected]>
Signed-off-by: Dan Williams <[email protected]>
---
drivers/cxl/mem.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/cxl/mem.c b/drivers/cxl/mem.c
index 759713b619ab..a8f750a9e2e4 100644
--- a/drivers/cxl/mem.c
+++ b/drivers/cxl/mem.c
@@ -1210,6 +1210,7 @@ static struct cxl_memdev *cxl_memdev_alloc(struct cxl_mem *cxlm)
dev->bus = &cxl_bus_type;
dev->devt = MKDEV(cxl_mem_major, cxlmd->id);
dev->type = &cxl_memdev_type;
+ device_set_pm_not_required(dev);
cdev = &cxlmd->cdev;
cdev_init(cdev, &cxl_memdev_fops);