This function will be useful for the incoming loadable support, so factor it out of file_to_sdram().
While at it, make it a bit safer as well: Only the first page needs to be copied with zero_page_memcpy if at all, so copy at most one page if the zero page is overlapped and then copy the rest as usual. file_to_sdram() is intentionally left as-is as it's going to be removed in a later commit. Signed-off-by: Ahmad Fatoum <[email protected]> --- include/libfile.h | 1 + lib/libfile.c | 29 +++++++++++++++++++++++++++++ 2 files changed, 30 insertions(+) diff --git a/include/libfile.h b/include/libfile.h index f44046fb0f7b..f61c45563c01 100644 --- a/include/libfile.h +++ b/include/libfile.h @@ -11,6 +11,7 @@ int pread_full(int fd, void *buf, size_t size, loff_t offset); int pwrite_full(int fd, const void *buf, size_t size, loff_t offset); int write_full(int fd, const void *buf, size_t size); int read_full(int fd, void *buf, size_t size); +int __read_full_anywhere(int fd, void *buf, size_t size); int copy_fd(int in, int out, size_t size); ssize_t read_file_into_buf(const char *filename, void *buf, size_t size); diff --git a/lib/libfile.c b/lib/libfile.c index 3be410855d2e..966350674a83 100644 --- a/lib/libfile.c +++ b/lib/libfile.c @@ -798,6 +798,35 @@ int cache_file(const char *path, char **newpath) return 0; } +/* + * __read_full_anywhere - read from filedescriptor, even into zero_page + * + * Like read_full, but this function will temporarily remap the zero + * page if data is to be placed there. You should not need to use this + * outside of boot code! + */ +int __read_full_anywhere(int fd, void *buf, size_t size) +{ + ssize_t now = 0; + + if (unlikely(zero_page_contains((ulong)buf))) { + void *tmp = malloc(PAGE_SIZE); + if (!tmp) + return -ENOMEM; + + now = read_full(fd, tmp, min_t(size_t, size, PAGE_SIZE)); + if (now > 0) + zero_page_memcpy(buf, tmp, now); + + free(tmp); + + if (now <= 0) + return now; + } + + return now + read_full(fd, buf + now, size - now); +} + #define BUFSIZ (PAGE_SIZE * 32) struct resource *file_to_sdram(const char *filename, unsigned long adr, -- 2.47.3
