/* SPDX-License-Identifier: GPL-2.0 */
/*
 * Driver Header File for FPGA Device Feature List (DFL) Support
 *
 * Copyright (C) 2017-2018 Intel Corporation, Inc.
 *
 * Authors:
 *   Kang Luwei <luwei.kang@intel.com>
 *   Zhang Yi <yi.z.zhang@intel.com>
 *   Wu Hao <hao.wu@intel.com>
 *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
 */

#ifndef __FPGA_DFL_H
#define __FPGA_DFL_H

#include <linux/bitfield.h>
#include <linux/cdev.h>
#include <linux/delay.h>
#include <linux/eventfd.h>
#include <linux/fs.h>
#include <linux/interrupt.h>
#include <linux/iopoll.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/uuid.h>
#include <linux/fpga/fpga-region.h>

/* maximum supported number of ports */
#define MAX_DFL_FPGA_PORT_NUM 4
/* plus one for fme device */
#define MAX_DFL_FEATURE_DEV_NUM    (MAX_DFL_FPGA_PORT_NUM + 1)

/* Reserved 0xfe for Header Group Register and 0xff for AFU */
#define FEATURE_ID_FIU_HEADER           0xfe
#define FEATURE_ID_AFU                  0xff

#define FME_FEATURE_ID_HEADER           FEATURE_ID_FIU_HEADER
#define FME_FEATURE_ID_THERMAL_MGMT     0x1
#define FME_FEATURE_ID_POWER_MGMT       0x2
#define FME_FEATURE_ID_GLOBAL_IPERF     0x3
#define FME_FEATURE_ID_GLOBAL_ERR       0x4
#define FME_FEATURE_ID_PR_MGMT          0x5
#define FME_FEATURE_ID_HSSI             0x6
#define FME_FEATURE_ID_GLOBAL_DPERF     0x7

#define PORT_FEATURE_ID_HEADER          FEATURE_ID_FIU_HEADER
#define PORT_FEATURE_ID_AFU             FEATURE_ID_AFU
#define PORT_FEATURE_ID_ERROR           0x10
#define PORT_FEATURE_ID_UMSG            0x11
#define PORT_FEATURE_ID_UINT            0x12
#define PORT_FEATURE_ID_STP             0x13

/*
 * Device Feature Header Register Set
 *
 * For FIUs, they all have DFH + GUID + NEXT_AFU as common header registers.
 * For AFUs, they have DFH + GUID as common header registers.
 * For private features, they only have DFH register as common header.
 */
#define DFH                     0x0
#define GUID_L                  0x8
#define GUID_H                  0x10
#define NEXT_AFU                0x18

#define DFH_SIZE                0x8

/* Device Feature Header Register Bitfield */
#define DFH_ID                  GENMASK_ULL(11, 0)      /* Feature ID */
#define DFH_ID_FIU_FME          0
#define DFH_ID_FIU_PORT         1
#define DFH_REVISION            GENMASK_ULL(15, 12)     /* Feature revision */
#define DFH_NEXT_HDR_OFST       GENMASK_ULL(39, 16)     /* Offset to next DFH */
#define DFH_EOL                 BIT_ULL(40)             /* End of list */
#define DFH_TYPE                GENMASK_ULL(63, 60)     /* Feature type */
#define DFH_TYPE_AFU            1
#define DFH_TYPE_PRIVATE        3
#define DFH_TYPE_FIU            4

/* Next AFU Register Bitfield */
#define NEXT_AFU_NEXT_DFH_OFST  GENMASK_ULL(23, 0)      /* Offset to next AFU */

/* FME Header Register Set */
#define FME_HDR_DFH             DFH
#define FME_HDR_GUID_L          GUID_L
#define FME_HDR_GUID_H          GUID_H
#define FME_HDR_NEXT_AFU        NEXT_AFU
#define FME_HDR_CAP             0x30
#define FME_HDR_PORT_OFST(n)    (0x38 + ((n) * 0x8))
#define FME_HDR_BITSTREAM_ID    0x60
#define FME_HDR_BITSTREAM_MD    0x68

/* FME Fab Capability Register Bitfield */
#define FME_CAP_FABRIC_VERID    GENMASK_ULL(7, 0)       /* Fabric version ID */
#define FME_CAP_SOCKET_ID       BIT_ULL(8)              /* Socket ID */
#define FME_CAP_PCIE0_LINK_AVL  BIT_ULL(12)             /* PCIE0 Link */
#define FME_CAP_PCIE1_LINK_AVL  BIT_ULL(13)             /* PCIE1 Link */
#define FME_CAP_COHR_LINK_AVL   BIT_ULL(14)             /* Coherent Link */
#define FME_CAP_IOMMU_AVL       BIT_ULL(16)             /* IOMMU available */
#define FME_CAP_NUM_PORTS       GENMASK_ULL(19, 17)     /* Number of ports */
#define FME_CAP_ADDR_WIDTH      GENMASK_ULL(29, 24)     /* Address bus width */
#define FME_CAP_CACHE_SIZE      GENMASK_ULL(43, 32)     /* cache size in KB */
#define FME_CAP_CACHE_ASSOC     GENMASK_ULL(47, 44)     /* Associativity */

/* FME Port Offset Register Bitfield */
/* Offset to port device feature header */
#define FME_PORT_OFST_DFH_OFST  GENMASK_ULL(23, 0)
/* PCI Bar ID for this port */
#define FME_PORT_OFST_BAR_ID    GENMASK_ULL(34, 32)
/* AFU MMIO access permission. 1 - VF, 0 - PF. */
#define FME_PORT_OFST_ACC_CTRL  BIT_ULL(55)
#define FME_PORT_OFST_ACC_PF    0
#define FME_PORT_OFST_ACC_VF    1
#define FME_PORT_OFST_IMP       BIT_ULL(60)

/* FME Error Capability Register */
#define FME_ERROR_CAP           0x70

/* FME Error Capability Register Bitfield */
#define FME_ERROR_CAP_SUPP_INT  BIT_ULL(0)              /* Interrupt Support */
#define FME_ERROR_CAP_INT_VECT  GENMASK_ULL(12, 1)      /* Interrupt vector */

/* PORT Header Register Set */
#define PORT_HDR_DFH            DFH
#define PORT_HDR_GUID_L         GUID_L
#define PORT_HDR_GUID_H         GUID_H
#define PORT_HDR_NEXT_AFU       NEXT_AFU
#define PORT_HDR_CAP            0x30
#define PORT_HDR_CTRL           0x38
#define PORT_HDR_STS            0x40
#define PORT_HDR_USRCLK_CMD0    0x50
#define PORT_HDR_USRCLK_CMD1    0x58
#define PORT_HDR_USRCLK_STS0    0x60
#define PORT_HDR_USRCLK_STS1    0x68

/* Port Capability Register Bitfield */
#define PORT_CAP_PORT_NUM       GENMASK_ULL(1, 0)       /* ID of this port */
#define PORT_CAP_MMIO_SIZE      GENMASK_ULL(23, 8)      /* MMIO size in KB */
#define PORT_CAP_SUPP_INT_NUM   GENMASK_ULL(35, 32)     /* Interrupts num */

/* Port Control Register Bitfield */
#define PORT_CTRL_SFTRST        BIT_ULL(0)              /* Port soft reset */
/* Latency tolerance reporting. '1' >= 40us, '0' < 40us.*/
#define PORT_CTRL_LATENCY       BIT_ULL(2)
#define PORT_CTRL_SFTRST_ACK    BIT_ULL(4)              /* HW ack for reset */

/* Port Status Register Bitfield */
#define PORT_STS_AP2_EVT        BIT_ULL(13)             /* AP2 event detected */
#define PORT_STS_AP1_EVT        BIT_ULL(12)             /* AP1 event detected */
#define PORT_STS_PWR_STATE      GENMASK_ULL(11, 8)      /* AFU power states */
#define PORT_STS_PWR_STATE_NORM 0
#define PORT_STS_PWR_STATE_AP1  1                       /* 50% throttling */
#define PORT_STS_PWR_STATE_AP2  2                       /* 90% throttling */
#define PORT_STS_PWR_STATE_AP6  6                       /* 100% throttling */

/* Port Error Capability Register */
#define PORT_ERROR_CAP          0x38

/* Port Error Capability Register Bitfield */
#define PORT_ERROR_CAP_SUPP_INT BIT_ULL(0)              /* Interrupt Support */
#define PORT_ERROR_CAP_INT_VECT GENMASK_ULL(12, 1)      /* Interrupt vector */

/* Port Uint Capability Register */
#define PORT_UINT_CAP           0x8

/* Port Uint Capability Register Bitfield */
#define PORT_UINT_CAP_INT_NUM   GENMASK_ULL(11, 0)      /* Interrupts num */
#define PORT_UINT_CAP_FST_VECT  GENMASK_ULL(23, 12)     /* First Vector */

/**
 * struct dfl_fpga_port_ops - port ops
 *
 * @name: name of this port ops, to match with port platform device.
 * @owner: pointer to the module which owns this port ops.
 * @node: node to link port ops to global list.
 * @get_id: get port id from hardware.
 * @enable_set: enable/disable the port.
 */
struct dfl_fpga_port_ops {
        const char *name;
        struct module *owner;
        struct list_head node;
        int (*get_id)(struct platform_device *pdev);
        int (*enable_set)(struct platform_device *pdev, bool enable);
};

void dfl_fpga_port_ops_add(struct dfl_fpga_port_ops *ops);
void dfl_fpga_port_ops_del(struct dfl_fpga_port_ops *ops);
struct dfl_fpga_port_ops *dfl_fpga_port_ops_get(struct platform_device *pdev);
void dfl_fpga_port_ops_put(struct dfl_fpga_port_ops *ops);
int dfl_fpga_check_port_id(struct platform_device *pdev, void *pport_id);

/**
 * struct dfl_feature_id - dfl private feature id
 *
 * @id: unique dfl private feature id.
 */
struct dfl_feature_id {
        u16 id;
};

/**
 * struct dfl_feature_driver - dfl private feature driver
 *
 * @id_table: id_table for dfl private features supported by this driver.
 * @ops: ops of this dfl private feature driver.
 */
struct dfl_feature_driver {
        const struct dfl_feature_id *id_table;
        const struct dfl_feature_ops *ops;
};

/**
 * struct dfl_feature_irq_ctx - dfl private feature interrupt context
 *
 * @irq: Linux IRQ number of this interrupt.
 * @trigger: eventfd context to signal when interrupt happens.
 * @name: irq name needed when requesting irq.
 */
struct dfl_feature_irq_ctx {
        int irq;
        struct eventfd_ctx *trigger;
        char *name;
};

/**
 * struct dfl_feature - sub feature of the feature devices
 *
 * @dev: ptr to pdev of the feature device which has the sub feature.
 * @id: sub feature id.
 * @resource_index: each sub feature has one mmio resource for its registers.
 *                  this index is used to find its mmio resource from the
 *                  feature dev (platform device)'s reources.
 * @ioaddr: mapped mmio resource address.
 * @irq_ctx: interrupt context list.
 * @nr_irqs: number of interrupt contexts.
 * @ops: ops of this sub feature.
 * @ddev: ptr to the dfl device of this sub feature.
 * @priv: priv data of this feature.
 */
struct dfl_feature {
        struct platform_device *dev;
        u16 id;
        int resource_index;
        void __iomem *ioaddr;
        struct dfl_feature_irq_ctx *irq_ctx;
        unsigned int nr_irqs;
        const struct dfl_feature_ops *ops;
        struct dfl_device *ddev;
        void *priv;
};

#define FEATURE_DEV_ID_UNUSED   (-1)

/**
 * struct dfl_feature_platform_data - platform data for feature devices
 *
 * @node: node to link feature devs to container device's port_dev_list.
 * @lock: mutex to protect platform data.
 * @cdev: cdev of feature dev.
 * @dev: ptr to platform device linked with this platform data.
 * @dfl_cdev: ptr to container device.
 * @id: id used for this feature device.
 * @disable_count: count for port disable.
 * @excl_open: set on feature device exclusive open.
 * @open_count: count for feature device open.
 * @num: number for sub features.
 * @private: ptr to feature dev private data.
 * @features: sub features of this feature dev.
 */
struct dfl_feature_platform_data {
        struct list_head node;
        struct mutex lock;
        struct cdev cdev;
        struct platform_device *dev;
        struct dfl_fpga_cdev *dfl_cdev;
        int id;
        unsigned int disable_count;
        bool excl_open;
        int open_count;
        void *private;
        int num;
        struct dfl_feature features[];
};

static inline
int dfl_feature_dev_use_begin(struct dfl_feature_platform_data *pdata,
                              bool excl)
{
        if (pdata->excl_open)
                return -EBUSY;

        if (excl) {
                if (pdata->open_count)
                        return -EBUSY;

                pdata->excl_open = true;
        }
        pdata->open_count++;

        return 0;
}

static inline
void dfl_feature_dev_use_end(struct dfl_feature_platform_data *pdata)
{
        pdata->excl_open = false;

        if (WARN_ON(pdata->open_count <= 0))
                return;

        pdata->open_count--;
}

static inline
int dfl_feature_dev_use_count(struct dfl_feature_platform_data *pdata)
{
        return pdata->open_count;
}

static inline
void dfl_fpga_pdata_set_private(struct dfl_feature_platform_data *pdata,
                                void *private)
{
        pdata->private = private;
}

static inline
void *dfl_fpga_pdata_get_private(struct dfl_feature_platform_data *pdata)
{
        return pdata->private;
}

struct dfl_feature_ops {
        int (*init)(struct platform_device *pdev, struct dfl_feature *feature);
        void (*uinit)(struct platform_device *pdev,
                      struct dfl_feature *feature);
        long (*ioctl)(struct platform_device *pdev, struct dfl_feature *feature,
                      unsigned int cmd, unsigned long arg);
};

#define DFL_FPGA_FEATURE_DEV_FME                "dfl-fme"
#define DFL_FPGA_FEATURE_DEV_PORT               "dfl-port"

void dfl_fpga_dev_feature_uinit(struct platform_device *pdev);
int dfl_fpga_dev_feature_init(struct platform_device *pdev,
                              struct dfl_feature_driver *feature_drvs);

int dfl_fpga_dev_ops_register(struct platform_device *pdev,
                              const struct file_operations *fops,
                              struct module *owner);
void dfl_fpga_dev_ops_unregister(struct platform_device *pdev);

static inline
struct platform_device *dfl_fpga_inode_to_feature_dev(struct inode *inode)
{
        struct dfl_feature_platform_data *pdata;

        pdata = container_of(inode->i_cdev, struct dfl_feature_platform_data,
                             cdev);
        return pdata->dev;
}

#define dfl_fpga_dev_for_each_feature(pdata, feature)                       \
        for ((feature) = (pdata)->features;                                 \
           (feature) < (pdata)->features + (pdata)->num; (feature)++)

static inline
struct dfl_feature *dfl_get_feature_by_id(struct device *dev, u16 id)
{
        struct dfl_feature_platform_data *pdata = dev_get_platdata(dev);
        struct dfl_feature *feature;

        dfl_fpga_dev_for_each_feature(pdata, feature)
                if (feature->id == id)
                        return feature;

        return NULL;
}

static inline
void __iomem *dfl_get_feature_ioaddr_by_id(struct device *dev, u16 id)
{
        struct dfl_feature *feature = dfl_get_feature_by_id(dev, id);

        if (feature && feature->ioaddr)
                return feature->ioaddr;

        WARN_ON(1);
        return NULL;
}

static inline bool is_dfl_feature_present(struct device *dev, u16 id)
{
        return !!dfl_get_feature_ioaddr_by_id(dev, id);
}

static inline
struct device *dfl_fpga_pdata_to_parent(struct dfl_feature_platform_data *pdata)
{
        return pdata->dev->dev.parent->parent;
}

static inline bool dfl_feature_is_fme(void __iomem *base)
{
        u64 v = readq(base + DFH);

        return (FIELD_GET(DFH_TYPE, v) == DFH_TYPE_FIU) &&
                (FIELD_GET(DFH_ID, v) == DFH_ID_FIU_FME);
}

static inline bool dfl_feature_is_port(void __iomem *base)
{
        u64 v = readq(base + DFH);

        return (FIELD_GET(DFH_TYPE, v) == DFH_TYPE_FIU) &&
                (FIELD_GET(DFH_ID, v) == DFH_ID_FIU_PORT);
}

static inline u8 dfl_feature_revision(void __iomem *base)
{
        return (u8)FIELD_GET(DFH_REVISION, readq(base + DFH));
}

/**
 * struct dfl_fpga_enum_info - DFL FPGA enumeration information
 *
 * @dev: parent device.
 * @dfls: list of device feature lists.
 * @nr_irqs: number of irqs for all feature devices.
 * @irq_table: Linux IRQ numbers for all irqs, indexed by hw irq numbers.
 */
struct dfl_fpga_enum_info {
        struct device *dev;
        struct list_head dfls;
        unsigned int nr_irqs;
        int *irq_table;
};

/**
 * struct dfl_fpga_enum_dfl - DFL FPGA enumeration device feature list info
 *
 * @start: base address of this device feature list.
 * @len: size of this device feature list.
 * @node: node in list of device feature lists.
 */
struct dfl_fpga_enum_dfl {
        resource_size_t start;
        resource_size_t len;
        struct list_head node;
};

struct dfl_fpga_enum_info *dfl_fpga_enum_info_alloc(struct device *dev);
int dfl_fpga_enum_info_add_dfl(struct dfl_fpga_enum_info *info,
                               resource_size_t start, resource_size_t len);
int dfl_fpga_enum_info_add_irq(struct dfl_fpga_enum_info *info,
                               unsigned int nr_irqs, int *irq_table);
void dfl_fpga_enum_info_free(struct dfl_fpga_enum_info *info);

/**
 * struct dfl_fpga_cdev - container device of DFL based FPGA
 *
 * @parent: parent device of this container device.
 * @region: base fpga region.
 * @fme_dev: FME feature device under this container device.
 * @lock: mutex lock to protect the port device list.
 * @port_dev_list: list of all port feature devices under this container device.
 * @released_port_num: released port number under this container device.
 */
struct dfl_fpga_cdev {
        struct device *parent;
        struct fpga_region *region;
        struct device *fme_dev;
        struct mutex lock;
        struct list_head port_dev_list;
        int released_port_num;
};

struct dfl_fpga_cdev *
dfl_fpga_feature_devs_enumerate(struct dfl_fpga_enum_info *info);
void dfl_fpga_feature_devs_remove(struct dfl_fpga_cdev *cdev);

/*
 * need to drop the device reference with put_device() after use port platform
 * device returned by __dfl_fpga_cdev_find_port and dfl_fpga_cdev_find_port
 * functions.
 */
struct platform_device *
__dfl_fpga_cdev_find_port(struct dfl_fpga_cdev *cdev, void *data,
                          int (*match)(struct platform_device *, void *));

static inline struct platform_device *
dfl_fpga_cdev_find_port(struct dfl_fpga_cdev *cdev, void *data,
                        int (*match)(struct platform_device *, void *))
{
        struct platform_device *pdev;

        mutex_lock(&cdev->lock);
        pdev = __dfl_fpga_cdev_find_port(cdev, data, match);
        mutex_unlock(&cdev->lock);

        return pdev;
}

int dfl_fpga_cdev_release_port(struct dfl_fpga_cdev *cdev, int port_id);
int dfl_fpga_cdev_assign_port(struct dfl_fpga_cdev *cdev, int port_id);
void dfl_fpga_cdev_config_ports_pf(struct dfl_fpga_cdev *cdev);
int dfl_fpga_cdev_config_ports_vf(struct dfl_fpga_cdev *cdev, int num_vf);
int dfl_fpga_set_irq_triggers(struct dfl_feature *feature, unsigned int start,
                              unsigned int count, int32_t *fds);
long dfl_feature_ioctl_get_num_irqs(struct platform_device *pdev,
                                    struct dfl_feature *feature,
                                    unsigned long arg);
long dfl_feature_ioctl_set_irq(struct platform_device *pdev,
                               struct dfl_feature *feature,
                               unsigned long arg);

/**
 * enum dfl_id_type - define the DFL FIU types
 */
enum dfl_id_type {
        FME_ID,
        PORT_ID,
        DFL_ID_MAX,
};

/**
 * struct dfl_device_id -  dfl device identifier
 * @type: contains 4 bits DFL FIU type of the device. See enum dfl_id_type.
 * @feature_id: contains 12 bits feature identifier local to its DFL FIU type.
 * @driver_data: driver specific data.
 */
struct dfl_device_id {
        u8 type;
        u16 feature_id;
        unsigned long driver_data;
};

/**
 * struct dfl_device - represent an dfl device on dfl bus
 *
 * @dev: generic device interface.
 * @id: id of the dfl device.
 * @type: type of DFL FIU of the device. See enum dfl_id_type.
 * @feature_id: 16 bits feature identifier local to its DFL FIU type.
 * @mmio_res: mmio resource of this dfl device.
 * @irqs: list of Linux IRQ numbers of this dfl device.
 * @num_irqs: number of IRQs supported by this dfl device.
 * @cdev: pointer to DFL FPGA container device this dfl device belongs to.
 * @id_entry: matched id entry in dfl driver's id table.
 */
struct dfl_device {
        struct device dev;
        int id;
        u8 type;
        u16 feature_id;
        struct resource mmio_res;
        int *irqs;
        unsigned int num_irqs;
        struct dfl_fpga_cdev *cdev;
        const struct dfl_device_id *id_entry;
};

/**
 * struct dfl_driver - represent an dfl device driver
 *
 * @drv: driver model structure.
 * @id_table: pointer to table of device IDs the driver is interested in.
 *            { } member terminated.
 * @probe: mandatory callback for device binding.
 * @remove: callback for device unbinding.
 */
struct dfl_driver {
        struct device_driver drv;
        const struct dfl_device_id *id_table;

        int (*probe)(struct dfl_device *dfl_dev);
        void (*remove)(struct dfl_device *dfl_dev);
};

#define to_dfl_dev(d) container_of(d, struct dfl_device, dev)
#define to_dfl_drv(d) container_of(d, struct dfl_driver, drv)

/*
 * use a macro to avoid include chaining to get THIS_MODULE.
 */
#define dfl_driver_register(drv) \
        __dfl_driver_register(drv, THIS_MODULE)
int __dfl_driver_register(struct dfl_driver *dfl_drv, struct module *owner);
void dfl_driver_unregister(struct dfl_driver *dfl_drv);

/*
 * module_dfl_driver() - Helper macro for drivers that don't do
 * anything special in module init/exit.  This eliminates a lot of
 * boilerplate.  Each module may only use this macro once, and
 * calling it replaces module_init() and module_exit().
 */
#define module_dfl_driver(__dfl_driver) \
        module_driver(__dfl_driver, dfl_driver_register, \
                      dfl_driver_unregister)

#endif /* __FPGA_DFL_H */