xref: /openbmc/linux/arch/x86/kernel/cpu/hygon.c (revision 6fa24b41)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Hygon Processor Support for Linux
4  *
5  * Copyright (C) 2018 Chengdu Haiguang IC Design Co., Ltd.
6  *
7  * Author: Pu Wen <puwen@hygon.cn>
8  */
9 #include <linux/io.h>
10 
11 #include <asm/apic.h>
12 #include <asm/cpu.h>
13 #include <asm/smp.h>
14 #include <asm/numa.h>
15 #include <asm/cacheinfo.h>
16 #include <asm/spec-ctrl.h>
17 #include <asm/delay.h>
18 
19 #include "cpu.h"
20 
21 #define APICID_SOCKET_ID_BIT 6
22 
23 /*
24  * nodes_per_socket: Stores the number of nodes per socket.
25  * Refer to CPUID Fn8000_001E_ECX Node Identifiers[10:8]
26  */
27 static u32 nodes_per_socket = 1;
28 
29 #ifdef CONFIG_NUMA
30 /*
31  * To workaround broken NUMA config.  Read the comment in
32  * srat_detect_node().
33  */
34 static int nearby_node(int apicid)
35 {
36 	int i, node;
37 
38 	for (i = apicid - 1; i >= 0; i--) {
39 		node = __apicid_to_node[i];
40 		if (node != NUMA_NO_NODE && node_online(node))
41 			return node;
42 	}
43 	for (i = apicid + 1; i < MAX_LOCAL_APIC; i++) {
44 		node = __apicid_to_node[i];
45 		if (node != NUMA_NO_NODE && node_online(node))
46 			return node;
47 	}
48 	return first_node(node_online_map); /* Shouldn't happen */
49 }
50 #endif
51 
52 static void hygon_get_topology_early(struct cpuinfo_x86 *c)
53 {
54 	if (cpu_has(c, X86_FEATURE_TOPOEXT))
55 		smp_num_siblings = ((cpuid_ebx(0x8000001e) >> 8) & 0xff) + 1;
56 }
57 
58 /*
59  * Fixup core topology information for
60  * (1) Hygon multi-node processors
61  *     Assumption: Number of cores in each internal node is the same.
62  * (2) Hygon processors supporting compute units
63  */
64 static void hygon_get_topology(struct cpuinfo_x86 *c)
65 {
66 	int cpu = smp_processor_id();
67 
68 	/* get information required for multi-node processors */
69 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
70 		int err;
71 		u32 eax, ebx, ecx, edx;
72 
73 		cpuid(0x8000001e, &eax, &ebx, &ecx, &edx);
74 
75 		c->cpu_die_id  = ecx & 0xff;
76 
77 		c->cpu_core_id = ebx & 0xff;
78 
79 		if (smp_num_siblings > 1)
80 			c->x86_max_cores /= smp_num_siblings;
81 
82 		/*
83 		 * In case leaf B is available, use it to derive
84 		 * topology information.
85 		 */
86 		err = detect_extended_topology(c);
87 		if (!err)
88 			c->x86_coreid_bits = get_count_order(c->x86_max_cores);
89 
90 		/*
91 		 * Socket ID is ApicId[6] for the processors with model <= 0x3
92 		 * when running on host.
93 		 */
94 		if (!boot_cpu_has(X86_FEATURE_HYPERVISOR) && c->x86_model <= 0x3)
95 			c->phys_proc_id = c->apicid >> APICID_SOCKET_ID_BIT;
96 
97 		cacheinfo_hygon_init_llc_id(c, cpu);
98 	} else if (cpu_has(c, X86_FEATURE_NODEID_MSR)) {
99 		u64 value;
100 
101 		rdmsrl(MSR_FAM10H_NODE_ID, value);
102 		c->cpu_die_id = value & 7;
103 
104 		per_cpu(cpu_llc_id, cpu) = c->cpu_die_id;
105 	} else
106 		return;
107 
108 	if (nodes_per_socket > 1)
109 		set_cpu_cap(c, X86_FEATURE_AMD_DCM);
110 }
111 
112 /*
113  * On Hygon setup the lower bits of the APIC id distinguish the cores.
114  * Assumes number of cores is a power of two.
115  */
116 static void hygon_detect_cmp(struct cpuinfo_x86 *c)
117 {
118 	unsigned int bits;
119 	int cpu = smp_processor_id();
120 
121 	bits = c->x86_coreid_bits;
122 	/* Low order bits define the core id (index of core in socket) */
123 	c->cpu_core_id = c->initial_apicid & ((1 << bits)-1);
124 	/* Convert the initial APIC ID into the socket ID */
125 	c->phys_proc_id = c->initial_apicid >> bits;
126 	/* use socket ID also for last level cache */
127 	per_cpu(cpu_llc_id, cpu) = c->cpu_die_id = c->phys_proc_id;
128 }
129 
130 static void srat_detect_node(struct cpuinfo_x86 *c)
131 {
132 #ifdef CONFIG_NUMA
133 	int cpu = smp_processor_id();
134 	int node;
135 	unsigned int apicid = c->apicid;
136 
137 	node = numa_cpu_node(cpu);
138 	if (node == NUMA_NO_NODE)
139 		node = per_cpu(cpu_llc_id, cpu);
140 
141 	/*
142 	 * On multi-fabric platform (e.g. Numascale NumaChip) a
143 	 * platform-specific handler needs to be called to fixup some
144 	 * IDs of the CPU.
145 	 */
146 	if (x86_cpuinit.fixup_cpu_id)
147 		x86_cpuinit.fixup_cpu_id(c, node);
148 
149 	if (!node_online(node)) {
150 		/*
151 		 * Two possibilities here:
152 		 *
153 		 * - The CPU is missing memory and no node was created.  In
154 		 *   that case try picking one from a nearby CPU.
155 		 *
156 		 * - The APIC IDs differ from the HyperTransport node IDs.
157 		 *   Assume they are all increased by a constant offset, but
158 		 *   in the same order as the HT nodeids.  If that doesn't
159 		 *   result in a usable node fall back to the path for the
160 		 *   previous case.
161 		 *
162 		 * This workaround operates directly on the mapping between
163 		 * APIC ID and NUMA node, assuming certain relationship
164 		 * between APIC ID, HT node ID and NUMA topology.  As going
165 		 * through CPU mapping may alter the outcome, directly
166 		 * access __apicid_to_node[].
167 		 */
168 		int ht_nodeid = c->initial_apicid;
169 
170 		if (__apicid_to_node[ht_nodeid] != NUMA_NO_NODE)
171 			node = __apicid_to_node[ht_nodeid];
172 		/* Pick a nearby node */
173 		if (!node_online(node))
174 			node = nearby_node(apicid);
175 	}
176 	numa_set_node(cpu, node);
177 #endif
178 }
179 
180 static void early_init_hygon_mc(struct cpuinfo_x86 *c)
181 {
182 #ifdef CONFIG_SMP
183 	unsigned int bits, ecx;
184 
185 	/* Multi core CPU? */
186 	if (c->extended_cpuid_level < 0x80000008)
187 		return;
188 
189 	ecx = cpuid_ecx(0x80000008);
190 
191 	c->x86_max_cores = (ecx & 0xff) + 1;
192 
193 	/* CPU telling us the core id bits shift? */
194 	bits = (ecx >> 12) & 0xF;
195 
196 	/* Otherwise recompute */
197 	if (bits == 0) {
198 		while ((1 << bits) < c->x86_max_cores)
199 			bits++;
200 	}
201 
202 	c->x86_coreid_bits = bits;
203 #endif
204 }
205 
206 static void bsp_init_hygon(struct cpuinfo_x86 *c)
207 {
208 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
209 		u64 val;
210 
211 		rdmsrl(MSR_K7_HWCR, val);
212 		if (!(val & BIT(24)))
213 			pr_warn(FW_BUG "TSC doesn't count with P0 frequency!\n");
214 	}
215 
216 	if (cpu_has(c, X86_FEATURE_MWAITX))
217 		use_mwaitx_delay();
218 
219 	if (boot_cpu_has(X86_FEATURE_TOPOEXT)) {
220 		u32 ecx;
221 
222 		ecx = cpuid_ecx(0x8000001e);
223 		__max_die_per_package = nodes_per_socket = ((ecx >> 8) & 7) + 1;
224 	} else if (boot_cpu_has(X86_FEATURE_NODEID_MSR)) {
225 		u64 value;
226 
227 		rdmsrl(MSR_FAM10H_NODE_ID, value);
228 		__max_die_per_package = nodes_per_socket = ((value >> 3) & 7) + 1;
229 	}
230 
231 	if (!boot_cpu_has(X86_FEATURE_AMD_SSBD) &&
232 	    !boot_cpu_has(X86_FEATURE_VIRT_SSBD)) {
233 		/*
234 		 * Try to cache the base value so further operations can
235 		 * avoid RMW. If that faults, do not enable SSBD.
236 		 */
237 		if (!rdmsrl_safe(MSR_AMD64_LS_CFG, &x86_amd_ls_cfg_base)) {
238 			setup_force_cpu_cap(X86_FEATURE_LS_CFG_SSBD);
239 			setup_force_cpu_cap(X86_FEATURE_SSBD);
240 			x86_amd_ls_cfg_ssbd_mask = 1ULL << 10;
241 		}
242 	}
243 }
244 
245 static void early_init_hygon(struct cpuinfo_x86 *c)
246 {
247 	u32 dummy;
248 
249 	early_init_hygon_mc(c);
250 
251 	set_cpu_cap(c, X86_FEATURE_K8);
252 
253 	rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy);
254 
255 	/*
256 	 * c->x86_power is 8000_0007 edx. Bit 8 is TSC runs at constant rate
257 	 * with P/T states and does not stop in deep C-states
258 	 */
259 	if (c->x86_power & (1 << 8)) {
260 		set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
261 		set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
262 	}
263 
264 	/* Bit 12 of 8000_0007 edx is accumulated power mechanism. */
265 	if (c->x86_power & BIT(12))
266 		set_cpu_cap(c, X86_FEATURE_ACC_POWER);
267 
268 	/* Bit 14 indicates the Runtime Average Power Limit interface. */
269 	if (c->x86_power & BIT(14))
270 		set_cpu_cap(c, X86_FEATURE_RAPL);
271 
272 #ifdef CONFIG_X86_64
273 	set_cpu_cap(c, X86_FEATURE_SYSCALL32);
274 #endif
275 
276 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_PCI)
277 	/*
278 	 * ApicID can always be treated as an 8-bit value for Hygon APIC So, we
279 	 * can safely set X86_FEATURE_EXTD_APICID unconditionally.
280 	 */
281 	if (boot_cpu_has(X86_FEATURE_APIC))
282 		set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
283 #endif
284 
285 	/*
286 	 * This is only needed to tell the kernel whether to use VMCALL
287 	 * and VMMCALL.  VMMCALL is never executed except under virt, so
288 	 * we can set it unconditionally.
289 	 */
290 	set_cpu_cap(c, X86_FEATURE_VMMCALL);
291 
292 	hygon_get_topology_early(c);
293 }
294 
295 static void init_hygon(struct cpuinfo_x86 *c)
296 {
297 	early_init_hygon(c);
298 
299 	/*
300 	 * Bit 31 in normal CPUID used for nonstandard 3DNow ID;
301 	 * 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway
302 	 */
303 	clear_cpu_cap(c, 0*32+31);
304 
305 	set_cpu_cap(c, X86_FEATURE_REP_GOOD);
306 
307 	/* get apicid instead of initial apic id from cpuid */
308 	c->apicid = read_apic_id();
309 
310 	/*
311 	 * XXX someone from Hygon needs to confirm this DTRT
312 	 *
313 	init_spectral_chicken(c);
314 	 */
315 
316 	set_cpu_cap(c, X86_FEATURE_ZEN);
317 	set_cpu_cap(c, X86_FEATURE_CPB);
318 
319 	cpu_detect_cache_sizes(c);
320 
321 	hygon_detect_cmp(c);
322 	hygon_get_topology(c);
323 	srat_detect_node(c);
324 
325 	init_hygon_cacheinfo(c);
326 
327 	if (cpu_has(c, X86_FEATURE_XMM2)) {
328 		/*
329 		 * Use LFENCE for execution serialization.  On families which
330 		 * don't have that MSR, LFENCE is already serializing.
331 		 * msr_set_bit() uses the safe accessors, too, even if the MSR
332 		 * is not present.
333 		 */
334 		msr_set_bit(MSR_AMD64_DE_CFG,
335 			    MSR_AMD64_DE_CFG_LFENCE_SERIALIZE_BIT);
336 
337 		/* A serializing LFENCE stops RDTSC speculation */
338 		set_cpu_cap(c, X86_FEATURE_LFENCE_RDTSC);
339 	}
340 
341 	/*
342 	 * Hygon processors have APIC timer running in deep C states.
343 	 */
344 	set_cpu_cap(c, X86_FEATURE_ARAT);
345 
346 	/* Hygon CPUs don't reset SS attributes on SYSRET, Xen does. */
347 	if (!cpu_feature_enabled(X86_FEATURE_XENPV))
348 		set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
349 
350 	check_null_seg_clears_base(c);
351 
352 	/* Hygon CPUs don't need fencing after x2APIC/TSC_DEADLINE MSR writes. */
353 	clear_cpu_cap(c, X86_FEATURE_APIC_MSRS_FENCE);
354 }
355 
356 static void cpu_detect_tlb_hygon(struct cpuinfo_x86 *c)
357 {
358 	u32 ebx, eax, ecx, edx;
359 	u16 mask = 0xfff;
360 
361 	if (c->extended_cpuid_level < 0x80000006)
362 		return;
363 
364 	cpuid(0x80000006, &eax, &ebx, &ecx, &edx);
365 
366 	tlb_lld_4k[ENTRIES] = (ebx >> 16) & mask;
367 	tlb_lli_4k[ENTRIES] = ebx & mask;
368 
369 	/* Handle DTLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
370 	if (!((eax >> 16) & mask))
371 		tlb_lld_2m[ENTRIES] = (cpuid_eax(0x80000005) >> 16) & 0xff;
372 	else
373 		tlb_lld_2m[ENTRIES] = (eax >> 16) & mask;
374 
375 	/* a 4M entry uses two 2M entries */
376 	tlb_lld_4m[ENTRIES] = tlb_lld_2m[ENTRIES] >> 1;
377 
378 	/* Handle ITLB 2M and 4M sizes, fall back to L1 if L2 is disabled */
379 	if (!(eax & mask)) {
380 		cpuid(0x80000005, &eax, &ebx, &ecx, &edx);
381 		tlb_lli_2m[ENTRIES] = eax & 0xff;
382 	} else
383 		tlb_lli_2m[ENTRIES] = eax & mask;
384 
385 	tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
386 }
387 
388 static const struct cpu_dev hygon_cpu_dev = {
389 	.c_vendor	= "Hygon",
390 	.c_ident	= { "HygonGenuine" },
391 	.c_early_init   = early_init_hygon,
392 	.c_detect_tlb	= cpu_detect_tlb_hygon,
393 	.c_bsp_init	= bsp_init_hygon,
394 	.c_init		= init_hygon,
395 	.c_x86_vendor	= X86_VENDOR_HYGON,
396 };
397 
398 cpu_dev_register(hygon_cpu_dev);
399