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Michael Neuling6f7f0b32015-05-27 16:07:18 +10001/*
2 * Copyright 2015 IBM Corp.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 */
9
10#ifndef _MISC_CXL_H
11#define _MISC_CXL_H
12
13#include <linux/pci.h>
14#include <linux/poll.h>
15#include <linux/interrupt.h>
16#include <uapi/misc/cxl.h>
17
18/*
19 * This documents the in kernel API for driver to use CXL. It allows kernel
20 * drivers to bind to AFUs using an AFU configuration record exposed as a PCI
21 * configuration record.
22 *
23 * This API enables control over AFU and contexts which can't be part of the
24 * generic PCI API. This API is agnostic to the actual AFU.
25 */
26
27/* Get the AFU associated with a pci_dev */
28struct cxl_afu *cxl_pci_to_afu(struct pci_dev *dev);
29
30/* Get the AFU conf record number associated with a pci_dev */
31unsigned int cxl_pci_to_cfg_record(struct pci_dev *dev);
32
Michael Neuling6f7f0b32015-05-27 16:07:18 +100033
34/*
35 * Context lifetime overview:
36 *
37 * An AFU context may be inited and then started and stoppped multiple times
38 * before it's released. ie.
39 * - cxl_dev_context_init()
40 * - cxl_start_context()
41 * - cxl_stop_context()
42 * - cxl_start_context()
43 * - cxl_stop_context()
44 * ...repeat...
45 * - cxl_release_context()
46 * Once released, a context can't be started again.
47 *
48 * One context is inited by the cxl driver for every pci_dev. This is to be
49 * used as a default kernel context. cxl_get_context() will get this
50 * context. This context will be released by PCI hot unplug, so doesn't need to
51 * be released explicitly by drivers.
52 *
53 * Additional kernel contexts may be inited using cxl_dev_context_init().
54 * These must be released using cxl_context_detach().
55 *
56 * Once a context has been inited, IRQs may be configured. Firstly these IRQs
57 * must be allocated (cxl_allocate_afu_irqs()), then individually mapped to
58 * specific handlers (cxl_map_afu_irq()).
59 *
60 * These IRQs can be unmapped (cxl_unmap_afu_irq()) and finally released
61 * (cxl_free_afu_irqs()).
62 *
63 * The AFU can be reset (cxl_afu_reset()). This will cause the PSL/AFU
64 * hardware to lose track of all contexts. It's upto the caller of
65 * cxl_afu_reset() to restart these contexts.
66 */
67
68/*
69 * On pci_enabled_device(), the cxl driver will init a single cxl context for
70 * use by the driver. It doesn't start this context (as that will likely
71 * generate DMA traffic for most AFUs).
72 *
73 * This gets the default context associated with this pci_dev. This context
74 * doesn't need to be released as this will be done by the PCI subsystem on hot
75 * unplug.
76 */
77struct cxl_context *cxl_get_context(struct pci_dev *dev);
78/*
79 * Allocate and initalise a context associated with a AFU PCI device. This
80 * doesn't start the context in the AFU.
81 */
82struct cxl_context *cxl_dev_context_init(struct pci_dev *dev);
83/*
84 * Release and free a context. Context should be stopped before calling.
85 */
86int cxl_release_context(struct cxl_context *ctx);
87
88/*
89 * Allocate AFU interrupts for this context. num=0 will allocate the default
90 * for this AFU as given in the AFU descriptor. This number doesn't include the
91 * interrupt 0 (CAIA defines AFU IRQ 0 for page faults). Each interrupt to be
92 * used must map a handler with cxl_map_afu_irq.
93 */
94int cxl_allocate_afu_irqs(struct cxl_context *cxl, int num);
95/* Free allocated interrupts */
96void cxl_free_afu_irqs(struct cxl_context *cxl);
97
98/*
99 * Map a handler for an AFU interrupt associated with a particular context. AFU
100 * IRQS numbers start from 1 (CAIA defines AFU IRQ 0 for page faults). cookie
101 * is private data is that will be provided to the interrupt handler.
102 */
103int cxl_map_afu_irq(struct cxl_context *cxl, int num,
104 irq_handler_t handler, void *cookie, char *name);
105/* unmap mapped IRQ handlers */
106void cxl_unmap_afu_irq(struct cxl_context *cxl, int num, void *cookie);
107
108/*
109 * Start work on the AFU. This starts an cxl context and associates it with a
110 * task. task == NULL will make it a kernel context.
111 */
112int cxl_start_context(struct cxl_context *ctx, u64 wed,
113 struct task_struct *task);
114/*
115 * Stop a context and remove it from the PSL
116 */
117int cxl_stop_context(struct cxl_context *ctx);
118
119/* Reset the AFU */
120int cxl_afu_reset(struct cxl_context *ctx);
121
122/*
123 * Set a context as a master context.
124 * This sets the default problem space area mapped as the full space, rather
125 * than just the per context area (for slaves).
126 */
127void cxl_set_master(struct cxl_context *ctx);
128
129/*
130 * Map and unmap the AFU Problem Space area. The amount and location mapped
131 * depends on if this context is a master or slave.
132 */
133void __iomem *cxl_psa_map(struct cxl_context *ctx);
134void cxl_psa_unmap(void __iomem *addr);
135
136/* Get the process element for this context */
137int cxl_process_element(struct cxl_context *ctx);
138
139
140/*
141 * These calls allow drivers to create their own file descriptors and make them
142 * identical to the cxl file descriptor user API. An example use case:
143 *
144 * struct file_operations cxl_my_fops = {};
145 * ......
146 * // Init the context
147 * ctx = cxl_dev_context_init(dev);
148 * if (IS_ERR(ctx))
149 * return PTR_ERR(ctx);
150 * // Create and attach a new file descriptor to my file ops
151 * file = cxl_get_fd(ctx, &cxl_my_fops, &fd);
152 * // Start context
153 * rc = cxl_start_work(ctx, &work.work);
154 * if (rc) {
155 * fput(file);
156 * put_unused_fd(fd);
157 * return -ENODEV;
158 * }
159 * // No error paths after installing the fd
160 * fd_install(fd, file);
161 * return fd;
162 *
163 * This inits a context, and gets a file descriptor and associates some file
164 * ops to that file descriptor. If the file ops are blank, the cxl driver will
165 * fill them in with the default ones that mimic the standard user API. Once
166 * completed, the file descriptor can be installed. Once the file descriptor is
167 * installed, it's visible to the user so no errors must occur past this point.
168 *
169 * If cxl_fd_release() file op call is installed, the context will be stopped
170 * and released when the fd is released. Hence the driver won't need to manage
171 * this itself.
172 */
173
174/*
175 * Take a context and associate it with my file ops. Returns the associated
176 * file and file descriptor. Any file ops which are blank are filled in by the
177 * cxl driver with the default ops to mimic the standard API.
178 */
179struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
180 int *fd);
181/* Get the context associated with this file */
182struct cxl_context *cxl_fops_get_context(struct file *file);
183/*
184 * Start a context associated a struct cxl_ioctl_start_work used by the
185 * standard cxl user API.
186 */
187int cxl_start_work(struct cxl_context *ctx,
188 struct cxl_ioctl_start_work *work);
189/*
190 * Export all the existing fops so drivers can use them
191 */
192int cxl_fd_open(struct inode *inode, struct file *file);
193int cxl_fd_release(struct inode *inode, struct file *file);
194long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
195int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm);
196unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll);
197ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
198 loff_t *off);
199
Daniel Axtens13e68d82015-08-14 17:41:25 +1000200/*
201 * For EEH, a driver may want to assert a PERST will reload the same image
202 * from flash into the FPGA.
203 *
204 * This is a property of the entire adapter, not a single AFU, so drivers
205 * should set this property with care!
206 */
207void cxl_perst_reloads_same_image(struct cxl_afu *afu,
208 bool perst_reloads_same_image);
209
Frederic Barratd601ea92016-03-04 12:26:40 +0100210/*
211 * Read the VPD for the card where the AFU resides
212 */
213ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);
214
Michael Neuling6f7f0b32015-05-27 16:07:18 +1000215#endif /* _MISC_CXL_H */