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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 Digital Thermal Sensor (DTS) thermal readings of > + DIMM components 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..2fcb8607137a > --- /dev/null > +++ b/drivers/hwmon/peci/dimmtemp.c > @@ -0,0 +1,508 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// Copyright (c) 2018-2021 Intel Corporation > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "common.h" > + > +#define DIMM_MASK_CHECK_DELAY_JIFFIES msecs_to_jiffies(5000) > +#define DIMM_MASK_CHECK_RETRY_MAX 60 /* 60 x 5 secs = 5 minutes */ > + > +/* 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 dimm_info { > + int chan_rank_max; > + int dimm_idx_max; > + u8 min_peci_revision; > +}; > + > +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 peci_sensor_data temp[DIMM_NUMS_MAX]; > + long temp_max[DIMM_NUMS_MAX]; > + long temp_crit[DIMM_NUMS_MAX]; > + int retry_count; > + 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) > +{ > + int dimm_order = dimm_no % priv->gen_info->dimm_idx_max; > + int chan_rank = dimm_no / priv->gen_info->dimm_idx_max; > + struct peci_device *peci_dev = priv->peci_dev; > + u8 cpu_seg, cpu_bus, dev, func; > + u64 offset; > + u32 data; > + u16 reg; > + int ret; > + > + if (!peci_sensor_need_update(&priv->temp[dimm_no])) > + return 0; > + > + ret = peci_pcs_read(peci_dev, PECI_PCS_DDR_DIMM_TEMP, chan_rank, &data); > + if (ret) > + return ret; > + Similar to the cpu driver, the lack of mutex protection needs to be explained. > + priv->temp[dimm_no].value = __dimm_temp(data, dimm_order) * MILLIDEGREE_PER_DEGREE; > + > + switch (peci_dev->info.model) { > + case INTEL_FAM6_ICELAKE_X: > + case INTEL_FAM6_ICELAKE_D: > + ret = peci_ep_pci_local_read(peci_dev, 0, 13, 0, 2, 0xd4, &data); > + if (ret || !(data & BIT(31))) > + break; /* Use default or previous value */ > + > + ret = peci_ep_pci_local_read(peci_dev, 0, 13, 0, 2, 0xd0, &data); > + if (ret) > + break; /* Use default or previous value */ > + > + cpu_seg = GET_CPU_SEG(data); > + cpu_bus = GET_CPU_BUS(data); > + > + /* > + * Device 26, Offset 224e0: IMC 0 channel 0 -> rank 0 > + * Device 26, Offset 264e0: IMC 0 channel 1 -> rank 1 > + * Device 27, Offset 224e0: IMC 1 channel 0 -> rank 2 > + * Device 27, Offset 264e0: IMC 1 channel 1 -> rank 3 > + * Device 28, Offset 224e0: IMC 2 channel 0 -> rank 4 > + * Device 28, Offset 264e0: IMC 2 channel 1 -> rank 5 > + * Device 29, Offset 224e0: IMC 3 channel 0 -> rank 6 > + * Device 29, Offset 264e0: IMC 3 channel 1 -> rank 7 > + */ > + dev = 0x1a + chan_rank / 2; > + offset = 0x224e0 + dimm_order * 4; > + if (chan_rank % 2) > + offset += 0x4000; > + > + ret = peci_mmio_read(peci_dev, 0, cpu_seg, cpu_bus, dev, 0, offset, &data); > + if (ret) > + return ret; > + > + priv->temp_max[dimm_no] = GET_TEMP_MAX(data) * MILLIDEGREE_PER_DEGREE; > + priv->temp_crit[dimm_no] = GET_TEMP_CRIT(data) * MILLIDEGREE_PER_DEGREE; > + > + break; > + case INTEL_FAM6_SKYLAKE_X: > + /* > + * Device 10, Function 2: IMC 0 channel 0 -> rank 0 > + * Device 10, Function 6: IMC 0 channel 1 -> rank 1 > + * Device 11, Function 2: IMC 0 channel 2 -> rank 2 > + * Device 12, Function 2: IMC 1 channel 0 -> rank 3 > + * Device 12, Function 6: IMC 1 channel 1 -> rank 4 > + * Device 13, Function 2: IMC 1 channel 2 -> rank 5 > + */ > + dev = 10 + chan_rank / 3 * 2 + (chan_rank % 3 == 2 ? 1 : 0); > + func = chan_rank % 3 == 1 ? 6 : 2; > + reg = 0x120 + dimm_order * 4; > + > + ret = peci_pci_local_read(peci_dev, 2, dev, func, reg, &data); > + if (ret) > + return ret; > + > + priv->temp_max[dimm_no] = GET_TEMP_MAX(data) * MILLIDEGREE_PER_DEGREE; > + priv->temp_crit[dimm_no] = GET_TEMP_CRIT(data) * MILLIDEGREE_PER_DEGREE; > + > + break; > + case INTEL_FAM6_BROADWELL_D: > + /* > + * Device 10, Function 2: IMC 0 channel 0 -> rank 0 > + * Device 10, Function 6: IMC 0 channel 1 -> rank 1 > + * Device 12, Function 2: IMC 1 channel 0 -> rank 2 > + * Device 12, Function 6: IMC 1 channel 1 -> rank 3 > + */ > + dev = 10 + chan_rank / 2 * 2; > + func = (chan_rank % 2) ? 6 : 2; > + reg = 0x120 + dimm_order * 4; > + > + ret = peci_pci_local_read(peci_dev, 2, dev, func, reg, &data); > + if (ret) > + return ret; > + > + priv->temp_max[dimm_no] = GET_TEMP_MAX(data) * MILLIDEGREE_PER_DEGREE; > + priv->temp_crit[dimm_no] = GET_TEMP_CRIT(data) * MILLIDEGREE_PER_DEGREE; > + > + break; > + case INTEL_FAM6_HASWELL_X: > + case INTEL_FAM6_BROADWELL_X: > + /* > + * Device 20, Function 0: IMC 0 channel 0 -> rank 0 > + * Device 20, Function 1: IMC 0 channel 1 -> rank 1 > + * Device 21, Function 0: IMC 0 channel 2 -> rank 2 > + * Device 21, Function 1: IMC 0 channel 3 -> rank 3 > + * Device 23, Function 0: IMC 1 channel 0 -> rank 4 > + * Device 23, Function 1: IMC 1 channel 1 -> rank 5 > + * Device 24, Function 0: IMC 1 channel 2 -> rank 6 > + * Device 24, Function 1: IMC 1 channel 3 -> rank 7 > + */ > + dev = 20 + chan_rank / 2 + chan_rank / 4; > + func = chan_rank % 2; > + reg = 0x120 + dimm_order * 4; > + > + ret = peci_pci_local_read(peci_dev, 1, dev, func, reg, &data); > + if (ret) > + return ret; > + > + priv->temp_max[dimm_no] = GET_TEMP_MAX(data) * MILLIDEGREE_PER_DEGREE; > + priv->temp_crit[dimm_no] = GET_TEMP_CRIT(data) * MILLIDEGREE_PER_DEGREE; > + > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + peci_sensor_mark_updated(&priv->temp[dimm_no]); > + > + return 0; > +} > + > +static int dimmtemp_read_string(struct device *dev, > + enum hwmon_sensor_types type, > + u32 attr, int channel, const char **str) > +{ > + struct peci_dimmtemp *priv = dev_get_drvdata(dev); > + > + if (attr != hwmon_temp_label) > + return -EOPNOTSUPP; > + > + *str = (const char *)priv->dimmtemp_label[channel]; > + > + return 0; > +} > + > +static int dimmtemp_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct peci_dimmtemp *priv = dev_get_drvdata(dev); > + int ret; > + > + ret = get_dimm_temp(priv, channel); > + if (ret) > + return ret; > + > + switch (attr) { > + case hwmon_temp_input: > + *val = priv->temp[channel].value; > + break; > + case hwmon_temp_max: > + *val = priv->temp_max[channel]; > + break; > + case hwmon_temp_crit: > + *val = priv->temp_crit[channel]; > + break; > + default: > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static umode_t dimmtemp_is_visible(const void *data, enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + const struct peci_dimmtemp *priv = data; > + > + if (test_bit(channel, priv->dimm_mask)) > + return 0444; > + > + return 0; > +} > + > +static const struct hwmon_ops peci_dimmtemp_ops = { > + .is_visible = dimmtemp_is_visible, > + .read_string = dimmtemp_read_string, > + .read = dimmtemp_read, > +}; > + > +static int check_populated_dimms(struct peci_dimmtemp *priv) > +{ > + int chan_rank_max = priv->gen_info->chan_rank_max; > + int dimm_idx_max = priv->gen_info->dimm_idx_max; > + int chan_rank, dimm_idx, ret; > + u64 dimm_mask = 0; > + u32 pcs; > + > + for (chan_rank = 0; chan_rank < chan_rank_max; chan_rank++) { > + ret = peci_pcs_read(priv->peci_dev, PECI_PCS_DDR_DIMM_TEMP, chan_rank, &pcs); > + if (ret) { > + /* > + * Overall, we expect either success or -EINVAL in > + * order to determine whether DIMM is populated or not. > + * For anything else - we fall back to defering the > + * detection to be performed at a later point in time. > + */ > + if (ret == -EINVAL) > + continue; > + else else after continue is unnecessary. > + return -EAGAIN; > + } > + > + for (dimm_idx = 0; dimm_idx < dimm_idx_max; dimm_idx++) > + if (__dimm_temp(pcs, dimm_idx)) > + dimm_mask |= BIT(chan_rank * dimm_idx_max + dimm_idx); > + } > + /* > + * It's possible that memory training is not done yet. In this case we > + * defer the detection to be performed at a later point in time. > + */ > + if (!dimm_mask) > + return -EAGAIN; > + > + dev_dbg(priv->dev, "Scanned populated DIMMs: %#llx\n", dimm_mask); > + > + bitmap_from_u64(priv->dimm_mask, dimm_mask); > + > + return 0; > +} > + > +static int create_dimm_temp_label(struct peci_dimmtemp *priv, int chan) > +{ > + int rank = chan / priv->gen_info->dimm_idx_max; > + int idx = chan % priv->gen_info->dimm_idx_max; > + > + priv->dimmtemp_label[chan] = devm_kasprintf(priv->dev, GFP_KERNEL, > + "DIMM %c%d", 'A' + rank, > + idx + 1); > + if (!priv->dimmtemp_label[chan]) > + return -ENOMEM; > + > + return 0; > +} > + > +static const u32 peci_dimmtemp_temp_channel_config[] = { > + [0 ... DIMM_NUMS_MAX - 1] = HWMON_T_LABEL | HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT, > + 0 > +}; > + > +static const struct hwmon_channel_info peci_dimmtemp_temp_channel = { > + .type = hwmon_temp, > + .config = peci_dimmtemp_temp_channel_config, > +}; > + > +static const struct hwmon_channel_info *peci_dimmtemp_temp_info[] = { > + &peci_dimmtemp_temp_channel, > + NULL > +}; > + > +static const struct hwmon_chip_info peci_dimmtemp_chip_info = { > + .ops = &peci_dimmtemp_ops, > + .info = peci_dimmtemp_temp_info, > +}; > + > +static int create_dimm_temp_info(struct peci_dimmtemp *priv) > +{ > + int ret, i, channels; > + struct device *dev; > + > + ret = check_populated_dimms(priv); > + if (ret == -EAGAIN) { The only error returned by check_populated_dimms() is -EAGAIN. Checking for specifically this error here suggests that there may be other (ignored) errors. The reader has to examine check_populated_dimms() to find out that -EAGAIN is indeed the only possible error. To avoid confusion, please only check for ret here. > + if (priv->retry_count < DIMM_MASK_CHECK_RETRY_MAX) { > + schedule_delayed_work(&priv->detect_work, > + DIMM_MASK_CHECK_DELAY_JIFFIES); > + priv->retry_count++; > + dev_dbg(priv->dev, "Deferred populating DIMM temp info\n"); > + return ret; > + } > + > + dev_info(priv->dev, "Timeout populating DIMM temp info\n"); If this returns an error, the message needs to be dev_err(). > + return -ETIMEDOUT; > + } > + > + channels = priv->gen_info->chan_rank_max * priv->gen_info->dimm_idx_max; > + > + priv->dimmtemp_label = devm_kzalloc(priv->dev, channels * sizeof(char *), GFP_KERNEL); > + if (!priv->dimmtemp_label) > + return -ENOMEM; > + > + for_each_set_bit(i, priv->dimm_mask, DIMM_NUMS_MAX) { > + ret = create_dimm_temp_label(priv, i); > + if (ret) > + return ret; > + } > + > + dev = devm_hwmon_device_register_with_info(priv->dev, priv->name, priv, > + &peci_dimmtemp_chip_info, NULL); > + if (IS_ERR(dev)) { > + dev_err(priv->dev, "Failed to register hwmon device\n"); > + return PTR_ERR(dev); > + } > + > + dev_dbg(priv->dev, "%s: sensor '%s'\n", dev_name(dev), priv->name); > + > + return 0; > +} > + > +static void create_dimm_temp_info_delayed(struct work_struct *work) > +{ > + struct peci_dimmtemp *priv = container_of(to_delayed_work(work), > + struct peci_dimmtemp, > + detect_work); > + int ret; > + > + ret = create_dimm_temp_info(priv); > + if (ret && ret != -EAGAIN) > + dev_dbg(priv->dev, "Failed to populate DIMM temp info\n"); > +} > + > +static int peci_dimmtemp_probe(struct auxiliary_device *adev, const struct auxiliary_device_id *id) > +{ > + struct device *dev = &adev->dev; > + struct peci_device *peci_dev = to_peci_device(dev->parent); > + struct peci_dimmtemp *priv; > + int ret; > + > + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->name = devm_kasprintf(dev, GFP_KERNEL, "peci_dimmtemp.cpu%d", > + peci_dev->info.socket_id); > + if (!priv->name) > + return -ENOMEM; > + > + dev_set_drvdata(dev, priv); > + priv->dev = dev; > + priv->peci_dev = peci_dev; > + priv->gen_info = (const struct dimm_info *)id->driver_data; > + > + INIT_DELAYED_WORK(&priv->detect_work, create_dimm_temp_info_delayed); > + > + ret = create_dimm_temp_info(priv); > + if (ret && ret != -EAGAIN) { > + dev_dbg(dev, "Failed to populate DIMM temp info\n"); > + return ret; > + } > + > + return 0; > +} > + > +static void peci_dimmtemp_remove(struct auxiliary_device *adev) > +{ > + struct peci_dimmtemp *priv = dev_get_drvdata(&adev->dev); > + > + cancel_delayed_work_sync(&priv->detect_work); > +} > + > +static const struct dimm_info dimm_hsx = { > + .chan_rank_max = CHAN_RANK_MAX_ON_HSX, > + .dimm_idx_max = DIMM_IDX_MAX_ON_HSX, > + .min_peci_revision = 0x30, > +}; > + > +static const struct dimm_info dimm_bdx = { > + .chan_rank_max = CHAN_RANK_MAX_ON_BDX, > + .dimm_idx_max = DIMM_IDX_MAX_ON_BDX, > + .min_peci_revision = 0x30, > +}; > + > +static const struct dimm_info dimm_bdxd = { > + .chan_rank_max = CHAN_RANK_MAX_ON_BDXD, > + .dimm_idx_max = DIMM_IDX_MAX_ON_BDXD, > + .min_peci_revision = 0x30, > +}; > + > +static const struct dimm_info dimm_skx = { > + .chan_rank_max = CHAN_RANK_MAX_ON_SKX, > + .dimm_idx_max = DIMM_IDX_MAX_ON_SKX, > + .min_peci_revision = 0x30, > +}; > + > +static const struct dimm_info dimm_icx = { > + .chan_rank_max = CHAN_RANK_MAX_ON_ICX, > + .dimm_idx_max = DIMM_IDX_MAX_ON_ICX, > + .min_peci_revision = 0x40, > +}; > + > +static const struct dimm_info dimm_icxd = { > + .chan_rank_max = CHAN_RANK_MAX_ON_ICXD, > + .dimm_idx_max = DIMM_IDX_MAX_ON_ICXD, > + .min_peci_revision = 0x40, > +}; > + > +static const struct auxiliary_device_id peci_dimmtemp_ids[] = { > + { > + .name = "peci_cpu.dimmtemp.hsx", > + .driver_data = (kernel_ulong_t)&dimm_hsx, > + }, > + { > + .name = "peci_cpu.dimmtemp.bdx", > + .driver_data = (kernel_ulong_t)&dimm_bdx, > + }, > + { > + .name = "peci_cpu.dimmtemp.bdxd", > + .driver_data = (kernel_ulong_t)&dimm_bdxd, > + }, > + { > + .name = "peci_cpu.dimmtemp.skx", > + .driver_data = (kernel_ulong_t)&dimm_skx, > + }, > + { > + .name = "peci_cpu.dimmtemp.icx", > + .driver_data = (kernel_ulong_t)&dimm_icx, > + }, > + { > + .name = "peci_cpu.dimmtemp.icxd", > + .driver_data = (kernel_ulong_t)&dimm_icxd, > + }, > + { } > +}; > +MODULE_DEVICE_TABLE(auxiliary, peci_dimmtemp_ids); > + > +static struct auxiliary_driver peci_dimmtemp_driver = { > + .probe = peci_dimmtemp_probe, > + .remove = peci_dimmtemp_remove, > + .id_table = peci_dimmtemp_ids, > +}; > + > +module_auxiliary_driver(peci_dimmtemp_driver); > + > +MODULE_AUTHOR("Jae Hyun Yoo "); > +MODULE_AUTHOR("Iwona Winiarska "); > +MODULE_DESCRIPTION("PECI dimmtemp driver"); > +MODULE_LICENSE("GPL"); > +MODULE_IMPORT_NS(PECI_CPU);