// SPDX-License-Identifier: GPL-2.0-only
/*
 * Driver to enumerate TPMI features and create devices
 *
 * Copyright (c) 2023, Intel Corporation.
 * All Rights Reserved.
 *
 * The TPMI (Topology Aware Register and PM Capsule Interface) provides a
 * flexible, extendable and PCIe enumerable MMIO interface for PM features.
 *
 * For example Intel RAPL (Running Average Power Limit) provides a MMIO
 * interface using TPMI. This has advantage over traditional MSR
 * (Model Specific Register) interface, where a thread needs to be scheduled
 * on the target CPU to read or write. Also the RAPL features vary between
 * CPU models, and hence lot of model specific code. Here TPMI provides an
 * architectural interface by providing hierarchical tables and fields,
 * which will not need any model specific implementation.
 *
 * The TPMI interface uses a PCI VSEC structure to expose the location of
 * MMIO region.
 *
 * This VSEC structure is present in the PCI configuration space of the
 * Intel Out-of-Band (OOB) device, which  is handled by the Intel VSEC
 * driver. The Intel VSEC driver parses VSEC structures present in the PCI
 * configuration space of the given device and creates an auxiliary device
 * object for each of them. In particular, it creates an auxiliary device
 * object representing TPMI that can be bound by an auxiliary driver.
 *
 * This TPMI driver will bind to the TPMI auxiliary device object created
 * by the Intel VSEC driver.
 *
 * The TPMI specification defines a PFS (PM Feature Structure) table.
 * This table is present in the TPMI MMIO region. The starting address
 * of PFS is derived from the tBIR (Bar Indicator Register) and "Address"
 * field from the VSEC header.
 *
 * Each TPMI PM feature has one entry in the PFS with a unique TPMI
 * ID and its access details. The TPMI driver creates device nodes
 * for the supported PM features.
 *
 * The names of the devices created by the TPMI driver start with the
 * "intel_vsec.tpmi-" prefix which is followed by a specific name of the
 * given PM feature (for example, "intel_vsec.tpmi-rapl.0").
 *
 * The device nodes are create by using interface "intel_vsec_add_aux()"
 * provided by the Intel VSEC driver.
 */

#include <linux/auxiliary_bus.h>
#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/intel_tpmi.h>
#include <linux/intel_vsec.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/security.h>
#include <linux/sizes.h>
#include <linux/string_helpers.h>

/**
 * struct intel_tpmi_pfs_entry - TPMI PM Feature Structure (PFS) entry
 * @tpmi_id:    TPMI feature identifier (what the feature is and its data format).
 * @num_entries: Number of feature interface instances present in the PFS.
 *               This represents the maximum number of Power domains in the SoC.
 * @entry_size: Interface instance entry size in 32-bit words.
 * @cap_offset: Offset from the PM_Features base address to the base of the PM VSEC
 *              register bank in KB.
 * @attribute:  Feature attribute: 0=BIOS. 1=OS. 2-3=Reserved.
 * @reserved:   Bits for use in the future.
 *
 * Represents one TPMI feature entry data in the PFS retrieved as is
 * from the hardware.
 */
struct intel_tpmi_pfs_entry {
        u64 tpmi_id:8;
        u64 num_entries:8;
        u64 entry_size:16;
        u64 cap_offset:16;
        u64 attribute:2;
        u64 reserved:14;
} __packed;

/**
 * struct intel_tpmi_pm_feature - TPMI PM Feature information for a TPMI ID
 * @pfs_header: PFS header retireved from the hardware.
 * @vsec_offset: Starting MMIO address for this feature in bytes. Essentially
 *               this offset = "Address" from VSEC header + PFS Capability
 *               offset for this feature entry.
 * @vsec_dev:   Pointer to intel_vsec_device structure for this TPMI device
 *
 * Represents TPMI instance information for one TPMI ID.
 */
struct intel_tpmi_pm_feature {
        struct intel_tpmi_pfs_entry pfs_header;
        u64 vsec_offset;
        struct intel_vsec_device *vsec_dev;
};

/**
 * struct intel_tpmi_info - TPMI information for all IDs in an instance
 * @tpmi_features:      Pointer to a list of TPMI feature instances
 * @vsec_dev:           Pointer to intel_vsec_device structure for this TPMI device
 * @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
 * @dbgfs_dir:          debugfs entry pointer
 *
 * Stores the information for all TPMI devices enumerated from a single PCI device.
 */
struct intel_tpmi_info {
        struct intel_tpmi_pm_feature *tpmi_features;
        struct intel_vsec_device *vsec_dev;
        int feature_count;
        u64 pfs_start;
        struct oobmsm_plat_info plat_info;
        void __iomem *tpmi_control_mem;
        struct dentry *dbgfs_dir;
};

/**
 * struct tpmi_info_header - CPU package ID to PCI device mapping information
 * @fn:         PCI function number
 * @dev:        PCI device number
 * @bus:        PCI bus number
 * @pkg:        CPU Package id
 * @segment:    PCI segment id
 * @partition:  Package Partition id
 * @cdie_mask:  Bitmap of compute dies in the current partition
 * @reserved:   Reserved for future use
 * @lock:       When set to 1 the register is locked and becomes read-only
 *              until next reset. Not for use by the OS driver.
 *
 * The structure to read hardware provided mapping information.
 */
struct tpmi_info_header {
        u64 fn:3;
        u64 dev:5;
        u64 bus:8;
        u64 pkg:8;
        u64 segment:8;
        u64 partition:2;
        u64 cdie_mask:16;
        u64 reserved:13;
        u64 lock:1;
} __packed;

/**
 * struct tpmi_feature_state - Structure to read hardware state of a feature
 * @enabled:    Enable state of a feature, 1: enabled, 0: disabled
 * @reserved_1: Reserved for future use
 * @write_blocked: Writes are blocked means all write operations are ignored
 * @read_blocked: Reads are blocked means will read 0xFFs
 * @pcs_select: Interface used by out of band software, not used in OS
 * @reserved_2: Reserved for future use
 * @id:         TPMI ID of the feature
 * @reserved_3: Reserved for future use
 * @locked:     When set to 1, OS can't change this register.
 *
 * The structure is used to read hardware state of a TPMI feature. This
 * information is used for debug and restricting operations for this feature.
 */
struct tpmi_feature_state {
        u32 enabled:1;
        u32 reserved_1:3;
        u32 write_blocked:1;
        u32 read_blocked:1;
        u32 pcs_select:1;
        u32 reserved_2:1;
        u32 id:8;
        u32 reserved_3:15;
        u32 locked:1;
} __packed;

/*
 * The size from hardware is in u32 units. This size is from a trusted hardware,
 * but better to verify for pre silicon platforms. Set size to 0, when invalid.
 */
#define TPMI_GET_SINGLE_ENTRY_SIZE(pfs)                                                 \
({                                                                                      \
        pfs->pfs_header.entry_size > SZ_1K ? 0 : pfs->pfs_header.entry_size << 2;       \
})

/* Used during auxbus device creation */
static DEFINE_IDA(intel_vsec_tpmi_ida);

struct oobmsm_plat_info *tpmi_get_platform_data(struct auxiliary_device *auxdev)
{
        struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);

        return vsec_dev->priv_data;
}
EXPORT_SYMBOL_NS_GPL(tpmi_get_platform_data, "INTEL_TPMI");

int tpmi_get_resource_count(struct auxiliary_device *auxdev)
{
        struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);

        if (vsec_dev)
                return vsec_dev->num_resources;

        return 0;
}
EXPORT_SYMBOL_NS_GPL(tpmi_get_resource_count, "INTEL_TPMI");

struct resource *tpmi_get_resource_at_index(struct auxiliary_device *auxdev, int index)
{
        struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);

        if (vsec_dev && index < vsec_dev->num_resources)
                return &vsec_dev->resource[index];

        return NULL;
}
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
#define TMPI_CONTROL_DATA_VAL_OFFSET    0x0c

/*
 * 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     (1 * 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 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)

/* 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 readq_poll_timeout(tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET,
                                  control, owner == FIELD_GET(TPMI_CONTROL_STATUS_OWNER, control),
                                  TPMI_CONTROL_TIMEOUT_US, TPMI_CONTROL_TIMEOUT_MAX_US);
}

static int tpmi_read_feature_status(struct intel_tpmi_info *tpmi_info, int feature_id,
                                    struct tpmi_feature_state *feature_state)
{
        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 = readq_poll_timeout(tpmi_info->tpmi_control_mem + TPMI_CONTROL_STATUS_OFFSET,
                                 control, !(control & TPMI_CONTROL_STATUS_RB),
                                 TPMI_RB_TIMEOUT_US, TPMI_RB_TIMEOUT_MAX_US);
        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 */
        memcpy_fromio(feature_state, tpmi_info->tpmi_control_mem + TMPI_CONTROL_DATA_VAL_OFFSET,
                      sizeof(*feature_state));

        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, bool *read_blocked, bool *write_blocked)
{
        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);
        struct tpmi_feature_state feature_state;
        int ret;

        ret = tpmi_read_feature_status(tpmi_info, feature_id, &feature_state);
        if (ret)
                return ret;

        *read_blocked = feature_state.read_blocked;
        *write_blocked = feature_state.write_blocked;

        return 0;
}
EXPORT_SYMBOL_NS_GPL(tpmi_get_feature_status, "INTEL_TPMI");

struct dentry *tpmi_get_debugfs_dir(struct auxiliary_device *auxdev)
{
        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_info->dbgfs_dir;
}
EXPORT_SYMBOL_NS_GPL(tpmi_get_debugfs_dir, "INTEL_TPMI");

static int tpmi_pfs_dbg_show(struct seq_file *s, void *unused)
{
        struct intel_tpmi_info *tpmi_info = s->private;
        int locked, disabled, read_blocked, write_blocked;
        struct tpmi_feature_state feature_state;
        struct intel_tpmi_pm_feature *pfs;
        int ret, i;


        seq_printf(s, "tpmi PFS start offset 0x:%llx\n", tpmi_info->pfs_start);
        seq_puts(s, "tpmi_id\t\tentries\t\tsize\t\tcap_offset\tattribute\tvsec_offset\tlocked\tdisabled\tread_blocked\twrite_blocked\n");
        for (i = 0; i < tpmi_info->feature_count; ++i) {
                pfs = &tpmi_info->tpmi_features[i];
                ret = tpmi_read_feature_status(tpmi_info, pfs->pfs_header.tpmi_id, &feature_state);
                if (ret) {
                        locked = 'U';
                        disabled = 'U';
                        read_blocked = 'U';
                        write_blocked = 'U';
                } else {
                        disabled = feature_state.enabled ? 'N' : 'Y';
                        locked = feature_state.locked ? 'Y' : 'N';
                        read_blocked = feature_state.read_blocked ? 'Y' : 'N';
                        write_blocked = feature_state.write_blocked ? 'Y' : 'N';
                }
                seq_printf(s, "0x%02x\t\t0x%02x\t\t0x%04x\t\t0x%04x\t\t0x%02x\t\t0x%016llx\t%c\t%c\t\t%c\t\t%c\n",
                           pfs->pfs_header.tpmi_id, pfs->pfs_header.num_entries,
                           pfs->pfs_header.entry_size, pfs->pfs_header.cap_offset,
                           pfs->pfs_header.attribute, pfs->vsec_offset, locked, disabled,
                           read_blocked, write_blocked);
        }

        return 0;
}
DEFINE_SHOW_ATTRIBUTE(tpmi_pfs_dbg);

#define MEM_DUMP_COLUMN_COUNT   8

static int tpmi_mem_dump_show(struct seq_file *s, void *unused)
{
        size_t row_size = MEM_DUMP_COLUMN_COUNT * sizeof(u32);
        struct intel_tpmi_pm_feature *pfs = s->private;
        int count, ret = 0;
        void __iomem *mem;
        u32 size;
        u64 off;
        u8 *buffer;

        size = TPMI_GET_SINGLE_ENTRY_SIZE(pfs);
        if (!size)
                return -EIO;

        buffer = kmalloc(size, GFP_KERNEL);
        if (!buffer)
                return -ENOMEM;

        off = pfs->vsec_offset;

        mutex_lock(&tpmi_dev_lock);

        for (count = 0; count < pfs->pfs_header.num_entries; ++count) {
                seq_printf(s, "TPMI Instance:%d offset:0x%llx\n", count, off);

                mem = ioremap(off, size);
                if (!mem) {
                        ret = -ENOMEM;
                        break;
                }

                memcpy_fromio(buffer, mem, size);

                seq_hex_dump(s, " ", DUMP_PREFIX_OFFSET, row_size, sizeof(u32), buffer, size,
                             false);

                iounmap(mem);

                off += size;
        }

        mutex_unlock(&tpmi_dev_lock);

        kfree(buffer);

        return ret;
}
DEFINE_SHOW_ATTRIBUTE(tpmi_mem_dump);

static ssize_t mem_write(struct file *file, const char __user *userbuf, size_t len, loff_t *ppos)
{
        struct seq_file *m = file->private_data;
        struct intel_tpmi_pm_feature *pfs = m->private;
        u32 addr, value, punit, size;
        u32 num_elems, *array;
        void __iomem *mem;
        int ret;

        size = TPMI_GET_SINGLE_ENTRY_SIZE(pfs);
        if (!size)
                return -EIO;

        ret = parse_int_array_user(userbuf, len, (int **)&array);
        if (ret < 0)
                return ret;

        num_elems = *array;
        if (num_elems != 3) {
                ret = -EINVAL;
                goto exit_write;
        }

        punit = array[1];
        addr = array[2];
        value = array[3];

        if (punit >= pfs->pfs_header.num_entries) {
                ret = -EINVAL;
                goto exit_write;
        }

        if (addr >= size) {
                ret = -EINVAL;
                goto exit_write;
        }

        mutex_lock(&tpmi_dev_lock);

        mem = ioremap(pfs->vsec_offset + punit * size, size);
        if (!mem) {
                ret = -ENOMEM;
                goto unlock_mem_write;
        }

        writel(value, mem + addr);

        iounmap(mem);

        ret = len;

unlock_mem_write:
        mutex_unlock(&tpmi_dev_lock);

exit_write:
        kfree(array);

        return ret;
}

static int mem_write_show(struct seq_file *s, void *unused)
{
        return 0;
}

static int mem_write_open(struct inode *inode, struct file *file)
{
        return single_open(file, mem_write_show, inode->i_private);
}

static const struct file_operations mem_write_ops = {
        .open           = mem_write_open,
        .read           = seq_read,
        .write          = mem_write,
        .llseek         = seq_lseek,
        .release        = single_release,
};

#define tpmi_to_dev(info)       (&info->vsec_dev->pcidev->dev)

static void tpmi_dbgfs_register(struct intel_tpmi_info *tpmi_info)
{
        char name[64];
        int i;

        snprintf(name, sizeof(name), "tpmi-%s", dev_name(tpmi_to_dev(tpmi_info)));
        tpmi_info->dbgfs_dir = debugfs_create_dir(name, NULL);

        debugfs_create_file("pfs_dump", 0444, tpmi_info->dbgfs_dir, tpmi_info, &tpmi_pfs_dbg_fops);

        for (i = 0; i < tpmi_info->feature_count; ++i) {
                struct intel_tpmi_pm_feature *pfs;
                struct dentry *dir;

                pfs = &tpmi_info->tpmi_features[i];
                snprintf(name, sizeof(name), "tpmi-id-%02x", pfs->pfs_header.tpmi_id);
                dir = debugfs_create_dir(name, tpmi_info->dbgfs_dir);

                debugfs_create_file("mem_dump", 0444, dir, pfs, &tpmi_mem_dump_fops);
                debugfs_create_file("mem_write", 0644, dir, pfs, &mem_write_ops);
        }
}

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 = TPMI_GET_SINGLE_ENTRY_SIZE(pfs);
        if (!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) {
        case TPMI_ID_RAPL:
                return "rapl";
        case TPMI_ID_PEM:
                return "pem";
        case TPMI_ID_UNCORE:
                return "uncore";
        case TPMI_ID_SST:
                return "sst";
        case TPMI_ID_PLR:
                return "plr";
        default:
                return NULL;
        }
}

/* String Length for tpmi-"feature_name(upto 8 bytes)" */
#define TPMI_FEATURE_NAME_LEN   14

static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
                              struct intel_tpmi_pm_feature *pfs,
                              u64 pfs_start)
{
        struct intel_vsec_device *vsec_dev = tpmi_info->vsec_dev;
        char feature_id_name[TPMI_FEATURE_NAME_LEN];
        struct intel_vsec_device *feature_vsec_dev;
        struct tpmi_feature_state feature_state;
        struct resource *res, *tmp;
        const char *name;
        int i, ret;

        ret = tpmi_read_feature_status(tpmi_info, pfs->pfs_header.tpmi_id, &feature_state);
        if (ret)
                return ret;

        /*
         * If not enabled, continue to look at other features in the PFS, so return -EOPNOTSUPP.
         * This will not cause failure of loading of this driver.
         */
        if (!feature_state.enabled)
                return -EOPNOTSUPP;

        name = intel_tpmi_name(pfs->pfs_header.tpmi_id);
        if (!name)
                return -EOPNOTSUPP;

        res = kzalloc_objs(*res, pfs->pfs_header.num_entries);
        if (!res)
                return -ENOMEM;

        feature_vsec_dev = kzalloc_obj(*feature_vsec_dev);
        if (!feature_vsec_dev) {
                kfree(res);
                return -ENOMEM;
        }

        snprintf(feature_id_name, sizeof(feature_id_name), "tpmi-%s", name);

        for (i = 0, tmp = res; i < pfs->pfs_header.num_entries; i++, tmp++) {
                u64 entry_size_bytes = pfs->pfs_header.entry_size * sizeof(u32);

                tmp->start = pfs->vsec_offset + entry_size_bytes * i;
                tmp->end = tmp->start + entry_size_bytes - 1;
                tmp->flags = IORESOURCE_MEM;
        }

        feature_vsec_dev->pcidev = vsec_dev->pcidev;
        feature_vsec_dev->resource = res;
        feature_vsec_dev->num_resources = pfs->pfs_header.num_entries;
        feature_vsec_dev->priv_data = &tpmi_info->plat_info;
        feature_vsec_dev->priv_data_size = sizeof(tpmi_info->plat_info);
        feature_vsec_dev->ida = &intel_vsec_tpmi_ida;

        /*
         * intel_vsec_add_aux() is resource managed, no explicit
         * delete is required on error or on module unload.
         * feature_vsec_dev and res memory are also freed as part of
         * device deletion.
         */
        return intel_vsec_add_aux(vsec_dev->pcidev, &vsec_dev->auxdev.dev,
                                  feature_vsec_dev, feature_id_name);
}

static int tpmi_create_devices(struct intel_tpmi_info *tpmi_info)
{
        struct intel_vsec_device *vsec_dev = tpmi_info->vsec_dev;
        int ret, i;

        for (i = 0; i < vsec_dev->num_resources; i++) {
                ret = tpmi_create_device(tpmi_info, &tpmi_info->tpmi_features[i],
                                         tpmi_info->pfs_start);
                /*
                 * Fail, if the supported features fails to create device,
                 * otherwise, continue. Even if one device failed to create,
                 * fail the loading of driver. Since intel_vsec_add_aux()
                 * is resource managed, no clean up is required for the
                 * successfully created devices.
                 */
                if (ret && ret != -EOPNOTSUPP)
                        return ret;
        }

        return 0;
}

#define TPMI_INFO_BUS_INFO_OFFSET       0x08
#define TPMI_INFO_MAJOR_VERSION         0x00
#define TPMI_INFO_MINOR_VERSION         0x02

static int tpmi_process_info(struct intel_tpmi_info *tpmi_info,
                             struct intel_tpmi_pm_feature *pfs)
{
        struct tpmi_info_header header;
        void __iomem *info_mem;
        u64 feature_header;
        int ret = 0;

        info_mem = ioremap(pfs->vsec_offset, pfs->pfs_header.entry_size * sizeof(u32));
        if (!info_mem)
                return -ENOMEM;

        feature_header = readq(info_mem);
        if (TPMI_MAJOR_VERSION(feature_header) != TPMI_INFO_MAJOR_VERSION) {
                ret = -ENODEV;
                goto error_info_header;
        }

        memcpy_fromio(&header, info_mem + TPMI_INFO_BUS_INFO_OFFSET, sizeof(header));

        tpmi_info->plat_info.package_id = header.pkg;
        tpmi_info->plat_info.bus_number = header.bus;
        tpmi_info->plat_info.device_number = header.dev;
        tpmi_info->plat_info.function_number = header.fn;

        if (TPMI_MINOR_VERSION(feature_header) >= TPMI_INFO_MINOR_VERSION) {
                tpmi_info->plat_info.cdie_mask = header.cdie_mask;
                tpmi_info->plat_info.partition = header.partition;
                tpmi_info->plat_info.segment = header.segment;
        }

error_info_header:
        iounmap(info_mem);

        return ret;
}

static int tpmi_fetch_pfs_header(struct intel_tpmi_pm_feature *pfs, u64 start, int size)
{
        void __iomem *pfs_mem;

        pfs_mem = ioremap(start, size);
        if (!pfs_mem)
                return -ENOMEM;

        memcpy_fromio(&pfs->pfs_header, pfs_mem, sizeof(pfs->pfs_header));

        iounmap(pfs_mem);

        return 0;
}

#define TPMI_CAP_OFFSET_UNIT    1024

static int intel_vsec_tpmi_init(struct auxiliary_device *auxdev)
{
        struct intel_vsec_device *vsec_dev = auxdev_to_ivdev(auxdev);
        struct pci_dev *pci_dev = vsec_dev->pcidev;
        struct intel_tpmi_info *tpmi_info;
        u64 pfs_start = 0;
        int ret, i;

        tpmi_info = devm_kzalloc(&auxdev->dev, sizeof(*tpmi_info), GFP_KERNEL);
        if (!tpmi_info)
                return -ENOMEM;

        tpmi_info->vsec_dev = vsec_dev;
        tpmi_info->feature_count = vsec_dev->num_resources;
        tpmi_info->plat_info.bus_number = pci_dev->bus->number;

        tpmi_info->tpmi_features = devm_kcalloc(&auxdev->dev, vsec_dev->num_resources,
                                                sizeof(*tpmi_info->tpmi_features),
                                                GFP_KERNEL);
        if (!tpmi_info->tpmi_features)
                return -ENOMEM;

        for (i = 0; i < vsec_dev->num_resources; i++) {
                struct intel_tpmi_pm_feature *pfs;
                struct resource *res;
                u64 res_start;
                int size, ret;

                pfs = &tpmi_info->tpmi_features[i];
                pfs->vsec_dev = vsec_dev;

                res = &vsec_dev->resource[i];
                if (!res)
                        continue;

                res_start = res->start;
                size = resource_size(res);
                if (size < 0)
                        continue;

                ret = tpmi_fetch_pfs_header(pfs, res_start, size);
                if (ret)
                        continue;

                if (!pfs_start)
                        pfs_start = res_start;

                pfs->vsec_offset = pfs_start + pfs->pfs_header.cap_offset * TPMI_CAP_OFFSET_UNIT;

                /*
                 * Process TPMI_INFO to get PCI device to CPU package ID.
                 * Device nodes for TPMI features are not created in this
                 * for loop. So, the mapping information will be available
                 * when actual device nodes created outside this
                 * loop via tpmi_create_devices().
                 */
                if (pfs->pfs_header.tpmi_id == TPMI_INFO_ID) {
                        ret = tpmi_process_info(tpmi_info, pfs);
                        if (ret)
                                return ret;

                        ret = intel_vsec_set_mapping(&tpmi_info->plat_info, vsec_dev);
                        if (ret)
                                return ret;
                }

                if (pfs->pfs_header.tpmi_id == TPMI_CONTROL_ID)
                        tpmi_set_control_base(auxdev, tpmi_info, pfs);
        }

        tpmi_info->pfs_start = pfs_start;

        auxiliary_set_drvdata(auxdev, tpmi_info);

        ret = tpmi_create_devices(tpmi_info);
        if (ret)
                return ret;

        /*
         * Allow debugfs when security policy allows. Everything this debugfs
         * interface provides, can also be done via /dev/mem access. If
         * /dev/mem interface is locked, don't allow debugfs to present any
         * information. Also check for CAP_SYS_RAWIO as /dev/mem interface.
         */
        if (!security_locked_down(LOCKDOWN_DEV_MEM) && capable(CAP_SYS_RAWIO))
                tpmi_dbgfs_register(tpmi_info);

        return 0;
}

static int tpmi_probe(struct auxiliary_device *auxdev,
                      const struct auxiliary_device_id *id)
{
        return intel_vsec_tpmi_init(auxdev);
}

static void tpmi_remove(struct auxiliary_device *auxdev)
{
        struct intel_tpmi_info *tpmi_info = auxiliary_get_drvdata(auxdev);

        debugfs_remove_recursive(tpmi_info->dbgfs_dir);
}

static const struct auxiliary_device_id tpmi_id_table[] = {
        { .name = "intel_vsec.tpmi" },
        {}
};
MODULE_DEVICE_TABLE(auxiliary, tpmi_id_table);

static struct auxiliary_driver tpmi_aux_driver = {
        .id_table       = tpmi_id_table,
        .probe          = tpmi_probe,
        .remove         = tpmi_remove,
};

module_auxiliary_driver(tpmi_aux_driver);

MODULE_IMPORT_NS("INTEL_VSEC");
MODULE_DESCRIPTION("Intel TPMI enumeration module");
MODULE_LICENSE("GPL");