The debugfs development interface lets one change the map attribute
at run time as well as observe what regions have been reserved.
Signed-off-by: Michal Nazarewicz <m.nazarewicz@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Documentation/contiguous-memory.txt | 4 +
include/linux/cma.h | 11 +
mm/Kconfig | 25 ++-
mm/cma.c | 501 ++++++++++++++++++++++++++++++++++-
4 files changed, 537 insertions(+), 4 deletions(-)
diff --git a/Documentation/contiguous-memory.txt b/Documentation/contiguous-memory.txt
index f1715ba..ec09d8e 100644
--- a/Documentation/contiguous-memory.txt
+++ b/Documentation/contiguous-memory.txt
@@ -258,6 +258,10 @@
iff it matched in previous pattern. If the second part is
omitted it will mach any type of memory requested by device.
+ If debugfs support is enabled, this attribute is accessible via
+ debugfs and can be changed at run-time by writing to
+ contiguous/map.
+
Some examples (whitespace added for better readability):
cma_map = foo/quaz = r1;
diff --git a/include/linux/cma.h b/include/linux/cma.h
index a6031a7..8437104 100644
--- a/include/linux/cma.h
+++ b/include/linux/cma.h
@@ -24,6 +24,7 @@
struct device;
struct cma_info;
+struct dentry;
/**
* struct cma - an allocated contiguous chunk of memory.
@@ -276,6 +277,11 @@ struct cma_region {
unsigned users;
struct list_head list;
+#if defined CONFIG_CMA_DEBUGFS
+ const char *to_alloc_link, *from_alloc_link;
+ struct dentry *dir, *to_alloc, *from_alloc;
+#endif
+
unsigned used:1;
unsigned registered:1;
unsigned reserved:1;
@@ -382,6 +388,11 @@ struct cma_allocator {
void (*unpin)(struct cma *chunk);
struct list_head list;
+
+#if defined CONFIG_CMA_DEBUGFS
+ const char *dir_name;
+ struct dentry *regs_dir;
+#endif
};
/**
diff --git a/mm/Kconfig b/mm/Kconfig
index c7eb1bc..a5480ea 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -351,16 +351,35 @@ config CMA
For more information see <Documentation/contiguous-memory.txt>.
If unsure, say "n".
-config CMA_DEBUG
- bool "CMA debug messages (DEVELOPEMENT)"
+config CMA_DEVELOPEMENT
+ bool "Include CMA developement features"
depends on CMA
help
+ This lets you enable some developement features of the CMA
+ framework. It does not add any code to the kernel.
+
+ Those options are mostly usable during development and testing.
+ If unsure, say "n".
+
+config CMA_DEBUG
+ bool "CMA debug messages"
+ depends on CMA_DEVELOPEMENT
+ help
Turns on debug messages in CMA. This produces KERN_DEBUG
messages for every CMA call as well as various messages while
processing calls such as cma_alloc(). This option does not
affect warning and error messages.
- This is mostly used during development. If unsure, say "n".
+config CMA_DEBUGFS
+ bool "CMA debugfs interface support"
+ depends on CMA_DEVELOPEMENT && DEBUG_FS
+ help
+ Enable support for debugfs interface. It is available under the
+ "contiguous" directory in the debugfs root directory. Each
+ region and allocator is represented there.
+
+ For more information consult
+ <Documentation/contiguous-memory.txt>.
config CMA_GENERIC_ALLOCATOR
bool "CMA generic allocator"
diff --git a/mm/cma.c b/mm/cma.c
index 17276b3..dfdeeb7 100644
--- a/mm/cma.c
+++ b/mm/cma.c
@@ -34,11 +34,16 @@
#include <linux/slab.h> /* kmalloc() */
#include <linux/string.h> /* str*() */
#include <linux/genalloc.h> /* gen_pool_*() */
+#include <linux/debugfs.h> /* debugfs stuff */
+#include <linux/uaccess.h> /* copy_{to,from}_user */
#include <linux/cma.h>
-/* Protects cma_regions, cma_allocators, cma_map and cma_map_length. */
+/*
+ * Protects cma_regions, cma_allocators, cma_map, cma_map_length,
+ * cma_dfs_regions and cma_dfs_allocators.
+ */
static DEFINE_MUTEX(cma_mutex);
@@ -139,7 +144,13 @@ int __init __must_check cma_early_region_register(struct cma_region *reg)
/************************* Regions & Allocators *************************/
+static void __cma_dfs_region_add(struct cma_region *reg);
+static void __cma_dfs_region_alloc_update(struct cma_region *reg);
+static void __cma_dfs_allocator_add(struct cma_allocator *alloc);
+
static int __cma_region_attach_alloc(struct cma_region *reg);
+static void __maybe_unused __cma_region_detach_alloc(struct cma_region *reg);
+
/* List of all regions. Named regions are kept before unnamed. */
static LIST_HEAD(cma_regions);
@@ -222,6 +233,8 @@ int __must_check cma_region_register(struct cma_region *reg)
else
list_add_tail(®->list, &cma_regions);
+ __cma_dfs_region_add(reg);
+
done:
mutex_unlock(&cma_mutex);
@@ -298,6 +311,8 @@ int cma_allocator_register(struct cma_allocator *alloc)
__cma_region_attach_alloc(reg);
}
+ __cma_dfs_allocator_add(alloc);
+
mutex_unlock(&cma_mutex);
pr_debug("%s: allocator registered\n", alloc->name ?: "(unnamed)");
@@ -481,6 +496,476 @@ static int __init cma_init(void)
subsys_initcall(cma_init);
+/************************* Debugfs *************************/
+
+#if defined CONFIG_CMA_DEBUGFS
+
+static struct dentry *cma_dfs_regions, *cma_dfs_allocators;
+
+struct cma_dfs_file {
+ const char *name;
+ const struct file_operations *ops;
+};
+
+static struct dentry *
+cma_dfs_create_file(const char *name, struct dentry *parent,
+ void *priv, const struct file_operations *ops)
+{
+ struct dentry *d;
+ d = debugfs_create_file(name, ops->write ? 0644 : 0444,
+ parent, priv, ops);
+ if (IS_ERR_OR_NULL(d)) {
+ pr_err("debugfs: %s: %s: unable to create\n",
+ parent->d_iname, name);
+ return NULL;
+ }
+
+ return d;
+}
+
+static void cma_dfs_create_files(const struct cma_dfs_file *files,
+ struct dentry *parent, void *priv)
+{
+ while (files->name
+ && cma_dfs_create_file(files->name, parent, priv, files->ops))
+ ++files;
+}
+
+static struct dentry *
+cma_dfs_create_dir(const char *name, struct dentry *parent)
+{
+ struct dentry *d = debugfs_create_dir(name, parent);
+
+ if (IS_ERR_OR_NULL(d)) {
+ pr_err("debugfs: %s: %s: unable to create\n",
+ parent ? (const char *)parent->d_iname : "<root>", name);
+ return NULL;
+ }
+
+ return d;
+}
+
+static struct dentry *
+cma_dfs_create_lnk(const char *name, struct dentry *parent, const char *target)
+{
+ struct dentry *d = debugfs_create_symlink(name, parent, target);
+
+ if (IS_ERR_OR_NULL(d)) {
+ pr_err("debugfs: %s: %s: unable to create\n",
+ parent->d_iname, name);
+ return NULL;
+ }
+
+ return d;
+}
+
+static int cma_dfs_open(struct inode *inode, struct file *file)
+{
+ file->private_data = inode->i_private;
+ return 0;
+}
+
+static ssize_t cma_dfs_map_read(struct file *file, char __user *buf,
+ size_t size, loff_t *offp)
+{
+ ssize_t len;
+
+ if (!cma_map_length || *offp)
+ return 0;
+
+ mutex_lock(&cma_mutex);
+
+ /* may have changed */
+ len = cma_map_length;
+ if (!len)
+ goto done;
+
+ len = min_t(size_t, size, len);
+ if (copy_to_user(buf, cma_map, len))
+ len = -EFAULT;
+ else if ((size_t)len < size && put_user('\n', buf + len++))
+ len = -EFAULT;
+
+done:
+ mutex_unlock(&cma_mutex);
+
+ if (len > 0)
+ *offp = len;
+
+ return len;
+}
+
+static ssize_t cma_dfs_map_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *offp)
+{
+ char *val, *v;
+ ssize_t len;
+
+ if (size >= PAGE_SIZE || *offp)
+ return -ENOSPC;
+
+ val = kmalloc(size + 1, GFP_KERNEL);
+ if (!val)
+ return -ENOMEM;
+
+ if (copy_from_user(val, buf, size)) {
+ len = -EFAULT;
+ goto done;
+ }
+ val[size] = '\0';
+
+ len = cma_map_validate(val);
+ if (len < 0)
+ goto done;
+ val[len] = '\0';
+
+ mutex_lock(&cma_mutex);
+ v = (char *)cma_map;
+ cma_map = val;
+ val = v;
+ cma_map_length = len;
+ mutex_unlock(&cma_mutex);
+
+done:
+ kfree(val);
+
+ if (len > 0)
+ *offp = len;
+
+ return len;
+}
+
+static int __init cma_dfs_init(void)
+{
+ static const struct file_operations map_ops = {
+ .read = cma_dfs_map_read,
+ .write = cma_dfs_map_write,
+ };
+
+ struct dentry *root, *a, *r;
+
+ root = cma_dfs_create_dir("contiguous", NULL);
+ if (!root)
+ return 0;
+
+ if (!cma_dfs_create_file("map", root, NULL, &map_ops))
+ goto error;
+
+ a = cma_dfs_create_dir("allocators", root);
+ if (!a)
+ goto error;
+
+ r = cma_dfs_create_dir("regions", root);
+ if (!r)
+ goto error;
+
+ mutex_lock(&cma_mutex);
+ {
+ struct cma_allocator *alloc;
+ cma_dfs_allocators = a;
+ cma_foreach_allocator(alloc)
+ __cma_dfs_allocator_add(alloc);
+ }
+
+ {
+ struct cma_region *reg;
+ cma_dfs_regions = r;
+ cma_foreach_region(reg)
+ __cma_dfs_region_add(reg);
+ }
+ mutex_unlock(&cma_mutex);
+
+ return 0;
+
+error:
+ debugfs_remove_recursive(root);
+ return 0;
+}
+device_initcall(cma_dfs_init);
+
+static ssize_t cma_dfs_region_name_read(struct file *file, char __user *buf,
+ size_t size, loff_t *offp)
+{
+ struct cma_region *reg = file->private_data;
+ size_t len;
+
+ if (!reg->name || *offp)
+ return 0;
+
+ len = min(strlen(reg->name), size);
+ if (copy_to_user(buf, reg->name, len))
+ return -EFAULT;
+ if (len < size && put_user('\n', buf + len++))
+ return -EFAULT;
+
+ *offp = len;
+ return len;
+}
+
+static ssize_t cma_dfs_region_info_read(struct file *file, char __user *buf,
+ size_t size, loff_t *offp)
+{
+ struct cma_region *reg = file->private_data;
+ char str[min((size_t)63, size) + 1];
+ int len;
+
+ if (*offp)
+ return 0;
+
+ len = snprintf(str, sizeof str, "%p %p %p\n",
+ (void *)reg->start, (void *)reg->size,
+ (void *)reg->free_space);
+
+ if (copy_to_user(buf, str, len))
+ return -EFAULT;
+
+ *offp = len;
+ return len;
+}
+
+static ssize_t cma_dfs_region_alloc_read(struct file *file, char __user *buf,
+ size_t size, loff_t *offp)
+{
+ struct cma_region *reg = file->private_data;
+ char str[min((size_t)63, size) + 1];
+ const char *fmt;
+ const void *arg;
+ int len = 0;
+
+ if (*offp)
+ return 0;
+
+ mutex_lock(&cma_mutex);
+
+ if (reg->alloc) {
+ if (reg->alloc->name) {
+ fmt = "%s\n";
+ arg = reg->alloc->name;
+ } else {
+ fmt = "0x%p\n";
+ arg = (void *)reg->alloc;
+ }
+ } else if (reg->alloc_name) {
+ fmt = "[%s]\n";
+ arg = reg->alloc_name;
+ } else {
+ goto done;
+ }
+
+ len = snprintf(str, sizeof str, fmt, arg);
+
+done:
+ mutex_unlock(&cma_mutex);
+
+ if (len) {
+ if (copy_to_user(buf, str, len))
+ return -EFAULT;
+ *offp = len;
+ }
+ return len;
+}
+
+static ssize_t
+cma_dfs_region_alloc_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *offp)
+{
+ struct cma_region *reg = file->private_data;
+ ssize_t ret;
+ char *s, *t;
+
+ if (size > 64 || *offp)
+ return -ENOSPC;
+
+ if (reg->alloc && reg->users)
+ return -EBUSY;
+
+ s = kmalloc(size + 1, GFP_KERNEL);
+ if (!s)
+ return -ENOMEM;
+
+ if (copy_from_user(s, buf, size)) {
+ ret = -EFAULT;
+ goto done_free;
+ }
+
+ s[size] = '\0';
+ t = strchr(s, '\n');
+ if (t == s) {
+ kfree(s);
+ s = NULL;
+ }
+ if (t)
+ *t = '\0';
+
+ mutex_lock(&cma_mutex);
+
+ /* things may have changed while we were acquiring lock */
+ if (reg->alloc && reg->users) {
+ ret = -EBUSY;
+ } else {
+ if (reg->alloc)
+ __cma_region_detach_alloc(reg);
+
+ t = s;
+ s = reg->free_alloc_name ? (char *)reg->alloc_name : NULL;
+
+ reg->alloc_name = t;
+ reg->free_alloc_name = 1;
+
+ ret = size;
+ }
+
+ mutex_unlock(&cma_mutex);
+
+done_free:
+ kfree(s);
+
+ if (ret > 0)
+ *offp = ret;
+ return ret;
+}
+
+static const struct cma_dfs_file __cma_dfs_region_files[] = {
+ {
+ "name", &(const struct file_operations){
+ .open = cma_dfs_open,
+ .read = cma_dfs_region_name_read,
+ },
+ },
+ {
+ "info", &(const struct file_operations){
+ .open = cma_dfs_open,
+ .read = cma_dfs_region_info_read,
+ },
+ },
+ {
+ "alloc", &(const struct file_operations){
+ .open = cma_dfs_open,
+ .read = cma_dfs_region_alloc_read,
+ .write = cma_dfs_region_alloc_write,
+ },
+ },
+ { }
+};
+
+static void __cma_dfs_region_add(struct cma_region *reg)
+{
+ struct dentry *d;
+
+ if (!cma_dfs_regions || reg->dir)
+ return;
+
+ /* Region's directory */
+ reg->from_alloc_link = kasprintf(GFP_KERNEL, "../../regions/0x%p",
+ (void *)reg->start);
+ if (!reg->from_alloc_link)
+ return;
+
+ d = cma_dfs_create_dir(reg->from_alloc_link + 14, cma_dfs_regions);
+ if (!d) {
+ kfree(reg->from_alloc_link);
+ return;
+ }
+
+ if (reg->name)
+ cma_dfs_create_lnk(reg->name, cma_dfs_regions,
+ reg->from_alloc_link + 14);
+
+ reg->dir = d;
+
+ /* Files */
+ cma_dfs_create_files(__cma_dfs_region_files, d, reg);
+
+ /* Link to allocator */
+ __cma_dfs_region_alloc_update(reg);
+}
+
+static void __cma_dfs_region_alloc_update(struct cma_region *reg)
+{
+ if (!cma_dfs_regions || !cma_dfs_allocators || !reg->dir)
+ return;
+
+ /* Remove stall links */
+ if (reg->to_alloc) {
+ debugfs_remove(reg->to_alloc);
+ reg->to_alloc = NULL;
+ }
+
+ if (reg->from_alloc) {
+ debugfs_remove(reg->from_alloc);
+ reg->from_alloc = NULL;
+ }
+
+ if (reg->to_alloc_link) {
+ kfree(reg->to_alloc_link);
+ reg->to_alloc_link = NULL;
+ }
+
+ if (!reg->alloc)
+ return;
+
+ /* Create new links */
+ if (reg->alloc->regs_dir)
+ reg->from_alloc =
+ cma_dfs_create_lnk(reg->from_alloc_link + 14,
+ reg->alloc->regs_dir,
+ reg->from_alloc_link);
+
+ if (!reg->alloc->dir_name)
+ return;
+
+ reg->to_alloc_link = kasprintf(GFP_KERNEL, "../allocators/%s",
+ reg->alloc->dir_name);
+ if (reg->to_alloc_link &&
+ !cma_dfs_create_lnk("allocator", reg->dir, reg->to_alloc_link)) {
+ kfree(reg->to_alloc_link);
+ reg->to_alloc_link = NULL;
+ }
+}
+
+static inline void __cma_dfs_allocator_add(struct cma_allocator *alloc)
+{
+ struct dentry *d;
+
+ if (!cma_dfs_allocators || alloc->dir_name)
+ return;
+
+ alloc->dir_name = alloc->name ?:
+ kasprintf(GFP_KERNEL, "0x%p", (void *)alloc);
+ if (!alloc->dir_name)
+ return;
+
+ d = cma_dfs_create_dir(alloc->dir_name, cma_dfs_allocators);
+ if (!d) {
+ if (!alloc->name)
+ kfree(alloc->dir_name);
+ alloc->dir_name = NULL;
+ return;
+ }
+
+ alloc->regs_dir = cma_dfs_create_dir("regions", d);
+}
+
+#else
+
+static inline void __cma_dfs_region_add(struct cma_region *reg)
+{
+ /* nop */
+}
+
+static inline void __cma_dfs_allocator_add(struct cma_allocator *alloc)
+{
+ /* nop */
+}
+
+static inline void __cma_dfs_region_alloc_update(struct cma_region *reg)
+{
+ /* nop */
+}
+
+#endif
+
+
/************************* The Device API *************************/
static const char *__must_check
@@ -731,10 +1216,24 @@ static int __cma_region_attach_alloc(struct cma_region *reg)
reg->alloc = alloc;
pr_debug("init: %s: %s: initialised allocator\n",
reg->name ?: "(private)", alloc->name ?: "(unnamed)");
+ __cma_dfs_region_alloc_update(reg);
}
return ret;
}
+static void __cma_region_detach_alloc(struct cma_region *reg)
+{
+ if (!reg->alloc)
+ return;
+
+ if (reg->alloc->cleanup)
+ reg->alloc->cleanup(reg);
+
+ reg->alloc = NULL;
+ reg->used = 1;
+ __cma_dfs_region_alloc_update(reg);
+}
+
/*
* s ::= rules
--
1.7.2.3
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