1 // SPDX-License-Identifier: GPL-2.0-or-later
3  * AMD Node helper functions and common defines
12 #include <asm/amd/node.h>
18  * The nodes are software-visible through PCI config space. All nodes are enumerated
20  * nodes) with 0x18 corresponding to node 0, 0x19 to node 1, etc. Each node can be a
21  * multi-function device.
23  * On legacy systems, these node devices represent integrated Northbridge functionality.
24  * On Zen-based systems, these node devices represent Data Fabric functionality.
27  * "Processor x86 Core" -> "Configuration Space" section in PPRs.
29 struct pci_dev *amd_node_get_func(u16 node, u8 func)  in amd_node_get_func()  argument
31 	if (node >= MAX_AMD_NUM_NODES)  in amd_node_get_func()
34 	return pci_get_domain_bus_and_slot(0, 0, PCI_DEVFN(AMD_NODE0_PCI_SLOT + node, func));  in amd_node_get_func()
54  * For SMN reads, the returned value may be zero if the register is Read-as-Zero.
58  * But the Read-as-Zero response cannot be verified here. A value of 0 may be
67  * 1) Bits that are "Write-1-to-Clear". In this case, the read value should
70  * 2) Bits that are "Read-as-Zero"/"Writes-Ignored". This information cannot be
86 static int __amd_smn_rw(u8 i_off, u8 d_off, u16 node, u32 address, u32 *value, bool write)  in __amd_smn_rw()  argument
88 	struct pci_dev *root;  in __amd_smn_rw()  local
89 	int err = -ENODEV;  in __amd_smn_rw()
91 	if (node >= amd_num_nodes())  in __amd_smn_rw()
94 	root = amd_roots[node];  in __amd_smn_rw()
95 	if (!root)  in __amd_smn_rw()
103 	err = pci_write_config_dword(root, i_off, address);  in __amd_smn_rw()
109 	err = (write ? pci_write_config_dword(root, d_off, *value)  in __amd_smn_rw()
110 		     : pci_read_config_dword(root, d_off, value));  in __amd_smn_rw()
115 int __must_check amd_smn_read(u16 node, u32 address, u32 *value)  in amd_smn_read()  argument
117 	int err = __amd_smn_rw(SMN_INDEX_OFFSET, SMN_DATA_OFFSET, node, address, value, false);  in amd_smn_read()
120 		err = -ENODEV;  in amd_smn_read()
128 int __must_check amd_smn_write(u16 node, u32 address, u32 value)  in amd_smn_write()  argument
130 	return __amd_smn_rw(SMN_INDEX_OFFSET, SMN_DATA_OFFSET, node, address, &value, true);  in amd_smn_write()
134 int __must_check amd_smn_hsmp_rdwr(u16 node, u32 address, u32 *value, bool write)  in amd_smn_hsmp_rdwr()  argument
136 	return __amd_smn_rw(HSMP_INDEX_OFFSET, HSMP_DATA_OFFSET, node, address, value, write);  in amd_smn_hsmp_rdwr()
147 	u16 node;  in smn_node_write()  local
150 	ret = kstrtou16_from_user(userbuf, count, 0, &node);  in smn_node_write()
154 	if (node >= amd_num_nodes())  in smn_node_write()
155 		return -ENODEV;  in smn_node_write()
157 	debug_node = node;  in smn_node_write()
221 static struct pci_dev *get_next_root(struct pci_dev *root)  in get_next_root()  argument
223 	while ((root = pci_get_class(PCI_CLASS_BRIDGE_HOST << 8, root))) {  in get_next_root()
224 		/* Root device is Device 0 Function 0. */  in get_next_root()
225 		if (root->devfn)  in get_next_root()
228 		if (root->vendor != PCI_VENDOR_ID_AMD &&  in get_next_root()
229 		    root->vendor != PCI_VENDOR_ID_HYGON)  in get_next_root()
235 	return root;  in get_next_root()
249 	u16 count, num_roots, roots_per_node, node, num_nodes;  in amd_smn_init()  local
250 	struct pci_dev *root;  in amd_smn_init()  local
261 	root = NULL;  in amd_smn_init()
262 	while ((root = get_next_root(root))) {  in amd_smn_init()
263 		pci_dbg(root, "Reserving PCI config space\n");  in amd_smn_init()
271 		if (!pci_request_config_region_exclusive(root, 0, PCI_CFG_SPACE_SIZE, NULL)) {  in amd_smn_init()
272 			pci_err(root, "Failed to reserve config space\n");  in amd_smn_init()
273 			return -EEXIST;  in amd_smn_init()
279 	pr_debug("Found %d AMD root devices\n", num_roots);  in amd_smn_init()
282 		return -ENODEV;  in amd_smn_init()
287 		return -ENOMEM;  in amd_smn_init()
292 	node = 0;  in amd_smn_init()
293 	root = NULL;  in amd_smn_init()
294 	while (node < num_nodes && (root = get_next_root(root))) {  in amd_smn_init()
295 		/* Use one root for each node and skip the rest. */  in amd_smn_init()
299 		pci_dbg(root, "is root for AMD node %u\n", node);  in amd_smn_init()
300 		amd_roots[node++] = root;  in amd_smn_init()
306 		debugfs_create_file("node",	0600, debugfs_dir, NULL, &smn_node_fops);  in amd_smn_init()