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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* Copyright 2016-17 IBM Corp.
*/
#ifndef _ASM_POWERPC_VAS_H
#define _ASM_POWERPC_VAS_H
#include <linux/sched/mm.h>
#include <linux/mmu_context.h>
#include <asm/icswx.h>
#include <uapi/asm/vas-api.h>
struct vas_window;
/*
* Min and max FIFO sizes are based on Version 1.05 Section 3.1.4.25
* (Local FIFO Size Register) of the VAS workbook.
*/
#define VAS_RX_FIFO_SIZE_MIN (1 << 10) /* 1KB */
#define VAS_RX_FIFO_SIZE_MAX (8 << 20) /* 8MB */
/*
* Threshold Control Mode: Have paste operation fail if the number of
* requests in receive FIFO exceeds a threshold.
*
* NOTE: No special error code yet if paste is rejected because of these
* limits. So users can't distinguish between this and other errors.
*/
#define VAS_THRESH_DISABLED 0
#define VAS_THRESH_FIFO_GT_HALF_FULL 1
#define VAS_THRESH_FIFO_GT_QTR_FULL 2
#define VAS_THRESH_FIFO_GT_EIGHTH_FULL 3
/*
* Get/Set bit fields
*/
#define GET_FIELD(m, v) (((v) & (m)) >> MASK_LSH(m))
#define MASK_LSH(m) (__builtin_ffsl(m) - 1)
#define SET_FIELD(m, v, val) \
(((v) & ~(m)) | ((((typeof(v))(val)) << MASK_LSH(m)) & (m)))
/*
* Co-processor Engine type.
*/
enum vas_cop_type {
VAS_COP_TYPE_FAULT,
VAS_COP_TYPE_842,
VAS_COP_TYPE_842_HIPRI,
VAS_COP_TYPE_GZIP,
VAS_COP_TYPE_GZIP_HIPRI,
VAS_COP_TYPE_FTW,
VAS_COP_TYPE_MAX,
};
/*
* User space VAS windows are opened by tasks and take references
* to pid and mm until windows are closed.
* Stores pid, mm, and tgid for each window.
*/
struct vas_user_win_ref {
struct pid *pid; /* PID of owner */
struct pid *tgid; /* Thread group ID of owner */
struct mm_struct *mm; /* Linux process mm_struct */
};
/*
* User space window operations used for powernv and powerVM
*/
struct vas_user_win_ops {
struct vas_window * (*open_win)(int vas_id, u64 flags,
enum vas_cop_type);
u64 (*paste_addr)(struct vas_window *);
int (*close_win)(struct vas_window *);
};
static inline void put_vas_user_win_ref(struct vas_user_win_ref *ref)
{
/* Drop references to pid, tgid, and mm */
put_pid(ref->pid);
put_pid(ref->tgid);
if (ref->mm)
mmdrop(ref->mm);
}
static inline void vas_user_win_add_mm_context(struct vas_user_win_ref *ref)
{
mm_context_add_vas_window(ref->mm);
/*
* Even a process that has no foreign real address mapping can
* use an unpaired COPY instruction (to no real effect). Issue
* CP_ABORT to clear any pending COPY and prevent a covert
* channel.
*
* __switch_to() will issue CP_ABORT on future context switches
* if process / thread has any open VAS window (Use
* current->mm->context.vas_windows).
*/
asm volatile(PPC_CP_ABORT);
}
/*
* Receive window attributes specified by the (in-kernel) owner of window.
*/
struct vas_rx_win_attr {
void *rx_fifo;
int rx_fifo_size;
int wcreds_max;
bool pin_win;
bool rej_no_credit;
bool tx_wcred_mode;
bool rx_wcred_mode;
bool tx_win_ord_mode;
bool rx_win_ord_mode;
bool data_stamp;
bool nx_win;
bool fault_win;
bool user_win;
bool notify_disable;
bool intr_disable;
bool notify_early;
int lnotify_lpid;
int lnotify_pid;
int lnotify_tid;
u32 pswid;
int tc_mode;
};
/*
* Window attributes specified by the in-kernel owner of a send window.
*/
struct vas_tx_win_attr {
enum vas_cop_type cop;
int wcreds_max;
int lpid;
int pidr; /* hardware PID (from SPRN_PID) */
int pswid;
int rsvd_txbuf_count;
int tc_mode;
bool user_win;
bool pin_win;
bool rej_no_credit;
bool rsvd_txbuf_enable;
bool tx_wcred_mode;
bool rx_wcred_mode;
bool tx_win_ord_mode;
bool rx_win_ord_mode;
};
/*
* Helper to map a chip id to VAS id.
* For POWER9, this is a 1:1 mapping. In the future this maybe a 1:N
* mapping in which case, we will need to update this helper.
*
* Return the VAS id or -1 if no matching vasid is found.
*/
int chip_to_vas_id(int chipid);
/*
* Helper to initialize receive window attributes to defaults for an
* NX window.
*/
void vas_init_rx_win_attr(struct vas_rx_win_attr *rxattr, enum vas_cop_type cop);
/*
* Open a VAS receive window for the instance of VAS identified by @vasid
* Use @attr to initialize the attributes of the window.
*
* Return a handle to the window or ERR_PTR() on error.
*/
struct vas_window *vas_rx_win_open(int vasid, enum vas_cop_type cop,
struct vas_rx_win_attr *attr);
/*
* Helper to initialize send window attributes to defaults for an NX window.
*/
extern void vas_init_tx_win_attr(struct vas_tx_win_attr *txattr,
enum vas_cop_type cop);
/*
* Open a VAS send window for the instance of VAS identified by @vasid
* and the co-processor type @cop. Use @attr to initialize attributes
* of the window.
*
* Note: The instance of VAS must already have an open receive window for
* the coprocessor type @cop.
*
* Return a handle to the send window or ERR_PTR() on error.
*/
struct vas_window *vas_tx_win_open(int vasid, enum vas_cop_type cop,
struct vas_tx_win_attr *attr);
/*
* Close the send or receive window identified by @win. For receive windows
* return -EAGAIN if there are active send windows attached to this receive
* window.
*/
int vas_win_close(struct vas_window *win);
/*
* Copy the co-processor request block (CRB) @crb into the local L2 cache.
*/
int vas_copy_crb(void *crb, int offset);
/*
* Paste a previously copied CRB (see vas_copy_crb()) from the L2 cache to
* the hardware address associated with the window @win. @re is expected/
* assumed to be true for NX windows.
*/
int vas_paste_crb(struct vas_window *win, int offset, bool re);
int vas_register_api_powernv(struct module *mod, enum vas_cop_type cop_type,
const char *name);
void vas_unregister_api_powernv(void);
/*
* Register / unregister coprocessor type to VAS API which will be exported
* to user space. Applications can use this API to open / close window
* which can be used to send / receive requests directly to cooprcessor.
*
* Only NX GZIP coprocessor type is supported now, but this API can be
* used for others in future.
*/
int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
const char *name,
const struct vas_user_win_ops *vops);
void vas_unregister_coproc_api(void);
int get_vas_user_win_ref(struct vas_user_win_ref *task_ref);
#endif /* __ASM_POWERPC_VAS_H */
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