lkml.org 
[lkml]   [2012]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[RFC Patch v1 53/55] ARC: Hostlink Pseudo-Driver for Metaware Debugger
Date
From: Vineet Gupta <vgupta@synopsys.com>

This allows ARC Target to do I/O to host in absence of any peripherals
whatsoever, assisted by Metaware Hostlink facility.

Further we have a FUSE based filesystem which makes us mount/access host
filesystem on target and do fops.

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
---
arch/arc/Kconfig | 9 +++
arch/arc/kernel/Makefile | 1 +
arch/arc/kernel/arc_hostlink.c | 114 ++++++++++++++++++++++++++++++++++++++++
3 files changed, 124 insertions(+), 0 deletions(-)
create mode 100644 arch/arc/kernel/arc_hostlink.c

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 79e8f2f..4653070 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -394,6 +394,15 @@ config HZ
int "Timer Frequency"
default 100

+config ARC_METAWARE_HLINK
+ bool "Support for Metaware debugger assisted Host access"
+ default n
+ help
+ This options allows a Linux userland apps to directly access
+ host file system (open/creat/read/write etc) with help from
+ Metaware Debugger. This can come in handy for Linux-host communication
+ when there is no real usable peripheral such as EMAC.
+
menuconfig ARC_DBG
bool "ARC debugging"
default y
diff --git a/arch/arc/kernel/Makefile b/arch/arc/kernel/Makefile
index a2b7493..ce14b45 100644
--- a/arch/arc/kernel/Makefile
+++ b/arch/arc/kernel/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_ARC_DW2_UNWIND) += unwind.o
obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_ARC_MISALIGN_ACCESS) += unaligned.o
obj-$(CONFIG_KGDB) += kgdb.o
+obj-$(CONFIG_ARC_METAWARE_HLINK) += arc_hostlink.o

obj-$(CONFIG_ARC_FPU_SAVE_RESTORE) += fpu.o
CFLAGS_fpu.o += -mdpfp
diff --git a/arch/arc/kernel/arc_hostlink.c b/arch/arc/kernel/arc_hostlink.c
new file mode 100644
index 0000000..de3bc42
--- /dev/null
+++ b/arch/arc/kernel/arc_hostlink.c
@@ -0,0 +1,114 @@
+/*
+ * arc_hostlink.c: Pseudo-driver for Metaware provided "hostlink" facility
+ *
+ * Allows Linux userland access to host in absence of any peripherals.
+ *
+ * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/fs.h> /* file_operations */
+#include <linux/device.h> /* class_create */
+#include <linux/cdev.h> /* cdev */
+#include <linux/mm.h> /* VM_IO */
+#include <linux/module.h>
+#include <linux/uaccess.h>
+
+static unsigned char __HOSTLINK__[4 * PAGE_SIZE] __aligned(PAGE_SIZE);
+
+static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma);
+static long arc_hl_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg);
+
+static const struct file_operations arc_hl_fops = {
+ .owner = THIS_MODULE,
+ .unlocked_ioctl = arc_hl_ioctl,
+ .mmap = arc_hl_mmap,
+};
+
+static int arc_hl_major;
+static int arc_hl_minor;
+static int arc_hl_nr_devs = 1;
+static const char arc_hl_devnm[] = "hostlink";
+static struct cdev arc_hl_cdev;
+static struct class *arc_hl_class;
+
+static int __init arc_hl_linux_glue(void)
+{
+ dev_t arc_hl_dev;
+ int i;
+
+ if (arc_hl_major) { /* Preallocated MAJOR */
+
+ arc_hl_dev = MKDEV(arc_hl_major, arc_hl_minor);
+ register_chrdev_region(arc_hl_dev, arc_hl_nr_devs,
+ arc_hl_devnm);
+ } else { /* allocates Major to devices */
+ alloc_chrdev_region(&arc_hl_dev, 0, arc_hl_nr_devs,
+ arc_hl_devnm);
+ arc_hl_major = MAJOR(arc_hl_dev);
+ }
+
+ /* Populate sysfs entries: creates /sys/class/ sub-node for device */
+
+ arc_hl_class = class_create(THIS_MODULE, arc_hl_devnm);
+
+ /* connect file ops with cdev */
+
+ cdev_init(&arc_hl_cdev, &arc_hl_fops);
+ arc_hl_cdev.owner = THIS_MODULE;
+
+ /* Connect major/minor number to cdev
+ * makes device available.
+ * device nodes created with 'mknod` are probably already active.
+ */
+
+ cdev_add(&arc_hl_cdev, arc_hl_dev, arc_hl_nr_devs);
+
+ /* creates /sys/devices/virtual/<dev_name>/<names[i]> node with
+ * link from/sys/class/<dev_name>, needed by mdev.
+ */
+
+ for (i = 0; i < arc_hl_nr_devs; i++)
+ device_create(arc_hl_class, NULL, MKDEV(MAJOR(arc_hl_dev), i),
+ NULL, arc_hl_devnm);
+
+ pr_info("Hostlink dev to mknod is %d:%d\n",
+ arc_hl_major, arc_hl_minor);
+ return 0;
+}
+
+static int __init arc_hl_init(void)
+{
+ arc_hl_linux_glue();
+
+ pr_info("Hlink buffer mmap @ 0x%p\n", __HOSTLINK__);
+
+ return 0;
+}
+
+static int arc_hl_mmap(struct file *fp, struct vm_area_struct *vma)
+{
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+ if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot)) {
+ pr_warn("Hostlink buffer mmap ERROR\n");
+ return -EAGAIN;
+ }
+ return 0;
+}
+
+static long arc_hl_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
+{
+ /* we only support, returning the physical addr to mmap in user space */
+ put_user((unsigned int)__HOSTLINK__, (int __user *)arg);
+ return 0;
+}
+
+module_init(arc_hl_init);
--
1.7.4.1


\
 
 \ /
  Last update: 2012-11-12 14:01    [W:0.294 / U:1.220 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site