xref: /titanic_41/usr/src/uts/i86pc/io/pcplusmp/apic_regops.c (revision d24234c24aeaca4ca56ee3ac2794507968f274c4)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 #include <sys/cpuvar.h>
27 #include <sys/psm.h>
28 #include <sys/archsystm.h>
29 #include <sys/apic.h>
30 #include <sys/sunddi.h>
31 #include <sys/ddi_impldefs.h>
32 #include <sys/mach_intr.h>
33 #include <sys/sysmacros.h>
34 #include <sys/trap.h>
35 #include <sys/x86_archext.h>
36 #include <sys/privregs.h>
37 #include <sys/psm_common.h>
38 
39 /* Function prototypes of local apic and X2APIC */
40 static uint64_t local_apic_read(uint32_t reg);
41 static void local_apic_write(uint32_t reg, uint64_t value);
42 static int get_local_apic_pri(void);
43 static void local_apic_write_task_reg(uint64_t value);
44 static void local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);
45 static uint64_t local_x2apic_read(uint32_t msr);
46 static void local_x2apic_write(uint32_t msr, uint64_t value);
47 static int get_local_x2apic_pri(void);
48 static void local_x2apic_write_task_reg(uint64_t value);
49 static void local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1);
50 
51 /*
52  * According to the X2APIC specification:
53  *
54  *   xAPIC global enable    X2APIC enable         Description
55  *   (IA32_APIC_BASE[11])   (IA32_APIC_BASE[10])
56  * -----------------------------------------------------------
57  *      0 			0 	APIC is disabled
58  * 	0			1	Invalid
59  *	1			0	APIC is enabled in xAPIC mode
60  *	1			1	APIC is enabled in X2APIC mode
61  * -----------------------------------------------------------
62  */
63 int	x2apic_enable = 1;
64 int 	apic_mode = LOCAL_APIC;		/* Default mode is Local APIC */
65 
66 /* Uses MMIO (Memory Mapped IO) */
67 static apic_reg_ops_t local_apic_regs_ops = {
68 	local_apic_read,
69 	local_apic_write,
70 	get_local_apic_pri,
71 	local_apic_write_task_reg,
72 	local_apic_write_int_cmd,
73 	apic_send_EOI,
74 };
75 
76 /* X2APIC : Uses RDMSR/WRMSR instructions to access APIC registers */
77 static apic_reg_ops_t x2apic_regs_ops = {
78 	local_x2apic_read,
79 	local_x2apic_write,
80 	get_local_x2apic_pri,
81 	local_x2apic_write_task_reg,
82 	local_x2apic_write_int_cmd,
83 	apic_send_EOI,
84 };
85 
86 int apic_have_32bit_cr8 = 0;
87 
88 /* The default ops is local APIC (Memory Mapped IO) */
89 apic_reg_ops_t *apic_reg_ops = &local_apic_regs_ops;
90 
91 /*
92  * APIC register ops related data sturctures and functions.
93  */
94 void apic_send_EOI();
95 void apic_send_directed_EOI(uint32_t irq);
96 
97 #define	X2APIC_CPUID_BIT	21
98 #define	X2APIC_ENABLE_BIT	10
99 
100 /*
101  * Local APIC Implementation
102  */
103 static uint64_t
104 local_apic_read(uint32_t reg)
105 {
106 	return ((uint32_t)apicadr[reg]);
107 }
108 
109 static void
110 local_apic_write(uint32_t reg, uint64_t value)
111 {
112 	apicadr[reg] = (uint32_t)value;
113 }
114 
115 static int
116 get_local_apic_pri(void)
117 {
118 #if defined(__amd64)
119 	return ((int)getcr8());
120 #else
121 	if (apic_have_32bit_cr8)
122 		return ((int)getcr8());
123 	return (apicadr[APIC_TASK_REG]);
124 #endif
125 }
126 
127 static void
128 local_apic_write_task_reg(uint64_t value)
129 {
130 #if defined(__amd64)
131 	setcr8((ulong_t)(value >> APIC_IPL_SHIFT));
132 #else
133 	if (apic_have_32bit_cr8)
134 		setcr8((ulong_t)(value >> APIC_IPL_SHIFT));
135 	else
136 		apicadr[APIC_TASK_REG] = (uint32_t)value;
137 #endif
138 }
139 
140 static void
141 local_apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
142 {
143 	apicadr[APIC_INT_CMD2] = cpu_id << APIC_ICR_ID_BIT_OFFSET;
144 	apicadr[APIC_INT_CMD1] = cmd1;
145 }
146 
147 /*
148  * X2APIC Implementation.
149  */
150 static uint64_t
151 local_x2apic_read(uint32_t msr)
152 {
153 	uint64_t i;
154 
155 	i = (uint64_t)(rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2)) & 0xffffffff);
156 	return (i);
157 }
158 
159 static void
160 local_x2apic_write(uint32_t msr, uint64_t value)
161 {
162 	uint64_t tmp;
163 
164 	if (msr != APIC_EOI_REG) {
165 		tmp = rdmsr(REG_X2APIC_BASE_MSR + (msr >> 2));
166 		tmp = (tmp & 0xffffffff00000000) | value;
167 	} else {
168 		tmp = 0;
169 	}
170 
171 	wrmsr((REG_X2APIC_BASE_MSR + (msr >> 2)), tmp);
172 }
173 
174 static int
175 get_local_x2apic_pri(void)
176 {
177 	return (rdmsr(REG_X2APIC_BASE_MSR + (APIC_TASK_REG >> 2)));
178 }
179 
180 static void
181 local_x2apic_write_task_reg(uint64_t value)
182 {
183 	X2APIC_WRITE(APIC_TASK_REG, value);
184 }
185 
186 static void
187 local_x2apic_write_int_cmd(uint32_t cpu_id, uint32_t cmd1)
188 {
189 	wrmsr((REG_X2APIC_BASE_MSR + (APIC_INT_CMD1 >> 2)),
190 	    (((uint64_t)cpu_id << 32) | cmd1));
191 }
192 
193 /*ARGSUSED*/
194 void
195 apic_send_EOI(uint32_t irq)
196 {
197 	apic_reg_ops->apic_write(APIC_EOI_REG, 0);
198 }
199 
200 /*
201  * Support for Directed EOI capability is available in both the xAPIC
202  * and x2APIC mode.
203  */
204 void
205 apic_send_directed_EOI(uint32_t irq)
206 {
207 	uchar_t ioapicindex;
208 	uchar_t vector;
209 	apic_irq_t *apic_irq;
210 	short intr_index;
211 
212 	/*
213 	 * Following the EOI to the local APIC unit, perform a directed
214 	 * EOI to the IOxAPIC generating the interrupt by writing to its
215 	 * EOI register.
216 	 *
217 	 * A broadcast EOI is not generated.
218 	 */
219 	apic_reg_ops->apic_write(APIC_EOI_REG, 0);
220 
221 	apic_irq = apic_irq_table[irq];
222 	while (apic_irq) {
223 		intr_index = apic_irq->airq_mps_intr_index;
224 		if (intr_index == ACPI_INDEX || intr_index >= 0) {
225 			ioapicindex = apic_irq->airq_ioapicindex;
226 			vector = apic_irq->airq_vector;
227 			ioapic_write_eoi(ioapicindex, vector);
228 		}
229 		apic_irq = apic_irq->airq_next;
230 	}
231 }
232 
233 int
234 apic_detect_x2apic(void)
235 {
236 	struct cpuid_regs cp;
237 
238 	if (x2apic_enable == 0)
239 		return (0);
240 
241 	cp.cp_eax = 1;
242 	(void) __cpuid_insn(&cp);
243 
244 	return ((cp.cp_ecx & (0x1 << X2APIC_CPUID_BIT)) ? 1 : 0);
245 }
246 
247 void
248 apic_enable_x2apic(void)
249 {
250 	uint64_t apic_base_msr;
251 
252 	if (apic_local_mode() == LOCAL_X2APIC) {
253 		/* BIOS apparently has enabled X2APIC */
254 		if (apic_mode != LOCAL_X2APIC)
255 			x2apic_update_psm();
256 		return;
257 	}
258 
259 	/*
260 	 * This is the first time we are enabling X2APIC on this CPU
261 	 */
262 	apic_base_msr = rdmsr(REG_APIC_BASE_MSR);
263 	apic_base_msr = apic_base_msr | (0x1 << X2APIC_ENABLE_BIT);
264 	wrmsr(REG_APIC_BASE_MSR, apic_base_msr);
265 
266 	if (apic_mode != LOCAL_X2APIC)
267 		x2apic_update_psm();
268 }
269 
270 /*
271  * Determine which mode the current CPU is in. See the table above.
272  * (IA32_APIC_BASE[11])   (IA32_APIC_BASE[10])
273  */
274 int
275 apic_local_mode(void)
276 {
277 	uint64_t apic_base_msr;
278 	int bit = ((0x1 << (X2APIC_ENABLE_BIT + 1)) |
279 	    (0x1 << X2APIC_ENABLE_BIT));
280 
281 	apic_base_msr = rdmsr(REG_APIC_BASE_MSR);
282 
283 	if ((apic_base_msr & bit) == bit)
284 		return (LOCAL_X2APIC);
285 	else
286 		return (LOCAL_APIC);
287 }
288 
289 void
290 apic_set_directed_EOI_handler()
291 {
292 	apic_reg_ops->apic_send_eoi = apic_send_directed_EOI;
293 }
294 
295 int
296 apic_directed_EOI_supported()
297 {
298 	uint32_t ver;
299 
300 	ver = apic_reg_ops->apic_read(APIC_VERS_REG);
301 	if (ver & APIC_DIRECTED_EOI_BIT)
302 		return (1);
303 
304 	return (0);
305 }
306 
307 /*
308  * Change apic_reg_ops depending upon the apic_mode.
309  */
310 void
311 apic_change_ops()
312 {
313 	if (apic_mode == LOCAL_APIC)
314 		apic_reg_ops = &local_apic_regs_ops;
315 	else if (apic_mode == LOCAL_X2APIC)
316 		apic_reg_ops = &x2apic_regs_ops;
317 }
318 
319 /*
320  * Generates an interprocessor interrupt to another CPU when X2APIC mode is
321  * enabled.
322  */
323 void
324 x2apic_send_ipi(int cpun, int ipl)
325 {
326 	int vector;
327 	ulong_t flag;
328 
329 	ASSERT(apic_mode == LOCAL_X2APIC);
330 
331 	/*
332 	 * With X2APIC, Intel relaxed the semantics of the
333 	 * WRMSR instruction such that references to the X2APIC
334 	 * MSR registers are no longer serializing instructions.
335 	 * The code that initiates IPIs assumes that some sort
336 	 * of memory serialization occurs. The old APIC code
337 	 * did a write to uncachable memory mapped registers.
338 	 * Any reference to uncached memory is a serializing
339 	 * operation. To mimic those semantics here, we do an
340 	 * atomic operation, which translates to a LOCK OR instruction,
341 	 * which is serializing.
342 	 */
343 	atomic_or_ulong(&flag, 1);
344 
345 	vector = apic_resv_vector[ipl];
346 
347 	flag = intr_clear();
348 
349 	/*
350 	 * According to X2APIC specification in section '2.3.5.1' of
351 	 * Interrupt Command Register Semantics, the semantics of
352 	 * programming Interrupt Command Register to dispatch an interrupt
353 	 * is simplified. A single MSR write to the 64-bit ICR is required
354 	 * for dispatching an interrupt. Specifically with the 64-bit MSR
355 	 * interface to ICR, system software is not required to check the
356 	 * status of the delivery status bit prior to writing to the ICR
357 	 * to send an IPI. With the removal of the Delivery Status bit,
358 	 * system software no longer has a reason to read the ICR. It remains
359 	 * readable only to aid in debugging.
360 	 */
361 #ifdef	DEBUG
362 	APIC_AV_PENDING_SET();
363 #endif	/* DEBUG */
364 
365 	if ((cpun == psm_get_cpu_id())) {
366 		X2APIC_WRITE(X2APIC_SELF_IPI, vector);
367 	} else {
368 		apic_reg_ops->apic_write_int_cmd(
369 		    apic_cpus[cpun].aci_local_id, vector);
370 	}
371 
372 	intr_restore(flag);
373 }
374 
375 /*
376  * Generates IPI to another CPU depending on the local APIC mode.
377  * apic_send_ipi() and x2apic_send_ipi() depends on the configured
378  * mode of the local APIC, but that may not match the actual mode
379  * early in CPU startup.
380  *
381  * Any changes made to this routine must be accompanied by similar
382  * changes to apic_send_ipi().
383  */
384 void
385 apic_common_send_ipi(int cpun, int ipl)
386 {
387 	int vector;
388 	ulong_t flag;
389 	int mode = apic_local_mode();
390 
391 	if (mode == LOCAL_X2APIC) {
392 		x2apic_send_ipi(cpun, ipl);
393 		return;
394 	}
395 
396 	ASSERT(mode == LOCAL_APIC);
397 
398 	vector = apic_resv_vector[ipl];
399 	ASSERT((vector >= APIC_BASE_VECT) && (vector <= APIC_SPUR_INTR));
400 	flag = intr_clear();
401 	while (local_apic_regs_ops.apic_read(APIC_INT_CMD1) & AV_PENDING)
402 		apic_ret();
403 	local_apic_regs_ops.apic_write_int_cmd(apic_cpus[cpun].aci_local_id,
404 	    vector);
405 	intr_restore(flag);
406 }
407