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* [PATCH v3 0/8] PCI: Drop duplicated tracking of a pci_dev's bound driver
@ 2021-08-11  8:06 Uwe Kleine-König
  2021-08-11  8:06 ` [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Uwe Kleine-König
  2021-08-11  8:06 ` [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver Uwe Kleine-König
  0 siblings, 2 replies; 7+ messages in thread
From: Uwe Kleine-König @ 2021-08-11  8:06 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Giovanni Cabiddu, Mark Rutland, Sathya Prakash,
	Alexander Shishkin, Alexander Duyck, x86, qat-linux, oss-drivers,
	Oliver O'Halloran, H. Peter Anvin, Jiri Olsa,
	Thomas Gleixner, Marco Chiappero, Stefano Stabellini,
	Arnd Bergmann, linux-scsi, Rafał Miłecki,
	Jesse Brandeburg, Peter Zijlstra, Ingo Molnar, linux-pci,
	linux-wireless, Jakub Kicinski, Yisen Zhuang,
	Suganath Prabu Subramani, Fiona Trahe, Andrew Donnellan,
	Uwe Kleine-König, Konrad Rzeszutek Wilk, Ido Schimmel,
	Simon Horman, linuxppc-dev, Arnaldo Carvalho de Melo, Jack Xu,
	Borislav Petkov, Michael Buesch, Jiri Pirko, Bjorn Helgaas,
	Namhyung Kim, Boris Ostrovsky, Andy Shevchenko, Herbert Xu,
	Juergen Gross, Salil Mehta, Sreekanth Reddy, xen-devel,
	Vadym Kochan, MPT-FusionLinux.pdl, Greg Kroah-Hartman, linux-usb,
	Wojciech Ziemba, linux-kernel, Mathias Nyman, Zhou Wang,
	linux-crypto, kernel, netdev, Frederic Barrat, Paul Mackerras,
	Tomaszx Kowalik, Taras Chornyi, David S. Miller,
	linux-perf-users

From: Uwe Kleine-König <uwe@kleine-koenig.org>

Hello,

Today the following is always true for a struct pci_dev *pdev:

	pdev->driver ==
		pdev->dev.driver ? to_pci_driver(pdev->dev.driver) : NULL

This series is about getting rid of struct pci_dev::driver. The first
three patches are unmodified compared to v2 (apart from an added
Reviewed-by tag) and are just minor cleanups.

Patch #4 replaces all usages of pci_dev::driver->name by
dev_driver_string().

Patch #5 simplifies struct mpt_pci_driver by dropping an unused
parameter from a function callback. The calculation of this parameter
made use of struct pci_dev::driver.

Patch #6 simplifies adf_enable_aer() and moves one assignment done in
that function to the initializer of the respective static data.

Patch #7 then modifies all remaining users of struct pci_dev::driver to
use to_pci_driver(pdev->dev.driver) instead and finally patch #8 gets
rid of the driver member.

Note this series is only build tested.

Theoretically patches #4 and #7 could be split by subsystem, there are
no dependencies, but I'd prefer that all patches go in together via the
pci tree to simplify the procedure. If you don't agree please speak up.

Best regards
Uwe

Uwe Kleine-König (8):
  PCI: Simplify pci_device_remove()
  PCI: Drop useless check from pci_device_probe()
  xen/pci: Drop some checks that are always true
  PCI: replace pci_dev::driver usage that gets the driver name
  scsi: message: fusion: Remove unused parameter of mpt_pci driver's
    probe()
  crypto: qat - simplify adf_enable_aer()
  PCI: Replace pci_dev::driver usage by pci_dev::dev.driver
  PCI: Drop duplicated tracking of a pci_dev's bound driver

 arch/powerpc/include/asm/ppc-pci.h            |  7 ++-
 arch/powerpc/kernel/eeh_driver.c              | 10 +--
 arch/x86/events/intel/uncore.c                |  2 +-
 arch/x86/kernel/probe_roms.c                  |  2 +-
 drivers/bcma/host_pci.c                       |  7 ++-
 drivers/crypto/hisilicon/qm.c                 |  2 +-
 drivers/crypto/qat/qat_4xxx/adf_drv.c         |  7 +--
 drivers/crypto/qat/qat_c3xxx/adf_drv.c        |  7 +--
 drivers/crypto/qat/qat_c62x/adf_drv.c         |  7 +--
 drivers/crypto/qat/qat_common/adf_aer.c       | 10 +--
 .../crypto/qat/qat_common/adf_common_drv.h    |  2 +-
 drivers/crypto/qat/qat_dh895xcc/adf_drv.c     |  7 +--
 drivers/message/fusion/mptbase.c              |  7 +--
 drivers/message/fusion/mptbase.h              |  2 +-
 drivers/message/fusion/mptctl.c               |  4 +-
 drivers/message/fusion/mptlan.c               |  2 +-
 drivers/misc/cxl/guest.c                      | 24 ++++---
 drivers/misc/cxl/pci.c                        | 30 +++++----
 .../ethernet/hisilicon/hns3/hns3_ethtool.c    |  2 +-
 .../ethernet/marvell/prestera/prestera_pci.c  |  2 +-
 drivers/net/ethernet/mellanox/mlxsw/pci.c     |  2 +-
 .../ethernet/netronome/nfp/nfp_net_ethtool.c  |  2 +-
 drivers/pci/iov.c                             | 25 +++++---
 drivers/pci/pci-driver.c                      | 45 ++++++-------
 drivers/pci/pci.c                             |  4 +-
 drivers/pci/pcie/err.c                        | 36 ++++++-----
 drivers/pci/xen-pcifront.c                    | 63 +++++++++----------
 drivers/ssb/pcihost_wrapper.c                 |  8 ++-
 drivers/usb/host/xhci-pci.c                   |  2 +-
 include/linux/pci.h                           |  1 -
 30 files changed, 164 insertions(+), 167 deletions(-)

base-commit: 2734d6c1b1a089fb593ef6a23d4b70903526fe0c
-- 
2.30.2


^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name
  2021-08-11  8:06 [PATCH v3 0/8] PCI: Drop duplicated tracking of a pci_dev's bound driver Uwe Kleine-König
@ 2021-08-11  8:06 ` Uwe Kleine-König
  2021-08-12  7:07   ` Christoph Hellwig
  2021-08-11  8:06 ` [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver Uwe Kleine-König
  1 sibling, 1 reply; 7+ messages in thread
From: Uwe Kleine-König @ 2021-08-11  8:06 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: linux-pci, Alexander Duyck, oss-drivers, Paul Mackerras,
	Herbert Xu, Rafał Miłecki, Jesse Brandeburg,
	Ido Schimmel, Jakub Kicinski, Yisen Zhuang, Vadym Kochan,
	Michael Buesch, Jiri Pirko, Salil Mehta, Greg Kroah-Hartman,
	linux-wireless, linux-kernel, Taras Chornyi, Zhou Wang,
	linux-crypto, kernel, netdev, Simon Horman,
	Oliver O'Halloran, linuxppc-dev, David S. Miller

struct pci_dev::driver holds (apart from a constant offset) the same
data as struct pci_dev::dev->driver. With the goal to remove struct
pci_dev::driver to get rid of data duplication replace getting the
driver name by dev_driver_string() which implicitly makes use of struct
pci_dev::dev->driver.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 arch/powerpc/include/asm/ppc-pci.h                   | 7 ++++++-
 drivers/bcma/host_pci.c                              | 7 ++++---
 drivers/crypto/hisilicon/qm.c                        | 2 +-
 drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c   | 2 +-
 drivers/net/ethernet/marvell/prestera/prestera_pci.c | 2 +-
 drivers/net/ethernet/mellanox/mlxsw/pci.c            | 2 +-
 drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c | 2 +-
 drivers/ssb/pcihost_wrapper.c                        | 8 +++++---
 8 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
index 2b9edbf6e929..3f89dda91e89 100644
--- a/arch/powerpc/include/asm/ppc-pci.h
+++ b/arch/powerpc/include/asm/ppc-pci.h
@@ -57,7 +57,12 @@ void eeh_sysfs_remove_device(struct pci_dev *pdev);
 
 static inline const char *eeh_driver_name(struct pci_dev *pdev)
 {
-	return (pdev && pdev->driver) ? pdev->driver->name : "<null>";
+	const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : "";
+
+	if (*drvstr == '\0')
+		return "<null>";
+
+	return drvstr;
 }
 
 #endif /* CONFIG_EEH */
diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c
index 69c10a7b7c61..dc2ffa686964 100644
--- a/drivers/bcma/host_pci.c
+++ b/drivers/bcma/host_pci.c
@@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev,
 	if (err)
 		goto err_kfree_bus;
 
-	name = dev_name(&dev->dev);
-	if (dev->driver && dev->driver->name)
-		name = dev->driver->name;
+	name = dev_driver_string(&dev->dev);
+	if (*name == '\0')
+		name = dev_name(&dev->dev);
+
 	err = pci_request_regions(dev, name);
 	if (err)
 		goto err_pci_disable;
diff --git a/drivers/crypto/hisilicon/qm.c b/drivers/crypto/hisilicon/qm.c
index 1d67f94a1d56..ddf8d0ea6a75 100644
--- a/drivers/crypto/hisilicon/qm.c
+++ b/drivers/crypto/hisilicon/qm.c
@@ -3003,7 +3003,7 @@ static int qm_alloc_uacce(struct hisi_qm *qm)
 	};
 	int ret;
 
-	ret = strscpy(interface.name, pdev->driver->name,
+	ret = strscpy(interface.name, dev_driver_string(&pdev->dev),
 		      sizeof(interface.name));
 	if (ret < 0)
 		return -ENAMETOOLONG;
diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
index 82061ab6930f..e7a2c8d4558f 100644
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_ethtool.c
@@ -593,7 +593,7 @@ static void hns3_get_drvinfo(struct net_device *netdev,
 		return;
 	}
 
-	strncpy(drvinfo->driver, h->pdev->driver->name,
+	strncpy(drvinfo->driver, dev_driver_string(&h->pdev->dev),
 		sizeof(drvinfo->driver));
 	drvinfo->driver[sizeof(drvinfo->driver) - 1] = '\0';
 
diff --git a/drivers/net/ethernet/marvell/prestera/prestera_pci.c b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
index a250d394da38..a8f007f6dad2 100644
--- a/drivers/net/ethernet/marvell/prestera/prestera_pci.c
+++ b/drivers/net/ethernet/marvell/prestera/prestera_pci.c
@@ -720,7 +720,7 @@ static int prestera_fw_load(struct prestera_fw *fw)
 static int prestera_pci_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *id)
 {
-	const char *driver_name = pdev->driver->name;
+	const char *driver_name = dev_driver_string(&pdev->dev);
 	struct prestera_fw *fw;
 	int err;
 
diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c
index 13b0259f7ea6..8f306364f7bf 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/pci.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c
@@ -1876,7 +1876,7 @@ static void mlxsw_pci_cmd_fini(struct mlxsw_pci *mlxsw_pci)
 
 static int mlxsw_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
-	const char *driver_name = pdev->driver->name;
+	const char *driver_name = dev_driver_string(&pdev->dev);
 	struct mlxsw_pci *mlxsw_pci;
 	int err;
 
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
index 1b482446536d..1c0a9edcd005 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
@@ -202,7 +202,7 @@ nfp_get_drvinfo(struct nfp_app *app, struct pci_dev *pdev,
 {
 	char nsp_version[ETHTOOL_FWVERS_LEN] = {};
 
-	strlcpy(drvinfo->driver, pdev->driver->name, sizeof(drvinfo->driver));
+	strlcpy(drvinfo->driver, dev_driver_string(&pdev->dev), sizeof(drvinfo->driver));
 	nfp_net_get_nspinfo(app, nsp_version);
 	snprintf(drvinfo->fw_version, sizeof(drvinfo->fw_version),
 		 "%s %s %s %s", vnic_version, nsp_version,
diff --git a/drivers/ssb/pcihost_wrapper.c b/drivers/ssb/pcihost_wrapper.c
index 410215c16920..4938ed5cfae5 100644
--- a/drivers/ssb/pcihost_wrapper.c
+++ b/drivers/ssb/pcihost_wrapper.c
@@ -78,9 +78,11 @@ static int ssb_pcihost_probe(struct pci_dev *dev,
 	err = pci_enable_device(dev);
 	if (err)
 		goto err_kfree_ssb;
-	name = dev_name(&dev->dev);
-	if (dev->driver && dev->driver->name)
-		name = dev->driver->name;
+
+	name = dev_driver_string(&dev->dev);
+	if (*name == '\0')
+		name = dev_name(&dev->dev);
+
 	err = pci_request_regions(dev, name);
 	if (err)
 		goto err_pci_disable;
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver
  2021-08-11  8:06 [PATCH v3 0/8] PCI: Drop duplicated tracking of a pci_dev's bound driver Uwe Kleine-König
  2021-08-11  8:06 ` [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Uwe Kleine-König
@ 2021-08-11  8:06 ` Uwe Kleine-König
  2021-08-11 14:07   ` Boris Ostrovsky
  1 sibling, 1 reply; 7+ messages in thread
From: Uwe Kleine-König @ 2021-08-11  8:06 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Mark Rutland, Peter Zijlstra, H. Peter Anvin,
	Oliver O'Halloran, Jiri Olsa, Boris Ostrovsky,
	Stefano Stabellini, Mathias Nyman, x86, Alexander Shishkin,
	Ingo Molnar, linux-pci, xen-devel, Andrew Donnellan,
	Arnd Bergmann, Konrad Rzeszutek Wilk, Arnaldo Carvalho de Melo,
	Borislav Petkov, Bjorn Helgaas, Namhyung Kim, Thomas Gleixner,
	Juergen Gross, Greg Kroah-Hartman, linux-usb, linux-perf-users,
	kernel, Frederic Barrat, Paul Mackerras, linuxppc-dev

struct pci_dev::driver contains (apart from a constant offset) the same
data as struct pci_dev::dev->driver. Replace all remaining users of the
former pointer by the latter to allow removing the former.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 arch/powerpc/kernel/eeh_driver.c | 10 ++++-----
 arch/x86/events/intel/uncore.c   |  2 +-
 arch/x86/kernel/probe_roms.c     |  2 +-
 drivers/misc/cxl/guest.c         | 24 ++++++++++++---------
 drivers/misc/cxl/pci.c           | 30 ++++++++++++++++----------
 drivers/pci/iov.c                | 25 ++++++++++++++--------
 drivers/pci/pci-driver.c         | 25 +++++++++++-----------
 drivers/pci/pci.c                |  4 ++--
 drivers/pci/pcie/err.c           | 36 ++++++++++++++++++--------------
 drivers/pci/xen-pcifront.c       |  4 ++--
 drivers/usb/host/xhci-pci.c      |  2 +-
 11 files changed, 93 insertions(+), 71 deletions(-)

diff --git a/arch/powerpc/kernel/eeh_driver.c b/arch/powerpc/kernel/eeh_driver.c
index 3eff6a4888e7..350dab18e137 100644
--- a/arch/powerpc/kernel/eeh_driver.c
+++ b/arch/powerpc/kernel/eeh_driver.c
@@ -104,13 +104,13 @@ static bool eeh_edev_actionable(struct eeh_dev *edev)
  */
 static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
 {
-	if (!pdev || !pdev->driver)
+	if (!pdev || !pdev->dev.driver)
 		return NULL;
 
-	if (!try_module_get(pdev->driver->driver.owner))
+	if (!try_module_get(pdev->dev.driver->owner))
 		return NULL;
 
-	return pdev->driver;
+	return to_pci_driver(pdev->dev.driver);
 }
 
 /**
@@ -122,10 +122,10 @@ static inline struct pci_driver *eeh_pcid_get(struct pci_dev *pdev)
  */
 static inline void eeh_pcid_put(struct pci_dev *pdev)
 {
-	if (!pdev || !pdev->driver)
+	if (!pdev || !pdev->dev.driver)
 		return;
 
-	module_put(pdev->driver->driver.owner);
+	module_put(pdev->dev.driver->owner);
 }
 
 /**
diff --git a/arch/x86/events/intel/uncore.c b/arch/x86/events/intel/uncore.c
index 9bf4dbbc26e2..2df95a483692 100644
--- a/arch/x86/events/intel/uncore.c
+++ b/arch/x86/events/intel/uncore.c
@@ -1176,7 +1176,7 @@ static int uncore_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id
 	 * PCI slot and func to indicate the uncore box.
 	 */
 	if (id->driver_data & ~0xffff) {
-		struct pci_driver *pci_drv = pdev->driver;
+		struct pci_driver *pci_drv = to_pci_driver(pdev->dev.driver);
 
 		pmu = uncore_pci_find_dev_pmu(pdev, pci_drv->id_table);
 		if (pmu == NULL)
diff --git a/arch/x86/kernel/probe_roms.c b/arch/x86/kernel/probe_roms.c
index 9e1def3744f2..36e84d904260 100644
--- a/arch/x86/kernel/probe_roms.c
+++ b/arch/x86/kernel/probe_roms.c
@@ -80,7 +80,7 @@ static struct resource video_rom_resource = {
  */
 static bool match_id(struct pci_dev *pdev, unsigned short vendor, unsigned short device)
 {
-	struct pci_driver *drv = pdev->driver;
+	struct pci_driver *drv = to_pci_driver(pdev->dev.driver);
 	const struct pci_device_id *id;
 
 	if (pdev->vendor == vendor && pdev->device == device)
diff --git a/drivers/misc/cxl/guest.c b/drivers/misc/cxl/guest.c
index 186308f1f8eb..d997c9c3ebb5 100644
--- a/drivers/misc/cxl/guest.c
+++ b/drivers/misc/cxl/guest.c
@@ -25,28 +25,32 @@ static void pci_error_handlers(struct cxl_afu *afu,
 		return;
 
 	list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
-		if (!afu_dev->driver)
+		struct pci_driver *afu_drv;
+
+		if (!afu_dev->dev.driver)
 			continue;
 
+		afu_drv = to_pci_driver(afu_dev->dev.driver);
+
 		switch (bus_error_event) {
 		case CXL_ERROR_DETECTED_EVENT:
 			afu_dev->error_state = state;
 
-			if (afu_dev->driver->err_handler &&
-			    afu_dev->driver->err_handler->error_detected)
-				afu_dev->driver->err_handler->error_detected(afu_dev, state);
+			if (afu_drv->err_handler &&
+			    afu_drv->err_handler->error_detected)
+				afu_drv->err_handler->error_detected(afu_dev, state);
 		break;
 		case CXL_SLOT_RESET_EVENT:
 			afu_dev->error_state = state;
 
-			if (afu_dev->driver->err_handler &&
-			    afu_dev->driver->err_handler->slot_reset)
-				afu_dev->driver->err_handler->slot_reset(afu_dev);
+			if (afu_drv->err_handler &&
+			    afu_drv->err_handler->slot_reset)
+				afu_drv->err_handler->slot_reset(afu_dev);
 		break;
 		case CXL_RESUME_EVENT:
-			if (afu_dev->driver->err_handler &&
-			    afu_dev->driver->err_handler->resume)
-				afu_dev->driver->err_handler->resume(afu_dev);
+			if (afu_drv->err_handler &&
+			    afu_drv->err_handler->resume)
+				afu_drv->err_handler->resume(afu_dev);
 		break;
 		}
 	}
diff --git a/drivers/misc/cxl/pci.c b/drivers/misc/cxl/pci.c
index 2ba899f5659f..7e7545d01e27 100644
--- a/drivers/misc/cxl/pci.c
+++ b/drivers/misc/cxl/pci.c
@@ -1805,14 +1805,16 @@ static pci_ers_result_t cxl_vphb_error_detected(struct cxl_afu *afu,
 		return result;
 
 	list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
-		if (!afu_dev->driver)
+		struct pci_driver *afu_drv;
+		if (!afu_dev->dev.driver)
 			continue;
 
+		afu_drv = to_pci_driver(afu_dev->dev.driver);
+
 		afu_dev->error_state = state;
 
-		if (afu_dev->driver->err_handler)
-			afu_result = afu_dev->driver->err_handler->error_detected(afu_dev,
-										  state);
+		if (afu_drv->err_handler)
+			afu_result = afu_drv->err_handler->error_detected(afu_dev, state);
 		/* Disconnect trumps all, NONE trumps NEED_RESET */
 		if (afu_result == PCI_ERS_RESULT_DISCONNECT)
 			result = PCI_ERS_RESULT_DISCONNECT;
@@ -2003,6 +2005,8 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev)
 			continue;
 
 		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
+			struct pci_driver *afu_drv;
+
 			/* Reset the device context.
 			 * TODO: make this less disruptive
 			 */
@@ -2028,12 +2032,14 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev)
 			 * shouldn't start new work until we call
 			 * their resume function.
 			 */
-			if (!afu_dev->driver)
+			if (!afu_dev->dev.driver)
 				continue;
 
-			if (afu_dev->driver->err_handler &&
-			    afu_dev->driver->err_handler->slot_reset)
-				afu_result = afu_dev->driver->err_handler->slot_reset(afu_dev);
+			afu_drv = to_pci_driver(afu_dev->dev.driver);
+
+			if (afu_drv->err_handler &&
+			    afu_drv->err_handler->slot_reset)
+				afu_result = afu_drv->err_handler->slot_reset(afu_dev);
 
 			if (afu_result == PCI_ERS_RESULT_DISCONNECT)
 				result = PCI_ERS_RESULT_DISCONNECT;
@@ -2074,9 +2080,11 @@ static void cxl_pci_resume(struct pci_dev *pdev)
 			continue;
 
 		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {
-			if (afu_dev->driver && afu_dev->driver->err_handler &&
-			    afu_dev->driver->err_handler->resume)
-				afu_dev->driver->err_handler->resume(afu_dev);
+			struct pci_driver *afu_drv;
+			if (afu_dev->dev.driver &&
+			    (afu_drv = to_pci_driver(afu_dev->dev.driver))->err_handler &&
+			    afu_drv->err_handler->resume)
+				afu_drv->err_handler->resume(afu_dev);
 		}
 	}
 	spin_unlock(&adapter->afu_list_lock);
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index dafdc652fcd0..f94660927544 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -164,13 +164,15 @@ static ssize_t sriov_vf_total_msix_show(struct device *dev,
 					char *buf)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_driver *pdrv;
 	u32 vf_total_msix = 0;
 
 	device_lock(dev);
-	if (!pdev->driver || !pdev->driver->sriov_get_vf_total_msix)
+	pdrv = to_pci_driver(dev->driver);
+	if (!pdrv || !pdrv->sriov_get_vf_total_msix)
 		goto unlock;
 
-	vf_total_msix = pdev->driver->sriov_get_vf_total_msix(pdev);
+	vf_total_msix = pdrv->sriov_get_vf_total_msix(pdev);
 unlock:
 	device_unlock(dev);
 	return sysfs_emit(buf, "%u\n", vf_total_msix);
@@ -183,6 +185,7 @@ static ssize_t sriov_vf_msix_count_store(struct device *dev,
 {
 	struct pci_dev *vf_dev = to_pci_dev(dev);
 	struct pci_dev *pdev = pci_physfn(vf_dev);
+	struct pci_driver *pdrv;
 	int val, ret;
 
 	ret = kstrtoint(buf, 0, &val);
@@ -193,13 +196,14 @@ static ssize_t sriov_vf_msix_count_store(struct device *dev,
 		return -EINVAL;
 
 	device_lock(&pdev->dev);
-	if (!pdev->driver || !pdev->driver->sriov_set_msix_vec_count) {
+	pdrv = to_pci_driver(pdev->dev.driver);
+	if (!pdrv || !pdrv->sriov_set_msix_vec_count) {
 		ret = -EOPNOTSUPP;
 		goto err_pdev;
 	}
 
 	device_lock(&vf_dev->dev);
-	if (vf_dev->driver) {
+	if (vf_dev->dev.driver) {
 		/*
 		 * A driver is already attached to this VF and has configured
 		 * itself based on the current MSI-X vector count. Changing
@@ -209,7 +213,7 @@ static ssize_t sriov_vf_msix_count_store(struct device *dev,
 		goto err_dev;
 	}
 
-	ret = pdev->driver->sriov_set_msix_vec_count(vf_dev, val);
+	ret = pdrv->sriov_set_msix_vec_count(vf_dev, val);
 
 err_dev:
 	device_unlock(&vf_dev->dev);
@@ -376,6 +380,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 				  const char *buf, size_t count)
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_driver *pdrv;
 	int ret;
 	u16 num_vfs;
 
@@ -392,14 +397,16 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 		goto exit;
 
 	/* is PF driver loaded */
-	if (!pdev->driver) {
+	if (!pdev->dev.driver) {
 		pci_info(pdev, "no driver bound to device; cannot configure SR-IOV\n");
 		ret = -ENOENT;
 		goto exit;
 	}
 
+	pdrv = to_pci_driver(pdev->dev.driver);
+
 	/* is PF driver loaded w/callback */
-	if (!pdev->driver->sriov_configure) {
+	if (!pdrv->sriov_configure) {
 		pci_info(pdev, "driver does not support SR-IOV configuration via sysfs\n");
 		ret = -ENOENT;
 		goto exit;
@@ -407,7 +414,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 
 	if (num_vfs == 0) {
 		/* disable VFs */
-		ret = pdev->driver->sriov_configure(pdev, 0);
+		ret = pdrv->sriov_configure(pdev, 0);
 		goto exit;
 	}
 
@@ -419,7 +426,7 @@ static ssize_t sriov_numvfs_store(struct device *dev,
 		goto exit;
 	}
 
-	ret = pdev->driver->sriov_configure(pdev, num_vfs);
+	ret = pdrv->sriov_configure(pdev, num_vfs);
 	if (ret < 0)
 		goto exit;
 
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 7dff574bb2fa..e4bab9d0d6d8 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -443,7 +443,7 @@ static int pci_device_probe(struct device *dev)
 static int pci_device_remove(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct pci_driver *drv = pci_dev->driver;
+	struct pci_driver *drv = to_pci_driver(pci_dev->dev.driver);
 
 	if (drv->remove) {
 		pm_runtime_get_sync(dev);
@@ -480,7 +480,7 @@ static int pci_device_remove(struct device *dev)
 static void pci_device_shutdown(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct pci_driver *drv = pci_dev->driver;
+	struct pci_driver *drv = to_pci_driver(pci_dev->dev.driver);
 
 	pm_runtime_resume(dev);
 
@@ -576,7 +576,7 @@ static int pci_pm_reenable_device(struct pci_dev *pci_dev)
 static int pci_legacy_suspend(struct device *dev, pm_message_t state)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct pci_driver *drv = pci_dev->driver;
+	struct pci_driver *drv = to_pci_driver(dev->driver);
 
 	if (drv && drv->suspend) {
 		pci_power_t prev = pci_dev->current_state;
@@ -617,7 +617,7 @@ static int pci_legacy_suspend_late(struct device *dev, pm_message_t state)
 static int pci_legacy_resume(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
-	struct pci_driver *drv = pci_dev->driver;
+	struct pci_driver *drv = to_pci_driver(pci_dev->dev.driver);
 
 	pci_fixup_device(pci_fixup_resume, pci_dev);
 
@@ -636,7 +636,7 @@ static void pci_pm_default_suspend(struct pci_dev *pci_dev)
 
 static bool pci_has_legacy_pm_support(struct pci_dev *pci_dev)
 {
-	struct pci_driver *drv = pci_dev->driver;
+	struct pci_driver *drv = to_pci_driver(pci_dev->dev.driver);
 	bool ret = drv && (drv->suspend || drv->resume);
 
 	/*
@@ -1229,11 +1229,11 @@ static int pci_pm_runtime_suspend(struct device *dev)
 	int error;
 
 	/*
-	 * If pci_dev->driver is not set (unbound), we leave the device in D0,
+	 * If pci_dev->dev.driver is not set (unbound), we leave the device in D0,
 	 * but it may go to D3cold when the bridge above it runtime suspends.
 	 * Save its config space in case that happens.
 	 */
-	if (!pci_dev->driver) {
+	if (!pci_dev->dev.driver) {
 		pci_save_state(pci_dev);
 		return 0;
 	}
@@ -1290,7 +1290,7 @@ static int pci_pm_runtime_resume(struct device *dev)
 	 */
 	pci_restore_standard_config(pci_dev);
 
-	if (!pci_dev->driver)
+	if (!dev->driver)
 		return 0;
 
 	pci_fixup_device(pci_fixup_resume_early, pci_dev);
@@ -1309,14 +1309,13 @@ static int pci_pm_runtime_resume(struct device *dev)
 
 static int pci_pm_runtime_idle(struct device *dev)
 {
-	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
 
 	/*
-	 * If pci_dev->driver is not set (unbound), the device should
+	 * If dev->driver is not set (unbound), the device should
 	 * always remain in D0 regardless of the runtime PM status
 	 */
-	if (!pci_dev->driver)
+	if (!dev->driver)
 		return 0;
 
 	if (!pm)
@@ -1423,8 +1422,8 @@ static struct pci_driver pci_compat_driver = {
  */
 struct pci_driver *pci_dev_driver(const struct pci_dev *dev)
 {
-	if (dev->driver)
-		return dev->driver;
+	if (dev->dev.driver)
+		return to_pci_driver(dev->dev.driver);
 	else {
 		int i;
 		for (i = 0; i <= PCI_ROM_RESOURCE; i++)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index aacf575c15cf..e21218a16098 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5070,7 +5070,7 @@ EXPORT_SYMBOL_GPL(pci_dev_unlock);
 static void pci_dev_save_and_disable(struct pci_dev *dev)
 {
 	const struct pci_error_handlers *err_handler =
-			dev->driver ? dev->driver->err_handler : NULL;
+			dev->dev.driver ? to_pci_driver(dev->dev.driver)->err_handler : NULL;
 
 	/*
 	 * dev->driver->err_handler->reset_prepare() is protected against
@@ -5101,7 +5101,7 @@ static void pci_dev_save_and_disable(struct pci_dev *dev)
 static void pci_dev_restore(struct pci_dev *dev)
 {
 	const struct pci_error_handlers *err_handler =
-			dev->driver ? dev->driver->err_handler : NULL;
+			dev->dev.driver ? to_pci_driver(dev->dev.driver)->err_handler : NULL;
 
 	pci_restore_state(dev);
 
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index b576aa890c76..b314b54f7821 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -49,14 +49,15 @@ static int report_error_detected(struct pci_dev *dev,
 				 pci_channel_state_t state,
 				 enum pci_ers_result *result)
 {
+	struct pci_driver *pdrv;
 	pci_ers_result_t vote;
 	const struct pci_error_handlers *err_handler;
 
 	device_lock(&dev->dev);
 	if (!pci_dev_set_io_state(dev, state) ||
-		!dev->driver ||
-		!dev->driver->err_handler ||
-		!dev->driver->err_handler->error_detected) {
+		!dev->dev.driver ||
+		!(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||
+		!pdrv->err_handler->error_detected) {
 		/*
 		 * If any device in the subtree does not have an error_detected
 		 * callback, PCI_ERS_RESULT_NO_AER_DRIVER prevents subsequent
@@ -70,7 +71,7 @@ static int report_error_detected(struct pci_dev *dev,
 			vote = PCI_ERS_RESULT_NONE;
 		}
 	} else {
-		err_handler = dev->driver->err_handler;
+		err_handler = pdrv->err_handler;
 		vote = err_handler->error_detected(dev, state);
 	}
 	pci_uevent_ers(dev, vote);
@@ -92,15 +93,16 @@ static int report_normal_detected(struct pci_dev *dev, void *data)
 static int report_mmio_enabled(struct pci_dev *dev, void *data)
 {
 	pci_ers_result_t vote, *result = data;
+	struct pci_driver *pdrv;
 	const struct pci_error_handlers *err_handler;
 
 	device_lock(&dev->dev);
-	if (!dev->driver ||
-		!dev->driver->err_handler ||
-		!dev->driver->err_handler->mmio_enabled)
+	if (!dev->dev.driver ||
+		!(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||
+		!pdrv->err_handler->mmio_enabled)
 		goto out;
 
-	err_handler = dev->driver->err_handler;
+	err_handler = pdrv->err_handler;
 	vote = err_handler->mmio_enabled(dev);
 	*result = merge_result(*result, vote);
 out:
@@ -112,14 +114,15 @@ static int report_slot_reset(struct pci_dev *dev, void *data)
 {
 	pci_ers_result_t vote, *result = data;
 	const struct pci_error_handlers *err_handler;
+	struct pci_driver *pdrv;
 
 	device_lock(&dev->dev);
-	if (!dev->driver ||
-		!dev->driver->err_handler ||
-		!dev->driver->err_handler->slot_reset)
+	if (!dev->dev.driver ||
+		!(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||
+		!pdrv->err_handler->slot_reset)
 		goto out;
 
-	err_handler = dev->driver->err_handler;
+	err_handler = pdrv->err_handler;
 	vote = err_handler->slot_reset(dev);
 	*result = merge_result(*result, vote);
 out:
@@ -130,15 +133,16 @@ static int report_slot_reset(struct pci_dev *dev, void *data)
 static int report_resume(struct pci_dev *dev, void *data)
 {
 	const struct pci_error_handlers *err_handler;
+	struct pci_driver *pdrv;
 
 	device_lock(&dev->dev);
 	if (!pci_dev_set_io_state(dev, pci_channel_io_normal) ||
-		!dev->driver ||
-		!dev->driver->err_handler ||
-		!dev->driver->err_handler->resume)
+		!dev->dev.driver ||
+		!(pdrv = to_pci_driver(dev->dev.driver))->err_handler ||
+		!pdrv->err_handler->resume)
 		goto out;
 
-	err_handler = dev->driver->err_handler;
+	err_handler = pdrv->err_handler;
 	err_handler->resume(dev);
 out:
 	pci_uevent_ers(dev, PCI_ERS_RESULT_RECOVERED);
diff --git a/drivers/pci/xen-pcifront.c b/drivers/pci/xen-pcifront.c
index 3c648e6cb8f8..2b2126dbc39b 100644
--- a/drivers/pci/xen-pcifront.c
+++ b/drivers/pci/xen-pcifront.c
@@ -598,12 +598,12 @@ static pci_ers_result_t pcifront_common_process(int cmd,
 	result = PCI_ERS_RESULT_NONE;
 
 	pcidev = pci_get_domain_bus_and_slot(domain, bus, devfn);
-	if (!pcidev || !pcidev->driver) {
+	if (!pcidev || !pcidev->dev.driver) {
 		dev_err(&pdev->xdev->dev, "device or AER driver is NULL\n");
 		pci_dev_put(pcidev);
 		return result;
 	}
-	pdrv = pcidev->driver;
+	pdrv = to_pci_driver(pcidev->dev.driver);
 
 	if (pdrv->err_handler && pdrv->err_handler->error_detected) {
 		pci_dbg(pcidev, "trying to call AER service\n");
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 18c2bbddf080..3ead2127967f 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -103,7 +103,7 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
 	struct xhci_driver_data         *driver_data;
 	const struct pci_device_id      *id;
 
-	id = pci_match_id(pdev->driver->id_table, pdev);
+	id = pci_match_id(to_pci_driver(pdev->dev.driver)->id_table, pdev);
 
 	if (id && id->driver_data) {
 		driver_data = (struct xhci_driver_data *)id->driver_data;
-- 
2.30.2


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver
  2021-08-11  8:06 ` [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver Uwe Kleine-König
@ 2021-08-11 14:07   ` Boris Ostrovsky
  0 siblings, 0 replies; 7+ messages in thread
From: Boris Ostrovsky @ 2021-08-11 14:07 UTC (permalink / raw)
  To: Uwe Kleine-König, Bjorn Helgaas
  Cc: Mark Rutland, Peter Zijlstra, H. Peter Anvin,
	Oliver O'Halloran, Jiri Olsa, Stefano Stabellini,
	Mathias Nyman, x86, Alexander Shishkin, Ingo Molnar, linux-pci,
	xen-devel, Andrew Donnellan, Arnd Bergmann,
	Konrad Rzeszutek Wilk, Arnaldo Carvalho de Melo, Borislav Petkov,
	Bjorn Helgaas, Namhyung Kim, Thomas Gleixner, Juergen Gross,
	Greg Kroah-Hartman, linux-usb, linux-perf-users, kernel,
	Frederic Barrat, Paul Mackerras, linuxppc-dev


On 8/11/21 4:06 AM, Uwe Kleine-König wrote:
> struct pci_dev::driver contains (apart from a constant offset) the same
> data as struct pci_dev::dev->driver. Replace all remaining users of the
> former pointer by the latter to allow removing the former.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>


Xen:


Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>



^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name
  2021-08-11  8:06 ` [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Uwe Kleine-König
@ 2021-08-12  7:07   ` Christoph Hellwig
  2021-08-12  8:14     ` Uwe Kleine-König
  0 siblings, 1 reply; 7+ messages in thread
From: Christoph Hellwig @ 2021-08-12  7:07 UTC (permalink / raw)
  To: Uwe Kleine-K??nig
  Cc: linux-pci, Alexander Duyck, oss-drivers, Paul Mackerras,
	Herbert Xu, Rafa?? Mi??ecki, Jesse Brandeburg, Bjorn Helgaas,
	Ido Schimmel, Jakub Kicinski, Yisen Zhuang, Vadym Kochan,
	Michael Buesch, Jiri Pirko, Salil Mehta, Greg Kroah-Hartman,
	linux-wireless, linux-kernel, Taras Chornyi, Zhou Wang,
	linux-crypto, kernel, netdev, Simon Horman,
	Oliver O'Halloran, linuxppc-dev, David S. Miller

On Wed, Aug 11, 2021 at 10:06:33AM +0200, Uwe Kleine-K??nig wrote:
>  static inline const char *eeh_driver_name(struct pci_dev *pdev)
>  {
> -	return (pdev && pdev->driver) ? pdev->driver->name : "<null>";
> +	const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : "";
> +
> +	if (*drvstr == '\0')
> +		return "<null>";
> +
> +	return drvstr;

This looks rather obsfucated due to the fact that dev_driver_string
never returns '\0', and due to the strange mix of a tenary operation
and the if on a related condition.


>  }
>  
>  #endif /* CONFIG_EEH */
> diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c
> index 69c10a7b7c61..dc2ffa686964 100644
> --- a/drivers/bcma/host_pci.c
> +++ b/drivers/bcma/host_pci.c
> @@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev,
>  	if (err)
>  		goto err_kfree_bus;
>  
> -	name = dev_name(&dev->dev);
> -	if (dev->driver && dev->driver->name)
> -		name = dev->driver->name;
> +	name = dev_driver_string(&dev->dev);
> +	if (*name == '\0')
> +		name = dev_name(&dev->dev);

Where does this '\0' check come from?

> +
> +	name = dev_driver_string(&dev->dev);
> +	if (*name == '\0')
> +		name = dev_name(&dev->dev);
> +

More of this weirdness.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name
  2021-08-12  7:07   ` Christoph Hellwig
@ 2021-08-12  8:14     ` Uwe Kleine-König
  2021-08-14  8:38       ` Christoph Hellwig
  0 siblings, 1 reply; 7+ messages in thread
From: Uwe Kleine-König @ 2021-08-12  8:14 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: Alexander Duyck, oss-drivers, Paul Mackerras, Herbert Xu,
	Ido Schimmel, Rafa?? Mi??ecki, Jesse Brandeburg, Bjorn Helgaas,
	linux-pci, Jakub Kicinski, Yisen Zhuang, Vadym Kochan,
	Michael Buesch, Jiri Pirko, Salil Mehta, Greg Kroah-Hartman,
	linux-wireless, linux-kernel, Taras Chornyi, Zhou Wang,
	linux-crypto, kernel, netdev, Simon Horman,
	Oliver O'Halloran, linuxppc-dev, David S. Miller

[-- Attachment #1: Type: text/plain, Size: 2565 bytes --]

On Thu, Aug 12, 2021 at 08:07:20AM +0100, Christoph Hellwig wrote:
> On Wed, Aug 11, 2021 at 10:06:33AM +0200, Uwe Kleine-K??nig wrote:
> >  static inline const char *eeh_driver_name(struct pci_dev *pdev)
> >  {
> > -	return (pdev && pdev->driver) ? pdev->driver->name : "<null>";
> > +	const char *drvstr = pdev ? dev_driver_string(&pdev->dev) : "";
> > +
> > +	if (*drvstr == '\0')
> > +		return "<null>";
> > +
> > +	return drvstr;
> 
> This looks rather obsfucated due to the fact that dev_driver_string
> never returns '\0', and due to the strange mix of a tenary operation
> and the if on a related condition.

dev_driver_string() might return "" (via dev_bus_name()). If that happens
*drvstr == '\0' becomes true.

Would the following be better?:

	const char *drvstr;

	if (pdev)
		return "<null>";

	drvstr = dev_driver_string(&pdev->dev);

	if (!strcmp(drvstr, ""))
		return "<null>";

	return drvstr;

When I thought about this hunk I considered it ugly to have "<null>" in
it twice.

> >  }
> >  
> >  #endif /* CONFIG_EEH */
> > diff --git a/drivers/bcma/host_pci.c b/drivers/bcma/host_pci.c
> > index 69c10a7b7c61..dc2ffa686964 100644
> > --- a/drivers/bcma/host_pci.c
> > +++ b/drivers/bcma/host_pci.c
> > @@ -175,9 +175,10 @@ static int bcma_host_pci_probe(struct pci_dev *dev,
> >  	if (err)
> >  		goto err_kfree_bus;
> >  
> > -	name = dev_name(&dev->dev);
> > -	if (dev->driver && dev->driver->name)
> > -		name = dev->driver->name;
> > +	name = dev_driver_string(&dev->dev);
> > +	if (*name == '\0')
> > +		name = dev_name(&dev->dev);
> 
> Where does this '\0' check come from?

The original code is equivalent to

	if (dev->driver && dev->driver->name)
		name = dev->driver->name;
	else:
		name = dev_name(...);

As dev_driver_string() implements something like:

	if (dev->driver && dev->driver->name)
		return dev->driver->name;
	else
		return "";

the change looks fine to me. (One could wonder if it's sensible to fall
back to the device name if the driver has no nice name, but this isn't
new with my change.)

> > +	name = dev_driver_string(&dev->dev);
> > +	if (*name == '\0')
> > +		name = dev_name(&dev->dev);
> > +
> 
> More of this weirdness.

I admit it's not pretty. Would it help to use !strcmp(name, "")
instead of *name == '\0'? Any other constructive suggestion?

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name
  2021-08-12  8:14     ` Uwe Kleine-König
@ 2021-08-14  8:38       ` Christoph Hellwig
  0 siblings, 0 replies; 7+ messages in thread
From: Christoph Hellwig @ 2021-08-14  8:38 UTC (permalink / raw)
  To: Uwe Kleine-K??nig
  Cc: Alexander Duyck, oss-drivers, Paul Mackerras, Herbert Xu,
	Ido Schimmel, Rafa?? Mi??ecki, Jesse Brandeburg,
	Christoph Hellwig, Bjorn Helgaas, linux-pci, Jakub Kicinski,
	Yisen Zhuang, Vadym Kochan, Michael Buesch, Jiri Pirko,
	Salil Mehta, Greg Kroah-Hartman, linux-wireless, linux-kernel,
	Taras Chornyi, Zhou Wang, linux-crypto, kernel, netdev,
	Simon Horman, Oliver O'Halloran, linuxppc-dev,
	David S. Miller

On Thu, Aug 12, 2021 at 10:14:25AM +0200, Uwe Kleine-K??nig wrote:
> dev_driver_string() might return "" (via dev_bus_name()). If that happens
> *drvstr == '\0' becomes true.
> 
> Would the following be better?:
> 
> 	const char *drvstr;
> 
> 	if (pdev)
> 		return "<null>";
> 
> 	drvstr = dev_driver_string(&pdev->dev);
> 
> 	if (!strcmp(drvstr, ""))
> 		return "<null>";
> 
> 	return drvstr;
> 
> When I thought about this hunk I considered it ugly to have "<null>" in
> it twice.

Well, if you want to avoid that you can do:

	if (pdev) {
		const char *name = dev_driver_string(&pdev->dev);

		if (strcmp(drvstr, ""))
			return name;
	}
	return "<null>";

Which would be a lot more readable.

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2021-08-14  8:42 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-11  8:06 [PATCH v3 0/8] PCI: Drop duplicated tracking of a pci_dev's bound driver Uwe Kleine-König
2021-08-11  8:06 ` [PATCH v3 4/8] PCI: replace pci_dev::driver usage that gets the driver name Uwe Kleine-König
2021-08-12  7:07   ` Christoph Hellwig
2021-08-12  8:14     ` Uwe Kleine-König
2021-08-14  8:38       ` Christoph Hellwig
2021-08-11  8:06 ` [PATCH v3 7/8] PCI: Replace pci_dev::driver usage by pci_dev::dev.driver Uwe Kleine-König
2021-08-11 14:07   ` Boris Ostrovsky

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