1 // SPDX-License-Identifier: GPL-2.0
3 * linux/arch/alpha/kernel/smp.c
5 * 2001-07-09 Phil Ezolt (Phillip.Ezolt@compaq.com)
6 * Renamed modified smp_call_function to smp_call_function_on_cpu()
7 * Created an function that conforms to the old calling convention
8 * of smp_call_function().
10 * This is helpful for DCPI.
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/module.h>
18 #include <linux/sched/mm.h>
20 #include <linux/err.h>
21 #include <linux/threads.h>
22 #include <linux/smp.h>
23 #include <linux/interrupt.h>
24 #include <linux/init.h>
25 #include <linux/delay.h>
26 #include <linux/spinlock.h>
27 #include <linux/irq.h>
28 #include <linux/cache.h>
29 #include <linux/profile.h>
30 #include <linux/bitops.h>
31 #include <linux/cpu.h>
33 #include <asm/hwrpb.h>
34 #include <asm/ptrace.h>
35 #include <linux/atomic.h>
39 #include <asm/pgtable.h>
40 #include <asm/pgalloc.h>
41 #include <asm/mmu_context.h>
42 #include <asm/tlbflush.h>
50 #define DBGS(args) printk args
55 /* A collection of per-processor data. */
56 struct cpuinfo_alpha cpu_data
[NR_CPUS
];
57 EXPORT_SYMBOL(cpu_data
);
59 /* A collection of single bit ipi messages. */
61 unsigned long bits ____cacheline_aligned
;
62 } ipi_data
[NR_CPUS
] __cacheline_aligned
;
64 enum ipi_message_type
{
70 /* Set to a secondary's cpuid when it comes online. */
71 static int smp_secondary_alive
= 0;
73 int smp_num_probed
; /* Internal processor count */
74 int smp_num_cpus
= 1; /* Number that came online. */
75 EXPORT_SYMBOL(smp_num_cpus
);
78 * Called by both boot and secondaries to move global data into
79 * per-processor storage.
81 static inline void __init
82 smp_store_cpu_info(int cpuid
)
84 cpu_data
[cpuid
].loops_per_jiffy
= loops_per_jiffy
;
85 cpu_data
[cpuid
].last_asn
= ASN_FIRST_VERSION
;
86 cpu_data
[cpuid
].need_new_asn
= 0;
87 cpu_data
[cpuid
].asn_lock
= 0;
91 * Ideally sets up per-cpu profiling hooks. Doesn't do much now...
93 static inline void __init
94 smp_setup_percpu_timer(int cpuid
)
96 cpu_data
[cpuid
].prof_counter
= 1;
97 cpu_data
[cpuid
].prof_multiplier
= 1;
101 wait_boot_cpu_to_stop(int cpuid
)
103 unsigned long stop
= jiffies
+ 10*HZ
;
105 while (time_before(jiffies
, stop
)) {
106 if (!smp_secondary_alive
)
111 printk("wait_boot_cpu_to_stop: FAILED on CPU %d, hanging now\n", cpuid
);
117 * Where secondaries begin a life of C.
122 int cpuid
= hard_smp_processor_id();
124 if (cpu_online(cpuid
)) {
125 printk("??, cpu 0x%x already present??\n", cpuid
);
128 set_cpu_online(cpuid
, true);
130 /* Turn on machine checks. */
133 /* Set trap vectors. */
136 /* Set interrupt vector. */
139 /* Get our local ticker going. */
140 smp_setup_percpu_timer(cpuid
);
143 /* Call platform-specific callin, if specified */
144 if (alpha_mv
.smp_callin
)
145 alpha_mv
.smp_callin();
147 /* All kernel threads share the same mm context. */
149 current
->active_mm
= &init_mm
;
151 /* inform the notifiers about the new cpu */
152 notify_cpu_starting(cpuid
);
154 /* Must have completely accurate bogos. */
157 /* Wait boot CPU to stop with irq enabled before running
159 wait_boot_cpu_to_stop(cpuid
);
163 smp_store_cpu_info(cpuid
);
164 /* Allow master to continue only after we written loops_per_jiffy. */
166 smp_secondary_alive
= 1;
168 DBGS(("smp_callin: commencing CPU %d current %p active_mm %p\n",
169 cpuid
, current
, current
->active_mm
));
172 cpu_startup_entry(CPUHP_AP_ONLINE_IDLE
);
175 /* Wait until hwrpb->txrdy is clear for cpu. Return -1 on timeout. */
177 wait_for_txrdy (unsigned long cpumask
)
179 unsigned long timeout
;
181 if (!(hwrpb
->txrdy
& cpumask
))
184 timeout
= jiffies
+ 10*HZ
;
185 while (time_before(jiffies
, timeout
)) {
186 if (!(hwrpb
->txrdy
& cpumask
))
196 * Send a message to a secondary's console. "START" is one such
197 * interesting message. ;-)
200 send_secondary_console_msg(char *str
, int cpuid
)
202 struct percpu_struct
*cpu
;
203 register char *cp1
, *cp2
;
204 unsigned long cpumask
;
207 cpu
= (struct percpu_struct
*)
209 + hwrpb
->processor_offset
210 + cpuid
* hwrpb
->processor_size
);
212 cpumask
= (1UL << cpuid
);
213 if (wait_for_txrdy(cpumask
))
218 *(unsigned int *)&cpu
->ipc_buffer
[0] = len
;
219 cp1
= (char *) &cpu
->ipc_buffer
[1];
220 memcpy(cp1
, cp2
, len
);
222 /* atomic test and set */
224 set_bit(cpuid
, &hwrpb
->rxrdy
);
226 if (wait_for_txrdy(cpumask
))
231 printk("Processor %x not ready\n", cpuid
);
235 * A secondary console wants to send a message. Receive it.
238 recv_secondary_console_msg(void)
241 unsigned long txrdy
= hwrpb
->txrdy
;
242 char *cp1
, *cp2
, buf
[80];
243 struct percpu_struct
*cpu
;
245 DBGS(("recv_secondary_console_msg: TXRDY 0x%lx.\n", txrdy
));
247 mycpu
= hard_smp_processor_id();
249 for (i
= 0; i
< NR_CPUS
; i
++) {
250 if (!(txrdy
& (1UL << i
)))
253 DBGS(("recv_secondary_console_msg: "
254 "TXRDY contains CPU %d.\n", i
));
256 cpu
= (struct percpu_struct
*)
258 + hwrpb
->processor_offset
259 + i
* hwrpb
->processor_size
);
261 DBGS(("recv_secondary_console_msg: on %d from %d"
262 " HALT_REASON 0x%lx FLAGS 0x%lx\n",
263 mycpu
, i
, cpu
->halt_reason
, cpu
->flags
));
265 cnt
= cpu
->ipc_buffer
[0] >> 32;
266 if (cnt
<= 0 || cnt
>= 80)
267 strcpy(buf
, "<<< BOGUS MSG >>>");
269 cp1
= (char *) &cpu
->ipc_buffer
[1];
271 memcpy(cp2
, cp1
, cnt
);
274 while ((cp2
= strchr(cp2
, '\r')) != 0) {
281 DBGS((KERN_INFO
"recv_secondary_console_msg: on %d "
282 "message is '%s'\n", mycpu
, buf
));
289 * Convince the console to have a secondary cpu begin execution.
292 secondary_cpu_start(int cpuid
, struct task_struct
*idle
)
294 struct percpu_struct
*cpu
;
295 struct pcb_struct
*hwpcb
, *ipcb
;
296 unsigned long timeout
;
298 cpu
= (struct percpu_struct
*)
300 + hwrpb
->processor_offset
301 + cpuid
* hwrpb
->processor_size
);
302 hwpcb
= (struct pcb_struct
*) cpu
->hwpcb
;
303 ipcb
= &task_thread_info(idle
)->pcb
;
305 /* Initialize the CPU's HWPCB to something just good enough for
306 us to get started. Immediately after starting, we'll swpctx
307 to the target idle task's pcb. Reuse the stack in the mean
308 time. Precalculate the target PCBB. */
309 hwpcb
->ksp
= (unsigned long)ipcb
+ sizeof(union thread_union
) - 16;
311 hwpcb
->ptbr
= ipcb
->ptbr
;
314 hwpcb
->unique
= virt_to_phys(ipcb
);
315 hwpcb
->flags
= ipcb
->flags
;
316 hwpcb
->res1
= hwpcb
->res2
= 0;
319 DBGS(("KSP 0x%lx PTBR 0x%lx VPTBR 0x%lx UNIQUE 0x%lx\n",
320 hwpcb
->ksp
, hwpcb
->ptbr
, hwrpb
->vptb
, hwpcb
->unique
));
322 DBGS(("Starting secondary cpu %d: state 0x%lx pal_flags 0x%lx\n",
323 cpuid
, idle
->state
, ipcb
->flags
));
325 /* Setup HWRPB fields that SRM uses to activate secondary CPU */
326 hwrpb
->CPU_restart
= __smp_callin
;
327 hwrpb
->CPU_restart_data
= (unsigned long) __smp_callin
;
329 /* Recalculate and update the HWRPB checksum */
330 hwrpb_update_checksum(hwrpb
);
333 * Send a "start" command to the specified processor.
336 /* SRM III 3.4.1.3 */
337 cpu
->flags
|= 0x22; /* turn on Context Valid and Restart Capable */
338 cpu
->flags
&= ~1; /* turn off Bootstrap In Progress */
341 send_secondary_console_msg("START\r\n", cpuid
);
343 /* Wait 10 seconds for an ACK from the console. */
344 timeout
= jiffies
+ 10*HZ
;
345 while (time_before(jiffies
, timeout
)) {
351 printk(KERN_ERR
"SMP: Processor %d failed to start.\n", cpuid
);
355 DBGS(("secondary_cpu_start: SUCCESS for CPU %d!!!\n", cpuid
));
360 * Bring one cpu online.
363 smp_boot_one_cpu(int cpuid
, struct task_struct
*idle
)
365 unsigned long timeout
;
367 /* Signal the secondary to wait a moment. */
368 smp_secondary_alive
= -1;
370 /* Whirrr, whirrr, whirrrrrrrrr... */
371 if (secondary_cpu_start(cpuid
, idle
))
374 /* Notify the secondary CPU it can run calibrate_delay. */
376 smp_secondary_alive
= 0;
378 /* We've been acked by the console; wait one second for
379 the task to start up for real. */
380 timeout
= jiffies
+ 1*HZ
;
381 while (time_before(jiffies
, timeout
)) {
382 if (smp_secondary_alive
== 1)
388 /* We failed to boot the CPU. */
390 printk(KERN_ERR
"SMP: Processor %d is stuck.\n", cpuid
);
394 /* Another "Red Snapper". */
399 * Called from setup_arch. Detect an SMP system and which processors
405 struct percpu_struct
*cpubase
, *cpu
;
408 if (boot_cpuid
!= 0) {
409 printk(KERN_WARNING
"SMP: Booting off cpu %d instead of 0?\n",
413 if (hwrpb
->nr_processors
> 1) {
416 DBGS(("setup_smp: nr_processors %ld\n",
417 hwrpb
->nr_processors
));
419 cpubase
= (struct percpu_struct
*)
420 ((char*)hwrpb
+ hwrpb
->processor_offset
);
421 boot_cpu_palrev
= cpubase
->pal_revision
;
423 for (i
= 0; i
< hwrpb
->nr_processors
; i
++) {
424 cpu
= (struct percpu_struct
*)
425 ((char *)cpubase
+ i
*hwrpb
->processor_size
);
426 if ((cpu
->flags
& 0x1cc) == 0x1cc) {
428 set_cpu_possible(i
, true);
429 set_cpu_present(i
, true);
430 cpu
->pal_revision
= boot_cpu_palrev
;
433 DBGS(("setup_smp: CPU %d: flags 0x%lx type 0x%lx\n",
434 i
, cpu
->flags
, cpu
->type
));
435 DBGS(("setup_smp: CPU %d: PAL rev 0x%lx\n",
436 i
, cpu
->pal_revision
));
442 printk(KERN_INFO
"SMP: %d CPUs probed -- cpu_present_mask = %lx\n",
443 smp_num_probed
, cpumask_bits(cpu_present_mask
)[0]);
447 * Called by smp_init prepare the secondaries
450 smp_prepare_cpus(unsigned int max_cpus
)
452 /* Take care of some initial bookkeeping. */
453 memset(ipi_data
, 0, sizeof(ipi_data
));
455 current_thread_info()->cpu
= boot_cpuid
;
457 smp_store_cpu_info(boot_cpuid
);
458 smp_setup_percpu_timer(boot_cpuid
);
460 /* Nothing to do on a UP box, or when told not to. */
461 if (smp_num_probed
== 1 || max_cpus
== 0) {
462 init_cpu_possible(cpumask_of(boot_cpuid
));
463 init_cpu_present(cpumask_of(boot_cpuid
));
464 printk(KERN_INFO
"SMP mode deactivated.\n");
468 printk(KERN_INFO
"SMP starting up secondaries.\n");
470 smp_num_cpus
= smp_num_probed
;
474 smp_prepare_boot_cpu(void)
479 __cpu_up(unsigned int cpu
, struct task_struct
*tidle
)
481 smp_boot_one_cpu(cpu
, tidle
);
483 return cpu_online(cpu
) ? 0 : -ENOSYS
;
487 smp_cpus_done(unsigned int max_cpus
)
490 unsigned long bogosum
= 0;
492 for(cpu
= 0; cpu
< NR_CPUS
; cpu
++)
494 bogosum
+= cpu_data
[cpu
].loops_per_jiffy
;
496 printk(KERN_INFO
"SMP: Total of %d processors activated "
497 "(%lu.%02lu BogoMIPS).\n",
499 (bogosum
+ 2500) / (500000/HZ
),
500 ((bogosum
+ 2500) / (5000/HZ
)) % 100);
504 setup_profiling_timer(unsigned int multiplier
)
510 send_ipi_message(const struct cpumask
*to_whom
, enum ipi_message_type operation
)
515 for_each_cpu(i
, to_whom
)
516 set_bit(operation
, &ipi_data
[i
].bits
);
519 for_each_cpu(i
, to_whom
)
524 handle_ipi(struct pt_regs
*regs
)
526 int this_cpu
= smp_processor_id();
527 unsigned long *pending_ipis
= &ipi_data
[this_cpu
].bits
;
531 DBGS(("handle_ipi: on CPU %d ops 0x%lx PC 0x%lx\n",
532 this_cpu
, *pending_ipis
, regs
->pc
));
535 mb(); /* Order interrupt and bit testing. */
536 while ((ops
= xchg(pending_ipis
, 0)) != 0) {
537 mb(); /* Order bit clearing and data access. */
543 which
= __ffs(which
);
551 generic_smp_call_function_interrupt();
558 printk(KERN_CRIT
"Unknown IPI on CPU %d: %lu\n",
564 mb(); /* Order data access and bit testing. */
567 cpu_data
[this_cpu
].ipi_count
++;
570 recv_secondary_console_msg();
574 smp_send_reschedule(int cpu
)
577 if (cpu
== hard_smp_processor_id())
579 "smp_send_reschedule: Sending IPI to self.\n");
581 send_ipi_message(cpumask_of(cpu
), IPI_RESCHEDULE
);
588 cpumask_copy(&to_whom
, cpu_possible_mask
);
589 cpumask_clear_cpu(smp_processor_id(), &to_whom
);
591 if (hard_smp_processor_id() != boot_cpu_id
)
592 printk(KERN_WARNING
"smp_send_stop: Not on boot cpu.\n");
594 send_ipi_message(&to_whom
, IPI_CPU_STOP
);
597 void arch_send_call_function_ipi_mask(const struct cpumask
*mask
)
599 send_ipi_message(mask
, IPI_CALL_FUNC
);
602 void arch_send_call_function_single_ipi(int cpu
)
604 send_ipi_message(cpumask_of(cpu
), IPI_CALL_FUNC
);
608 ipi_imb(void *ignored
)
616 /* Must wait other processors to flush their icache before continue. */
617 on_each_cpu(ipi_imb
, NULL
, 1);
619 EXPORT_SYMBOL(smp_imb
);
622 ipi_flush_tlb_all(void *ignored
)
630 /* Although we don't have any data to pass, we do want to
631 synchronize with the other processors. */
632 on_each_cpu(ipi_flush_tlb_all
, NULL
, 1);
635 #define asn_locked() (cpu_data[smp_processor_id()].asn_lock)
638 ipi_flush_tlb_mm(void *x
)
640 struct mm_struct
*mm
= (struct mm_struct
*) x
;
641 if (mm
== current
->active_mm
&& !asn_locked())
642 flush_tlb_current(mm
);
648 flush_tlb_mm(struct mm_struct
*mm
)
652 if (mm
== current
->active_mm
) {
653 flush_tlb_current(mm
);
654 if (atomic_read(&mm
->mm_users
) <= 1) {
655 int cpu
, this_cpu
= smp_processor_id();
656 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
657 if (!cpu_online(cpu
) || cpu
== this_cpu
)
659 if (mm
->context
[cpu
])
660 mm
->context
[cpu
] = 0;
667 smp_call_function(ipi_flush_tlb_mm
, mm
, 1);
671 EXPORT_SYMBOL(flush_tlb_mm
);
673 struct flush_tlb_page_struct
{
674 struct vm_area_struct
*vma
;
675 struct mm_struct
*mm
;
680 ipi_flush_tlb_page(void *x
)
682 struct flush_tlb_page_struct
*data
= (struct flush_tlb_page_struct
*)x
;
683 struct mm_struct
* mm
= data
->mm
;
685 if (mm
== current
->active_mm
&& !asn_locked())
686 flush_tlb_current_page(mm
, data
->vma
, data
->addr
);
692 flush_tlb_page(struct vm_area_struct
*vma
, unsigned long addr
)
694 struct flush_tlb_page_struct data
;
695 struct mm_struct
*mm
= vma
->vm_mm
;
699 if (mm
== current
->active_mm
) {
700 flush_tlb_current_page(mm
, vma
, addr
);
701 if (atomic_read(&mm
->mm_users
) <= 1) {
702 int cpu
, this_cpu
= smp_processor_id();
703 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
704 if (!cpu_online(cpu
) || cpu
== this_cpu
)
706 if (mm
->context
[cpu
])
707 mm
->context
[cpu
] = 0;
718 smp_call_function(ipi_flush_tlb_page
, &data
, 1);
722 EXPORT_SYMBOL(flush_tlb_page
);
725 flush_tlb_range(struct vm_area_struct
*vma
, unsigned long start
, unsigned long end
)
727 /* On the Alpha we always flush the whole user tlb. */
728 flush_tlb_mm(vma
->vm_mm
);
730 EXPORT_SYMBOL(flush_tlb_range
);
733 ipi_flush_icache_page(void *x
)
735 struct mm_struct
*mm
= (struct mm_struct
*) x
;
736 if (mm
== current
->active_mm
&& !asn_locked())
737 __load_new_mm_context(mm
);
743 flush_icache_user_range(struct vm_area_struct
*vma
, struct page
*page
,
744 unsigned long addr
, int len
)
746 struct mm_struct
*mm
= vma
->vm_mm
;
748 if ((vma
->vm_flags
& VM_EXEC
) == 0)
753 if (mm
== current
->active_mm
) {
754 __load_new_mm_context(mm
);
755 if (atomic_read(&mm
->mm_users
) <= 1) {
756 int cpu
, this_cpu
= smp_processor_id();
757 for (cpu
= 0; cpu
< NR_CPUS
; cpu
++) {
758 if (!cpu_online(cpu
) || cpu
== this_cpu
)
760 if (mm
->context
[cpu
])
761 mm
->context
[cpu
] = 0;
768 smp_call_function(ipi_flush_icache_page
, mm
, 1);