Add peci-dimmtemp driver for Temperature Sensor on DIMM readings that
are accessible via the processor PECI interface.
The main use case for the driver (and PECI interface) is out-of-band
management, where we're able to obtain thermal readings from an external
entity connected with PECI, e.g. BMC on server platforms.
Co-developed-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@xxxxxxxxxxxxxxx>
Signed-off-by: Iwona Winiarska <iwona.winiarska@xxxxxxxxx>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
Note that the timeout was completely removed - we're going to probe
for detected DIMMs every 5 seconds until we reach "stable" state of
either getting correct DIMM data or getting all -EINVAL (which
suggest that the CPU doesn't have any DIMMs).
drivers/hwmon/peci/Kconfig | 13 +
drivers/hwmon/peci/Makefile | 2 +
drivers/hwmon/peci/dimmtemp.c | 614 ++++++++++++++++++++++++++++++++++
3 files changed, 629 insertions(+)
create mode 100644 drivers/hwmon/peci/dimmtemp.c
diff --git a/drivers/hwmon/peci/Kconfig b/drivers/hwmon/peci/Kconfig
index e10eed68d70a..9d32a57badfe 100644
--- a/drivers/hwmon/peci/Kconfig
+++ b/drivers/hwmon/peci/Kconfig
@@ -14,5 +14,18 @@ config SENSORS_PECI_CPUTEMP
This driver can also be built as a module. If so, the module
will be called peci-cputemp.
+config SENSORS_PECI_DIMMTEMP
+ tristate "PECI DIMM temperature monitoring client"
+ depends on PECI
+ select SENSORS_PECI
+ select PECI_CPU
+ help
+ If you say yes here you get support for the generic Intel PECI
hwmon
+ driver which provides Temperature Sensor on DIMM readings that are
+ accessible via the processor PECI interface.
+
+ This driver can also be built as a module. If so, the module
+ will be called peci-dimmtemp.
+
config SENSORS_PECI
tristate
diff --git a/drivers/hwmon/peci/Makefile b/drivers/hwmon/peci/Makefile
index e8a0ada5ab1f..191cfa0227f3 100644
--- a/drivers/hwmon/peci/Makefile
+++ b/drivers/hwmon/peci/Makefile
@@ -1,5 +1,7 @@
# SPDX-License-Identifier: GPL-2.0-only
peci-cputemp-y := cputemp.o
+peci-dimmtemp-y := dimmtemp.o
obj-$(CONFIG_SENSORS_PECI_CPUTEMP) += peci-cputemp.o
+obj-$(CONFIG_SENSORS_PECI_DIMMTEMP) += peci-dimmtemp.o
diff --git a/drivers/hwmon/peci/dimmtemp.c b/drivers/hwmon/peci/dimmtemp.c
new file mode 100644
index 000000000000..6264c29bb6c0
--- /dev/null
+++ b/drivers/hwmon/peci/dimmtemp.c
@@ -0,0 +1,614 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/auxiliary_bus.h>
+#include <linux/bitfield.h>
+#include <linux/bitops.h>
+#include <linux/hwmon.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/peci.h>
+#include <linux/peci-cpu.h>
+#include <linux/units.h>
+#include <linux/workqueue.h>
+#include <linux/x86/intel-family.h>
+
+#include "common.h"
+
+#define DIMM_MASK_CHECK_DELAY_JIFFIES msecs_to_jiffies(5000)
+
+/* Max number of channel ranks and DIMM index per channel */
+#define CHAN_RANK_MAX_ON_HSX 8
+#define DIMM_IDX_MAX_ON_HSX 3
+#define CHAN_RANK_MAX_ON_BDX 4
+#define DIMM_IDX_MAX_ON_BDX 3
+#define CHAN_RANK_MAX_ON_BDXD 2
+#define DIMM_IDX_MAX_ON_BDXD 2
+#define CHAN_RANK_MAX_ON_SKX 6
+#define DIMM_IDX_MAX_ON_SKX 2
+#define CHAN_RANK_MAX_ON_ICX 8
+#define DIMM_IDX_MAX_ON_ICX 2
+#define CHAN_RANK_MAX_ON_ICXD 4
+#define DIMM_IDX_MAX_ON_ICXD 2
+
+#define CHAN_RANK_MAX CHAN_RANK_MAX_ON_HSX
+#define DIMM_IDX_MAX DIMM_IDX_MAX_ON_HSX
+#define DIMM_NUMS_MAX (CHAN_RANK_MAX * DIMM_IDX_MAX)
+
+#define CPU_SEG_MASK GENMASK(23, 16)
+#define GET_CPU_SEG(x) (((x) & CPU_SEG_MASK) >> 16)
+#define CPU_BUS_MASK GENMASK(7, 0)
+#define GET_CPU_BUS(x) ((x) & CPU_BUS_MASK)
+
+#define DIMM_TEMP_MAX GENMASK(15, 8)
+#define DIMM_TEMP_CRIT GENMASK(23, 16)
+#define GET_TEMP_MAX(x) (((x) & DIMM_TEMP_MAX) >> 8)
+#define GET_TEMP_CRIT(x) (((x) & DIMM_TEMP_CRIT) >> 16)
+
+struct peci_dimmtemp;
+
+struct dimm_info {
+ int chan_rank_max;
+ int dimm_idx_max;
+ u8 min_peci_revision;
+ int (*read_thresholds)(struct peci_dimmtemp *priv, int dimm_order,
+ int chan_rank, u32 *data);
+};
+
+struct peci_dimm_thresholds {
+ long temp_max;
+ long temp_crit;
+ struct peci_sensor_state state;
+};
+
+enum peci_dimm_threshold_type {
+ temp_max_type,
+ temp_crit_type,
+};
+
+struct peci_dimmtemp {
+ struct peci_device *peci_dev;
+ struct device *dev;
+ const char *name;
+ const struct dimm_info *gen_info;
+ struct delayed_work detect_work;
+ struct {
+ struct peci_sensor_data temp;
+ struct peci_dimm_thresholds thresholds;
+ } dimm[DIMM_NUMS_MAX];
+ char **dimmtemp_label;
+ DECLARE_BITMAP(dimm_mask, DIMM_NUMS_MAX);
+};
+
+static u8 __dimm_temp(u32 reg, int dimm_order)
+{
+ return (reg >> (dimm_order * 8)) & 0xff;
+}
+
+static int get_dimm_temp(struct peci_dimmtemp *priv, int dimm_no, long
*val)
+{
+ int dimm_order = dimm_no % priv->gen_info->dimm_idx_max;
+ int chan_rank = dimm_no / priv->gen_info->dimm_idx_max;
+ u32 data;
+ int ret;
+
+ mutex_lock(&priv->dimm[dimm_no].temp.state.lock);
+ if (!peci_sensor_need_update(&priv->dimm[dimm_no].temp.state))
+ goto skip_update;
+
+ ret = peci_pcs_read(priv->peci_dev, PECI_PCS_DDR_DIMM_TEMP,
chan_rank, &data);
+ if (ret) {
+ mutex_unlock(&priv->dimm[dimm_no].temp.state.lock);
+ return ret;
+ }
