1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
|
/*
* Copyright 2015 IBM Corp.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#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);
/*
* 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. task == NULL will make it a kernel context.
*/
int cxl_start_context(struct cxl_context *ctx, u64 wed,
struct task_struct *task);
/*
* Stop a context and remove it from the PSL
*/
int cxl_stop_context(struct cxl_context *ctx);
/* Reset the AFU */
int cxl_afu_reset(struct cxl_context *ctx);
/*
* Set a context as a master context.
* This sets the default problem space area mapped as the full space, rather
* than just the per context area (for slaves).
*/
void cxl_set_master(struct cxl_context *ctx);
/*
* Map and unmap the AFU Problem Space area. The amount and location mapped
* depends on if this context is a master or slave.
*/
void __iomem *cxl_psa_map(struct cxl_context *ctx);
void cxl_psa_unmap(void __iomem *addr);
/* Get the process element for this context */
int cxl_process_element(struct cxl_context *ctx);
/*
* These calls allow drivers to create their own file descriptors and make them
* identical to the cxl file descriptor user API. An example use case:
*
* struct file_operations cxl_my_fops = {};
* ......
* // Init the context
* ctx = cxl_dev_context_init(dev);
* if (IS_ERR(ctx))
* return PTR_ERR(ctx);
* // Create and attach a new file descriptor to my file ops
* file = cxl_get_fd(ctx, &cxl_my_fops, &fd);
* // Start context
* rc = cxl_start_work(ctx, &work.work);
* if (rc) {
* fput(file);
* put_unused_fd(fd);
* return -ENODEV;
* }
* // No error paths after installing the fd
* fd_install(fd, file);
* return fd;
*
* This inits a context, and gets a file descriptor and associates some file
* ops to that file descriptor. If the file ops are blank, the cxl driver will
* fill them in with the default ones that mimic the standard user API. Once
* completed, the file descriptor can be installed. Once the file descriptor is
* installed, it's visible to the user so no errors must occur past this point.
*
* If cxl_fd_release() file op call is installed, the context will be stopped
* and released when the fd is released. Hence the driver won't need to manage
* this itself.
*/
/*
* Take a context and associate it with my file ops. Returns the associated
* file and file descriptor. Any file ops which are blank are filled in by the
* cxl driver with the default ops to mimic the standard API.
*/
struct file *cxl_get_fd(struct cxl_context *ctx, struct file_operations *fops,
int *fd);
/* Get the context associated with this file */
struct cxl_context *cxl_fops_get_context(struct file *file);
/*
* Start a context associated a struct cxl_ioctl_start_work used by the
* standard cxl user API.
*/
int cxl_start_work(struct cxl_context *ctx,
struct cxl_ioctl_start_work *work);
/*
* Export all the existing fops so drivers can use them
*/
int cxl_fd_open(struct inode *inode, struct file *file);
int cxl_fd_release(struct inode *inode, struct file *file);
long cxl_fd_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
int cxl_fd_mmap(struct file *file, struct vm_area_struct *vm);
unsigned int cxl_fd_poll(struct file *file, struct poll_table_struct *poll);
ssize_t cxl_fd_read(struct file *file, char __user *buf, size_t count,
loff_t *off);
/*
* For EEH, a driver may want to assert a PERST will reload the same image
* from flash into the FPGA.
*
* This is a property of the entire adapter, not a single AFU, so drivers
* should set this property with care!
*/
void cxl_perst_reloads_same_image(struct cxl_afu *afu,
bool perst_reloads_same_image);
/*
* Read the VPD for the card where the AFU resides
*/
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);
#endif /* _MISC_CXL_H */
|
