From 95e0d57fd49780db89193bc2df67b9eec640c4be Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 18 Aug 2020 10:56:58 +0200 Subject: vc_screen: extract vcs_write_buf This is the counterpart of the previous patch: here, we extract buffer writing with attributes from vcs_write. Now, there is no need for org to be initialized to NULL. The org0 check before update_region() confuses compilers, so check org instead. It provides the same semantics. And it also eliminates the need for initialization of org0. We switch the branches of the attr 'if' too, as the inversion brings only confusion now. Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20200818085706.12163-8-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/vc_screen.c | 168 +++++++++++++++++++++++++-------------------- 1 file changed, 92 insertions(+), 76 deletions(-) diff --git a/drivers/tty/vt/vc_screen.c b/drivers/tty/vt/vc_screen.c index 62e6d240f0dd..10a26fd5f1b7 100644 --- a/drivers/tty/vt/vc_screen.c +++ b/drivers/tty/vt/vc_screen.c @@ -481,14 +481,93 @@ static u16 *vcs_write_buf_noattr(struct vc_data *vc, const char *con_buf, return org; } +static u16 *vcs_write_buf(struct vc_data *vc, const char *con_buf, + unsigned int pos, unsigned int count, bool viewed, u16 **org0) +{ + u16 *org; + unsigned int col, maxcol = vc->vc_cols; + unsigned char c; + + /* header */ + if (pos < HEADER_SIZE) { + char header[HEADER_SIZE]; + + getconsxy(vc, header + 2); + while (pos < HEADER_SIZE && count > 0) { + count--; + header[pos++] = *con_buf++; + } + if (!viewed) + putconsxy(vc, header + 2); + } + + if (!count) + return NULL; + + pos -= HEADER_SIZE; + col = (pos/2) % maxcol; + + *org0 = org = screen_pos(vc, pos/2, viewed); + + /* odd pos -- the first single character */ + if (pos & 1) { + count--; + c = *con_buf++; +#ifdef __BIG_ENDIAN + vcs_scr_writew(vc, c | + (vcs_scr_readw(vc, org) & 0xff00), org); +#else + vcs_scr_writew(vc, (c << 8) | + (vcs_scr_readw(vc, org) & 0xff), org); +#endif + org++; + pos++; + if (++col == maxcol) { + org = screen_pos(vc, pos/2, viewed); + col = 0; + } + } + + pos /= 2; + pos += maxcol - col; + + /* even pos -- handle attr+character pairs */ + while (count > 1) { + unsigned short w; + + w = get_unaligned(((unsigned short *)con_buf)); + vcs_scr_writew(vc, w, org++); + con_buf += 2; + count -= 2; + if (++col == maxcol) { + org = screen_pos(vc, pos, viewed); + col = 0; + pos += maxcol; + } + } + + if (!count) + return org; + + /* odd pos -- the remaining character */ + c = *con_buf++; +#ifdef __BIG_ENDIAN + vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org); +#else + vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org); +#endif + + return org; +} + static ssize_t vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct inode *inode = file_inode(file); struct vc_data *vc; - char *con_buf0, *con_buf; - u16 *org0 = NULL, *org = NULL; - unsigned int written, col, maxcol; + char *con_buf; + u16 *org0, *org; + unsigned int written; int size; ssize_t ret; loff_t pos; @@ -526,7 +605,7 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) count = size - pos; written = 0; while (count) { - unsigned int orig_count, p, this_round = count; + unsigned int this_round = count; if (this_round > CON_BUF_SIZE) this_round = CON_BUF_SIZE; @@ -571,81 +650,18 @@ vcs_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) * under the lock using the local kernel buffer. */ - if (!attr) { + if (attr) + org = vcs_write_buf(vc, con_buf, pos, this_round, + viewed, &org0); + else org = vcs_write_buf_noattr(vc, con_buf, pos, this_round, viewed, &org0); - } else { - con_buf0 = con_buf; - orig_count = this_round; - maxcol = vc->vc_cols; - p = pos; - - if (p < HEADER_SIZE) { - char header[HEADER_SIZE]; - - getconsxy(vc, header + 2); - while (p < HEADER_SIZE && this_round > 0) { - this_round--; - header[p++] = *con_buf0++; - } - if (!viewed) - putconsxy(vc, header + 2); - } - p -= HEADER_SIZE; - col = (p/2) % maxcol; - if (this_round > 0) { - org0 = org = screen_pos(vc, p/2, viewed); - if ((p & 1) && this_round > 0) { - char c; - - this_round--; - c = *con_buf0++; -#ifdef __BIG_ENDIAN - vcs_scr_writew(vc, c | - (vcs_scr_readw(vc, org) & 0xff00), org); -#else - vcs_scr_writew(vc, (c << 8) | - (vcs_scr_readw(vc, org) & 0xff), org); -#endif - org++; - p++; - if (++col == maxcol) { - org = screen_pos(vc, p/2, viewed); - col = 0; - } - } - p /= 2; - p += maxcol - col; - } - while (this_round > 1) { - unsigned short w; - w = get_unaligned(((unsigned short *)con_buf0)); - vcs_scr_writew(vc, w, org++); - con_buf0 += 2; - this_round -= 2; - if (++col == maxcol) { - org = screen_pos(vc, p, viewed); - col = 0; - p += maxcol; - } - } - if (this_round > 0) { - unsigned char c; - - c = *con_buf0++; -#ifdef __BIG_ENDIAN - vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff) | (c << 8), org); -#else - vcs_scr_writew(vc, (vcs_scr_readw(vc, org) & 0xff00) | c, org); -#endif - } - } - count -= orig_count; - written += orig_count; - buf += orig_count; - pos += orig_count; - if (org0) + count -= this_round; + written += this_round; + buf += this_round; + pos += this_round; + if (org) update_region(vc, (unsigned long)(org0), org - org0); } *ppos += written; -- cgit v1.2.3