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author | Takashi Iwai <tiwai@suse.de> | 2023-08-15 21:01:14 +0200 |
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committer | Takashi Iwai <tiwai@suse.de> | 2023-08-18 12:18:16 +0200 |
commit | 561b4fa9c1111292ec975a04ecd8372ac0256e1e (patch) | |
tree | 06c324a483aeaf35c8bda0c4eafd9901435b32f1 /sound/core | |
parent | cf393babb37a1679a1ec1d864df1090353465e23 (diff) | |
download | lwn-561b4fa9c1111292ec975a04ecd8372ac0256e1e.tar.gz lwn-561b4fa9c1111292ec975a04ecd8372ac0256e1e.zip |
ALSA: core: Add memory copy helpers between iov_iter and iomem
Add two more helpers for copying memory between iov_iter and iomem,
which will be used by the new PCM copy ops in a few drivers.
The existing helpers became wrappers of those now.
Note that copy_from/to_iter() returns the copied bytes, hence the
error condition is adjusted accordingly.
Link: https://lore.kernel.org/r/20230815190136.8987-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'sound/core')
-rw-r--r-- | sound/core/memory.c | 56 |
1 files changed, 48 insertions, 8 deletions
diff --git a/sound/core/memory.c b/sound/core/memory.c index 5d894dc32f7d..2d2d0094c897 100644 --- a/sound/core/memory.c +++ b/sound/core/memory.c @@ -9,6 +9,7 @@ #include <linux/io.h> #include <linux/uaccess.h> #include <sound/core.h> +#include <sound/pcm.h> /** * copy_to_user_fromio - copy data from mmio-space to user-space @@ -22,8 +23,29 @@ */ int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count) { + struct iov_iter iter; + + if (import_ubuf(ITER_DEST, dst, count, &iter)) + return -EFAULT; + return copy_to_iter_fromio(&iter, (const void __iomem *)src, count); +} +EXPORT_SYMBOL(copy_to_user_fromio); + +/** + * copy_to_iter_fromio - copy data from mmio-space to iov_iter + * @dst: the destination iov_iter + * @src: the source pointer on mmio + * @count: the data size to copy in bytes + * + * Copies the data from mmio-space to iov_iter. + * + * Return: Zero if successful, or non-zero on failure. + */ +int copy_to_iter_fromio(struct iov_iter *dst, const void __iomem *src, + size_t count) +{ #if defined(__i386__) || defined(CONFIG_SPARC32) - return copy_to_user(dst, (const void __force*)src, count) ? -EFAULT : 0; + return copy_to_iter((const void __force *)src, count, dst) == count ? 0 : -EFAULT; #else char buf[256]; while (count) { @@ -31,16 +53,15 @@ int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size if (c > sizeof(buf)) c = sizeof(buf); memcpy_fromio(buf, (void __iomem *)src, c); - if (copy_to_user(dst, buf, c)) + if (copy_to_iter(buf, c, dst) != c) return -EFAULT; count -= c; - dst += c; src += c; } return 0; #endif } -EXPORT_SYMBOL(copy_to_user_fromio); +EXPORT_SYMBOL(copy_to_iter_fromio); /** * copy_from_user_toio - copy data from user-space to mmio-space @@ -54,22 +75,41 @@ EXPORT_SYMBOL(copy_to_user_fromio); */ int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count) { + struct iov_iter iter; + + if (import_ubuf(ITER_SOURCE, (void __user *)src, count, &iter)) + return -EFAULT; + return copy_from_iter_toio((void __iomem *)dst, &iter, count); +} +EXPORT_SYMBOL(copy_from_user_toio); + +/** + * copy_from_iter_toio - copy data from iov_iter to mmio-space + * @dst: the destination pointer on mmio-space + * @src: the source iov_iter + * @count: the data size to copy in bytes + * + * Copies the data from iov_iter to mmio-space. + * + * Return: Zero if successful, or non-zero on failure. + */ +int copy_from_iter_toio(void __iomem *dst, struct iov_iter *src, size_t count) +{ #if defined(__i386__) || defined(CONFIG_SPARC32) - return copy_from_user((void __force *)dst, src, count) ? -EFAULT : 0; + return copy_from_iter((void __force *)dst, count, src) == count ? 0 : -EFAULT; #else char buf[256]; while (count) { size_t c = count; if (c > sizeof(buf)) c = sizeof(buf); - if (copy_from_user(buf, src, c)) + if (copy_from_iter(buf, c, src) != c) return -EFAULT; memcpy_toio(dst, buf, c); count -= c; dst += c; - src += c; } return 0; #endif } -EXPORT_SYMBOL(copy_from_user_toio); +EXPORT_SYMBOL(copy_from_iter_toio); |