[RFC PATCH 04/28] lkl: host interface

[Octavian Purdila <octavian.purdila@intel.com>]

This patch introduces the host operations that define the interface
between the LKL and the host. These operations must be provided either
by a host library or by the application itself.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
---
 arch/lkl/include/asm/host_ops.h      |  9 ++++
 arch/lkl/include/uapi/asm/host_ops.h | 81 ++++++++++++++++++++++++++++++++++++
 2 files changed, 90 insertions(+)
 create mode 100644 arch/lkl/include/asm/host_ops.h
 create mode 100644 arch/lkl/include/uapi/asm/host_ops.h

diff --git a/arch/lkl/include/asm/host_ops.h b/arch/lkl/include/asm/host_ops.h
new file mode 100644
index 0000000..7fb0381
--- /dev/null
+++ b/arch/lkl/include/asm/host_ops.h
@@ -0,0 +1,9 @@
+#ifndef _ASM_LKL_HOST_OPS_H
+#define _ASM_LKL_HOST_OPS_H
+
+#include "irq.h"
+#include <uapi/asm/host_ops.h>
+
+extern struct lkl_host_operations *lkl_ops;
+
+#endif
diff --git a/arch/lkl/include/uapi/asm/host_ops.h b/arch/lkl/include/uapi/asm/host_ops.h
new file mode 100644
index 0000000..e126154
--- /dev/null
+++ b/arch/lkl/include/uapi/asm/host_ops.h
@@ -0,0 +1,81 @@
+#ifndef _ASM_UAPI_LKL_HOST_OPS_H
+#define _ASM_UAPI_LKL_HOST_OPS_H
+
+/**
+ * lkl_host_operations - host operations used by the Linux kernel
+ *
+ * These operations must be provided by a host library or by the application
+ * itself.
+ *
+ * @virtio_devices - string containg the list of virtio devices in virtio mmio
+ * command line format. This string is appended to the kernel command line and
+ * is provided here for convenience to be implemented by the host library.
+ *
+ * @print - optional operation that receives console messages
+ *
+ * @panic - called during a kernel panic
+ *
+ * @sem_alloc - allocate a host semaphore an initialize it to count
+ * @sem_free - free a host semaphore
+ * @sem_up - perform an up operation on the semaphore
+ * @sem_down - perform a down operation on the semaphore
+ *
+ * @thread_create - create a new thread and run f(arg) in its context; returns a
+ * thread handle or NULL if the thread could not be created
+ * @thread_exit - terminates the current thread
+ *
+ * @mem_alloc - allocate memory
+ * @mem_free - free memory
+ *
+ * @timer_create - allocate a host timer that runs fn(arg) when the timer
+ * fires.
+ * @timer_free - disarms and free the timer
+ * @timer_set_oneshot - arm the timer to fire once, after delta ns.
+ * @timer_set_periodic - arm the timer to fire periodically, with a period of
+ * delta ns.
+ *
+ */
+struct lkl_host_operations {
+	const char *virtio_devices;
+
+	void (*print)(const char *str, int len);
+	void (*panic)(void);
+
+	void* (*sem_alloc)(int count);
+	void (*sem_free)(void *sem);
+	void (*sem_up)(void *sem);
+	void (*sem_down)(void *sem);
+
+	int (*thread_create)(void (*f)(void *), void *arg);
+	void (*thread_exit)(void);
+
+	void* (*mem_alloc)(unsigned long);
+	void (*mem_free)(void *);
+
+	unsigned long long (*time)(void);
+
+	void* (*timer_alloc)(void (*fn)(void *), void *arg);
+	int (*timer_set_oneshot)(void *timer, unsigned long delta);
+	void (*timer_free)(void *timer);
+
+	void* (*ioremap)(long addr, int size);
+	int (*iomem_access)(const volatile void *addr, void *val, int size,
+			    int write);
+
+};
+
+/**
+ * lkl_start_kernel - registers the host operations and starts the kernel
+ *
+ * The function returns only after the kernel is shutdown with lkl_sys_halt.
+ *
+ * @lkl_ops - pointer to host operations
+ * @mem_size - how much memory to allocate to the Linux kernel
+ * @cmd_line - format for command line string that is going to be used to
+ * generate the Linux kernel command line
+ */
+int lkl_start_kernel(struct lkl_host_operations *lkl_ops,
+		     unsigned long mem_size,
+		     const char *cmd_line, ...);
+
+#endif
-- 
2.1.0