[PATCH/RFCv4 5/6] mm: cma: Test device and application added

Michal Nazarewicz
2010-08-20T09:50:45Z

This patch adds a "cma" misc device which lets user space use the
CMA API. This device is meant for testing. A testing application
is also provided.

Signed-off-by: Michal Nazarewicz <m.nazarewicz@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
---
drivers/misc/Kconfig | 8 +
drivers/misc/Makefile | 1 +
drivers/misc/cma-dev.c | 185 ++++++++++++++++++++++++
include/linux/cma.h | 30 ++++
tools/cma/cma-test.c | 373 ++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 597 insertions(+), 0 deletions(-)
create mode 100644 drivers/misc/cma-dev.c
create mode 100644 tools/cma/cma-test.c

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 0b591b6..f93e812 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -395,4 +395,12 @@ source "drivers/misc/eeprom/Kconfig"
source "drivers/misc/cb710/Kconfig"
source "drivers/misc/iwmc3200top/Kconfig"

+config CMA_DEVICE
+ tristate "CMA misc device (DEVELOPEMENT)"
+ depends on CMA_DEVELOPEMENT
+ help
+ The CMA misc device allows allocating contiguous memory areas
+ from user space. This is mostly for testing of the CMA
+ framework.
+
endif # MISC_DEVICES
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index 255a80d..2e82898 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -35,3 +35,4 @@ obj-y += eeprom/
obj-y += cb710/
obj-$(CONFIG_VMWARE_BALLOON) += vmware_balloon.o
obj-$(CONFIG_ARM_CHARLCD) += arm-charlcd.o
+obj-$(CONFIG_CMA_DEVICE) += cma-dev.o
diff --git a/drivers/misc/cma-dev.c b/drivers/misc/cma-dev.c
new file mode 100644
index 0000000..de534f0
--- /dev/null
+++ b/drivers/misc/cma-dev.c
@@ -0,0 +1,185 @@
+/*
+ * Contiguous Memory Allocator userspace driver
+ * Copyright (c) 2010 by Samsung Electronics.
+ * Written by Michal Nazarewicz (m.nazarewicz at samsung.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License or (at your optional) any later version of the license.
+ */
+
+#define pr_fmt(fmt) "cma: " fmt
+
+#ifdef CONFIG_CMA_DEBUG
+# define DEBUG
+#endif
+
+#include <linux/errno.h> /* Error numbers */
+#include <linux/err.h> /* IS_ERR_VALUE() */
+#include <linux/fs.h> /* struct file */
+#include <linux/mm.h> /* Memory stuff */
+#include <linux/mman.h>
+#include <linux/slab.h>
+#include <linux/module.h> /* Standard module stuff */
+#include <linux/device.h> /* struct device, dev_dbg() */
+#include <linux/types.h> /* Just to be safe ;) */
+#include <linux/uaccess.h> /* __copy_{to,from}_user */
+#include <linux/miscdevice.h> /* misc_register() and company */
+
+#include <linux/cma.h>
+
+static int cma_file_open(struct inode *inode, struct file *file);
+static int cma_file_release(struct inode *inode, struct file *file);
+static long cma_file_ioctl(struct file *file, unsigned cmd, unsigned long arg);
+static int cma_file_mmap(struct file *file, struct vm_area_struct *vma);
+
+
+static struct miscdevice cma_miscdev = {
+ .minor = MISC_DYNAMIC_MINOR,
+ .name = "cma",
+ .fops = &(const struct file_operations) {
+ .owner = THIS_MODULE,
+ .open = cma_file_open,
+ .release = cma_file_release,
+ .unlocked_ioctl = cma_file_ioctl,
+ .mmap = cma_file_mmap,
+ },
+};
+#define cma_dev (cma_miscdev.this_device)
+
+
+#define cma_file_start(file) (((dma_addr_t *)(file)->private_data)[0])
+#define cma_file_size(file) (((dma_addr_t *)(file)->private_data)[1])
+
+
+static int cma_file_open(struct inode *inode, struct file *file)
+{
+ dev_dbg(cma_dev, "%s(%p)\n", __func__, (void *)file);
+
+ file->private_data = NULL;
+
+ return 0;
+}
+
+
+static int cma_file_release(struct inode *inode, struct file *file)
+{
+ dev_dbg(cma_dev, "%s(%p)\n", __func__, (void *)file);
+
+ if (file->private_data) {
+ cma_free(cma_file_start(file));
+ kfree(file->private_data);
+ }
+
+ return 0;
+}
+
+
+static long cma_file_ioctl(struct file *file, unsigned cmd, unsigned long arg)
+{
+ struct cma_alloc_request req;
+ struct device fake_device;
+ unsigned long addr;
+ long ret;
+
+ dev_dbg(cma_dev, "%s(%p)\n", __func__, (void *)file);
+
+ if (cmd != IOCTL_CMA_ALLOC)
+ return -ENOTTY;
+
+ if (!arg)
+ return -EINVAL;
+
+ if (file->private_data) /* Already allocated */
+ return -EBADFD;
+
+ if (copy_from_user(&req, (void *)arg, sizeof req))
+ return -EFAULT;
+
+ if (req.magic != CMA_MAGIC)
+ return -ENOTTY;
+
+ /* May happen on 32 bit system. */
+ if (req.size > ~(typeof(req.size))0 ||
+ req.alignment > ~(typeof(req.alignment))0)
+ return -EINVAL;
+
+ if (strnlen(req.name, sizeof req.name) >= sizeof req.name
+ || strnlen(req.kind, sizeof req.kind) >= sizeof req.kind)
+ return -EINVAL;
+
+ file->private_data = kmalloc(2 * sizeof(dma_addr_t), GFP_KERNEL);
+ if (!file->private_data)
+ return -ENOMEM;
+
+ fake_device.init_name = req.name;
+ fake_device.kobj.name = req.name;
+ addr = cma_alloc(&fake_device, req.kind, req.size, req.alignment);
+ if (IS_ERR_VALUE(addr)) {
+ ret = addr;
+ goto error_priv;
+ }
+
+ if (put_user(addr, (typeof(req.start) *)(arg + offsetof(typeof(req),
+ start)))) {
+ ret = -EFAULT;
+ goto error_put;
+ }
+
+ cma_file_start(file) = addr;
+ cma_file_size(file) = req.size;
+
+ dev_dbg(cma_dev, "allocated %p@%p\n",
+ (void *)(dma_addr_t)req.size, (void *)addr);
+
+ return 0;
+
+error_put:
+ cma_free(addr);
+error_priv:
+ kfree(file->private_data);
+ file->private_data = NULL;
+ return ret;
+}
+
+
+static int cma_file_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ unsigned long pgoff, offset, length;
+
+ dev_dbg(cma_dev, "%s(%p)\n", __func__, (void *)file);
+
+ if (!file->private_data)
+ return -EBADFD;
+
+ pgoff = vma->vm_pgoff;
+ offset = pgoff << PAGE_SHIFT;
+ length = vma->vm_end - vma->vm_start;
+
+ if (offset >= cma_file_size(file)
+ || length > cma_file_size(file)
+ || offset + length > cma_file_size(file))
+ return -ENOSPC;
+
+ return remap_pfn_range(vma, vma->vm_start,
+ __phys_to_pfn(cma_file_start(file) + offset),
+ length, vma->vm_page_prot);
+}
+
+
+
+static int __init cma_dev_init(void)
+{
+ int ret = misc_register(&cma_miscdev);
+ pr_debug("miscdev: register returned: %d\n", ret);
+ return ret;
+}
+module_init(cma_dev_init);
+
+static void __exit cma_dev_exit(void)
+{
+ dev_dbg(cma_dev, "deregisterring\n");
+ misc_deregister(&cma_miscdev);
+}
+module_exit(cma_dev_exit);
diff --git a/include/linux/cma.h b/include/linux/cma.h
index eede28d..4334bb8 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -11,6 +11,36 @@
* See Documentation/contiguous-memory.txt for details.
*/

+#include <linux/ioctl.h>
+#include <linux/types.h>
+
+
+#define CMA_MAGIC (('c' << 24) | ('M' << 16) | ('a' << 8) | 0x42)
+
+/**
+ * An information about area exportable to user space.
+ * @magic: must always be CMA_MAGIC.
+ * @name: name of the device to allocate as.
+ * @kind: kind of the memory.
+ * @_pad: reserved.
+ * @size: size of the chunk to allocate.
+ * @alignment: desired alignment of the chunk (must be power of two or zero).
+ * @start: when ioctl() finishes this stores physical address of the chunk.
+ */
+struct cma_alloc_request {
+ __u32 magic;
+ char name[17];
+ char kind[17];
+ __u16 pad;
+ /* __u64 to be compatible accross 32 and 64 bit systems. */
+ __u64 size;
+ __u64 alignment;
+ __u64 start;
+};
+
+#define IOCTL_CMA_ALLOC _IOWR('p', 0, struct cma_alloc_request)
+
+
/***************************** Kernel lever API *****************************/

#ifdef __KERNEL__
diff --git a/tools/cma/cma-test.c b/tools/cma/cma-test.c
new file mode 100644
index 0000000..567c57b
--- /dev/null
+++ b/tools/cma/cma-test.c
@@ -0,0 +1,373 @@
+/*
+ * cma-test.c -- CMA testing application
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ * Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+/* $(CROSS_COMPILE)gcc -Wall -Wextra -g -o cma-test cma-test.c */
+
+#include <linux/cma.h>
+
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <ctype.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+
+static void handle_command(char *line);
+
+int main(void)
+{
+ unsigned no = 1;
+ char line[1024];
+ int skip = 0;
+
+ fputs("commands:\n"
+ " l or list list allocated chunks\n"
+ " a or alloc <name> <size>[/<alignment>] allocate chunk\n"
+ " f or free [<num>] free an chunk\n"
+ " # ... comment\n"
+ " <empty line> repeat previous\n"
+ "\n", stderr);
+
+ while (fgets(line, sizeof line, stdin)) {
+ char *nl = strchr(line, '\n');
+ if (nl) {
+ if (skip) {
+ fprintf(stderr, "cma: %d: line too long\n", no);
+ skip = 0;
+ } else {
+ *nl = '\0';
+ handle_command(line);
+ }
+ ++no;
+ } else {
+ skip = 1;
+ }
+ }
+
+ if (skip)
+ fprintf(stderr, "cma: %d: no new line at EOF\n", no);
+ return 0;
+}
+
+
+
+static void cmd_list(char *name, char *line);
+static void cmd_alloc(char *name, char *line);
+static void cmd_free(char *name, char *line);
+
+static const struct command {
+ const char name[8];
+ void (*handle)(char *name, char *line);
+} commands[] = {
+ { "list", cmd_list },
+ { "l", cmd_list },
+ { "alloc", cmd_alloc },
+ { "a", cmd_alloc },
+ { "free", cmd_free },
+ { "f", cmd_free },
+ { "", NULL }
+};
+
+
+#define SKIP_SPACE(ch) do while (isspace(*(ch))) ++(ch); while (0)
+
+
+static void handle_command(char *line)
+{
+ static char last_line[1024];
+
+ const struct command *cmd;
+ char *name;
+
+ SKIP_SPACE(line);
+ if (*line == '#')
+ return;
+
+ if (!*line)
+ strcpy(line, last_line);
+ else
+ strcpy(last_line, line);
+
+ name = line;
+ while (*line && !isspace(*line))
+ ++line;
+
+ if (*line) {
+ *line = '\0';
+ ++line;
+ }
+
+ for (cmd = commands; *(cmd->name); ++cmd)
+ if (!strcmp(name, cmd->name)) {
+ cmd->handle(name, line);
+ return;
+ }
+
+ fprintf(stderr, "%s: unknown command\n", name);
+}
+
+
+
+struct chunk {
+ struct chunk *next, *prev;
+ int fd;
+ unsigned long size;
+ unsigned long start;
+};
+
+static struct chunk root = {
+ .next = &root,
+ .prev = &root,
+};
+
+#define for_each(a) for (a = root.next; a != &root; a = a->next)
+
+static struct chunk *chunk_create(const char *prefix);
+static void chunk_destroy(struct chunk *chunk);
+static void chunk_add(struct chunk *chunk);
+
+static int memparse(char *ptr, char **retptr, unsigned long *ret);
+
+
+static void cmd_list(char *name, char *line)
+{
+ struct chunk *chunk;
+
+ (void)name; (void)line;
+
+ for_each(chunk)
+ printf("%3d: %p@%p\n", chunk->fd,
+ (void *)chunk->size, (void *)chunk->start);
+}
+
+
+static void cmd_alloc(char *name, char *line)
+{
+ unsigned long size, alignment = 0;
+ struct cma_alloc_request req;
+ char *dev, *kind = NULL;
+ struct chunk *chunk;
+ int ret;
+
+ SKIP_SPACE(line);
+ if (!*line) {
+ fprintf(stderr, "%s: expecting name\n", name);
+ return;
+ }
+
+ for (dev = line; *line && !isspace(*line); ++line)
+ if (*line == '/')
+ kind = line;
+
+ if (!*line) {
+ fprintf(stderr, "%s: expecting size after name\n", name);
+ return;
+ }
+
+ if (kind)
+ *kind++ = '\0';
+ *line++ = '\0';
+
+ if (( kind && (size_t)(kind - dev ) > sizeof req.name)
+ || (!kind && (size_t)(line - dev ) > sizeof req.name)
+ || ( kind && (size_t)(line - kind) > sizeof req.kind)) {
+ fprintf(stderr, "%s: name or kind too long\n", name);
+ return;
+ }
+
+
+ if (memparse(line, &line, &size) < 0 || !size) {
+ fprintf(stderr, "%s: invalid size\n", name);
+ return;
+ }
+
+ if (*line == '/')
+ if (memparse(line, &line, &alignment) < 0) {
+ fprintf(stderr, "%s: invalid alignment\n", name);
+ return;
+ }
+
+ SKIP_SPACE(line);
+ if (*line) {
+ fprintf(stderr, "%s: unknown arguments@the end: %s\n",
+ name, line);
+ return;
+ }
+
+
+ chunk = chunk_create(name);
+ if (!chunk)
+ return;
+
+ fprintf(stderr, "%s: allocating %p/%p\n", name,
+ (void *)size, (void *)alignment);
+
+ req.magic = CMA_MAGIC;
+ req.size = size;
+ req.alignment = alignment;
+
+ strcpy(req.name, dev);
+ if (kind)
+ strcpy(req.kind, kind);
+ else
+ req.kind[0] = '\0';
+
+
+ ret = ioctl(chunk->fd, IOCTL_CMA_ALLOC, &req);
+ if (ret < 0) {
+ fprintf(stderr, "%s: cma_alloc: %s\n", name, strerror(errno));
+ chunk_destroy(chunk);
+ } else {
+ chunk_add(chunk);
+ chunk->size = req.size;
+ chunk->start = req.start;
+
+ printf("%3d: %p@%p\n", chunk->fd,
+ (void *)chunk->size, (void *)chunk->start);
+ }
+}
+
+
+static void cmd_free(char *name, char *line)
+{
+ struct chunk *chunk;
+
+ SKIP_SPACE(line);
+
+ if (*line) {
+ unsigned long num;
+
+ errno = 0;
+ num = strtoul(line, &line, 10);
+
+ if (errno || num > INT_MAX) {
+ fprintf(stderr, "%s: invalid number\n", name);
+ return;
+ }
+
+ SKIP_SPACE(line);
+ if (*line) {
+ fprintf(stderr, "%s: unknown arguments at the end: %s\n",
+ name, line);
+ return;
+ }
+
+ for_each(chunk)
+ if (chunk->fd == (int)num)
+ goto ok;
+ fprintf(stderr, "%s: no chunk %3lu\n", name, num);
+ return;
+
+ } else {
+ chunk = root.prev;
+ if (chunk == &root) {
+ fprintf(stderr, "%s: no chunks\n", name);
+ return;
+ }
+ }
+
+ok:
+ fprintf(stderr, "%s: freeing %p@%p\n", name,
+ (void *)chunk->size, (void *)chunk->start);
+ chunk_destroy(chunk);
+}
+
+
+static struct chunk *chunk_create(const char *prefix)
+{
+ struct chunk *chunk;
+ int fd;
+
+ chunk = malloc(sizeof *chunk);
+ if (!chunk) {
+ fprintf(stderr, "%s: %s\n", prefix, strerror(errno));
+ return NULL;
+ }
+
+ fd = open("/dev/cma", O_RDWR);
+ if (fd < 0) {
+ fprintf(stderr, "%s: /dev/cma: %s\n", prefix, strerror(errno));
+ return NULL;
+ }
+
+ chunk->prev = chunk;
+ chunk->next = chunk;
+ chunk->fd = fd;
+ return chunk;
+}
+
+static void chunk_destroy(struct chunk *chunk)
+{
+ chunk->prev->next = chunk->next;
+ chunk->next->prev = chunk->prev;
+ close(chunk->fd);
+}
+
+static void chunk_add(struct chunk *chunk)
+{
+ chunk->next = &root;
+ chunk->prev = root.prev;
+ root.prev->next = chunk;
+ root.prev = chunk;
+}
+
+
+
+static int memparse(char *ptr, char **retptr, unsigned long *ret)
+{
+ unsigned long val;
+
+ SKIP_SPACE(ptr);
+
+ errno = 0;
+ val = strtoul(ptr, &ptr, 0);
+ if (errno)
+ return -1;
+
+ switch (*ptr) {
+ case 'G':
+ case 'g':
+ val <<= 10;
+ case 'M':
+ case 'm':
+ val <<= 10;
+ case 'K':
+ case 'k':
+ val <<= 10;
+ ++ptr;
+ }
+
+ if (retptr) {
+ SKIP_SPACE(ptr);
+ *retptr = ptr;
+ }
+
+ *ret = val;
+ return 0;
+}
--
1.7.1