Some of the PM features can be locked or disabled. In that case, write interface can be locked. This status is read via a mailbox. There is one TPMI ID which provides base address for interface and data register for mail box operation. The mailbox operations is defined in the TPMI specification. Refer to https://github.com/intel/tpmi_power_management/ for TPMI specifications. An API is exposed to feature drivers to read feature control status. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx> --- The external interface will be used by all feature drivers, will submit patch for that. v2 - Renaming of register names as suggested by llpo - cosmetic changes as suggested by llpo - size change to u32 for checking with max 4K size v1 This has all changes suggested by Andi drivers/platform/x86/intel/tpmi.c | 178 ++++++++++++++++++++++++++++++ include/linux/intel_tpmi.h | 2 + 2 files changed, 180 insertions(+) diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c index d1fd6e69401c..024e7671687a 100644 --- a/drivers/platform/x86/intel/tpmi.c +++ b/drivers/platform/x86/intel/tpmi.c @@ -47,8 +47,11 @@ */ #include <linux/auxiliary_bus.h> +#include <linux/bitfield.h> +#include <linux/delay.h> #include <linux/intel_tpmi.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/module.h> #include <linux/pci.h> @@ -98,6 +101,7 @@ struct intel_tpmi_pm_feature { * @feature_count: Number of TPMI of TPMI instances pointed by tpmi_features * @pfs_start: Start of PFS offset for the TPMI instances in this device * @plat_info: Stores platform info which can be used by the client drivers + * @tpmi_control_mem: Memory mapped IO for getting control information * * Stores the information for all TPMI devices enumerated from a single PCI device. */ @@ -107,6 +111,7 @@ struct intel_tpmi_info { int feature_count; u64 pfs_start; struct intel_tpmi_plat_info plat_info; + void __iomem *tpmi_control_mem; }; /** @@ -139,9 +144,16 @@ enum intel_tpmi_id { TPMI_ID_PEM = 1, /* Power and Perf excursion Monitor */ TPMI_ID_UNCORE = 2, /* Uncore Frequency Scaling */ TPMI_ID_SST = 5, /* Speed Select Technology */ + TPMI_CONTROL_ID = 0x80, /* Special ID for getting feature status */ TPMI_INFO_ID = 0x81, /* Special ID for PCI BDF and Package ID information */ }; +/* + * TPMI PFS and per feature memory size can't exceed 4K. + * Also PFS start and feature memory is 4K aligned. + */ +#define TPMI_MAX_BUFFER_SIZE (4 * 1024) + /* Used during auxbus device creation */ static DEFINE_IDA(intel_vsec_tpmi_ida); @@ -175,6 +187,169 @@ struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int } EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_at_index, INTEL_TPMI); +/* TPMI Control Interface */ + +#define TPMI_CONTROL_STATUS_OFFSET 0x00 +#define TPMI_COMMAND_OFFSET 0x08 + +/* + * Spec is calling for max 1 seconds to get ownership at the worst + * case. Read at 10 ms timeouts and repeat up to 1 second. + */ +#define TPMI_CONTROL_TIMEOUT_US (10 * USEC_PER_MSEC) +#define TPMI_CONTROL_TIMEOUT_MAX_US USEC_PER_SEC + +#define TPMI_RB_TIMEOUT_US (10 * USEC_PER_MSEC) +#define TPMI_RB_TIMEOUT_MAX_US USEC_PER_SEC + +/* TPMI Control status register defines */ + +#define TPMI_CONTROL_STATUS_RB BIT_ULL(0) + +#define TPMI_CONTROL_STATUS_OWNER GENMASK_ULL(5, 4) +#define TPMI_OWNER_NONE 0 +#define TPMI_OWNER_IN_BAND 1 + +#define TPMI_CONTROL_STATUS_CPL BIT_ULL(6) +#define TPMI_CONTROL_STATUS_RESULT GENMASK_ULL(15, 8) +#define TPMI_CONTROL_STATUS_LEN GENMASK_ULL(31, 16) + +#define TPMI_CMD_PKT_LEN 2 +#define TPMI_CMD_STATUS_SUCCESS 0x40 + +/* TPMI command data registers */ +#define TMPI_CONTROL_DATA_CMD GENMASK_ULL(7, 0) +#define TMPI_CONTROL_DATA_VAL GENMASK_ULL(63, 32) +#define TPMI_CONTROL_DATA_VAL_FEATURE GENMASK_ULL(48, 40) + +/* Command to send via control interface */ +#define TPMI_CONTROL_GET_STATE_CMD 0x10 + +#define TPMI_CONTROL_CMD_MASK GENMASK_ULL(48, 40) + +#define TPMI_CMD_LEN_MASK GENMASK_ULL(18, 16) + +#define TPMI_STATE_DISABLED BIT_ULL(0) +#define TPMI_STATE_LOCKED BIT_ULL(31) + +/* Mutex to complete get feature status without interruption */ +static DEFINE_MUTEX(tpmi_dev_lock); + +static int tpmi_wait_for_owner(struct intel_tpmi_info *tpmi_info, u8 owner) +{ + u64 control; + + return read_poll_timeout(readq, control, + owner == FIELD_GET(TPMI_CONTROL_STATUS_OWNER, control), + TPMI_CONTROL_TIMEOUT_US, TPMI_CONTROL_TIMEOUT_MAX_US, false, + tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET); +} + +static int tpmi_read_feature_status(struct intel_tpmi_info *tpmi_info, int feature_id, + int *locked, int *disabled) +{ + u64 control, data; + int ret; + + if (!tpmi_info->tpmi_control_mem) + return -EFAULT; + + mutex_lock(&tpmi_dev_lock); + + /* Wait for owner bit set to 0 (none) */ + ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_NONE); + if (ret) + goto err_unlock; + + /* set command id to 0x10 for TPMI_GET_STATE */ + data = FIELD_PREP(TMPI_CONTROL_DATA_CMD, TPMI_CONTROL_GET_STATE_CMD); + + /* 32 bits for DATA offset and +8 for feature_id field */ + data |= FIELD_PREP(TPMI_CONTROL_DATA_VAL_FEATURE, feature_id); + + /* Write at command offset for qword access */ + writeq(data, tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET); + + /* Wait for owner bit set to in-band */ + ret = tpmi_wait_for_owner(tpmi_info, TPMI_OWNER_IN_BAND); + if (ret) + goto err_unlock; + + /* Set Run Busy and packet length of 2 dwords */ + control = TPMI_CONTROL_STATUS_RB; + control |= FIELD_PREP(TPMI_CONTROL_STATUS_LEN, TPMI_CMD_PKT_LEN); + + /* Write at status offset for qword access */ + writeq(control, tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET); + + /* Wait for Run Busy clear */ + ret = read_poll_timeout(readq, control, !(control & TPMI_CONTROL_STATUS_RB), + TPMI_RB_TIMEOUT_US, TPMI_RB_TIMEOUT_MAX_US, false, + tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET); + if (ret) + goto done_proc; + + control = FIELD_GET(TPMI_CONTROL_STATUS_RESULT, control); + if (control != TPMI_CMD_STATUS_SUCCESS) { + ret = -EBUSY; + goto done_proc; + } + + /* Response is ready */ + data = readq(tpmi_info->tpmi_control_mem + TPMI_COMMAND_OFFSET); + data = FIELD_GET(TMPI_CONTROL_DATA_VAL, data); + + *disabled = 0; + *locked = 0; + + if (!(data & TPMI_STATE_DISABLED)) + *disabled = 1; + + if (data & TPMI_STATE_LOCKED) + *locked = 1; + + ret = 0; + +done_proc: + /* Set CPL "completion" bit */ + writeq(TPMI_CONTROL_STATUS_CPL, tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET); + +err_unlock: + mutex_unlock(&tpmi_dev_lock); + + return ret; +} + +int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id, + int *locked, int *disabled) +{ + struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(auxdev->dev.parent); + struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(&intel_vsec_dev->auxdev); + + return tpmi_read_feature_status(tpmi_info, feature_id, locked, disabled); +} +EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, INTEL_TPMI); + +static void tpmi_set_control_base(struct auxiliary_device *auxdev, + struct intel_tpmi_info *tpmi_info, + struct intel_tpmi_pm_feature *pfs) +{ + void __iomem *mem; + u32 size; + + size = pfs->pfs_header.num_entries * pfs->pfs_header.entry_size * sizeof(u32); + /* This size is coming from trusted hardware, but verify anyway */ + if (size > TPMI_MAX_BUFFER_SIZE) + return; + + mem = devm_ioremap(&auxdev->dev, pfs->vsec_offset, size); + if (!mem) + return; + + /* mem is pointing to TPMI CONTROL base */ + tpmi_info->tpmi_control_mem = mem; +} + static const char *intel_tpmi_name(enum intel_tpmi_id id) { switch (id) { @@ -367,6 +542,9 @@ static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev) */ if (pfs->pfs_header.tpmi_id == TPMI_INFO_ID) tpmi_process_info(tpmi_info, pfs); + + if (pfs->pfs_header.tpmi_id == TPMI_CONTROL_ID) + tpmi_set_control_base(auxdev, tpmi_info, pfs); } tpmi_info->pfs_start = pfs_start; diff --git a/include/linux/intel_tpmi.h b/include/linux/intel_tpmi.h index f505788c05da..04d937ad4dc4 100644 --- a/include/linux/intel_tpmi.h +++ b/include/linux/intel_tpmi.h @@ -27,4 +27,6 @@ struct intel_tpmi_plat_info *tpmi_get_platform_data(struct auxiliary_device *aux struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int index); int tpmi_get_resource_count(struct auxiliary_device *auxdev); +int tpmi_get_feature_status(struct auxiliary_device *auxdev, int feature_id, int *locked, + int *disabled); #endif -- 2.40.1
