2 * Copyright (c) 2009, Microsoft Corporation.
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * You should have received a copy of the GNU General Public License along with
14 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
15 * Place - Suite 330, Boston, MA 02111-1307 USA.
18 * Haiyang Zhang <haiyangz@microsoft.com>
19 * Hank Janssen <hjanssen@microsoft.com>
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
24 #include <linux/kernel.h>
26 #include <linux/slab.h>
27 #include <linux/vmalloc.h>
28 #include <linux/hyperv.h>
29 #include <linux/version.h>
30 #include <linux/random.h>
31 #include <linux/clockchips.h>
32 #include <asm/mshyperv.h>
33 #include "hyperv_vmbus.h"
35 /* The one and only */
36 struct hv_context hv_context
;
39 * If false, we're using the old mechanism for stimer0 interrupts
40 * where it sends a VMbus message when it expires. The old
41 * mechanism is used when running on older versions of Hyper-V
42 * that don't support Direct Mode. While Hyper-V provides
43 * four stimer's per CPU, Linux uses only stimer0.
45 static bool direct_mode_enabled
;
46 static int stimer0_irq
;
47 static int stimer0_vector
;
49 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
50 #define HV_MAX_MAX_DELTA_TICKS 0xffffffff
51 #define HV_MIN_DELTA_TICKS 1
54 * hv_init - Main initialization routine.
56 * This routine must be called before any other routines in here are called
60 hv_context
.cpu_context
= alloc_percpu(struct hv_per_cpu_context
);
61 if (!hv_context
.cpu_context
)
64 direct_mode_enabled
= ms_hyperv
.misc_features
&
65 HV_STIMER_DIRECT_MODE_AVAILABLE
;
70 * hv_post_message - Post a message using the hypervisor message IPC.
72 * This involves a hypercall.
74 int hv_post_message(union hv_connection_id connection_id
,
75 enum hv_message_type message_type
,
76 void *payload
, size_t payload_size
)
78 struct hv_input_post_message
*aligned_msg
;
79 struct hv_per_cpu_context
*hv_cpu
;
82 if (payload_size
> HV_MESSAGE_PAYLOAD_BYTE_COUNT
)
85 hv_cpu
= get_cpu_ptr(hv_context
.cpu_context
);
86 aligned_msg
= hv_cpu
->post_msg_page
;
87 aligned_msg
->connectionid
= connection_id
;
88 aligned_msg
->reserved
= 0;
89 aligned_msg
->message_type
= message_type
;
90 aligned_msg
->payload_size
= payload_size
;
91 memcpy((void *)aligned_msg
->payload
, payload
, payload_size
);
93 status
= hv_do_hypercall(HVCALL_POST_MESSAGE
, aligned_msg
, NULL
);
95 /* Preemption must remain disabled until after the hypercall
96 * so some other thread can't get scheduled onto this cpu and
97 * corrupt the per-cpu post_msg_page
101 return status
& 0xFFFF;
105 * ISR for when stimer0 is operating in Direct Mode. Direct Mode
106 * does not use VMbus or any VMbus messages, so process here and not
107 * in the VMbus driver code.
110 static void hv_stimer0_isr(void)
112 struct hv_per_cpu_context
*hv_cpu
;
114 hv_cpu
= this_cpu_ptr(hv_context
.cpu_context
);
115 hv_cpu
->clk_evt
->event_handler(hv_cpu
->clk_evt
);
116 add_interrupt_randomness(stimer0_vector
, 0);
119 static int hv_ce_set_next_event(unsigned long delta
,
120 struct clock_event_device
*evt
)
124 WARN_ON(!clockevent_state_oneshot(evt
));
126 current_tick
= hyperv_cs
->read(NULL
);
127 current_tick
+= delta
;
128 hv_init_timer(0, current_tick
);
132 static int hv_ce_shutdown(struct clock_event_device
*evt
)
135 hv_init_timer_config(0, 0);
136 if (direct_mode_enabled
)
137 hv_disable_stimer0_percpu_irq(stimer0_irq
);
142 static int hv_ce_set_oneshot(struct clock_event_device
*evt
)
144 union hv_stimer_config timer_cfg
;
146 timer_cfg
.as_uint64
= 0;
147 timer_cfg
.enable
= 1;
148 timer_cfg
.auto_enable
= 1;
149 if (direct_mode_enabled
) {
151 * When it expires, the timer will directly interrupt
152 * on the specified hardware vector/IRQ.
154 timer_cfg
.direct_mode
= 1;
155 timer_cfg
.apic_vector
= stimer0_vector
;
156 hv_enable_stimer0_percpu_irq(stimer0_irq
);
159 * When it expires, the timer will generate a VMbus message,
160 * to be handled by the normal VMbus interrupt handler.
162 timer_cfg
.direct_mode
= 0;
163 timer_cfg
.sintx
= VMBUS_MESSAGE_SINT
;
165 hv_init_timer_config(0, timer_cfg
.as_uint64
);
169 static void hv_init_clockevent_device(struct clock_event_device
*dev
, int cpu
)
171 dev
->name
= "Hyper-V clockevent";
172 dev
->features
= CLOCK_EVT_FEAT_ONESHOT
;
173 dev
->cpumask
= cpumask_of(cpu
);
176 * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will
177 * result in clockevents_config_and_register() taking additional
178 * references to the hv_vmbus module making it impossible to unload.
181 dev
->set_state_shutdown
= hv_ce_shutdown
;
182 dev
->set_state_oneshot
= hv_ce_set_oneshot
;
183 dev
->set_next_event
= hv_ce_set_next_event
;
187 int hv_synic_alloc(void)
190 struct hv_per_cpu_context
*hv_cpu
;
193 * First, zero all per-cpu memory areas so hv_synic_free() can
194 * detect what memory has been allocated and cleanup properly
195 * after any failures.
197 for_each_present_cpu(cpu
) {
198 hv_cpu
= per_cpu_ptr(hv_context
.cpu_context
, cpu
);
199 memset(hv_cpu
, 0, sizeof(*hv_cpu
));
202 hv_context
.hv_numa_map
= kcalloc(nr_node_ids
, sizeof(struct cpumask
),
204 if (hv_context
.hv_numa_map
== NULL
) {
205 pr_err("Unable to allocate NUMA map\n");
209 for_each_present_cpu(cpu
) {
210 hv_cpu
= per_cpu_ptr(hv_context
.cpu_context
, cpu
);
212 tasklet_init(&hv_cpu
->msg_dpc
,
213 vmbus_on_msg_dpc
, (unsigned long) hv_cpu
);
215 hv_cpu
->clk_evt
= kzalloc(sizeof(struct clock_event_device
),
217 if (hv_cpu
->clk_evt
== NULL
) {
218 pr_err("Unable to allocate clock event device\n");
221 hv_init_clockevent_device(hv_cpu
->clk_evt
, cpu
);
223 hv_cpu
->synic_message_page
=
224 (void *)get_zeroed_page(GFP_ATOMIC
);
225 if (hv_cpu
->synic_message_page
== NULL
) {
226 pr_err("Unable to allocate SYNIC message page\n");
230 hv_cpu
->synic_event_page
= (void *)get_zeroed_page(GFP_ATOMIC
);
231 if (hv_cpu
->synic_event_page
== NULL
) {
232 pr_err("Unable to allocate SYNIC event page\n");
236 hv_cpu
->post_msg_page
= (void *)get_zeroed_page(GFP_ATOMIC
);
237 if (hv_cpu
->post_msg_page
== NULL
) {
238 pr_err("Unable to allocate post msg page\n");
242 INIT_LIST_HEAD(&hv_cpu
->chan_list
);
245 if (direct_mode_enabled
&&
246 hv_setup_stimer0_irq(&stimer0_irq
, &stimer0_vector
,
253 * Any memory allocations that succeeded will be freed when
254 * the caller cleans up by calling hv_synic_free()
260 void hv_synic_free(void)
264 for_each_present_cpu(cpu
) {
265 struct hv_per_cpu_context
*hv_cpu
266 = per_cpu_ptr(hv_context
.cpu_context
, cpu
);
268 kfree(hv_cpu
->clk_evt
);
269 free_page((unsigned long)hv_cpu
->synic_event_page
);
270 free_page((unsigned long)hv_cpu
->synic_message_page
);
271 free_page((unsigned long)hv_cpu
->post_msg_page
);
274 kfree(hv_context
.hv_numa_map
);
278 * hv_synic_init - Initialize the Synthetic Interrupt Controller.
280 * If it is already initialized by another entity (ie x2v shim), we need to
281 * retrieve the initialized message and event pages. Otherwise, we create and
282 * initialize the message and event pages.
284 int hv_synic_init(unsigned int cpu
)
286 struct hv_per_cpu_context
*hv_cpu
287 = per_cpu_ptr(hv_context
.cpu_context
, cpu
);
288 union hv_synic_simp simp
;
289 union hv_synic_siefp siefp
;
290 union hv_synic_sint shared_sint
;
291 union hv_synic_scontrol sctrl
;
293 /* Setup the Synic's message page */
294 hv_get_simp(simp
.as_uint64
);
295 simp
.simp_enabled
= 1;
296 simp
.base_simp_gpa
= virt_to_phys(hv_cpu
->synic_message_page
)
299 hv_set_simp(simp
.as_uint64
);
301 /* Setup the Synic's event page */
302 hv_get_siefp(siefp
.as_uint64
);
303 siefp
.siefp_enabled
= 1;
304 siefp
.base_siefp_gpa
= virt_to_phys(hv_cpu
->synic_event_page
)
307 hv_set_siefp(siefp
.as_uint64
);
309 /* Setup the shared SINT. */
310 hv_get_synint_state(VMBUS_MESSAGE_SINT
, shared_sint
.as_uint64
);
312 shared_sint
.vector
= HYPERVISOR_CALLBACK_VECTOR
;
313 shared_sint
.masked
= false;
314 if (ms_hyperv
.hints
& HV_DEPRECATING_AEOI_RECOMMENDED
)
315 shared_sint
.auto_eoi
= false;
317 shared_sint
.auto_eoi
= true;
319 hv_set_synint_state(VMBUS_MESSAGE_SINT
, shared_sint
.as_uint64
);
321 /* Enable the global synic bit */
322 hv_get_synic_state(sctrl
.as_uint64
);
325 hv_set_synic_state(sctrl
.as_uint64
);
328 * Register the per-cpu clockevent source.
330 if (ms_hyperv
.features
& HV_MSR_SYNTIMER_AVAILABLE
)
331 clockevents_config_and_register(hv_cpu
->clk_evt
,
334 HV_MAX_MAX_DELTA_TICKS
);
339 * hv_synic_clockevents_cleanup - Cleanup clockevent devices
341 void hv_synic_clockevents_cleanup(void)
345 if (!(ms_hyperv
.features
& HV_MSR_SYNTIMER_AVAILABLE
))
348 if (direct_mode_enabled
)
349 hv_remove_stimer0_irq(stimer0_irq
);
351 for_each_present_cpu(cpu
) {
352 struct hv_per_cpu_context
*hv_cpu
353 = per_cpu_ptr(hv_context
.cpu_context
, cpu
);
355 clockevents_unbind_device(hv_cpu
->clk_evt
, cpu
);
360 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
362 int hv_synic_cleanup(unsigned int cpu
)
364 union hv_synic_sint shared_sint
;
365 union hv_synic_simp simp
;
366 union hv_synic_siefp siefp
;
367 union hv_synic_scontrol sctrl
;
368 struct vmbus_channel
*channel
, *sc
;
369 bool channel_found
= false;
372 hv_get_synic_state(sctrl
.as_uint64
);
373 if (sctrl
.enable
!= 1)
377 * Search for channels which are bound to the CPU we're about to
378 * cleanup. In case we find one and vmbus is still connected we need to
379 * fail, this will effectively prevent CPU offlining. There is no way
380 * we can re-bind channels to different CPUs for now.
382 mutex_lock(&vmbus_connection
.channel_mutex
);
383 list_for_each_entry(channel
, &vmbus_connection
.chn_list
, listentry
) {
384 if (channel
->target_cpu
== cpu
) {
385 channel_found
= true;
388 spin_lock_irqsave(&channel
->lock
, flags
);
389 list_for_each_entry(sc
, &channel
->sc_list
, sc_list
) {
390 if (sc
->target_cpu
== cpu
) {
391 channel_found
= true;
395 spin_unlock_irqrestore(&channel
->lock
, flags
);
399 mutex_unlock(&vmbus_connection
.channel_mutex
);
401 if (channel_found
&& vmbus_connection
.conn_state
== CONNECTED
)
404 /* Turn off clockevent device */
405 if (ms_hyperv
.features
& HV_MSR_SYNTIMER_AVAILABLE
) {
406 struct hv_per_cpu_context
*hv_cpu
407 = this_cpu_ptr(hv_context
.cpu_context
);
409 clockevents_unbind_device(hv_cpu
->clk_evt
, cpu
);
410 hv_ce_shutdown(hv_cpu
->clk_evt
);
413 hv_get_synint_state(VMBUS_MESSAGE_SINT
, shared_sint
.as_uint64
);
415 shared_sint
.masked
= 1;
417 /* Need to correctly cleanup in the case of SMP!!! */
418 /* Disable the interrupt */
419 hv_set_synint_state(VMBUS_MESSAGE_SINT
, shared_sint
.as_uint64
);
421 hv_get_simp(simp
.as_uint64
);
422 simp
.simp_enabled
= 0;
423 simp
.base_simp_gpa
= 0;
425 hv_set_simp(simp
.as_uint64
);
427 hv_get_siefp(siefp
.as_uint64
);
428 siefp
.siefp_enabled
= 0;
429 siefp
.base_siefp_gpa
= 0;
431 hv_set_siefp(siefp
.as_uint64
);
433 /* Disable the global synic bit */
435 hv_set_synic_state(sctrl
.as_uint64
);