Nouveau - Aug 2023 - [PATCH 0/5] Add the pci_get_base_class() helper and use it

From: Sui Jingfeng <suijingfeng at loongson.cn>

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. Therefore, add
the pci_get_base_class() function to suit the need.

For example, if an application want to process all PCI(e) display devices
in a system, it can achieve such goal by writing the code as following:

    pdev = NULL;
    do {
        pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev);
        if (!pdev)
            break;

        do_something_for_pci_display_device(pdev);
    } while (1);

Sui Jingfeng (5):
  PCI: Add the pci_get_base_class() helper
  ALSA: hda/intel: Use pci_get_base_class() to reduce duplicated code
  drm/nouveau: Use pci_get_base_class() to reduce duplicated code
  drm/amdgpu: Use pci_get_base_class() to reduce duplicated code
  drm/radeon: Use pci_get_base_class() to reduce duplicated code

 drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 11 +++------
 drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 20 ++++-----------
 drivers/gpu/drm/nouveau/nouveau_acpi.c   | 11 +++------
 drivers/gpu/drm/radeon/radeon_bios.c     | 20 ++++-----------
 drivers/pci/search.c                     | 31 ++++++++++++++++++++++++
 include/linux/pci.h                      |  5 ++++
 sound/pci/hda/hda_intel.c                | 16 ++++--------
 7 files changed, 59 insertions(+), 55 deletions(-)

-- 
2.34.1

From: Sui Jingfeng <suijingfeng at loongson.cn>

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. Therefore, add
the pci_get_base_class() function to suit the need.

For example, if an application want to process all PCI(e) display devices
in a system, it can achieve such goal by writing the code as following:

pdev = NULL;
do {
    pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev);
    if (!pdev)
        break;

    do_something_for_pci_display_device(pdev);
} while (1);

Cc: Bjorn Helgaas <bhelgaas at google.com>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 drivers/pci/search.c | 31 +++++++++++++++++++++++++++++++
 include/linux/pci.h  |  5 +++++
 2 files changed, 36 insertions(+)

diff --git a/drivers/pci/search.c b/drivers/pci/search.c
index b4c138a6ec02..53840634fbfc 100644
--- a/drivers/pci/search.c
+++ b/drivers/pci/search.c
@@ -363,6 +363,37 @@ struct pci_dev *pci_get_class(unsigned int class, struct
pci_dev *from)
 }
 EXPORT_SYMBOL(pci_get_class);
 
+/**
+ * pci_get_base_class - searching for a PCI device by matching against the base
class code only
+ * @class: search for a PCI device with this base class code
+ * @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 base class code, the reference count to the device is
+ * incremented. See pci_match_one_device() to figure out how does this works.
+ * 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.
+ *
+ * Returns:
+ * A pointer to a matched PCI device, %NULL Otherwise.
+ */
+struct pci_dev *pci_get_base_class(unsigned int class, 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 = 0xFF0000,
+		.class = class << 16,
+	};
+
+	return pci_get_dev_by_id(&id, from);
+}
+EXPORT_SYMBOL(pci_get_base_class);
+
 /**
  * pci_dev_present - Returns 1 if device matching the device list is present, 0
if not.
  * @ids: A pointer to a null terminated list of struct pci_device_id structures
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 71c85380676c..486ad959e1f9 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1180,6 +1180,8 @@ 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_base_class(unsigned int class, 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,
@@ -1896,6 +1898,9 @@ static inline struct pci_dev *pci_get_class(unsigned int
class,
 					    struct pci_dev *from)
 { return NULL; }
 
+static inline struct pci_dev *pci_get_base_class(unsigned int class,
+						 struct pci_dev *from)
+{ return NULL; }
 
 static inline int pci_dev_present(const struct pci_device_id *ids)
 { return 0; }
-- 
2.34.1

From: Sui Jingfeng <suijingfeng at loongson.cn>

Should be no functional change

Cc: Jaroslav Kysela <perex at perex.cz>
Cc: Takashi Iwai <tiwai at suse.com>
Cc: Fred Oh <fred.oh at linux.intel.com>
Cc: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
Cc: Kai Vehmanen <kai.vehmanen at linux.intel.com>
Cc: Bjorn Helgaas <bhelgaas at google.com>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 sound/pci/hda/hda_intel.c | 16 +++++-----------
 1 file changed, 5 insertions(+), 11 deletions(-)

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index a21b61ad08d1..811a149584f2 100644
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -1429,17 +1429,11 @@ static bool atpx_present(void)
 	acpi_handle dhandle, atpx_handle;
 	acpi_status status;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL)
{
-		dhandle = ACPI_HANDLE(&pdev->dev);
-		if (dhandle) {
-			status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
-			if (ACPI_SUCCESS(status)) {
-				pci_dev_put(pdev);
-				return true;
-			}
-		}
-	}
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) !=
NULL) {
+	while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+		if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
+		    (pdev->class != PCI_CLASS_DISPLAY_OTHER << 8))
+			continue;
+
 		dhandle = ACPI_HANDLE(&pdev->dev);
 		if (dhandle) {
 			status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
-- 
2.34.1

From: Sui Jingfeng <suijingfeng at loongson.cn>

Should be no functional change.

Cc: Ben Skeggs <bskeggs at redhat.com>
Cc: Karol Herbst <kherbst at redhat.com>
Cc: Lyude Paul <lyude at redhat.com>
Cc: David Airlie <airlied at gmail.com>
Cc: Daniel Vetter <daniel at ffwll.ch>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 drivers/gpu/drm/nouveau/nouveau_acpi.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c
b/drivers/gpu/drm/nouveau/nouveau_acpi.c
index a2ae8c21e4dc..8f0c69aad248 100644
--- a/drivers/gpu/drm/nouveau/nouveau_acpi.c
+++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c
@@ -284,14 +284,11 @@ static bool nouveau_dsm_detect(void)
 		printk("MXM: GUID detected in BIOS\n");
 
 	/* now do DSM detection */
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL)
{
-		vga_count++;
-
-		nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
-				      &has_optimus_flags, &has_power_resources);
-	}
+	while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+		if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
+		    (pdev->class != PCI_CLASS_DISPLAY_3D << 8))
+			continue;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL)
{
 		vga_count++;
 
 		nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
-- 
2.34.1

From: Sui Jingfeng <suijingfeng at loongson.cn>

Should be no functional change.

Cc: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 11 ++++-------
 drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 20 +++++---------------
 2 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
index a5a2b06c6588..4f18af877105 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c
@@ -1389,14 +1389,11 @@ void amdgpu_acpi_detect(void)
 	struct pci_dev *pdev = NULL;
 	int ret;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL)
{
-		if (!atif->handle)
-			amdgpu_atif_pci_probe_handle(pdev);
-		if (!atcs->handle)
-			amdgpu_atcs_pci_probe_handle(pdev);
-	}
+	while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+		if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
+		    (pdev->class != PCI_CLASS_DISPLAY_OTHER << 8))
+			continue;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) !=
NULL) {
 		if (!atif->handle)
 			amdgpu_atif_pci_probe_handle(pdev);
 		if (!atcs->handle)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
index 38ccec913f00..5bbb23e102ba 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
@@ -287,7 +287,11 @@ static bool amdgpu_atrm_get_bios(struct amdgpu_device
*adev)
 	if (adev->flags & AMD_IS_APU)
 		return false;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL)
{
+	while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+		if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
+		    (pdev->class != PCI_CLASS_DISPLAY_OTHER << 8))
+			continue;
+
 		dhandle = ACPI_HANDLE(&pdev->dev);
 		if (!dhandle)
 			continue;
@@ -299,20 +303,6 @@ static bool amdgpu_atrm_get_bios(struct amdgpu_device
*adev)
 		}
 	}
 
-	if (!found) {
-		while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) !=
NULL) {
-			dhandle = ACPI_HANDLE(&pdev->dev);
-			if (!dhandle)
-				continue;
-
-			status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
-			if (ACPI_SUCCESS(status)) {
-				found = true;
-				break;
-			}
-		}
-	}
-
 	if (!found)
 		return false;
 	pci_dev_put(pdev);
-- 
2.34.1

From: Sui Jingfeng <suijingfeng at loongson.cn>

Should be no functional change.

Cc: Alex Deucher <alexander.deucher at amd.com>
Signed-off-by: Sui Jingfeng <suijingfeng at loongson.cn>
---
 drivers/gpu/drm/radeon/radeon_bios.c | 20 +++++---------------
 1 file changed, 5 insertions(+), 15 deletions(-)

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c
b/drivers/gpu/drm/radeon/radeon_bios.c
index 63bdc9f6fc24..3a8c5199a0fe 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -199,7 +199,11 @@ static bool radeon_atrm_get_bios(struct radeon_device
*rdev)
 	if (rdev->flags & RADEON_IS_IGP)
 		return false;
 
-	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL)
{
+	while ((pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev))) {
+		if ((pdev->class != PCI_CLASS_DISPLAY_VGA << 8) &&
+		    (pdev->class != PCI_CLASS_DISPLAY_OTHER << 8))
+			continue;
+
 		dhandle = ACPI_HANDLE(&pdev->dev);
 		if (!dhandle)
 			continue;
@@ -211,20 +215,6 @@ static bool radeon_atrm_get_bios(struct radeon_device
*rdev)
 		}
 	}
 
-	if (!found) {
-		while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, pdev)) !=
NULL) {
-			dhandle = ACPI_HANDLE(&pdev->dev);
-			if (!dhandle)
-				continue;
-
-			status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
-			if (ACPI_SUCCESS(status)) {
-				found = true;
-				break;
-			}
-		}
-	}
-
 	if (!found)
 		return false;
 	pci_dev_put(pdev);
-- 
2.34.1

[Public]
> -----Original Message-----
> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
Sui
> Jingfeng
> Sent: Friday, August 25, 2023 2:27 AM
> To: Bjorn Helgaas <bhelgaas at google.com>
> Cc: alsa-devel at alsa-project.org; Sui Jingfeng <suijingfeng at
loongson.cn>;
> nouveau at lists.freedesktop.org; linux-kernel at vger.kernel.org; dri-
> devel at lists.freedesktop.org; amd-gfx at lists.freedesktop.org; linux-
> pci at vger.kernel.org
> Subject: [PATCH 0/5] Add the pci_get_base_class() helper and use it
>
> From: Sui Jingfeng <suijingfeng at loongson.cn>
>
> 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. Therefore, add the
> pci_get_base_class() function to suit the need.
>
> For example, if an application want to process all PCI(e) display devices
in a
> system, it can achieve such goal by writing the code as following:
>
>     pdev = NULL;
>     do {
>         pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev);
>         if (!pdev)
>             break;
>
>         do_something_for_pci_display_device(pdev);
>     } while (1);
>
> Sui Jingfeng (5):
>   PCI: Add the pci_get_base_class() helper
>   ALSA: hda/intel: Use pci_get_base_class() to reduce duplicated code
>   drm/nouveau: Use pci_get_base_class() to reduce duplicated code
>   drm/amdgpu: Use pci_get_base_class() to reduce duplicated code
>   drm/radeon: Use pci_get_base_class() to reduce duplicated code
>
Series is:
Reviewed-by: Alex Deucher <alexander.deucher at amd.com>
>  drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 11 +++------
> drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 20 ++++-----------
>  drivers/gpu/drm/nouveau/nouveau_acpi.c   | 11 +++------
>  drivers/gpu/drm/radeon/radeon_bios.c     | 20 ++++-----------
>  drivers/pci/search.c                     | 31 ++++++++++++++++++++++++
>  include/linux/pci.h                      |  5 ++++
>  sound/pci/hda/hda_intel.c                | 16 ++++--------
>  7 files changed, 59 insertions(+), 55 deletions(-)
>
> --
> 2.34.1

On Fri, Aug 25, 2023 at 02:27:09PM +0800, Sui Jingfeng
wrote:
> From: Sui Jingfeng <suijingfeng at loongson.cn>
> 
> 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. Therefore, add
> the pci_get_base_class() function to suit the need.
> 
> For example, if an application want to process all PCI(e) display devices
> in a system, it can achieve such goal by writing the code as following:
> 
>     pdev = NULL;
>     do {
>         pdev = pci_get_base_class(PCI_BASE_CLASS_DISPLAY, pdev);
>         if (!pdev)
>             break;
> 
>         do_something_for_pci_display_device(pdev);
>     } while (1);
> 
> Sui Jingfeng (5):
>   PCI: Add the pci_get_base_class() helper
>   ALSA: hda/intel: Use pci_get_base_class() to reduce duplicated code
>   drm/nouveau: Use pci_get_base_class() to reduce duplicated code
>   drm/amdgpu: Use pci_get_base_class() to reduce duplicated code
>   drm/radeon: Use pci_get_base_class() to reduce duplicated code
> 
>  drivers/gpu/drm/amd/amdgpu/amdgpu_acpi.c | 11 +++------
>  drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 20 ++++-----------
>  drivers/gpu/drm/nouveau/nouveau_acpi.c   | 11 +++------
>  drivers/gpu/drm/radeon/radeon_bios.c     | 20 ++++-----------
>  drivers/pci/search.c                     | 31 ++++++++++++++++++++++++
>  include/linux/pci.h                      |  5 ++++
>  sound/pci/hda/hda_intel.c                | 16 ++++--------
>  7 files changed, 59 insertions(+), 55 deletions(-)
Applied to pci/enumeration for v6.7, thanks.