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  
52  extern ctxd_t *srmmu_ctx_table_phys;
53  static int smp_processors_ready;
54  extern volatile unsigned long cpu_callin_map[NR_CPUS];
55  extern cpumask_t smp_commenced_mask;
56  void leon_configure_cache_smp(void);
57  static void leon_ipi_init(void);
58  
59  /* IRQ number of LEON IPIs */
60  int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
61  
do_swap(volatile unsigned long * ptr,unsigned long val)62  static 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  
leon_cpu_pre_starting(void * arg)71  void leon_cpu_pre_starting(void *arg)
72  {
73  	leon_configure_cache_smp();
74  }
75  
leon_cpu_pre_online(void * arg)76  void 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  
106  extern struct linux_prom_registers smp_penguin_ctable;
107  
leon_configure_cache_smp(void)108  void 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  
leon_smp_setbroadcast(unsigned int mask)132  static 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  
leon_smp_nrcpus(void)150  int 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  
leon_boot_cpus(void)158  void __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  
leon_boot_one_cpu(int i,struct task_struct * idle)181  int 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  
leon_smp_done(void)228  void __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  
261  struct leon_ipi_work {
262  	int single;
263  	int msk;
264  	int resched;
265  };
266  
267  static 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   */
leon_ipi_init(void)272  static 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  
leon_send_ipi(int cpu,int level)303  static 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  
leon_ipi_single(int cpu)310  static 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  
leon_ipi_mask_one(int cpu)321  static 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  
leon_ipi_resched(int cpu)332  static 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  
leonsmp_ipi_interrupt(void)343  void 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  
361  static 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  
372  static DEFINE_SPINLOCK(cross_call_lock);
373  
374  /* Cross calls must be serialized, at least currently. */
leon_cross_call(void * func,cpumask_t mask,unsigned long arg1,unsigned long arg2,unsigned long arg3,unsigned long arg4)375  static 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. */
leon_cross_call_irq(void)445  void 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  
457  static 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  
leon_init_smp(void)464  void __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