1// SPDX-License-Identifier: GPL-2.0
2/* leon_smp.c: Sparc-Leon SMP support.
3 *
4 * based on sun4m_smp.c
5 * Copyright (C) 1996 David S. Miller (davem@caip.rutgers.edu)
6 * Copyright (C) 2009 Daniel Hellstrom (daniel@gaisler.com) Aeroflex Gaisler AB
7 * Copyright (C) 2009 Konrad Eisele (konrad@gaisler.com) Aeroflex Gaisler AB
8 */
9
10#include <asm/head.h>
11
12#include <linux/kernel.h>
13#include <linux/sched/mm.h>
14#include <linux/threads.h>
15#include <linux/smp.h>
16#include <linux/interrupt.h>
17#include <linux/kernel_stat.h>
18#include <linux/of.h>
19#include <linux/init.h>
20#include <linux/spinlock.h>
21#include <linux/mm.h>
22#include <linux/swap.h>
23#include <linux/profile.h>
24#include <linux/pm.h>
25#include <linux/delay.h>
26#include <linux/gfp.h>
27#include <linux/cpu.h>
28#include <linux/clockchips.h>
29
30#include <asm/cacheflush.h>
31#include <asm/tlbflush.h>
32
33#include <asm/ptrace.h>
34#include <linux/atomic.h>
35#include <asm/irq_regs.h>
36#include <asm/traps.h>
37
38#include <asm/delay.h>
39#include <asm/irq.h>
40#include <asm/page.h>
41#include <asm/oplib.h>
42#include <asm/cpudata.h>
43#include <asm/asi.h>
44#include <asm/leon.h>
45#include <asm/leon_amba.h>
46#include <asm/timer.h>
47
48#include "kernel.h"
49
50#include "irq.h"
51
52extern ctxd_t *srmmu_ctx_table_phys;
53static int smp_processors_ready;
54extern volatile unsigned long cpu_callin_map[NR_CPUS];
55extern cpumask_t smp_commenced_mask;
56void leon_configure_cache_smp(void);
57static void leon_ipi_init(void);
58
59/* IRQ number of LEON IPIs */
60int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
61
62static inline unsigned long do_swap(volatile unsigned long *ptr,
63				    unsigned long val)
64{
65	__asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
66			     : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
67			     : "memory");
68	return val;
69}
70
71void leon_cpu_pre_starting(void *arg)
72{
73	leon_configure_cache_smp();
74}
75
76void leon_cpu_pre_online(void *arg)
77{
78	int cpuid = hard_smp_processor_id();
79
80	/* Allow master to continue. The master will then give us the
81	 * go-ahead by setting the smp_commenced_mask and will wait without
82	 * timeouts until our setup is completed fully (signified by
83	 * our bit being set in the cpu_online_mask).
84	 */
85	do_swap(&cpu_callin_map[cpuid], 1);
86
87	local_ops->cache_all();
88	local_ops->tlb_all();
89
90	/* Fix idle thread fields. */
91	__asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
92			     : "memory" /* paranoid */);
93
94	/* Attach to the address space of init_task. */
95	mmgrab(&init_mm);
96	current->active_mm = &init_mm;
97
98	while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
99		mb();
100}
101
102/*
103 *	Cycle through the processors asking the PROM to start each one.
104 */
105
106extern struct linux_prom_registers smp_penguin_ctable;
107
108void leon_configure_cache_smp(void)
109{
110	unsigned long cfg = sparc_leon3_get_dcachecfg();
111	int me = smp_processor_id();
112
113	if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
114		printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
115		     (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
116		     (unsigned int)cfg, (unsigned int)me);
117		sparc_leon3_disable_cache();
118	} else {
119		if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
120			sparc_leon3_enable_snooping();
121		} else {
122			printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
123			     me);
124			sparc_leon3_disable_cache();
125		}
126	}
127
128	local_ops->cache_all();
129	local_ops->tlb_all();
130}
131
132static void leon_smp_setbroadcast(unsigned int mask)
133{
134	int broadcast =
135	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
136	      LEON3_IRQMPSTATUS_BROADCAST) & 1);
137	if (!broadcast) {
138		prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
139		     leon_smp_nrcpus());
140		if (leon_smp_nrcpus() > 1) {
141			BUG();
142		} else {
143			prom_printf("continue anyway\n");
144			return;
145		}
146	}
147	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
148}
149
150int leon_smp_nrcpus(void)
151{
152	int nrcpu =
153	    ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
154	      LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
155	return nrcpu;
156}
157
158void __init leon_boot_cpus(void)
159{
160	int nrcpu = leon_smp_nrcpus();
161	int me = smp_processor_id();
162
163	/* Setup IPI */
164	leon_ipi_init();
165
166	printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
167	       (unsigned int)nrcpu, (unsigned int)NR_CPUS,
168	       (unsigned int)&(leon3_irqctrl_regs->mpstatus));
169
170	leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
171	leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
172	leon_enable_irq_cpu(leon_ipi_irq, me);
173
174	leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
175
176	leon_configure_cache_smp();
177	local_ops->cache_all();
178
179}
180
181int leon_boot_one_cpu(int i, struct task_struct *idle)
182{
183	int timeout;
184
185	current_set[i] = task_thread_info(idle);
186
187	/* See trampoline.S:leon_smp_cpu_startup for details...
188	 * Initialize the contexts table
189	 * Since the call to prom_startcpu() trashes the structure,
190	 * we need to re-initialize it for each cpu
191	 */
192	smp_penguin_ctable.which_io = 0;
193	smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
194	smp_penguin_ctable.reg_size = 0;
195
196	/* whirrr, whirrr, whirrrrrrrrr... */
197	printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
198	       (unsigned int)&leon3_irqctrl_regs->mpstatus);
199	local_ops->cache_all();
200
201	/* Make sure all IRQs are of from the start for this new CPU */
202	LEON_BYPASS_STORE_PA(&leon3_irqctrl_regs->mask[i], 0);
203
204	/* Wake one CPU */
205	LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
206
207	/* wheee... it's going... */
208	for (timeout = 0; timeout < 10000; timeout++) {
209		if (cpu_callin_map[i])
210			break;
211		udelay(200);
212	}
213	printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
214
215	if (!(cpu_callin_map[i])) {
216		printk(KERN_ERR "Processor %d is stuck.\n", i);
217		return -ENODEV;
218	} else {
219		leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
220		leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
221		leon_enable_irq_cpu(leon_ipi_irq, i);
222	}
223
224	local_ops->cache_all();
225	return 0;
226}
227
228void __init leon_smp_done(void)
229{
230
231	int i, first;
232	int *prev;
233
234	/* setup cpu list for irq rotation */
235	first = 0;
236	prev = &first;
237	for (i = 0; i < NR_CPUS; i++) {
238		if (cpu_online(i)) {
239			*prev = i;
240			prev = &cpu_data(i).next;
241		}
242	}
243	*prev = first;
244	local_ops->cache_all();
245
246	/* Free unneeded trap tables */
247	if (!cpu_present(1)) {
248		free_reserved_page(virt_to_page(&trapbase_cpu1[0]));
249	}
250	if (!cpu_present(2)) {
251		free_reserved_page(virt_to_page(&trapbase_cpu2[0]));
252	}
253	if (!cpu_present(3)) {
254		free_reserved_page(virt_to_page(&trapbase_cpu3[0]));
255	}
256	/* Ok, they are spinning and ready to go. */
257	smp_processors_ready = 1;
258
259}
260
261struct leon_ipi_work {
262	int single;
263	int msk;
264	int resched;
265};
266
267static DEFINE_PER_CPU_SHARED_ALIGNED(struct leon_ipi_work, leon_ipi_work);
268
269/* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
270 * is used for all three types of IPIs.
271 */
272static void __init leon_ipi_init(void)
273{
274	int cpu, len;
275	struct leon_ipi_work *work;
276	struct property *pp;
277	struct device_node *rootnp;
278	struct tt_entry *trap_table;
279	unsigned long flags;
280
281	/* Find IPI IRQ or stick with default value */
282	rootnp = of_find_node_by_path("/ambapp0");
283	if (rootnp) {
284		pp = of_find_property(rootnp, "ipi_num", &len);
285		if (pp && (*(int *)pp->value))
286			leon_ipi_irq = *(int *)pp->value;
287	}
288	printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
289
290	/* Adjust so that we jump directly to smpleon_ipi */
291	local_irq_save(flags);
292	trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
293	trap_table->inst_three += smpleon_ipi - real_irq_entry;
294	local_ops->cache_all();
295	local_irq_restore(flags);
296
297	for_each_possible_cpu(cpu) {
298		work = &per_cpu(leon_ipi_work, cpu);
299		work->single = work->msk = work->resched = 0;
300	}
301}
302
303static void leon_send_ipi(int cpu, int level)
304{
305	unsigned long mask;
306	mask = leon_get_irqmask(level);
307	LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
308}
309
310static void leon_ipi_single(int cpu)
311{
312	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
313
314	/* Mark work */
315	work->single = 1;
316
317	/* Generate IRQ on the CPU */
318	leon_send_ipi(cpu, leon_ipi_irq);
319}
320
321static void leon_ipi_mask_one(int cpu)
322{
323	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
324
325	/* Mark work */
326	work->msk = 1;
327
328	/* Generate IRQ on the CPU */
329	leon_send_ipi(cpu, leon_ipi_irq);
330}
331
332static void leon_ipi_resched(int cpu)
333{
334	struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
335
336	/* Mark work */
337	work->resched = 1;
338
339	/* Generate IRQ on the CPU (any IRQ will cause resched) */
340	leon_send_ipi(cpu, leon_ipi_irq);
341}
342
343void leonsmp_ipi_interrupt(void)
344{
345	struct leon_ipi_work *work = this_cpu_ptr(&leon_ipi_work);
346
347	if (work->single) {
348		work->single = 0;
349		smp_call_function_single_interrupt();
350	}
351	if (work->msk) {
352		work->msk = 0;
353		smp_call_function_interrupt();
354	}
355	if (work->resched) {
356		work->resched = 0;
357		smp_resched_interrupt();
358	}
359}
360
361static struct smp_funcall {
362	void *func;
363	unsigned long arg1;
364	unsigned long arg2;
365	unsigned long arg3;
366	unsigned long arg4;
367	unsigned long arg5;
368	unsigned long processors_in[NR_CPUS];	/* Set when ipi entered. */
369	unsigned long processors_out[NR_CPUS];	/* Set when ipi exited. */
370} ccall_info __attribute__((aligned(8)));
371
372static DEFINE_SPINLOCK(cross_call_lock);
373
374/* Cross calls must be serialized, at least currently. */
375static void leon_cross_call(void *func, cpumask_t mask, unsigned long arg1,
376			    unsigned long arg2, unsigned long arg3,
377			    unsigned long arg4)
378{
379	if (smp_processors_ready) {
380		register int high = NR_CPUS - 1;
381		unsigned long flags;
382
383		spin_lock_irqsave(&cross_call_lock, flags);
384
385		{
386			/* If you make changes here, make sure gcc generates proper code... */
387			register void *f asm("i0") = func;
388			register unsigned long a1 asm("i1") = arg1;
389			register unsigned long a2 asm("i2") = arg2;
390			register unsigned long a3 asm("i3") = arg3;
391			register unsigned long a4 asm("i4") = arg4;
392			register unsigned long a5 asm("i5") = 0;
393
394			__asm__ __volatile__("std %0, [%6]\n\t"
395					     "std %2, [%6 + 8]\n\t"
396					     "std %4, [%6 + 16]\n\t" : :
397					     "r"(f), "r"(a1), "r"(a2), "r"(a3),
398					     "r"(a4), "r"(a5),
399					     "r"(&ccall_info.func));
400		}
401
402		/* Init receive/complete mapping, plus fire the IPI's off. */
403		{
404			register int i;
405
406			cpumask_clear_cpu(smp_processor_id(), &mask);
407			cpumask_and(&mask, cpu_online_mask, &mask);
408			for (i = 0; i <= high; i++) {
409				if (cpumask_test_cpu(i, &mask)) {
410					ccall_info.processors_in[i] = 0;
411					ccall_info.processors_out[i] = 0;
412					leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
413
414				}
415			}
416		}
417
418		{
419			register int i;
420
421			i = 0;
422			do {
423				if (!cpumask_test_cpu(i, &mask))
424					continue;
425
426				while (!ccall_info.processors_in[i])
427					barrier();
428			} while (++i <= high);
429
430			i = 0;
431			do {
432				if (!cpumask_test_cpu(i, &mask))
433					continue;
434
435				while (!ccall_info.processors_out[i])
436					barrier();
437			} while (++i <= high);
438		}
439
440		spin_unlock_irqrestore(&cross_call_lock, flags);
441	}
442}
443
444/* Running cross calls. */
445void leon_cross_call_irq(void)
446{
447	void (*func)(unsigned long, unsigned long, unsigned long, unsigned long,
448		     unsigned long) = ccall_info.func;
449	int i = smp_processor_id();
450
451	ccall_info.processors_in[i] = 1;
452	func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3, ccall_info.arg4,
453	     ccall_info.arg5);
454	ccall_info.processors_out[i] = 1;
455}
456
457static const struct sparc32_ipi_ops leon_ipi_ops = {
458	.cross_call = leon_cross_call,
459	.resched    = leon_ipi_resched,
460	.single     = leon_ipi_single,
461	.mask_one   = leon_ipi_mask_one,
462};
463
464void __init leon_init_smp(void)
465{
466	/* Patch ipi15 trap table */
467	t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
468
469	sparc32_ipi_ops = &leon_ipi_ops;
470}
471