Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * arch/arm/kernel/crunch.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Cirrus MaverickCrunch context switching and handling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  * Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) #include <linux/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/sched.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/init.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/io.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <asm/thread_notify.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include "soc.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) struct crunch_state *crunch_owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) void crunch_task_release(struct thread_info *thread)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	local_irq_disable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	if (crunch_owner == &thread->crunchstate)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		crunch_owner = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 	local_irq_enable();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) static int crunch_enabled(u32 devcfg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	return !!(devcfg & EP93XX_SYSCON_DEVCFG_CPENA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static int crunch_do(struct notifier_block *self, unsigned long cmd, void *t)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	struct thread_info *thread = (struct thread_info *)t;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	struct crunch_state *crunch_state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	u32 devcfg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	crunch_state = &thread->crunchstate;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 	case THREAD_NOTIFY_FLUSH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		memset(crunch_state, 0, sizeof(*crunch_state));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 		 * FALLTHROUGH: Ensure we don't try to overwrite our newly
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 		 * initialised state information on the first fault.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		fallthrough;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	case THREAD_NOTIFY_EXIT:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		crunch_task_release(thread);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 	case THREAD_NOTIFY_SWITCH:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		devcfg = __raw_readl(EP93XX_SYSCON_DEVCFG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 		if (crunch_enabled(devcfg) || crunch_owner == crunch_state) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 			/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 			 * We don't use ep93xx_syscon_swlocked_write() here
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 			 * because we are on the context switch path and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 			 * preemption is already disabled.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 			 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 			devcfg ^= EP93XX_SYSCON_DEVCFG_CPENA;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 			__raw_writel(0xaa, EP93XX_SYSCON_SWLOCK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 			__raw_writel(devcfg, EP93XX_SYSCON_DEVCFG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 		break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 	return NOTIFY_DONE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) static struct notifier_block crunch_notifier_block = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 	.notifier_call	= crunch_do,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) int __init crunch_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 	thread_register_notifier(&crunch_notifier_block);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) 	elf_hwcap |= HWCAP_CRUNCH;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) }