1 /*
2  * Copyright 2015 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  */
22 
23 #ifndef __AMD_PCIE_HELPERS_H__
24 #define __AMD_PCIE_HELPERS_H__
25 
26 #include "amd_pcie.h"
27 
28 static inline bool is_pcie_gen3_supported(uint32_t pcie_link_speed_cap)
29 {
30 	if (pcie_link_speed_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN3)
31 		return true;
32 
33 	return false;
34 }
35 
36 static inline bool is_pcie_gen2_supported(uint32_t pcie_link_speed_cap)
37 {
38 	if (pcie_link_speed_cap & CAIL_PCIE_LINK_SPEED_SUPPORT_GEN2)
39 		return true;
40 
41 	return false;
42 }
43 
44 /* Get the new PCIE speed given the ASIC PCIE Cap and the NewState's requested PCIE speed*/
45 static inline uint16_t get_pcie_gen_support(uint32_t pcie_link_speed_cap,
46 					    uint16_t ns_pcie_gen)
47 {
48 	uint32_t asic_pcie_link_speed_cap = (pcie_link_speed_cap &
49 		CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_MASK);
50 	uint32_t sys_pcie_link_speed_cap  = (pcie_link_speed_cap &
51 		CAIL_PCIE_LINK_SPEED_SUPPORT_MASK);
52 
53 	switch (asic_pcie_link_speed_cap) {
54 	case CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_GEN1:
55 		return PP_PCIEGen1;
56 
57 	case CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_GEN2:
58 		return PP_PCIEGen2;
59 
60 	case CAIL_ASIC_PCIE_LINK_SPEED_SUPPORT_GEN3:
61 		return PP_PCIEGen3;
62 
63 	default:
64 		if (is_pcie_gen3_supported(sys_pcie_link_speed_cap) &&
65 			(ns_pcie_gen == PP_PCIEGen3)) {
66 			return PP_PCIEGen3;
67 		} else if (is_pcie_gen2_supported(sys_pcie_link_speed_cap) &&
68 			((ns_pcie_gen == PP_PCIEGen3) || (ns_pcie_gen == PP_PCIEGen2))) {
69 			return PP_PCIEGen2;
70 		}
71 	}
72 
73 	return PP_PCIEGen1;
74 }
75 
76 static inline uint16_t get_pcie_lane_support(uint32_t pcie_lane_width_cap,
77 					     uint16_t ns_pcie_lanes)
78 {
79 	int i, j;
80 	uint16_t new_pcie_lanes = ns_pcie_lanes;
81 	uint16_t pcie_lanes[7] = {1, 2, 4, 8, 12, 16, 32};
82 
83 	switch (pcie_lane_width_cap) {
84 	case 0:
85 		printk(KERN_ERR "No valid PCIE lane width reported");
86 		break;
87 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X1:
88 		new_pcie_lanes = 1;
89 		break;
90 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X2:
91 		new_pcie_lanes = 2;
92 		break;
93 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X4:
94 		new_pcie_lanes = 4;
95 		break;
96 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X8:
97 		new_pcie_lanes = 8;
98 		break;
99 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X12:
100 		new_pcie_lanes = 12;
101 		break;
102 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X16:
103 		new_pcie_lanes = 16;
104 		break;
105 	case CAIL_PCIE_LINK_WIDTH_SUPPORT_X32:
106 		new_pcie_lanes = 32;
107 		break;
108 	default:
109 		for (i = 0; i < 7; i++) {
110 			if (ns_pcie_lanes == pcie_lanes[i]) {
111 				if (pcie_lane_width_cap & (0x10000 << i)) {
112 					break;
113 				} else {
114 					for (j = i - 1; j >= 0; j--) {
115 						if (pcie_lane_width_cap & (0x10000 << j)) {
116 							new_pcie_lanes = pcie_lanes[j];
117 							break;
118 						}
119 					}
120 
121 					if (j < 0) {
122 						for (j = i + 1; j < 7; j++) {
123 							if (pcie_lane_width_cap & (0x10000 << j)) {
124 								new_pcie_lanes = pcie_lanes[j];
125 								break;
126 							}
127 						}
128 						if (j > 7)
129 							printk(KERN_ERR "Cannot find a valid PCIE lane width!");
130 					}
131 				}
132 				break;
133 			}
134 		}
135 		break;
136 	}
137 
138 	return new_pcie_lanes;
139 }
140 
141 #endif
142