diff mbox series

[net-next,13/14] mlxsw: pci: Implement PCI reset handlers

Message ID 3bb150e9efd7fbf2ced0a2fb6f3ea321fbcf6046.1700047319.git.petrm@nvidia.com (mailing list archive)
State Accepted
Commit 5e12d0898583026581e4f0506ff7c0b15a73a1c5
Delegated to: Netdev Maintainers
Headers show
Series mlxsw: Add support for new reset flow | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1134 this patch: 1134
netdev/cc_maintainers success CCed 6 of 6 maintainers
netdev/build_clang success Errors and warnings before: 1161 this patch: 1161
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1161 this patch: 1161
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 51 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Petr Machata Nov. 15, 2023, 12:17 p.m. UTC 
From: Ido Schimmel <idosch@nvidia.com>

Implement reset_prepare() and reset_done() handlers that are invoked by
the PCI core before and after issuing a PCI reset, respectively.

Specifically, implement reset_prepare() by calling
mlxsw_core_bus_device_unregister() and reset_done() by calling
mlxsw_core_bus_device_register(). This is the same implementation as the
reload_{down,up}() devlink operations with the following differences:

1. The devlink instance is unregistered and then registered again after
   the reset.

2. A reset via the device's command interface (using MRSR register) is
   not issued during reset_done() as PCI core already issued a PCI
   reset.

Tested:

 # for i in $(seq 1 10); do echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset; done

Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/pci.c | 28 +++++++++++++++++++++++
 1 file changed, 28 insertions(+)

Comments

Simon Horman Nov. 17, 2023, 3:54 p.m. UTC | #1 
On Wed, Nov 15, 2023 at 01:17:22PM +0100, Petr Machata wrote:
> From: Ido Schimmel <idosch@nvidia.com>
> 
> Implement reset_prepare() and reset_done() handlers that are invoked by
> the PCI core before and after issuing a PCI reset, respectively.
> 
> Specifically, implement reset_prepare() by calling
> mlxsw_core_bus_device_unregister() and reset_done() by calling
> mlxsw_core_bus_device_register(). This is the same implementation as the
> reload_{down,up}() devlink operations with the following differences:
> 
> 1. The devlink instance is unregistered and then registered again after
>    the reset.
> 
> 2. A reset via the device's command interface (using MRSR register) is
>    not issued during reset_done() as PCI core already issued a PCI
>    reset.
> 
> Tested:
> 
>  # for i in $(seq 1 10); do echo 1 > /sys/bus/pci/devices/0000\:01\:00.0/reset; done
> 
> Reviewed-by: Petr Machata <petrm@nvidia.com>
> Signed-off-by: Ido Schimmel <idosch@nvidia.com>
> Signed-off-by: Petr Machata <petrm@nvidia.com>

Reviewed-by: Simon Horman <horms@kernel.org>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlxsw/pci.c b/drivers/net/ethernet/mellanox/mlxsw/pci.c
index 726ed707e27b..5b1f2483a3cc 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/pci.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/pci.c
@@ -130,6 +130,7 @@  struct mlxsw_pci {
 	const struct pci_device_id *id;
 	enum mlxsw_pci_cqe_v max_cqe_ver; /* Maximal supported CQE version */
 	u8 num_sdq_cqs; /* Number of CQs used for SDQs */
+	bool skip_reset;
 };
 
 static void mlxsw_pci_queue_tasklet_schedule(struct mlxsw_pci_queue *q)
@@ -1527,6 +1528,10 @@  mlxsw_pci_reset(struct mlxsw_pci *mlxsw_pci, const struct pci_device_id *id)
 		return err;
 	}
 
+	/* PCI core already issued a PCI reset, do not issue another reset. */
+	if (mlxsw_pci->skip_reset)
+		return 0;
+
 	mlxsw_reg_mcam_pack(mcam_pl,
 			    MLXSW_REG_MCAM_FEATURE_GROUP_ENHANCED_FEATURES);
 	err = mlxsw_reg_query(mlxsw_pci->core, MLXSW_REG(mcam), mcam_pl);
@@ -2107,11 +2112,34 @@  static void mlxsw_pci_remove(struct pci_dev *pdev)
 	kfree(mlxsw_pci);
 }
 
+static void mlxsw_pci_reset_prepare(struct pci_dev *pdev)
+{
+	struct mlxsw_pci *mlxsw_pci = pci_get_drvdata(pdev);
+
+	mlxsw_core_bus_device_unregister(mlxsw_pci->core, false);
+}
+
+static void mlxsw_pci_reset_done(struct pci_dev *pdev)
+{
+	struct mlxsw_pci *mlxsw_pci = pci_get_drvdata(pdev);
+
+	mlxsw_pci->skip_reset = true;
+	mlxsw_core_bus_device_register(&mlxsw_pci->bus_info, &mlxsw_pci_bus,
+				       mlxsw_pci, false, NULL, NULL);
+	mlxsw_pci->skip_reset = false;
+}
+
+static const struct pci_error_handlers mlxsw_pci_err_handler = {
+	.reset_prepare = mlxsw_pci_reset_prepare,
+	.reset_done = mlxsw_pci_reset_done,
+};
+
 int mlxsw_pci_driver_register(struct pci_driver *pci_driver)
 {
 	pci_driver->probe = mlxsw_pci_probe;
 	pci_driver->remove = mlxsw_pci_remove;
 	pci_driver->shutdown = mlxsw_pci_remove;
+	pci_driver->err_handler = &mlxsw_pci_err_handler;
 	return pci_register_driver(pci_driver);
 }
 EXPORT_SYMBOL(mlxsw_pci_driver_register);