Re: [PATCH v2 02/11] PCI: Add the pci_get_class_masked() helper
On Thu, 10 Aug 2023, suijingfeng wrote:
> Hi,
>
>
> On 2023/8/9 22:01, Ilpo Järvinen wrote:
> > On Wed, 9 Aug 2023, Sui Jingfeng wrote:
> >
> > > From: Sui Jingfeng
> > >
> > > Because there is no good way to get the mask member used to searching for
> > > devices that conform to a specific PCI class code, an application needs to
> > > process all PCI display devices can achieve its goal as follows:
> > This is mixing old and new way in a single sentence (which is confusing)?
>
>
> Thanks for reviewing, but I can't understand this sentence.
> Are you telling me that my description have grammar problem or something else?
I think it's a bit of both.
> I means that before apply this patch, we don't have a function can be used
> to get all PCI(e) devices in a system by matching against its the PCI base
> class code only,
> while keep the Sub-Class code and the Programming Interface ignored.
> By supply a mask as argument, such thing become possible.
This explanation you put into this reply is much easier to follow and
understand. I recommend you'd use it to replace the unclear fragment
above. So something along the lines of:
There is no function that can be used to get all PCI(e) devices in a
system by matching against its the PCI base class code only, while keep
the Sub-Class code and the Programming Interface ignored.
Add pci_get_class_masked() to allow supplying a mask for the get.
[After this you can put the explanining code block+its intro if you
want]
--
i.
> If an application want to process all PCI display devices in the system,
> then it can achieve its goal by calling pci_get_class_masked() function.
>
>
> > > pdev = NULL;
> > > do {
> > > pdev = pci_get_class_masked(PCI_BASE_CLASS_DISPLAY << 16, 0xFF,
> > > pdev);
> > > if (pdev)
> > > do_something_for_pci_display_device(pdev);
> > > } while (pdev);
> > >
> > > While previously, we just can not ignore Sub-Class code and the
> > > Programming
> > cannot
> >
> > > Interface byte when do the searching.
> > doing the search.
>
>
> OK, will be fixed at the next version.
>
>
> > > Signed-off-by: Sui Jingfeng
> > > ---
> > > drivers/pci/search.c | 30 ++
> > > include/linux/pci.h | 7 +++
> > > 2 files changed, 37 insertions(+)
> > >
> > > diff --git a/drivers/pci/search.c b/drivers/pci/search.c
> > > index b4c138a6ec02..f1c15aea868b 100644
> > > --- a/drivers/pci/search.c
> > > +++ b/drivers/pci/search.c
> > > @@ -334,6 +334,36 @@ struct pci_dev *pci_get_device(unsigned int vendor,
> > > unsigned int device,
> > > }
> > > EXPORT_SYMBOL(pci_get_device);
> > > +/**
> > > + * pci_get_class_masked - begin or continue searching for a PCI device by
> > > class and mask
> > > + * @class: search for a PCI device with this class designation
> > > + * @from: Previous PCI device found in search, or %NULL for new search.
> > > + *
> > > + * Iterates through the list of known PCI devices. If a PCI device is
> > No double spaces in kernel comments. Perhaps your editor might be adding
> > them on reflow (might be configurable to not do that).
> >
> > > + * found with a matching @class, the reference count to the device is
> > > + * incremented and a pointer to its device structure is returned.
> > > + * Otherwise, %NULL is returned.
> > > + * A new search is initiated by passing %NULL as the @from argument.
> > > + * Otherwise if @from is not %NULL, searches continue from next device
> > > + * on the global list. The reference count for @from is always
> > > decremented
> > > + * if it is not %NULL.
> > Use kerneldoc's Return: section for describing return value.
> >
> > > + */
> > > +struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int
> > > mask,
> > > + struct pci_dev *from)
> > > +{
> > > + struct pci_device_id id = {
> > > + .vendor = PCI_ANY_ID,
> > > + .device = PCI_ANY_ID,
> > > + .subvendor = PCI_ANY_ID,
> > > + .subdevice = PCI_ANY_ID,
> > > + .class_mask = mask,
> > > + .class = class,
> > > + };
> > > +
> > > + return pci_get_dev_by_id(, from);
> > > +}
> > > +EXPORT_SYMBOL(pci_get_class_masked);
> > > +
> > > /**
> > >* pci_get_class - begin or continue searching for a PCI device by class
> > >* @class: search for a PCI device with this class designation
> > > diff --git a/include/linux/pci.h b/include/linux/pci.h
> > > index 0ff7500772e6..b20e7ba844bf 100644
> > > --- a/include/linux/pci.h
> > > +++ b/include/linux/pci.h
> > > @@ -1180,6 +1180,9 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus,
> > > unsigned int devfn);
> > > struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int
> > > bus,
> > > unsigned int devfn);
> > > struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
> > > +struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int
> > >
Re: [PATCH v2 02/11] PCI: Add the pci_get_class_masked() helper
Hi,
On 2023/8/9 22:01, Ilpo Järvinen wrote:
On Wed, 9 Aug 2023, Sui Jingfeng wrote:
From: Sui Jingfeng
Because there is no good way to get the mask member used to searching for
devices that conform to a specific PCI class code, an application needs to
process all PCI display devices can achieve its goal as follows:
This is mixing old and new way in a single sentence (which is confusing)?
Thanks for reviewing, but I can't understand this sentence.
Are you telling me that my description have grammar problem or something else?
I means that before apply this patch, we don't have a function can be used
to get all PCI(e) devices in a system by matching against its the PCI base
class code only,
while keep the Sub-Class code and the Programming Interface ignored.
By supply a mask as argument, such thing become possible.
If an application want to process all PCI display devices in the system,
then it can achieve its goal by calling pci_get_class_masked() function.
pdev = NULL;
do {
pdev = pci_get_class_masked(PCI_BASE_CLASS_DISPLAY << 16, 0xFF,
pdev);
if (pdev)
do_something_for_pci_display_device(pdev);
} while (pdev);
While previously, we just can not ignore Sub-Class code and the Programming
cannot
Interface byte when do the searching.
doing the search.
OK, will be fixed at the next version.
Signed-off-by: Sui Jingfeng
---
drivers/pci/search.c | 30 ++
include/linux/pci.h | 7 +++
2 files changed, 37 insertions(+)
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index b4c138a6ec02..f1c15aea868b 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -334,6 +334,36 @@ struct pci_dev *pci_get_device(unsigned int vendor,
unsigned int device,
}
EXPORT_SYMBOL(pci_get_device);
+/**
+ * pci_get_class_masked - begin or continue searching for a PCI device by
class and mask
+ * @class: search for a PCI device with this class designation
+ * @from: Previous PCI device found in search, or %NULL for new search.
+ *
+ * Iterates through the list of known PCI devices. If a PCI device is
No double spaces in kernel comments. Perhaps your editor might be adding
them on reflow (might be configurable to not do that).
+ * found with a matching @class, the reference count to the device is
+ * incremented and a pointer to its device structure is returned.
+ * Otherwise, %NULL is returned.
+ * A new search is initiated by passing %NULL as the @from argument.
+ * Otherwise if @from is not %NULL, searches continue from next device
+ * on the global list. The reference count for @from is always decremented
+ * if it is not %NULL.
Use kerneldoc's Return: section for describing return value.
+ */
+struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
+struct pci_dev *from)
+{
+ struct pci_device_id id = {
+ .vendor = PCI_ANY_ID,
+ .device = PCI_ANY_ID,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .class_mask = mask,
+ .class = class,
+ };
+
+ return pci_get_dev_by_id(, from);
+}
+EXPORT_SYMBOL(pci_get_class_masked);
+
/**
* pci_get_class - begin or continue searching for a PCI device by class
* @class: search for a PCI device with this class designation
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0ff7500772e6..b20e7ba844bf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1180,6 +1180,9 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus,
unsigned int devfn);
struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
unsigned int devfn);
struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
+struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
+struct pci_dev *from);
+
int pci_dev_present(const struct pci_device_id *ids);
int pci_bus_read_config_byte(struct pci_bus *bus, unsigned int devfn,
@@ -1895,6 +1898,10 @@ static inline struct pci_dev *pci_get_class(unsigned int
class,
struct pci_dev *from)
{ return NULL; }
+static inline struct pci_dev *pci_get_class_masked(unsigned int class,
+ unsigned int mask,
+ struct pci_dev *from)
+{ return NULL; }
static inline int pci_dev_present(const struct pci_device_id *ids)
{ return 0; }
Re: [PATCH v2 02/11] PCI: Add the pci_get_class_masked() helper
On Wed, 9 Aug 2023, Sui Jingfeng wrote:
> From: Sui Jingfeng
>
> Because there is no good way to get the mask member used to searching for
> devices that conform to a specific PCI class code, an application needs to
> process all PCI display devices can achieve its goal as follows:
This is mixing old and new way in a single sentence (which is confusing)?
> pdev = NULL;
> do {
> pdev = pci_get_class_masked(PCI_BASE_CLASS_DISPLAY << 16, 0xFF,
> pdev);
> if (pdev)
> do_something_for_pci_display_device(pdev);
> } while (pdev);
>
> While previously, we just can not ignore Sub-Class code and the Programming
cannot
> Interface byte when do the searching.
doing the search.
>
> Signed-off-by: Sui Jingfeng
> ---
> drivers/pci/search.c | 30 ++
> include/linux/pci.h | 7 +++
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/pci/search.c b/drivers/pci/search.c
> index b4c138a6ec02..f1c15aea868b 100644
> --- a/drivers/pci/search.c
> +++ b/drivers/pci/search.c
> @@ -334,6 +334,36 @@ struct pci_dev *pci_get_device(unsigned int vendor,
> unsigned int device,
> }
> EXPORT_SYMBOL(pci_get_device);
>
> +/**
> + * pci_get_class_masked - begin or continue searching for a PCI device by
> class and mask
> + * @class: search for a PCI device with this class designation
> + * @from: Previous PCI device found in search, or %NULL for new search.
> + *
> + * Iterates through the list of known PCI devices. If a PCI device is
No double spaces in kernel comments. Perhaps your editor might be adding
them on reflow (might be configurable to not do that).
> + * found with a matching @class, the reference count to the device is
> + * incremented and a pointer to its device structure is returned.
> + * Otherwise, %NULL is returned.
> + * A new search is initiated by passing %NULL as the @from argument.
> + * Otherwise if @from is not %NULL, searches continue from next device
> + * on the global list. The reference count for @from is always decremented
> + * if it is not %NULL.
Use kerneldoc's Return: section for describing return value.
> + */
> +struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
> + struct pci_dev *from)
> +{
> + struct pci_device_id id = {
> + .vendor = PCI_ANY_ID,
> + .device = PCI_ANY_ID,
> + .subvendor = PCI_ANY_ID,
> + .subdevice = PCI_ANY_ID,
> + .class_mask = mask,
> + .class = class,
> + };
> +
> + return pci_get_dev_by_id(, from);
> +}
> +EXPORT_SYMBOL(pci_get_class_masked);
> +
> /**
> * pci_get_class - begin or continue searching for a PCI device by class
> * @class: search for a PCI device with this class designation
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 0ff7500772e6..b20e7ba844bf 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1180,6 +1180,9 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus,
> unsigned int devfn);
> struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
> unsigned int devfn);
> struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
> +struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
> + struct pci_dev *from);
> +
> int pci_dev_present(const struct pci_device_id *ids);
>
> int pci_bus_read_config_byte(struct pci_bus *bus, unsigned int devfn,
> @@ -1895,6 +1898,10 @@ static inline struct pci_dev *pci_get_class(unsigned
> int class,
> struct pci_dev *from)
> { return NULL; }
>
> +static inline struct pci_dev *pci_get_class_masked(unsigned int class,
> +unsigned int mask,
> +struct pci_dev *from)
> +{ return NULL; }
>
> static inline int pci_dev_present(const struct pci_device_id *ids)
> { return 0; }
>
--
i.
[PATCH v2 02/11] PCI: Add the pci_get_class_masked() helper
From: Sui Jingfeng
Because there is no good way to get the mask member used to searching for
devices that conform to a specific PCI class code, an application needs to
process all PCI display devices can achieve its goal as follows:
pdev = NULL;
do {
pdev = pci_get_class_masked(PCI_BASE_CLASS_DISPLAY << 16, 0xFF,
pdev);
if (pdev)
do_something_for_pci_display_device(pdev);
} while (pdev);
While previously, we just can not ignore Sub-Class code and the Programming
Interface byte when do the searching.
Signed-off-by: Sui Jingfeng
---
drivers/pci/search.c | 30 ++
include/linux/pci.h | 7 +++
2 files changed, 37 insertions(+)
diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index b4c138a6ec02..f1c15aea868b 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -334,6 +334,36 @@ struct pci_dev *pci_get_device(unsigned int vendor,
unsigned int device,
}
EXPORT_SYMBOL(pci_get_device);
+/**
+ * pci_get_class_masked - begin or continue searching for a PCI device by
class and mask
+ * @class: search for a PCI device with this class designation
+ * @from: Previous PCI device found in search, or %NULL for new search.
+ *
+ * Iterates through the list of known PCI devices. If a PCI device is
+ * found with a matching @class, the reference count to the device is
+ * incremented and a pointer to its device structure is returned.
+ * Otherwise, %NULL is returned.
+ * A new search is initiated by passing %NULL as the @from argument.
+ * Otherwise if @from is not %NULL, searches continue from next device
+ * on the global list. The reference count for @from is always decremented
+ * if it is not %NULL.
+ */
+struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
+struct pci_dev *from)
+{
+ struct pci_device_id id = {
+ .vendor = PCI_ANY_ID,
+ .device = PCI_ANY_ID,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .class_mask = mask,
+ .class = class,
+ };
+
+ return pci_get_dev_by_id(, from);
+}
+EXPORT_SYMBOL(pci_get_class_masked);
+
/**
* pci_get_class - begin or continue searching for a PCI device by class
* @class: search for a PCI device with this class designation
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0ff7500772e6..b20e7ba844bf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1180,6 +1180,9 @@ struct pci_dev *pci_get_slot(struct pci_bus *bus,
unsigned int devfn);
struct pci_dev *pci_get_domain_bus_and_slot(int domain, unsigned int bus,
unsigned int devfn);
struct pci_dev *pci_get_class(unsigned int class, struct pci_dev *from);
+struct pci_dev *pci_get_class_masked(unsigned int class, unsigned int mask,
+struct pci_dev *from);
+
int pci_dev_present(const struct pci_device_id *ids);
int pci_bus_read_config_byte(struct pci_bus *bus, unsigned int devfn,
@@ -1895,6 +1898,10 @@ static inline struct pci_dev *pci_get_class(unsigned int
class,
struct pci_dev *from)
{ return NULL; }
+static inline struct pci_dev *pci_get_class_masked(unsigned int class,
+ unsigned int mask,
+ struct pci_dev *from)
+{ return NULL; }
static inline int pci_dev_present(const struct pci_device_id *ids)
{ return 0; }
--
2.34.1
