xref: /openbmc/linux/include/misc/ocxl.h (revision b696d282)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017 IBM Corp.
3 #ifndef _MISC_OCXL_H_
4 #define _MISC_OCXL_H_
5 
6 #include <linux/pci.h>
7 
8 /*
9  * Opencapi drivers all need some common facilities, like parsing the
10  * device configuration space, adding a Process Element to the Shared
11  * Process Area, etc...
12  *
13  * The ocxl module provides a kernel API, to allow other drivers to
14  * reuse common code. A bit like a in-kernel library.
15  */
16 
17 #define OCXL_AFU_NAME_SZ      (24+1)  /* add 1 for NULL termination */
18 
19 /*
20  * The following 2 structures are a fairly generic way of representing
21  * the configuration data for a function and AFU, as read from the
22  * configuration space.
23  */
24 struct ocxl_afu_config {
25 	u8 idx;
26 	int dvsec_afu_control_pos; /* offset of AFU control DVSEC */
27 	char name[OCXL_AFU_NAME_SZ];
28 	u8 version_major;
29 	u8 version_minor;
30 	u8 afuc_type;
31 	u8 afum_type;
32 	u8 profile;
33 	u8 global_mmio_bar;     /* global MMIO area */
34 	u64 global_mmio_offset;
35 	u32 global_mmio_size;
36 	u8 pp_mmio_bar;         /* per-process MMIO area */
37 	u64 pp_mmio_offset;
38 	u32 pp_mmio_stride;
39 	u8 log_mem_size;
40 	u8 pasid_supported_log;
41 	u16 actag_supported;
42 };
43 
44 struct ocxl_fn_config {
45 	int dvsec_tl_pos;       /* offset of the Transaction Layer DVSEC */
46 	int dvsec_function_pos; /* offset of the Function DVSEC */
47 	int dvsec_afu_info_pos; /* offset of the AFU information DVSEC */
48 	s8 max_pasid_log;
49 	s8 max_afu_index;
50 };
51 
52 /*
53  * Read the configuration space of a function and fill in a
54  * ocxl_fn_config structure with all the function details
55  */
56 int ocxl_config_read_function(struct pci_dev *dev,
57 				struct ocxl_fn_config *fn);
58 
59 /*
60  * Read the configuration space of a function for the AFU specified by
61  * the index 'afu_idx'. Fills in a ocxl_afu_config structure
62  */
63 int ocxl_config_read_afu(struct pci_dev *dev,
64 				struct ocxl_fn_config *fn,
65 				struct ocxl_afu_config *afu,
66 				u8 afu_idx);
67 
68 /*
69  * Tell an AFU, by writing in the configuration space, the PASIDs that
70  * it can use. Range starts at 'pasid_base' and its size is a multiple
71  * of 2
72  *
73  * 'afu_control_offset' is the offset of the AFU control DVSEC which
74  * can be found in the function configuration
75  */
76 void ocxl_config_set_afu_pasid(struct pci_dev *dev,
77 				int afu_control_offset,
78 				int pasid_base, u32 pasid_count_log);
79 
80 /*
81  * Get the actag configuration for the function:
82  * 'base' is the first actag value that can be used.
83  * 'enabled' it the number of actags available, starting from base.
84  * 'supported' is the total number of actags desired by all the AFUs
85  *             of the function.
86  */
87 int ocxl_config_get_actag_info(struct pci_dev *dev,
88 				u16 *base, u16 *enabled, u16 *supported);
89 
90 /*
91  * Tell a function, by writing in the configuration space, the actags
92  * it can use.
93  *
94  * 'func_offset' is the offset of the Function DVSEC that can found in
95  * the function configuration
96  */
97 void ocxl_config_set_actag(struct pci_dev *dev, int func_offset,
98 				u32 actag_base, u32 actag_count);
99 
100 /*
101  * Tell an AFU, by writing in the configuration space, the actags it
102  * can use.
103  *
104  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
105  * desired AFU. It can be found in the AFU configuration
106  */
107 void ocxl_config_set_afu_actag(struct pci_dev *dev,
108 				int afu_control_offset,
109 				int actag_base, int actag_count);
110 
111 /*
112  * Enable/disable an AFU, by writing in the configuration space.
113  *
114  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
115  * desired AFU. It can be found in the AFU configuration
116  */
117 void ocxl_config_set_afu_state(struct pci_dev *dev,
118 				int afu_control_offset, int enable);
119 
120 /*
121  * Set the Transaction Layer configuration in the configuration space.
122  * Only needed for function 0.
123  *
124  * It queries the host TL capabilities, find some common ground
125  * between the host and device, and set the Transaction Layer on both
126  * accordingly.
127  */
128 int ocxl_config_set_TL(struct pci_dev *dev, int tl_dvsec);
129 
130 /*
131  * Request an AFU to terminate a PASID.
132  * Will return once the AFU has acked the request, or an error in case
133  * of timeout.
134  *
135  * The hardware can only terminate one PASID at a time, so caller must
136  * guarantee some kind of serialization.
137  *
138  * 'afu_control_offset' is the offset of the AFU control DVSEC for the
139  * desired AFU. It can be found in the AFU configuration
140  */
141 int ocxl_config_terminate_pasid(struct pci_dev *dev,
142 				int afu_control_offset, int pasid);
143 
144 /*
145  * Set up the opencapi link for the function.
146  *
147  * When called for the first time for a link, it sets up the Shared
148  * Process Area for the link and the interrupt handler to process
149  * translation faults.
150  *
151  * Returns a 'link handle' that should be used for further calls for
152  * the link
153  */
154 int ocxl_link_setup(struct pci_dev *dev, int PE_mask,
155 			void **link_handle);
156 
157 /*
158  * Remove the association between the function and its link.
159  */
160 void ocxl_link_release(struct pci_dev *dev, void *link_handle);
161 
162 /*
163  * Add a Process Element to the Shared Process Area for a link.
164  * The process is defined by its PASID, pid, tid and its mm_struct.
165  *
166  * 'xsl_err_cb' is an optional callback if the driver wants to be
167  * notified when the translation fault interrupt handler detects an
168  * address error.
169  * 'xsl_err_data' is an argument passed to the above callback, if
170  * defined
171  */
172 int ocxl_link_add_pe(void *link_handle, int pasid, u32 pidr, u32 tidr,
173 		u64 amr, struct mm_struct *mm,
174 		void (*xsl_err_cb)(void *data, u64 addr, u64 dsisr),
175 		void *xsl_err_data);
176 
177 /*
178  * Remove a Process Element from the Shared Process Area for a link
179  */
180 int ocxl_link_remove_pe(void *link_handle, int pasid);
181 
182 /*
183  * Allocate an AFU interrupt associated to the link.
184  *
185  * 'hw_irq' is the hardware interrupt number
186  * 'obj_handle' is the 64-bit object handle to be passed to the AFU to
187  * trigger the interrupt.
188  * On P9, 'obj_handle' is an address, which, if written, triggers the
189  * interrupt. It is an MMIO address which needs to be remapped (one
190  * page).
191  */
192 int ocxl_link_irq_alloc(void *link_handle, int *hw_irq,
193 			u64 *obj_handle);
194 
195 /*
196  * Free a previously allocated AFU interrupt
197  */
198 void ocxl_link_free_irq(void *link_handle, int hw_irq);
199 
200 #endif /* _MISC_OCXL_H_ */
201