Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2)  * This file is subject to the terms and conditions of the GNU General Public
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * License.  See the file "COPYING" in the main directory of this archive
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  * for more details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Copyright (C) 2005, 06 Ralf Baechle (ralf@linux-mips.org)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * Copyright (C) 2013 Imagination Technologies Ltd.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/syscalls.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/moduleloader.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/atomic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/sched/signal.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include <asm/mipsmtregs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include <asm/mips_mt.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) #include <asm/processor.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) #include <asm/rtlx.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) #include <asm/setup.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22) #include <asm/vpe.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24) static int sp_stopping;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25) struct rtlx_info *rtlx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) struct chan_waitqueues channel_wqs[RTLX_CHANNELS];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) struct vpe_notifications rtlx_notify;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) void (*aprp_hook)(void) = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) EXPORT_SYMBOL(aprp_hook);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) static void __used dump_rtlx(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	pr_info("id 0x%lx state %d\n", rtlx->id, rtlx->state);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	for (i = 0; i < RTLX_CHANNELS; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) 		struct rtlx_channel *chan = &rtlx->channel[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) 		pr_info(" rt_state %d lx_state %d buffer_size %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) 			chan->rt_state, chan->lx_state, chan->buffer_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 		pr_info(" rt_read %d rt_write %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) 			chan->rt_read, chan->rt_write);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 		pr_info(" lx_read %d lx_write %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) 			chan->lx_read, chan->lx_write);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 		pr_info(" rt_buffer <%s>\n", chan->rt_buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 		pr_info(" lx_buffer <%s>\n", chan->lx_buffer);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) /* call when we have the address of the shared structure from the SP side. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) static int rtlx_init(struct rtlx_info *rtlxi)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	if (rtlxi->id != RTLX_ID) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) 		pr_err("no valid RTLX id at 0x%p 0x%lx\n", rtlxi, rtlxi->id);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 		return -ENOEXEC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	rtlx = rtlxi;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) /* notifications */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) void rtlx_starting(int vpe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	sp_stopping = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) 	/* force a reload of rtlx */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 	rtlx = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) 	/* wake up any sleeping rtlx_open's */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	for (i = 0; i < RTLX_CHANNELS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 		wake_up_interruptible(&channel_wqs[i].lx_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) void rtlx_stopping(int vpe)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	sp_stopping = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	for (i = 0; i < RTLX_CHANNELS; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 		wake_up_interruptible(&channel_wqs[i].lx_queue);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) int rtlx_open(int index, int can_sleep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 	struct rtlx_info **p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 	struct rtlx_channel *chan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 	enum rtlx_state state;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 	int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 	if (index >= RTLX_CHANNELS) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		pr_debug("rtlx_open index out of range\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 		return -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	if (atomic_inc_return(&channel_wqs[index].in_open) > 1) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 		pr_debug("rtlx_open channel %d already opened\n", index);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 		ret = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) 		goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) 	if (rtlx == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) 		p = vpe_get_shared(aprp_cpu_index());
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) 		if (p == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) 			if (can_sleep) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) 				ret = __wait_event_interruptible(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) 					channel_wqs[index].lx_queue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 					(p = vpe_get_shared(aprp_cpu_index())));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) 				if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 					goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) 				pr_debug("No SP program loaded, and device opened with O_NONBLOCK\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) 				ret = -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) 				goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 		smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 		if (*p == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 			if (can_sleep) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 				DEFINE_WAIT(wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 				for (;;) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 					prepare_to_wait(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 						&channel_wqs[index].lx_queue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 						&wait, TASK_INTERRUPTIBLE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 					smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 					if (*p != NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 						break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 					if (!signal_pending(current)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 						schedule();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 						continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 					}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 					ret = -ERESTARTSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 					goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 				}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 				finish_wait(&channel_wqs[index].lx_queue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 					    &wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 			} else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 				pr_err(" *vpe_get_shared is NULL. Has an SP program been loaded?\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 				ret = -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 				goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 			}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 		if ((unsigned int)*p < KSEG0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 			pr_warn("vpe_get_shared returned an invalid pointer maybe an error code %d\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 				(int)*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 			ret = -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 			goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) 		ret = rtlx_init(*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 		if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 			goto out_ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	chan = &rtlx->channel[index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	state = xchg(&chan->lx_state, RTLX_STATE_OPENED);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) 	if (state == RTLX_STATE_OPENED) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 		ret = -EBUSY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 		goto out_fail;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) out_fail:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	atomic_dec(&channel_wqs[index].in_open);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	smp_mb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) out_ret:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) int rtlx_release(int index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 	if (rtlx == NULL) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		pr_err("rtlx_release() with null rtlx\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	rtlx->channel[index].lx_state = RTLX_STATE_UNUSED;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) unsigned int rtlx_read_poll(int index, int can_sleep)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 	struct rtlx_channel *chan;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) 	if (rtlx == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 	chan = &rtlx->channel[index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 	/* data available to read? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	if (chan->lx_read == chan->lx_write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		if (can_sleep) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 			int ret = __wait_event_interruptible(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 				channel_wqs[index].lx_queue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) 				(chan->lx_read != chan->lx_write) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 				sp_stopping);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) 			if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) 				return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 			if (sp_stopping)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) 				return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 		} else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) 			return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	return (chan->lx_write + chan->buffer_size - chan->lx_read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 	       % chan->buffer_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) static inline int write_spacefree(int read, int write, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) 	if (read == write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 		/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) 		 * Never fill the buffer completely, so indexes are always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 		 * equal if empty and only empty, or !equal if data available
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 		 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 		return size - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 	return ((read + size - write) % size) - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) unsigned int rtlx_write_poll(int index)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	struct rtlx_channel *chan = &rtlx->channel[index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 	return write_spacefree(chan->rt_read, chan->rt_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 				chan->buffer_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) ssize_t rtlx_read(int index, void __user *buff, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	size_t lx_write, fl = 0L;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 	struct rtlx_channel *lx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 	unsigned long failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	if (rtlx == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 		return -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	lx = &rtlx->channel[index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	mutex_lock(&channel_wqs[index].mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	lx_write = lx->lx_write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 	/* find out how much in total */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) 	count = min(count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) 		     (size_t)(lx_write + lx->buffer_size - lx->lx_read)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) 		     % lx->buffer_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) 	/* then how much from the read pointer onwards */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	fl = min(count, (size_t)lx->buffer_size - lx->lx_read);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	failed = copy_to_user(buff, lx->lx_buffer + lx->lx_read, fl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 	if (failed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 	/* and if there is anything left at the beginning of the buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) 	if (count - fl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 		failed = copy_to_user(buff + fl, lx->lx_buffer, count - fl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	count -= failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 	smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) 	lx->lx_read = (lx->lx_read + count) % lx->buffer_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) 	smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	mutex_unlock(&channel_wqs[index].mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) ssize_t rtlx_write(int index, const void __user *buffer, size_t count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	struct rtlx_channel *rt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 	unsigned long failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 	size_t rt_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	size_t fl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) 	if (rtlx == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 		return -ENOSYS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) 	rt = &rtlx->channel[index];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 	mutex_lock(&channel_wqs[index].mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	smp_rmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 	rt_read = rt->rt_read;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	/* total number of bytes to copy */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 	count = min_t(size_t, count, write_spacefree(rt_read, rt->rt_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 						     rt->buffer_size));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 	/* first bit from write pointer to the end of the buffer, or count */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	fl = min(count, (size_t) rt->buffer_size - rt->rt_write);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 	failed = copy_from_user(rt->rt_buffer + rt->rt_write, buffer, fl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) 	if (failed)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	/* if there's any left copy to the beginning of the buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 	if (count - fl)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 		failed = copy_from_user(rt->rt_buffer, buffer + fl, count - fl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	count -= failed;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 	smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	rt->rt_write = (rt->rt_write + count) % rt->buffer_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 	smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	mutex_unlock(&channel_wqs[index].mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 	_interrupt_sp();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 	return count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) static int file_open(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 	return rtlx_open(iminor(inode), (filp->f_flags & O_NONBLOCK) ? 0 : 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) static int file_release(struct inode *inode, struct file *filp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 	return rtlx_release(iminor(inode));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) static __poll_t file_poll(struct file *file, poll_table *wait)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 	int minor = iminor(file_inode(file));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	__poll_t mask = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	poll_wait(file, &channel_wqs[minor].rt_queue, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) 	poll_wait(file, &channel_wqs[minor].lx_queue, wait);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 	if (rtlx == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 	/* data available to read? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) 	if (rtlx_read_poll(minor, 0))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) 		mask |= EPOLLIN | EPOLLRDNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 	/* space to write */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	if (rtlx_write_poll(minor))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 		mask |= EPOLLOUT | EPOLLWRNORM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 	return mask;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) static ssize_t file_read(struct file *file, char __user *buffer, size_t count,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 			 loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) 	int minor = iminor(file_inode(file));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) 	/* data available? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) 	if (!rtlx_read_poll(minor, (file->f_flags & O_NONBLOCK) ? 0 : 1))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) 		return 0;	/* -EAGAIN makes 'cat' whine */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) 	return rtlx_read(minor, buffer, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) static ssize_t file_write(struct file *file, const char __user *buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) 			  size_t count, loff_t *ppos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) 	int minor = iminor(file_inode(file));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) 	/* any space left... */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) 	if (!rtlx_write_poll(minor)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) 		int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) 		if (file->f_flags & O_NONBLOCK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) 			return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) 		ret = __wait_event_interruptible(channel_wqs[minor].rt_queue,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) 					   rtlx_write_poll(minor));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) 		if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) 			return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) 	return rtlx_write(minor, buffer, count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) const struct file_operations rtlx_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) 	.owner =   THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) 	.open =    file_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) 	.release = file_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) 	.write =   file_write,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) 	.read =    file_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) 	.poll =    file_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) 	.llseek =  noop_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) module_init(rtlx_module_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) module_exit(rtlx_module_exit);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) MODULE_DESCRIPTION("MIPS RTLX");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) MODULE_AUTHOR("Elizabeth Oldham, MIPS Technologies, Inc.");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) MODULE_LICENSE("GPL");