MIPS: APRP: Add RTLX API support for CMP platforms.

This patch adds RTLX API support for platforms having a CMP.
Signed-off-by: Deng-Cheng Zhu <dengcheng.zhu@imgtec.com>
Signed-off-by: Steven J. Hill <Steven.Hill@imgtec.com>
Reviewed-by: Qais Yousef <Qais.Yousef@imgtec.com>
Patchwork: http://patchwork.linux-mips.org/patch/6095/Reviewed-by: John Crispin <blogic@openwrt.org>

arch/mips/Kconfig

@@ -1956,6 +1956,11 @@ config MIPS_VPE_APSP_API
 	depends on MIPS_VPE_LOADER
 	help
 
+config MIPS_VPE_APSP_API_CMP
+	bool
+	default "y"
+	depends on MIPS_VPE_APSP_API && MIPS_CMP
+
 config MIPS_VPE_APSP_API_MT
 	bool
 	default "y"

arch/mips/include/asm/rtlx.h

@@ -78,6 +78,7 @@ struct rtlx_channel {
 extern struct rtlx_info {
 	unsigned long id;
 	enum rtlx_state state;
+	int ap_int_pending;	/* Status of 0 or 1 for CONFIG_MIPS_CMP only */
 
 	struct rtlx_channel channel[RTLX_CHANNELS];
 } *rtlx;

arch/mips/kernel/Makefile

@@ -59,6 +59,7 @@ obj-$(CONFIG_MIPS_VPE_LOADER)	+= vpe.o
 obj-$(CONFIG_MIPS_VPE_LOADER_CMP) += vpe-cmp.o
 obj-$(CONFIG_MIPS_VPE_LOADER_MT) += vpe-mt.o
 obj-$(CONFIG_MIPS_VPE_APSP_API) += rtlx.o
+obj-$(CONFIG_MIPS_VPE_APSP_API_CMP) += rtlx-cmp.o
 obj-$(CONFIG_MIPS_VPE_APSP_API_MT) += rtlx-mt.o
 
 obj-$(CONFIG_I8259)		+= i8259.o

arch/mips/kernel/rtlx-cmp.c

+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2005 MIPS Technologies, Inc.  All rights reserved.
+ * Copyright (C) 2013 Imagination Technologies Ltd.
+ */
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/err.h>
+#include <linux/wait.h>
+#include <linux/sched.h>
+#include <linux/smp.h>
+
+#include <asm/mips_mt.h>
+#include <asm/vpe.h>
+#include <asm/rtlx.h>
+
+static int major;
+
+static void rtlx_interrupt(void)
+{
+	int i;
+	struct rtlx_info *info;
+	struct rtlx_info **p = vpe_get_shared(aprp_cpu_index());
+
+	if (p == NULL || *p == NULL)
+		return;
+
+	info = *p;
+
+	if (info->ap_int_pending == 1 && smp_processor_id() == 0) {
+		for (i = 0; i < RTLX_CHANNELS; i++) {
+			wake_up(&channel_wqs[i].lx_queue);
+			wake_up(&channel_wqs[i].rt_queue);
+		}
+		info->ap_int_pending = 0;
+	}
+}
+
+void _interrupt_sp(void)
+{
+	smp_send_reschedule(aprp_cpu_index());
+}
+
+int __init rtlx_module_init(void)
+{
+	struct device *dev;
+	int i, err;
+
+	if (!cpu_has_mipsmt) {
+		pr_warn("VPE loader: not a MIPS MT capable processor\n");
+		return -ENODEV;
+	}
+
+	if (num_possible_cpus() - aprp_cpu_index() < 1) {
+		pr_warn("No TCs reserved for AP/SP, not initializing RTLX.\n"
+			"Pass maxcpus=<n> argument as kernel argument\n");
+
+		return -ENODEV;
+	}
+
+	major = register_chrdev(0, RTLX_MODULE_NAME, &rtlx_fops);
+	if (major < 0) {
+		pr_err("rtlx_module_init: unable to register device\n");
+		return major;
+	}
+
+	/* initialise the wait queues */
+	for (i = 0; i < RTLX_CHANNELS; i++) {
+		init_waitqueue_head(&channel_wqs[i].rt_queue);
+		init_waitqueue_head(&channel_wqs[i].lx_queue);
+		atomic_set(&channel_wqs[i].in_open, 0);
+		mutex_init(&channel_wqs[i].mutex);
+
+		dev = device_create(mt_class, NULL, MKDEV(major, i), NULL,
+				    "%s%d", RTLX_MODULE_NAME, i);
+		if (IS_ERR(dev)) {
+			err = PTR_ERR(dev);
+			goto out_chrdev;
+		}
+	}
+
+	/* set up notifiers */
+	rtlx_notify.start = rtlx_starting;
+	rtlx_notify.stop = rtlx_stopping;
+	vpe_notify(aprp_cpu_index(), &rtlx_notify);
+
+	if (cpu_has_vint) {
+		aprp_hook = rtlx_interrupt;
+	} else {
+		pr_err("APRP RTLX init on non-vectored-interrupt processor\n");
+		err = -ENODEV;
+		goto out_class;
+	}
+
+	return 0;
+
+out_class:
+	for (i = 0; i < RTLX_CHANNELS; i++)
+		device_destroy(mt_class, MKDEV(major, i));
+out_chrdev:
+	unregister_chrdev(major, RTLX_MODULE_NAME);
+
+	return err;
+}
+
+void __exit rtlx_module_exit(void)
+{
+	int i;
+
+	for (i = 0; i < RTLX_CHANNELS; i++)
+		device_destroy(mt_class, MKDEV(major, i));
+	unregister_chrdev(major, RTLX_MODULE_NAME);
+}