2024-06-10 08:20:12

by Greg Kroah-Hartman

[permalink] [raw]
Subject: [PATCH] nvdimm: make nd_class constant

Now that the driver core allows for struct class to be in read-only
memory, we should make all 'class' structures declared at build time
placing them into read-only memory, instead of having to be dynamically
allocated at runtime.

Cc: Dan Williams <[email protected]>
Cc: Vishal Verma <[email protected]>
Cc: Dave Jiang <[email protected]>
Cc: Ira Weiny <[email protected]>
Cc: [email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/nvdimm/bus.c | 19 ++++++++++---------
1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/nvdimm/bus.c b/drivers/nvdimm/bus.c
index 508aed017ddc..101c425f3e8b 100644
--- a/drivers/nvdimm/bus.c
+++ b/drivers/nvdimm/bus.c
@@ -25,9 +25,12 @@

int nvdimm_major;
static int nvdimm_bus_major;
-static struct class *nd_class;
static DEFINE_IDA(nd_ida);

+static const struct class nd_class = {
+ .name = "nd",
+};
+
static int to_nd_device_type(const struct device *dev)
{
if (is_nvdimm(dev))
@@ -742,7 +745,7 @@ int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)
device_initialize(dev);
lockdep_set_class(&dev->mutex, &nvdimm_ndctl_key);
device_set_pm_not_required(dev);
- dev->class = nd_class;
+ dev->class = &nd_class;
dev->parent = &nvdimm_bus->dev;
dev->devt = devt;
dev->release = ndctl_release;
@@ -765,7 +768,7 @@ int nvdimm_bus_create_ndctl(struct nvdimm_bus *nvdimm_bus)

void nvdimm_bus_destroy_ndctl(struct nvdimm_bus *nvdimm_bus)
{
- device_destroy(nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
+ device_destroy(&nd_class, MKDEV(nvdimm_bus_major, nvdimm_bus->id));
}

static const struct nd_cmd_desc __nd_cmd_dimm_descs[] = {
@@ -1320,11 +1323,9 @@ int __init nvdimm_bus_init(void)
goto err_dimm_chrdev;
nvdimm_major = rc;

- nd_class = class_create("nd");
- if (IS_ERR(nd_class)) {
- rc = PTR_ERR(nd_class);
+ rc = class_register(&nd_class);
+ if (rc)
goto err_class;
- }

rc = driver_register(&nd_bus_driver.drv);
if (rc)
@@ -1333,7 +1334,7 @@ int __init nvdimm_bus_init(void)
return 0;

err_nd_bus:
- class_destroy(nd_class);
+ class_unregister(&nd_class);
err_class:
unregister_chrdev(nvdimm_major, "dimmctl");
err_dimm_chrdev:
@@ -1347,7 +1348,7 @@ int __init nvdimm_bus_init(void)
void nvdimm_bus_exit(void)
{
driver_unregister(&nd_bus_driver.drv);
- class_destroy(nd_class);
+ class_unregister(&nd_class);
unregister_chrdev(nvdimm_bus_major, "ndctl");
unregister_chrdev(nvdimm_major, "dimmctl");
bus_unregister(&nvdimm_bus_type);
--
2.45.2



2024-06-10 17:45:14

by Dan Williams

[permalink] [raw]
Subject: Re: [PATCH] nvdimm: make nd_class constant

Greg Kroah-Hartman wrote:
> Now that the driver core allows for struct class to be in read-only
> memory, we should make all 'class' structures declared at build time
> placing them into read-only memory, instead of having to be dynamically
> allocated at runtime.

Change looks good to me,

Reviewed-by: Dan Williams <[email protected]>

...changelog grammar tripped me up though, how about:

"Now that the driver core allows for struct class to be in read-only
memory, it is possible to make all 'class' structures be declared at
build time. Move the class to a 'static const' declaration and register
it rather than dynamically create it."

2024-06-12 10:02:31

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] nvdimm: make nd_class constant

On Mon, Jun 10, 2024 at 10:44:42AM -0700, Dan Williams wrote:
> Greg Kroah-Hartman wrote:
> > Now that the driver core allows for struct class to be in read-only
> > memory, we should make all 'class' structures declared at build time
> > placing them into read-only memory, instead of having to be dynamically
> > allocated at runtime.
>
> Change looks good to me,
>
> Reviewed-by: Dan Williams <[email protected]>
>
> ...changelog grammar tripped me up though, how about:
>
> "Now that the driver core allows for struct class to be in read-only
> memory, it is possible to make all 'class' structures be declared at
> build time. Move the class to a 'static const' declaration and register
> it rather than dynamically create it."

That works too, want me to resubmit with this, or can I update it when I
commit it to my tree?

thanks,

greg "the changelog is the hardest part" k-h

2024-06-12 15:38:38

by Dan Williams

[permalink] [raw]
Subject: Re: [PATCH] nvdimm: make nd_class constant

Greg Kroah-Hartman wrote:
> On Mon, Jun 10, 2024 at 10:44:42AM -0700, Dan Williams wrote:
> > Greg Kroah-Hartman wrote:
> > > Now that the driver core allows for struct class to be in read-only
> > > memory, we should make all 'class' structures declared at build time
> > > placing them into read-only memory, instead of having to be dynamically
> > > allocated at runtime.
> >
> > Change looks good to me,
> >
> > Reviewed-by: Dan Williams <[email protected]>
> >
> > ...changelog grammar tripped me up though, how about:
> >
> > "Now that the driver core allows for struct class to be in read-only
> > memory, it is possible to make all 'class' structures be declared at
> > build time. Move the class to a 'static const' declaration and register
> > it rather than dynamically create it."
>
> That works too, want me to resubmit with this, or can I update it when I
> commit it to my tree?

Take it through your tree sounds good to me.

> thanks,
>
> greg "the changelog is the hardest part" k-h

lol!

dan "can't code, but can proofread" williams


2024-06-12 21:20:09

by Ira Weiny

[permalink] [raw]
Subject: Re: [PATCH] nvdimm: make nd_class constant

Greg Kroah-Hartman wrote:
> On Mon, Jun 10, 2024 at 10:44:42AM -0700, Dan Williams wrote:
> > Greg Kroah-Hartman wrote:
> > > Now that the driver core allows for struct class to be in read-only
> > > memory, we should make all 'class' structures declared at build time
> > > placing them into read-only memory, instead of having to be dynamically
> > > allocated at runtime.
> >
> > Change looks good to me,
> >
> > Reviewed-by: Dan Williams <[email protected]>
> >
> > ...changelog grammar tripped me up though, how about:
> >
> > "Now that the driver core allows for struct class to be in read-only
> > memory, it is possible to make all 'class' structures be declared at
> > build time. Move the class to a 'static const' declaration and register
> > it rather than dynamically create it."
>
> That works too, want me to resubmit with this, or can I update it when I
> commit it to my tree?

In that case.

Reviewed-by: Ira Weiny <[email protected]>

>
> thanks,
>
> greg "the changelog is the hardest part" k-h