/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2001  Dave Engebretsen & Todd Inglett IBM Corporation.
 * Copyright 2001-2012 IBM Corporation.
 */

#ifndef _POWERPC_EEH_H
#define _POWERPC_EEH_H
#ifdef __KERNEL__

#include <linux/init.h>
#include <linux/list.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/atomic.h>

#include <uapi/asm/eeh.h>

struct pci_dev;
struct pci_bus;
struct pci_dn;

#ifdef CONFIG_EEH

/* EEH subsystem flags */
#define EEH_ENABLED             0x01    /* EEH enabled                       */
#define EEH_FORCE_DISABLED      0x02    /* EEH disabled                      */
#define EEH_PROBE_MODE_DEV      0x04    /* From PCI device                   */
#define EEH_PROBE_MODE_DEVTREE  0x08    /* From device tree                  */
#define EEH_ENABLE_IO_FOR_LOG   0x20    /* Enable IO for log                 */
#define EEH_EARLY_DUMP_LOG      0x40    /* Dump log immediately              */

/*
 * Delay for PE reset, all in ms
 *
 * PCI specification has reset hold time of 100 milliseconds.
 * We have 250 milliseconds here. The PCI bus settlement time
 * is specified as 1.5 seconds and we have 1.8 seconds.
 */
#define EEH_PE_RST_HOLD_TIME            250
#define EEH_PE_RST_SETTLE_TIME          1800

/*
 * The struct is used to trace PE related EEH functionality.
 * In theory, there will have one instance of the struct to
 * be created against particular PE. In nature, PEs correlate
 * to each other. the struct has to reflect that hierarchy in
 * order to easily pick up those affected PEs when one particular
 * PE has EEH errors.
 *
 * Also, one particular PE might be composed of PCI device, PCI
 * bus and its subordinate components. The struct also need ship
 * the information. Further more, one particular PE is only meaingful
 * in the corresponding PHB. Therefore, the root PEs should be created
 * against existing PHBs in on-to-one fashion.
 */
#define EEH_PE_INVALID  (1 << 0)        /* Invalid   */
#define EEH_PE_PHB      (1 << 1)        /* PHB PE    */
#define EEH_PE_DEVICE   (1 << 2)        /* Device PE */
#define EEH_PE_BUS      (1 << 3)        /* Bus PE    */
#define EEH_PE_VF       (1 << 4)        /* VF PE     */

#define EEH_PE_ISOLATED         (1 << 0)        /* Isolated PE          */
#define EEH_PE_RECOVERING       (1 << 1)        /* Recovering PE        */
#define EEH_PE_CFG_BLOCKED      (1 << 2)        /* Block config access  */
#define EEH_PE_RESET            (1 << 3)        /* PE reset in progress */

#define EEH_PE_KEEP             (1 << 8)        /* Keep PE on hotplug   */
#define EEH_PE_CFG_RESTRICTED   (1 << 9)        /* Block config on error */
#define EEH_PE_REMOVED          (1 << 10)       /* Removed permanently  */
#define EEH_PE_PRI_BUS          (1 << 11)       /* Cached primary bus   */

struct eeh_pe {
        int type;                       /* PE type: PHB/Bus/Device      */
        int state;                      /* PE EEH dependent mode        */
        int addr;                       /* PE configuration address     */
        struct pci_controller *phb;     /* Associated PHB               */
        struct pci_bus *bus;            /* Top PCI bus for bus PE       */
        int check_count;                /* Times of ignored error       */
        int freeze_count;               /* Times of froze up            */
        time64_t tstamp;                /* Time on first-time freeze    */
        int false_positives;            /* Times of reported #ff's      */
        atomic_t pass_dev_cnt;          /* Count of passed through devs */
        struct eeh_pe *parent;          /* Parent PE                    */
        void *data;                     /* PE auxiliary data            */
        struct list_head child_list;    /* List of PEs below this PE    */
        struct list_head child;         /* Memb. child_list/eeh_phb_pe  */
        struct list_head edevs;         /* List of eeh_dev in this PE   */

#ifdef CONFIG_STACKTRACE
        /*
         * Saved stack trace. When we find a PE freeze in eeh_dev_check_failure
         * the stack trace is saved here so we can print it in the recovery
         * thread if it turns out to due to a real problem rather than
         * a hot-remove.
         *
         * A max of 64 entries might be overkill, but it also might not be.
         */
        unsigned long stack_trace[64];
        int trace_entries;
#endif /* CONFIG_STACKTRACE */
};

#define eeh_pe_for_each_dev(pe, edev, tmp) \
                list_for_each_entry_safe(edev, tmp, &pe->edevs, entry)

#define eeh_for_each_pe(root, pe) \
        for (pe = root; pe; pe = eeh_pe_next(pe, root))

static inline bool eeh_pe_passed(struct eeh_pe *pe)
{
        return pe ? !!atomic_read(&pe->pass_dev_cnt) : false;
}

/*
 * The struct is used to trace EEH state for the associated
 * PCI device node or PCI device. In future, it might
 * represent PE as well so that the EEH device to form
 * another tree except the currently existing tree of PCI
 * buses and PCI devices
 */
#define EEH_DEV_BRIDGE          (1 << 0)        /* PCI bridge           */
#define EEH_DEV_ROOT_PORT       (1 << 1)        /* PCIe root port       */
#define EEH_DEV_DS_PORT         (1 << 2)        /* Downstream port      */
#define EEH_DEV_IRQ_DISABLED    (1 << 3)        /* Interrupt disabled   */
#define EEH_DEV_DISCONNECTED    (1 << 4)        /* Removing from PE     */

#define EEH_DEV_NO_HANDLER      (1 << 8)        /* No error handler     */
#define EEH_DEV_SYSFS           (1 << 9)        /* Sysfs created        */
#define EEH_DEV_REMOVED         (1 << 10)       /* Removed permanently  */

struct eeh_dev {
        int mode;                       /* EEH mode                     */
        int bdfn;                       /* bdfn of device (for cfg ops) */
        struct pci_controller *controller;
        int pe_config_addr;             /* PE config address            */
        u32 config_space[16];           /* Saved PCI config space       */
        int pcix_cap;                   /* Saved PCIx capability        */
        int pcie_cap;                   /* Saved PCIe capability        */
        int aer_cap;                    /* Saved AER capability         */
        int af_cap;                     /* Saved AF capability          */
        struct eeh_pe *pe;              /* Associated PE                */
        struct list_head entry;         /* Membership in eeh_pe.edevs   */
        struct list_head rmv_entry;     /* Membership in rmv_list       */
        struct pci_dn *pdn;             /* Associated PCI device node   */
        struct pci_dev *pdev;           /* Associated PCI device        */
        bool in_error;                  /* Error flag for edev          */

        /* VF specific properties */
        struct pci_dev *physfn;         /* Associated SRIOV PF          */
        int vf_index;                   /* Index of this VF             */
};

/* "fmt" must be a simple literal string */
#define EEH_EDEV_PRINT(level, edev, fmt, ...) \
        pr_##level("PCI %04x:%02x:%02x.%x#%04x: EEH: " fmt, \
        (edev)->controller->global_number, PCI_BUSNO((edev)->bdfn), \
        PCI_SLOT((edev)->bdfn), PCI_FUNC((edev)->bdfn), \
        ((edev)->pe ? (edev)->pe_config_addr : 0xffff), ##__VA_ARGS__)
#define eeh_edev_dbg(edev, fmt, ...) EEH_EDEV_PRINT(debug, (edev), fmt, ##__VA_ARGS__)
#define eeh_edev_info(edev, fmt, ...) EEH_EDEV_PRINT(info, (edev), fmt, ##__VA_ARGS__)
#define eeh_edev_warn(edev, fmt, ...) EEH_EDEV_PRINT(warn, (edev), fmt, ##__VA_ARGS__)
#define eeh_edev_err(edev, fmt, ...) EEH_EDEV_PRINT(err, (edev), fmt, ##__VA_ARGS__)

static inline struct pci_dn *eeh_dev_to_pdn(struct eeh_dev *edev)
{
        return edev ? edev->pdn : NULL;
}

static inline struct pci_dev *eeh_dev_to_pci_dev(struct eeh_dev *edev)
{
        return edev ? edev->pdev : NULL;
}

static inline struct eeh_pe *eeh_dev_to_pe(struct eeh_dev* edev)
{
        return edev ? edev->pe : NULL;
}

/* Return values from eeh_ops::next_error */
enum {
        EEH_NEXT_ERR_NONE = 0,
        EEH_NEXT_ERR_INF,
        EEH_NEXT_ERR_FROZEN_PE,
        EEH_NEXT_ERR_FENCED_PHB,
        EEH_NEXT_ERR_DEAD_PHB,
        EEH_NEXT_ERR_DEAD_IOC
};

/*
 * The struct is used to trace the registered EEH operation
 * callback functions. Actually, those operation callback
 * functions are heavily platform dependent. That means the
 * platform should register its own EEH operation callback
 * functions before any EEH further operations.
 */
#define EEH_OPT_DISABLE         0       /* EEH disable  */
#define EEH_OPT_ENABLE          1       /* EEH enable   */
#define EEH_OPT_THAW_MMIO       2       /* MMIO enable  */
#define EEH_OPT_THAW_DMA        3       /* DMA enable   */
#define EEH_OPT_FREEZE_PE       4       /* Freeze PE    */
#define EEH_STATE_UNAVAILABLE   (1 << 0)        /* State unavailable    */
#define EEH_STATE_NOT_SUPPORT   (1 << 1)        /* EEH not supported    */
#define EEH_STATE_RESET_ACTIVE  (1 << 2)        /* Active reset         */
#define EEH_STATE_MMIO_ACTIVE   (1 << 3)        /* Active MMIO          */
#define EEH_STATE_DMA_ACTIVE    (1 << 4)        /* Active DMA           */
#define EEH_STATE_MMIO_ENABLED  (1 << 5)        /* MMIO enabled         */
#define EEH_STATE_DMA_ENABLED   (1 << 6)        /* DMA enabled          */
#define EEH_RESET_DEACTIVATE    0       /* Deactivate the PE reset      */
#define EEH_RESET_HOT           1       /* Hot reset                    */
#define EEH_RESET_FUNDAMENTAL   3       /* Fundamental reset            */
#define EEH_LOG_TEMP            1       /* EEH temporary error log      */
#define EEH_LOG_PERM            2       /* EEH permanent error log      */

struct eeh_ops {
        char *name;
        struct eeh_dev *(*probe)(struct pci_dev *pdev);
        int (*set_option)(struct eeh_pe *pe, int option);
        int (*get_state)(struct eeh_pe *pe, int *delay);
        int (*reset)(struct eeh_pe *pe, int option);
        int (*get_log)(struct eeh_pe *pe, int severity, char *drv_log, unsigned long len);
        int (*configure_bridge)(struct eeh_pe *pe);
        int (*err_inject)(struct eeh_pe *pe, int type, int func,
                          unsigned long addr, unsigned long mask);
        int (*read_config)(struct eeh_dev *edev, int where, int size, u32 *val);
        int (*write_config)(struct eeh_dev *edev, int where, int size, u32 val);
        int (*next_error)(struct eeh_pe **pe);
        int (*restore_config)(struct eeh_dev *edev);
        int (*notify_resume)(struct eeh_dev *edev);
};

extern int eeh_subsystem_flags;
extern u32 eeh_max_freezes;
extern bool eeh_debugfs_no_recover;
extern struct eeh_ops *eeh_ops;
extern raw_spinlock_t confirm_error_lock;

static inline void eeh_add_flag(int flag)
{
        eeh_subsystem_flags |= flag;
}

static inline void eeh_clear_flag(int flag)
{
        eeh_subsystem_flags &= ~flag;
}

static inline bool eeh_has_flag(int flag)
{
        return !!(eeh_subsystem_flags & flag);
}

static inline bool eeh_enabled(void)
{
        return eeh_has_flag(EEH_ENABLED) && !eeh_has_flag(EEH_FORCE_DISABLED);
}

static inline void eeh_serialize_lock(unsigned long *flags)
{
        raw_spin_lock_irqsave(&confirm_error_lock, *flags);
}

static inline void eeh_serialize_unlock(unsigned long flags)
{
        raw_spin_unlock_irqrestore(&confirm_error_lock, flags);
}

static inline bool eeh_state_active(int state)
{
        return (state & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE))
        == (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
}

typedef void (*eeh_edev_traverse_func)(struct eeh_dev *edev, void *flag);
typedef void *(*eeh_pe_traverse_func)(struct eeh_pe *pe, void *flag);
void eeh_set_pe_aux_size(int size);
int eeh_phb_pe_create(struct pci_controller *phb);
int eeh_wait_state(struct eeh_pe *pe, int max_wait);
struct eeh_pe *eeh_phb_pe_get(struct pci_controller *phb);
struct eeh_pe *eeh_pe_next(struct eeh_pe *pe, struct eeh_pe *root);
struct eeh_pe *eeh_pe_get(struct pci_controller *phb, int pe_no);
int eeh_pe_tree_insert(struct eeh_dev *edev, struct eeh_pe *new_pe_parent);
int eeh_pe_tree_remove(struct eeh_dev *edev);
void eeh_pe_update_time_stamp(struct eeh_pe *pe);
void *eeh_pe_traverse(struct eeh_pe *root,
                      eeh_pe_traverse_func fn, void *flag);
void eeh_pe_dev_traverse(struct eeh_pe *root,
                         eeh_edev_traverse_func fn, void *flag);
void eeh_pe_restore_bars(struct eeh_pe *pe);
const char *eeh_pe_loc_get(struct eeh_pe *pe);
struct pci_bus *eeh_pe_bus_get(struct eeh_pe *pe);
const char *eeh_pe_loc_get_bus(struct pci_bus *bus);
struct pci_bus *eeh_pe_bus_get_nolock(struct eeh_pe *pe);

void eeh_show_enabled(void);
int __init eeh_init(struct eeh_ops *ops);
int eeh_check_failure(const volatile void __iomem *token);
int eeh_dev_check_failure(struct eeh_dev *edev);
void eeh_addr_cache_init(void);
void eeh_probe_device(struct pci_dev *pdev);
void eeh_remove_device(struct pci_dev *);
int eeh_unfreeze_pe(struct eeh_pe *pe);
int eeh_pe_reset_and_recover(struct eeh_pe *pe);
int eeh_dev_open(struct pci_dev *pdev);
void eeh_dev_release(struct pci_dev *pdev);
struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group);
int eeh_pe_set_option(struct eeh_pe *pe, int option);
int eeh_pe_get_state(struct eeh_pe *pe);
int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed);
int eeh_pe_configure(struct eeh_pe *pe);
int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
                      unsigned long addr, unsigned long mask);
int eeh_pe_inject_mmio_error(struct pci_dev *pdev);

/**
 * EEH_POSSIBLE_ERROR() -- test for possible MMIO failure.
 *
 * If this macro yields TRUE, the caller relays to eeh_check_failure()
 * which does further tests out of line.
 */
#define EEH_POSSIBLE_ERROR(val, type)   ((val) == (type)~0 && eeh_enabled())

/*
 * Reads from a device which has been isolated by EEH will return
 * all 1s.  This macro gives an all-1s value of the given size (in
 * bytes: 1, 2, or 4) for comparing with the result of a read.
 */
#define EEH_IO_ERROR_VALUE(size)        (~0U >> ((4 - (size)) * 8))

#else /* !CONFIG_EEH */

static inline bool eeh_enabled(void)
{
        return false;
}

static inline void eeh_show_enabled(void) { }

static inline int eeh_check_failure(const volatile void __iomem *token)
{
        return 0;
}

#define eeh_dev_check_failure(x) (0)

static inline void eeh_addr_cache_init(void) { }

static inline void eeh_probe_device(struct pci_dev *dev) { }

static inline void eeh_remove_device(struct pci_dev *dev) { }

#define EEH_POSSIBLE_ERROR(val, type) (0)
#define EEH_IO_ERROR_VALUE(size) (-1UL)
static inline int eeh_phb_pe_create(struct pci_controller *phb) { return 0; }
#endif /* CONFIG_EEH */

#if defined(CONFIG_PPC_PSERIES) && defined(CONFIG_EEH)
void pseries_eeh_init_edev_recursive(struct pci_dn *pdn);
#endif

#ifdef CONFIG_PPC64
/*
 * MMIO read/write operations with EEH support.
 */
static inline u8 eeh_readb(const volatile void __iomem *addr)
{
        u8 val = in_8(addr);
        if (EEH_POSSIBLE_ERROR(val, u8))
                eeh_check_failure(addr);
        return val;
}

static inline u16 eeh_readw(const volatile void __iomem *addr)
{
        u16 val = in_le16(addr);
        if (EEH_POSSIBLE_ERROR(val, u16))
                eeh_check_failure(addr);
        return val;
}

static inline u32 eeh_readl(const volatile void __iomem *addr)
{
        u32 val = in_le32(addr);
        if (EEH_POSSIBLE_ERROR(val, u32))
                eeh_check_failure(addr);
        return val;
}

static inline u64 eeh_readq(const volatile void __iomem *addr)
{
        u64 val = in_le64(addr);
        if (EEH_POSSIBLE_ERROR(val, u64))
                eeh_check_failure(addr);
        return val;
}

static inline u16 eeh_readw_be(const volatile void __iomem *addr)
{
        u16 val = in_be16(addr);
        if (EEH_POSSIBLE_ERROR(val, u16))
                eeh_check_failure(addr);
        return val;
}

static inline u32 eeh_readl_be(const volatile void __iomem *addr)
{
        u32 val = in_be32(addr);
        if (EEH_POSSIBLE_ERROR(val, u32))
                eeh_check_failure(addr);
        return val;
}

static inline u64 eeh_readq_be(const volatile void __iomem *addr)
{
        u64 val = in_be64(addr);
        if (EEH_POSSIBLE_ERROR(val, u64))
                eeh_check_failure(addr);
        return val;
}

static inline void eeh_memcpy_fromio(void *dest, const
                                     volatile void __iomem *src,
                                     unsigned long n)
{
        _memcpy_fromio(dest, src, n);

        /* Look for ffff's here at dest[n].  Assume that at least 4 bytes
         * were copied. Check all four bytes.
         */
        if (n >= 4 && EEH_POSSIBLE_ERROR(*((u32 *)(dest + n - 4)), u32))
                eeh_check_failure(src);
}

/* in-string eeh macros */
static inline void eeh_readsb(const volatile void __iomem *addr, void * buf,
                              int ns)
{
        _insb(addr, buf, ns);
        if (EEH_POSSIBLE_ERROR((*(((u8*)buf)+ns-1)), u8))
                eeh_check_failure(addr);
}

static inline void eeh_readsw(const volatile void __iomem *addr, void * buf,
                              int ns)
{
        _insw(addr, buf, ns);
        if (EEH_POSSIBLE_ERROR((*(((u16*)buf)+ns-1)), u16))
                eeh_check_failure(addr);
}

static inline void eeh_readsl(const volatile void __iomem *addr, void * buf,
                              int nl)
{
        _insl(addr, buf, nl);
        if (EEH_POSSIBLE_ERROR((*(((u32*)buf)+nl-1)), u32))
                eeh_check_failure(addr);
}


void __init eeh_cache_debugfs_init(void);

#endif /* CONFIG_PPC64 */
#endif /* __KERNEL__ */
#endif /* _POWERPC_EEH_H */