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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-14 16:05:21 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-14 16:05:21 -0500
commit4964e0664c80680fa6b28ef91381c076a5b25c2c (patch)
tree62099c5aaeee7274bcc66bcfba35d479affa97cf /arch/mips/kernel/smp-bmips.c
parent0a80939b3e6af4b0dc93bf88ec02fd7e90a16f1b (diff)
parent7bf6612e8a9d6a0b3b82e8e2611942be1258b307 (diff)
Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (119 commits) MIPS: Delete unused function add_temporary_entry. MIPS: Set default pci cache line size. MIPS: Flush huge TLB MIPS: Octeon: Remove SYS_SUPPORTS_HIGHMEM. MIPS: Octeon: Add support for OCTEON II PCIe MIPS: Octeon: Update PCI Latency timer and enable more error reporting. MIPS: Alchemy: Update cpu-feature-overrides MIPS: Alchemy: db1200: Improve PB1200 detection. MIPS: Alchemy: merge Au1000 and Au1300-style IRQ controller code. MIPS: Alchemy: chain IRQ controllers to MIPS IRQ controller MIPS: Alchemy: irq: register pm at irq init time MIPS: Alchemy: Touchscreen support on DB1100 MIPS: Alchemy: Hook up IrDA on DB1000/DB1100 net/irda: convert au1k_ir to platform driver. MIPS: Alchemy: remove unused board headers MTD: nand: make au1550nd.c a platform_driver MIPS: Netlogic: Mark Netlogic chips as SMT capable MIPS: Netlogic: Add support for XLP 3XX cores MIPS: Netlogic: Merge some of XLR/XLP wakup code MIPS: Netlogic: Add default XLP config. ... Fix up trivial conflicts in arch/mips/kernel/{perf_event_mipsxx.c, traps.c} and drivers/tty/serial/Makefile
Diffstat (limited to 'arch/mips/kernel/smp-bmips.c')
-rw-r--r--arch/mips/kernel/smp-bmips.c458
1 files changed, 458 insertions, 0 deletions
diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c
new file mode 100644
index 000000000000..58fe71afd879
--- /dev/null
+++ b/arch/mips/kernel/smp-bmips.c
@@ -0,0 +1,458 @@
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 2011 by Kevin Cernekee (cernekee@gmail.com)
7 *
8 * SMP support for BMIPS
9 */
10
11#include <linux/version.h>
12#include <linux/init.h>
13#include <linux/sched.h>
14#include <linux/mm.h>
15#include <linux/delay.h>
16#include <linux/smp.h>
17#include <linux/interrupt.h>
18#include <linux/spinlock.h>
19#include <linux/init.h>
20#include <linux/cpu.h>
21#include <linux/cpumask.h>
22#include <linux/reboot.h>
23#include <linux/io.h>
24#include <linux/compiler.h>
25#include <linux/linkage.h>
26#include <linux/bug.h>
27#include <linux/kernel.h>
28
29#include <asm/time.h>
30#include <asm/pgtable.h>
31#include <asm/processor.h>
32#include <asm/system.h>
33#include <asm/bootinfo.h>
34#include <asm/pmon.h>
35#include <asm/cacheflush.h>
36#include <asm/tlbflush.h>
37#include <asm/mipsregs.h>
38#include <asm/bmips.h>
39#include <asm/traps.h>
40#include <asm/barrier.h>
41
42static int __maybe_unused max_cpus = 1;
43
44/* these may be configured by the platform code */
45int bmips_smp_enabled = 1;
46int bmips_cpu_offset;
47cpumask_t bmips_booted_mask;
48
49#ifdef CONFIG_SMP
50
51/* initial $sp, $gp - used by arch/mips/kernel/bmips_vec.S */
52unsigned long bmips_smp_boot_sp;
53unsigned long bmips_smp_boot_gp;
54
55static void bmips_send_ipi_single(int cpu, unsigned int action);
56static irqreturn_t bmips_ipi_interrupt(int irq, void *dev_id);
57
58/* SW interrupts 0,1 are used for interprocessor signaling */
59#define IPI0_IRQ (MIPS_CPU_IRQ_BASE + 0)
60#define IPI1_IRQ (MIPS_CPU_IRQ_BASE + 1)
61
62#define CPUNUM(cpu, shift) (((cpu) + bmips_cpu_offset) << (shift))
63#define ACTION_CLR_IPI(cpu, ipi) (0x2000 | CPUNUM(cpu, 9) | ((ipi) << 8))
64#define ACTION_SET_IPI(cpu, ipi) (0x3000 | CPUNUM(cpu, 9) | ((ipi) << 8))
65#define ACTION_BOOT_THREAD(cpu) (0x08 | CPUNUM(cpu, 0))
66
67static void __init bmips_smp_setup(void)
68{
69 int i;
70
71#if defined(CONFIG_CPU_BMIPS4350) || defined(CONFIG_CPU_BMIPS4380)
72 /* arbitration priority */
73 clear_c0_brcm_cmt_ctrl(0x30);
74
75 /* NBK and weak order flags */
76 set_c0_brcm_config_0(0x30000);
77
78 /*
79 * MIPS interrupts 0,1 (SW INT 0,1) cross over to the other thread
80 * MIPS interrupt 2 (HW INT 0) is the CPU0 L1 controller output
81 * MIPS interrupt 3 (HW INT 1) is the CPU1 L1 controller output
82 */
83 change_c0_brcm_cmt_intr(0xf8018000,
84 (0x02 << 27) | (0x03 << 15));
85
86 /* single core, 2 threads (2 pipelines) */
87 max_cpus = 2;
88#elif defined(CONFIG_CPU_BMIPS5000)
89 /* enable raceless SW interrupts */
90 set_c0_brcm_config(0x03 << 22);
91
92 /* route HW interrupt 0 to CPU0, HW interrupt 1 to CPU1 */
93 change_c0_brcm_mode(0x1f << 27, 0x02 << 27);
94
95 /* N cores, 2 threads per core */
96 max_cpus = (((read_c0_brcm_config() >> 6) & 0x03) + 1) << 1;
97
98 /* clear any pending SW interrupts */
99 for (i = 0; i < max_cpus; i++) {
100 write_c0_brcm_action(ACTION_CLR_IPI(i, 0));
101 write_c0_brcm_action(ACTION_CLR_IPI(i, 1));
102 }
103#endif
104
105 if (!bmips_smp_enabled)
106 max_cpus = 1;
107
108 /* this can be overridden by the BSP */
109 if (!board_ebase_setup)
110 board_ebase_setup = &bmips_ebase_setup;
111
112 for (i = 0; i < max_cpus; i++) {
113 __cpu_number_map[i] = 1;
114 __cpu_logical_map[i] = 1;
115 set_cpu_possible(i, 1);
116 set_cpu_present(i, 1);
117 }
118}
119
120/*
121 * IPI IRQ setup - runs on CPU0
122 */
123static void bmips_prepare_cpus(unsigned int max_cpus)
124{
125 if (request_irq(IPI0_IRQ, bmips_ipi_interrupt, IRQF_PERCPU,
126 "smp_ipi0", NULL))
127 panic("Can't request IPI0 interrupt\n");
128 if (request_irq(IPI1_IRQ, bmips_ipi_interrupt, IRQF_PERCPU,
129 "smp_ipi1", NULL))
130 panic("Can't request IPI1 interrupt\n");
131}
132
133/*
134 * Tell the hardware to boot CPUx - runs on CPU0
135 */
136static void bmips_boot_secondary(int cpu, struct task_struct *idle)
137{
138 bmips_smp_boot_sp = __KSTK_TOS(idle);
139 bmips_smp_boot_gp = (unsigned long)task_thread_info(idle);
140 mb();
141
142 /*
143 * Initial boot sequence for secondary CPU:
144 * bmips_reset_nmi_vec @ a000_0000 ->
145 * bmips_smp_entry ->
146 * plat_wired_tlb_setup (cached function call; optional) ->
147 * start_secondary (cached jump)
148 *
149 * Warm restart sequence:
150 * play_dead WAIT loop ->
151 * bmips_smp_int_vec @ BMIPS_WARM_RESTART_VEC ->
152 * eret to play_dead ->
153 * bmips_secondary_reentry ->
154 * start_secondary
155 */
156
157 pr_info("SMP: Booting CPU%d...\n", cpu);
158
159 if (cpumask_test_cpu(cpu, &bmips_booted_mask))
160 bmips_send_ipi_single(cpu, 0);
161 else {
162#if defined(CONFIG_CPU_BMIPS4350) || defined(CONFIG_CPU_BMIPS4380)
163 set_c0_brcm_cmt_ctrl(0x01);
164#elif defined(CONFIG_CPU_BMIPS5000)
165 if (cpu & 0x01)
166 write_c0_brcm_action(ACTION_BOOT_THREAD(cpu));
167 else {
168 /*
169 * core N thread 0 was already booted; just
170 * pulse the NMI line
171 */
172 bmips_write_zscm_reg(0x210, 0xc0000000);
173 udelay(10);
174 bmips_write_zscm_reg(0x210, 0x00);
175 }
176#endif
177 cpumask_set_cpu(cpu, &bmips_booted_mask);
178 }
179}
180
181/*
182 * Early setup - runs on secondary CPU after cache probe
183 */
184static void bmips_init_secondary(void)
185{
186 /* move NMI vector to kseg0, in case XKS01 is enabled */
187
188#if defined(CONFIG_CPU_BMIPS4350) || defined(CONFIG_CPU_BMIPS4380)
189 void __iomem *cbr = BMIPS_GET_CBR();
190 unsigned long old_vec;
191
192 old_vec = __raw_readl(cbr + BMIPS_RELO_VECTOR_CONTROL_1);
193 __raw_writel(old_vec & ~0x20000000, cbr + BMIPS_RELO_VECTOR_CONTROL_1);
194
195 clear_c0_cause(smp_processor_id() ? C_SW1 : C_SW0);
196#elif defined(CONFIG_CPU_BMIPS5000)
197 write_c0_brcm_bootvec(read_c0_brcm_bootvec() &
198 (smp_processor_id() & 0x01 ? ~0x20000000 : ~0x2000));
199
200 write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), 0));
201#endif
202
203 /* make sure there won't be a timer interrupt for a little while */
204 write_c0_compare(read_c0_count() + mips_hpt_frequency / HZ);
205
206 irq_enable_hazard();
207 set_c0_status(IE_SW0 | IE_SW1 | IE_IRQ1 | IE_IRQ5 | ST0_IE);
208 irq_enable_hazard();
209}
210
211/*
212 * Late setup - runs on secondary CPU before entering the idle loop
213 */
214static void bmips_smp_finish(void)
215{
216 pr_info("SMP: CPU%d is running\n", smp_processor_id());
217}
218
219/*
220 * Runs on CPU0 after all CPUs have been booted
221 */
222static void bmips_cpus_done(void)
223{
224}
225
226#if defined(CONFIG_CPU_BMIPS5000)
227
228/*
229 * BMIPS5000 raceless IPIs
230 *
231 * Each CPU has two inbound SW IRQs which are independent of all other CPUs.
232 * IPI0 is used for SMP_RESCHEDULE_YOURSELF
233 * IPI1 is used for SMP_CALL_FUNCTION
234 */
235
236static void bmips_send_ipi_single(int cpu, unsigned int action)
237{
238 write_c0_brcm_action(ACTION_SET_IPI(cpu, action == SMP_CALL_FUNCTION));
239}
240
241static irqreturn_t bmips_ipi_interrupt(int irq, void *dev_id)
242{
243 int action = irq - IPI0_IRQ;
244
245 write_c0_brcm_action(ACTION_CLR_IPI(smp_processor_id(), action));
246
247 if (action == 0)
248 scheduler_ipi();
249 else
250 smp_call_function_interrupt();
251
252 return IRQ_HANDLED;
253}
254
255#else
256
257/*
258 * BMIPS43xx racey IPIs
259 *
260 * We use one inbound SW IRQ for each CPU.
261 *
262 * A spinlock must be held in order to keep CPUx from accidentally clearing
263 * an incoming IPI when it writes CP0 CAUSE to raise an IPI on CPUy. The
264 * same spinlock is used to protect the action masks.
265 */
266
267static DEFINE_SPINLOCK(ipi_lock);
268static DEFINE_PER_CPU(int, ipi_action_mask);
269
270static void bmips_send_ipi_single(int cpu, unsigned int action)
271{
272 unsigned long flags;
273
274 spin_lock_irqsave(&ipi_lock, flags);
275 set_c0_cause(cpu ? C_SW1 : C_SW0);
276 per_cpu(ipi_action_mask, cpu) |= action;
277 irq_enable_hazard();
278 spin_unlock_irqrestore(&ipi_lock, flags);
279}
280
281static irqreturn_t bmips_ipi_interrupt(int irq, void *dev_id)
282{
283 unsigned long flags;
284 int action, cpu = irq - IPI0_IRQ;
285
286 spin_lock_irqsave(&ipi_lock, flags);
287 action = __get_cpu_var(ipi_action_mask);
288 per_cpu(ipi_action_mask, cpu) = 0;
289 clear_c0_cause(cpu ? C_SW1 : C_SW0);
290 spin_unlock_irqrestore(&ipi_lock, flags);
291
292 if (action & SMP_RESCHEDULE_YOURSELF)
293 scheduler_ipi();
294 if (action & SMP_CALL_FUNCTION)
295 smp_call_function_interrupt();
296
297 return IRQ_HANDLED;
298}
299
300#endif /* BMIPS type */
301
302static void bmips_send_ipi_mask(const struct cpumask *mask,
303 unsigned int action)
304{
305 unsigned int i;
306
307 for_each_cpu(i, mask)
308 bmips_send_ipi_single(i, action);
309}
310
311#ifdef CONFIG_HOTPLUG_CPU
312
313static int bmips_cpu_disable(void)
314{
315 unsigned int cpu = smp_processor_id();
316
317 if (cpu == 0)
318 return -EBUSY;
319
320 pr_info("SMP: CPU%d is offline\n", cpu);
321
322 cpu_clear(cpu, cpu_online_map);
323 cpu_clear(cpu, cpu_callin_map);
324
325 local_flush_tlb_all();
326 local_flush_icache_range(0, ~0);
327
328 return 0;
329}
330
331static void bmips_cpu_die(unsigned int cpu)
332{
333}
334
335void __ref play_dead(void)
336{
337 idle_task_exit();
338
339 /* flush data cache */
340 _dma_cache_wback_inv(0, ~0);
341
342 /*
343 * Wakeup is on SW0 or SW1; disable everything else
344 * Use BEV !IV (BMIPS_WARM_RESTART_VEC) to avoid the regular Linux
345 * IRQ handlers; this clears ST0_IE and returns immediately.
346 */
347 clear_c0_cause(CAUSEF_IV | C_SW0 | C_SW1);
348 change_c0_status(IE_IRQ5 | IE_IRQ1 | IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV,
349 IE_SW0 | IE_SW1 | ST0_IE | ST0_BEV);
350 irq_disable_hazard();
351
352 /*
353 * wait for SW interrupt from bmips_boot_secondary(), then jump
354 * back to start_secondary()
355 */
356 __asm__ __volatile__(
357 " wait\n"
358 " j bmips_secondary_reentry\n"
359 : : : "memory");
360}
361
362#endif /* CONFIG_HOTPLUG_CPU */
363
364struct plat_smp_ops bmips_smp_ops = {
365 .smp_setup = bmips_smp_setup,
366 .prepare_cpus = bmips_prepare_cpus,
367 .boot_secondary = bmips_boot_secondary,
368 .smp_finish = bmips_smp_finish,
369 .init_secondary = bmips_init_secondary,
370 .cpus_done = bmips_cpus_done,
371 .send_ipi_single = bmips_send_ipi_single,
372 .send_ipi_mask = bmips_send_ipi_mask,
373#ifdef CONFIG_HOTPLUG_CPU
374 .cpu_disable = bmips_cpu_disable,
375 .cpu_die = bmips_cpu_die,
376#endif
377};
378
379#endif /* CONFIG_SMP */
380
381/***********************************************************************
382 * BMIPS vector relocation
383 * This is primarily used for SMP boot, but it is applicable to some
384 * UP BMIPS systems as well.
385 ***********************************************************************/
386
387static void __cpuinit bmips_wr_vec(unsigned long dst, char *start, char *end)
388{
389 memcpy((void *)dst, start, end - start);
390 dma_cache_wback((unsigned long)start, end - start);
391 local_flush_icache_range(dst, dst + (end - start));
392 instruction_hazard();
393}
394
395static inline void __cpuinit bmips_nmi_handler_setup(void)
396{
397 bmips_wr_vec(BMIPS_NMI_RESET_VEC, &bmips_reset_nmi_vec,
398 &bmips_reset_nmi_vec_end);
399 bmips_wr_vec(BMIPS_WARM_RESTART_VEC, &bmips_smp_int_vec,
400 &bmips_smp_int_vec_end);
401}
402
403void __cpuinit bmips_ebase_setup(void)
404{
405 unsigned long new_ebase = ebase;
406 void __iomem __maybe_unused *cbr;
407
408 BUG_ON(ebase != CKSEG0);
409
410#if defined(CONFIG_CPU_BMIPS4350)
411 /*
412 * BMIPS4350 cannot relocate the normal vectors, but it
413 * can relocate the BEV=1 vectors. So CPU1 starts up at
414 * the relocated BEV=1, IV=0 general exception vector @
415 * 0xa000_0380.
416 *
417 * set_uncached_handler() is used here because:
418 * - CPU1 will run this from uncached space
419 * - None of the cacheflush functions are set up yet
420 */
421 set_uncached_handler(BMIPS_WARM_RESTART_VEC - CKSEG0,
422 &bmips_smp_int_vec, 0x80);
423 __sync();
424 return;
425#elif defined(CONFIG_CPU_BMIPS4380)
426 /*
427 * 0x8000_0000: reset/NMI (initially in kseg1)
428 * 0x8000_0400: normal vectors
429 */
430 new_ebase = 0x80000400;
431 cbr = BMIPS_GET_CBR();
432 __raw_writel(0x80080800, cbr + BMIPS_RELO_VECTOR_CONTROL_0);
433 __raw_writel(0xa0080800, cbr + BMIPS_RELO_VECTOR_CONTROL_1);
434#elif defined(CONFIG_CPU_BMIPS5000)
435 /*
436 * 0x8000_0000: reset/NMI (initially in kseg1)
437 * 0x8000_1000: normal vectors
438 */
439 new_ebase = 0x80001000;
440 write_c0_brcm_bootvec(0xa0088008);
441 write_c0_ebase(new_ebase);
442 if (max_cpus > 2)
443 bmips_write_zscm_reg(0xa0, 0xa008a008);
444#else
445 return;
446#endif
447 board_nmi_handler_setup = &bmips_nmi_handler_setup;
448 ebase = new_ebase;
449}
450
451asmlinkage void __weak plat_wired_tlb_setup(void)
452{
453 /*
454 * Called when starting/restarting a secondary CPU.
455 * Kernel stacks and other important data might only be accessible
456 * once the wired entries are present.
457 */
458}