MAJOR=4
MINOR=17
DEVNAME=tty17
  *   €l–Ь4э( ©і( 	ЕЂfаB¦-яАѓ}Ч_†I|ҐЏ+АГ &!    /* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright 2015 IBM Corp.
 */

#ifndef _MISC_CXL_H
#define _MISC_CXL_H

#include <linux/pci.h>
#include <linux/poll.h>
#include <linux/interrupt.h>
#include <uapi/misc/cxl.h>

/*
 * This documents the in kernel API for driver to use CXL. It allows kernel
 * drivers to bind to AFUs using an AFU configuration record exposed as a PCI
 * configuration record.
 *
 * This API enables control over AFU and contexts which can't be part of the
 * generic PCI API. This API is agnostic to the actual AFU.
 */

/* Get the AFU associated with a pci_dev */
struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);

/* Get the AFU conf record number associated with a pci_dev */
unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev);


/*
 * Context lifetime overview:
 *
 * An AFU context may be inited and then started and stoppped multiple times
 * before it's released. ie.
 *    - cxl_dev_context_init()
 *      - cxl_start_context()
 *      - cxl_stop_context()
 *      - cxl_start_context()
 *      - cxl_stop_context()
 *     ...repeat...
 *    - cxl_release_context()
 * Once released, a context can't be started again.
 *
 * One context is inited by the cxl driver for every pci_dev. This is to be
 * used as a default kernel context. cxl_get_context() will get this
 * context. This context will be released by PCI hot unplug, so doesn't need to
 * be released explicitly by drivers.
 *
 * Additional kernel contexts may be inited using cxl_dev_context_init().
 * These must be released using cxl_context_detach().
 *
 * Once a context has been inited, IRQs may be configured. Firstly these IRQs
 * must be allocated (cxl_allocate_afu_irqs()), then individually mapped to
 * specific handlers (cxl_map_afu_irq()).
 *
 * These IRQs can be unmapped (cxl_unmap_afu_irq()) and finally released
 * (cxl_free_afu_irqs()).
 *
 * The AFU can be reset (cxl_afu_reset()). This will cause the PSL/AFU
 * hardware to lose track of all contexts. It's upto the caller of
 * cxl_afu_reset() to restart these contexts.
 */

/*
 * On pci_enabled_device(), the cxl driver will init a single cxl context for
 * use by the driver. It doesn't start this context (as that will likely
 * generate DMA traffic for most AFUs).
 *
 * This gets the default context associated with this pci_dev.  This context
 * doesn't need to be released as this will be done by the PCI subsystem on hot
 * unplug.
 */
struct cxl_context *cxl_get_context(struct pci_dev *dev);
/*
 * Allocate and initalise a context associated with a AFU PCI device. This
 * doesn't start the context in the AFU.
 */
struct cxl_context *cxl_dev_context_init(struct pci_dev *dev);
/*
 * Release and free a context. Context should be stopped before calling.
 */
int cxl_release_context(struct cxl_context *ctx);

/*
 * Set and get private data associated with a context. Allows drivers to have a
 * back pointer to some useful structure.
 */
int cxl_set_priv(struct cxl_context *ctx, void *priv);
void *cxl_get_priv(struct cxl_context *ctx);

/*
 * Allocate AFU interrupts for this context. num=0 will allocate the default
 * for this AFU as given in the AFU descriptor. This number doesn't include the
 * interrupt 0 (CAIA defines AFU IRQ 0 for page faults). Each interrupt to be
 * used must map a handler with cxl_map_afu_irq.
 */
int cxl_allocate_afu_irqs(struct cxl_context *cxl, int num);
/* Free allocated interrupts */
void cxl_free_afu_irqs(struct cxl_context *cxl);

/*
 * Map a handler for an AFU interrupt associated with a particular context. AFU
 * IRQS numbers start from 1 (CAIA defines AFU IRQ 0 for page faults). cookie
 * is private data is that will be provided to the interrupt handler.
 */
int cxl_map_afu_irq(struct cxl_context *cxl, int num,
		    irq_handler_t handler, void *cookie, char *name);
/* unmap mapped IRQ handlers */
void cxl_unmap_afu_irq(struct cxl_context *cxl, int num, void *cookie);

/*
 * Start work on the AFU. This starts an cxl context and associates it with a
 * task