xref: /dpdk/drivers/gpu/cuda/gdrcopy.c (revision 1c839246f934340e8dfb8fd71bc436f81541a587)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright (c) 2022 NVIDIA Corporation & Affiliates
3  */
4 
5 #include "common.h"
6 
7 #ifdef DRIVERS_GPU_CUDA_GDRCOPY_H
8 
9 static void *gdrclib;
10 static gdr_t (*sym_gdr_open)(void);
11 static int (*sym_gdr_pin_buffer)(gdr_t g, unsigned long addr, size_t size,
12 		uint64_t p2p_token, uint32_t va_space, gdr_mh_t *handle);
13 static int (*sym_gdr_unpin_buffer)(gdr_t g, gdr_mh_t handle);
14 static int (*sym_gdr_map)(gdr_t g, gdr_mh_t handle, void **va, size_t size);
15 static int (*sym_gdr_unmap)(gdr_t g, gdr_mh_t handle, void *va, size_t size);
16 
17 static int
18 gdrcopy_loader(void)
19 {
20 	char gdrcopy_path[1024];
21 
22 	if (getenv("GDRCOPY_PATH_L") == NULL)
23 		snprintf(gdrcopy_path, 1024, "%s", "libgdrapi.so");
24 	else
25 		snprintf(gdrcopy_path, 1024, "%s/%s", getenv("GDRCOPY_PATH_L"), "libgdrapi.so");
26 
27 	gdrclib = dlopen(gdrcopy_path, RTLD_LAZY);
28 	if (gdrclib == NULL) {
29 		rte_cuda_log(ERR, "Failed to find GDRCopy library %s (GDRCOPY_PATH_L=%s)\n",
30 				gdrcopy_path, getenv("GDRCOPY_PATH_L"));
31 		return -1;
32 	}
33 
34 	sym_gdr_open = dlsym(gdrclib, "gdr_open");
35 	if (sym_gdr_open == NULL) {
36 		rte_cuda_log(ERR, "Failed to load GDRCopy symbols\n");
37 		return -1;
38 	}
39 
40 	sym_gdr_pin_buffer = dlsym(gdrclib, "gdr_pin_buffer");
41 	if (sym_gdr_pin_buffer == NULL) {
42 		rte_cuda_log(ERR, "Failed to load GDRCopy symbols\n");
43 		return -1;
44 	}
45 
46 	sym_gdr_unpin_buffer = dlsym(gdrclib, "gdr_unpin_buffer");
47 	if (sym_gdr_unpin_buffer == NULL) {
48 		rte_cuda_log(ERR, "Failed to load GDRCopy symbols\n");
49 		return -1;
50 	}
51 
52 	sym_gdr_map = dlsym(gdrclib, "gdr_map");
53 	if (sym_gdr_map == NULL) {
54 		rte_cuda_log(ERR, "Failed to load GDRCopy symbols\n");
55 		return -1;
56 	}
57 
58 	sym_gdr_unmap = dlsym(gdrclib, "gdr_unmap");
59 	if (sym_gdr_unmap == NULL) {
60 		rte_cuda_log(ERR, "Failed to load GDRCopy symbols\n");
61 		return -1;
62 	}
63 
64 	return 0;
65 }
66 
67 static int
68 gdrcopy_open(gdr_t *g)
69 {
70 	gdr_t g_;
71 
72 	g_ = sym_gdr_open();
73 	if (!g_)
74 		return -1;
75 	*g = g_;
76 
77 	return 0;
78 }
79 
80 #endif
81 
82 int
83 gdrcopy_pin(gdr_t *gdrc_h, __rte_unused gdr_mh_t *mh, uint64_t d_addr, size_t size, void **h_addr)
84 {
85 #ifdef DRIVERS_GPU_CUDA_GDRCOPY_H
86 	if (*gdrc_h == NULL) {
87 		if (gdrcopy_loader())
88 			return -ENOTSUP;
89 
90 		if (gdrcopy_open(gdrc_h)) {
91 			rte_cuda_log(ERR,
92 					"GDRCopy gdrdrv kernel module not found. Can't CPU map GPU memory.");
93 			return -EPERM;
94 		}
95 	}
96 
97 	/* Pin the device buffer */
98 	if (sym_gdr_pin_buffer(*gdrc_h, d_addr, size, 0, 0, mh) != 0) {
99 		rte_cuda_log(ERR, "GDRCopy pin buffer error.");
100 		return -1;
101 	}
102 
103 	/* Map the buffer to user space */
104 	if (sym_gdr_map(*gdrc_h, *mh, h_addr, size) != 0) {
105 		rte_cuda_log(ERR, "GDRCopy map buffer error.");
106 		sym_gdr_unpin_buffer(*gdrc_h, *mh);
107 		return -1;
108 	}
109 
110 	return 0;
111 #else
112 	rte_cuda_log(ERR,
113 			"GDRCopy headers not provided at DPDK building time. Can't CPU map GPU memory.");
114 	return -ENOTSUP;
115 #endif
116 }
117 
118 int
119 gdrcopy_unpin(gdr_t gdrc_h, __rte_unused gdr_mh_t mh, void *d_addr, size_t size)
120 {
121 	if (gdrc_h == NULL)
122 		return -EINVAL;
123 
124 #ifdef DRIVERS_GPU_CUDA_GDRCOPY_H
125 	/* Unmap the buffer from user space */
126 	if (sym_gdr_unmap(gdrc_h, mh, d_addr, size) != 0) {
127 		rte_cuda_log(ERR, "GDRCopy unmap buffer error.");
128 		return -1;
129 	}
130 	/* Unpin the device buffer */
131 	if (sym_gdr_unpin_buffer(gdrc_h, mh) != 0) {
132 		rte_cuda_log(ERR, "GDRCopy unpin buffer error.");
133 		return -1;
134 	}
135 #endif
136 
137 	return 0;
138 }
139