Android pmem: add google's process memory allocator driver

The pmem driver is used to manage large (1-16+MB) physically contiguous
regions of memory shared between userspace and kernel drivers (dsp, gpu,
etc).

Signed-off-by: Rebecca Schultz <rschultz@google.com>
Signed-off-by: Dima Zavin <dima@android.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/include/linux/android_pmem.h b/include/linux/android_pmem.h
new file mode 100644
index 000000000000..f940946646e6
--- /dev/null
+++ b/include/linux/android_pmem.h
@@ -0,0 +1,91 @@
+/* include/linux/android_pmem.h
+ *
+ * Copyright (C) 2007 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef _ANDROID_PMEM_H_
+#define _ANDROID_PMEM_H_
+
+#define PMEM_IOCTL_MAGIC 'p'
+#define PMEM_GET_PHYS		_IOW(PMEM_IOCTL_MAGIC, 1, unsigned int)
+#define PMEM_MAP		_IOW(PMEM_IOCTL_MAGIC, 2, unsigned int)
+#define PMEM_GET_SIZE		_IOW(PMEM_IOCTL_MAGIC, 3, unsigned int)
+#define PMEM_UNMAP		_IOW(PMEM_IOCTL_MAGIC, 4, unsigned int)
+/* This ioctl will allocate pmem space, backing the file, it will fail
+ * if the file already has an allocation, pass it the len as the argument
+ * to the ioctl */
+#define PMEM_ALLOCATE		_IOW(PMEM_IOCTL_MAGIC, 5, unsigned int)
+/* This will connect a one pmem file to another, pass the file that is already
+ * backed in memory as the argument to the ioctl
+ */
+#define PMEM_CONNECT		_IOW(PMEM_IOCTL_MAGIC, 6, unsigned int)
+/* Returns the total size of the pmem region it is sent to as a pmem_region
+ * struct (with offset set to 0).
+ */
+#define PMEM_GET_TOTAL_SIZE	_IOW(PMEM_IOCTL_MAGIC, 7, unsigned int)
+#define PMEM_CACHE_FLUSH	_IOW(PMEM_IOCTL_MAGIC, 8, unsigned int)
+
+struct android_pmem_platform_data {
+	const char *name;
+	/* starting physical address of memory region */
+	unsigned long start;
+	/* size of memory region */
+	unsigned long size;
+	/* set to indicate the region should not be managed with an allocator */
+	unsigned no_allocator;
+	/* set to indicate maps of this region should be cached, if a mix of
+	 * cached and uncached is desired, set this and open the device with
+	 * O_SYNC to get an uncached region */
+	unsigned cached;
+	/* The MSM7k has bits to enable a write buffer in the bus controller*/
+	unsigned buffered;
+};
+
+struct pmem_region {
+	unsigned long offset;
+	unsigned long len;
+};
+
+#ifdef CONFIG_ANDROID_PMEM
+int is_pmem_file(struct file *file);
+int get_pmem_file(int fd, unsigned long *start, unsigned long *vstart,
+		  unsigned long *end, struct file **filp);
+int get_pmem_user_addr(struct file *file, unsigned long *start,
+		       unsigned long *end);
+void put_pmem_file(struct file *file);
+void flush_pmem_file(struct file *file, unsigned long start, unsigned long len);
+int pmem_setup(struct android_pmem_platform_data *pdata,
+	       long (*ioctl)(struct file *, unsigned int, unsigned long),
+	       int (*release)(struct inode *, struct file *));
+int pmem_remap(struct pmem_region *region, struct file *file,
+	       unsigned operation);
+
+#else
+static inline int is_pmem_file(struct file *file) { return 0; }
+static inline int get_pmem_file(int fd, unsigned long *start,
+				unsigned long *vstart, unsigned long *end,
+				struct file **filp) { return -ENOSYS; }
+static inline int get_pmem_user_addr(struct file *file, unsigned long *start,
+				     unsigned long *end) { return -ENOSYS; }
+static inline void put_pmem_file(struct file *file) { return; }
+static inline void flush_pmem_file(struct file *file, unsigned long start,
+				   unsigned long len) { return; }
+static inline int pmem_setup(struct android_pmem_platform_data *pdata,
+	      long (*ioctl)(struct file *, unsigned int, unsigned long),
+	      int (*release)(struct inode *, struct file *)) { return -ENOSYS; }
+
+static inline int pmem_remap(struct pmem_region *region, struct file *file,
+			     unsigned operation) { return -ENOSYS; }
+#endif
+
+#endif /* _ANDROID_PMEM_H_ */