diff mbox series

[net-next,V2,07/10] net/mlx5: Implement PTM cross timestamping support

Message ID 20240708080025.1593555-8-tariqt@nvidia.com (mailing list archive)
State Changes Requested
Delegated to: Netdev Maintainers
Headers show
Series mlx5 misc patches 2023-07-08 | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
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: 816 this patch: 816
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers warning 2 maintainers not CCed: richardcochran@gmail.com linux-rdma@vger.kernel.org
netdev/build_clang success Errors and warnings before: 821 this patch: 821
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: 821 this patch: 821
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns WARNING: line length of 89 exceeds 80 columns WARNING: line length of 90 exceeds 80 columns WARNING: line length of 92 exceeds 80 columns
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
netdev/contest success net-next-2024-07-08--15-00 (tests: 694)

Commit Message

Tariq Toukan July 8, 2024, 8 a.m. UTC
From: Rahul Rameshbabu <rrameshbabu@nvidia.com>

Expose Precision Time Measurement support through related PTP ioctl.

Signed-off-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Co-developed-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
 .../ethernet/mellanox/mlx5/core/lib/clock.c   | 88 +++++++++++++++++++
 1 file changed, 88 insertions(+)

Comments

Jakub Kicinski July 10, 2024, 1:58 a.m. UTC | #1
On Mon, 8 Jul 2024 11:00:22 +0300 Tariq Toukan wrote:
> From: Rahul Rameshbabu <rrameshbabu@nvidia.com>
> 
> Expose Precision Time Measurement support through related PTP ioctl.

Please repost the PTM patches separately and CC the timing, pci and x86
people. Looks fairly reasonable, but IDK what the latest is on cross
timestamping.
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
index 0361741632a6..5e7bd1ce54c5 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/lib/clock.c
@@ -38,6 +38,11 @@ 
 #include "lib/eq.h"
 #include "en.h"
 #include "clock.h"
+#ifdef CONFIG_X86
+#include <asm/tsc.h>
+#include <linux/timekeeping.h>
+#include <linux/cpufeature.h>
+#endif /* CONFIG_X86 */
 
 enum {
 	MLX5_PIN_MODE_IN		= 0x0,
@@ -148,6 +153,83 @@  static int mlx5_set_mtutc(struct mlx5_core_dev *dev, u32 *mtutc, u32 size)
 				    MLX5_REG_MTUTC, 0, 1);
 }
 
+#ifdef CONFIG_X86
+static bool mlx5_is_ptm_source_time_available(struct mlx5_core_dev *dev)
+{
+	u32 out[MLX5_ST_SZ_DW(mtptm_reg)] = {0};
+	u32 in[MLX5_ST_SZ_DW(mtptm_reg)] = {0};
+	int err;
+
+	if (!MLX5_CAP_MCAM_REG3(dev, mtptm))
+		return false;
+
+	err = mlx5_core_access_reg(dev, in, sizeof(in), out, sizeof(out), MLX5_REG_MTPTM,
+				   0, 0);
+	if (err)
+		return false;
+
+	return !!MLX5_GET(mtptm_reg, out, psta);
+}
+
+static int mlx5_mtctr_syncdevicetime(ktime_t *device_time,
+				     struct system_counterval_t *sys_counterval,
+				     void *ctx)
+{
+	u32 out[MLX5_ST_SZ_DW(mtctr_reg)] = {0};
+	u32 in[MLX5_ST_SZ_DW(mtctr_reg)] = {0};
+	struct mlx5_core_dev *mdev = ctx;
+	bool real_time_mode;
+	u64 host, device;
+	int err;
+
+	real_time_mode = mlx5_real_time_mode(mdev);
+
+	MLX5_SET(mtctr_reg, in, first_clock_timestamp_request,
+		 MLX5_MTCTR_REQUEST_PTM_ROOT_CLOCK);
+	MLX5_SET(mtctr_reg, in, second_clock_timestamp_request,
+		 real_time_mode ? MLX5_MTCTR_REQUEST_REAL_TIME_CLOCK :
+		 MLX5_MTCTR_REQUEST_FREE_RUNNING_COUNTER);
+
+	err = mlx5_core_access_reg(mdev, in, sizeof(in), out, sizeof(out), MLX5_REG_MTCTR,
+				   0, 0);
+	if (err)
+		return err;
+
+	if (!MLX5_GET(mtctr_reg, out, first_clock_valid) ||
+	    !MLX5_GET(mtctr_reg, out, second_clock_valid))
+		return -EINVAL;
+
+	host = MLX5_GET64(mtctr_reg, out, first_clock_timestamp);
+	*sys_counterval = convert_art_ns_to_tsc(host);
+
+	device = MLX5_GET64(mtctr_reg, out, second_clock_timestamp);
+	if (real_time_mode)
+		*device_time = ns_to_ktime(REAL_TIME_TO_NS(device >> 32, device & U32_MAX));
+	else
+		*device_time = mlx5_timecounter_cyc2time(&mdev->clock, device);
+
+	return 0;
+}
+
+static int mlx5_ptp_getcrosststamp(struct ptp_clock_info *ptp,
+				   struct system_device_crosststamp *cts)
+{
+	struct mlx5_clock *clock = container_of(ptp, struct mlx5_clock, ptp_info);
+	struct system_time_snapshot history_begin = {0};
+	struct mlx5_core_dev *mdev;
+
+	mdev = container_of(clock, struct mlx5_core_dev, clock);
+
+	if (!mlx5_is_ptm_source_time_available(mdev))
+		return -EBUSY;
+
+	ktime_get_snapshot(&history_begin);
+
+	return get_device_system_crosststamp(mlx5_mtctr_syncdevicetime, mdev,
+					     &history_begin, cts);
+}
+#endif /* CONFIG_X86 */
+
 static u64 mlx5_read_time(struct mlx5_core_dev *dev,
 			  struct ptp_system_timestamp *sts,
 			  bool real_time)
@@ -1034,6 +1116,12 @@  static void mlx5_init_timer_clock(struct mlx5_core_dev *mdev)
 	if (MLX5_CAP_MCAM_REG(mdev, mtutc))
 		mlx5_init_timer_max_freq_adjustment(mdev);
 
+#ifdef CONFIG_X86
+	if (MLX5_CAP_MCAM_REG3(mdev, mtptm) &&
+	    MLX5_CAP_MCAM_REG3(mdev, mtctr) && boot_cpu_has(X86_FEATURE_ART))
+		clock->ptp_info.getcrosststamp = mlx5_ptp_getcrosststamp;
+#endif /* CONFIG_X86 */
+
 	mlx5_timecounter_init(mdev);
 	mlx5_init_clock_info(mdev);
 	mlx5_init_overflow_period(clock);