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authorKrzysztof Helt <krzysztof.h1@wp.pl>2009-06-30 14:41:29 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-30 21:56:00 -0400
commit537a1bf059fa312355696fa6db80726e655e7f17 (patch)
tree4f5b3c6917311cfefad21eaf3dd92978334282de /drivers/video/sm501fb.c
parent70d6027ff2bc8bab180273b77e7ab3e8a62cca51 (diff)
fbdev: add mutex for fb_mmap locking
Add a mutex to avoid a circular locking problem between the mm layer semaphore and fbdev ioctl mutex through the fb_mmap() call. Also, add mutex to all places where smem_start and smem_len fields change so the mutex inside the fb_mmap() is actually used. Changing of these fields before calling the framebuffer_register() are not mutexed. This is 2.6.31 material. It removes one lockdep (fb_mmap() and register_framebuffer()) but there is still another one (fb_release() and register_framebuffer()). It also cleans up handling of the smem_start and smem_len fields used by mutexed section of the fb_mmap(). Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/video/sm501fb.c')
-rw-r--r--drivers/video/sm501fb.c21
1 files changed, 13 insertions, 8 deletions
diff --git a/drivers/video/sm501fb.c b/drivers/video/sm501fb.c
index eb5d73a06702..98f24f0ec00d 100644
--- a/drivers/video/sm501fb.c
+++ b/drivers/video/sm501fb.c
@@ -145,7 +145,7 @@ static inline void sm501fb_sync_regs(struct sm501fb_info *info)
145#define SM501_MEMF_ACCEL (8) 145#define SM501_MEMF_ACCEL (8)
146 146
147static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem, 147static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
148 unsigned int why, size_t size) 148 unsigned int why, size_t size, u32 smem_len)
149{ 149{
150 struct sm501fb_par *par; 150 struct sm501fb_par *par;
151 struct fb_info *fbi; 151 struct fb_info *fbi;
@@ -172,7 +172,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
172 if (ptr > 0) 172 if (ptr > 0)
173 ptr &= ~(PAGE_SIZE - 1); 173 ptr &= ~(PAGE_SIZE - 1);
174 174
175 if (fbi && ptr < fbi->fix.smem_len) 175 if (fbi && ptr < smem_len)
176 return -ENOMEM; 176 return -ENOMEM;
177 177
178 break; 178 break;
@@ -197,7 +197,7 @@ static int sm501_alloc_mem(struct sm501fb_info *inf, struct sm501_mem *mem,
197 197
198 case SM501_MEMF_ACCEL: 198 case SM501_MEMF_ACCEL:
199 fbi = inf->fb[HEAD_CRT]; 199 fbi = inf->fb[HEAD_CRT];
200 ptr = fbi ? fbi->fix.smem_len : 0; 200 ptr = fbi ? smem_len : 0;
201 201
202 fbi = inf->fb[HEAD_PANEL]; 202 fbi = inf->fb[HEAD_PANEL];
203 if (fbi) { 203 if (fbi) {
@@ -413,6 +413,7 @@ static int sm501fb_set_par_common(struct fb_info *info,
413 unsigned int mem_type; 413 unsigned int mem_type;
414 unsigned int clock_type; 414 unsigned int clock_type;
415 unsigned int head_addr; 415 unsigned int head_addr;
416 unsigned int smem_len;
416 417
417 dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n", 418 dev_dbg(fbi->dev, "%s: %dx%d, bpp = %d, virtual %dx%d\n",
418 __func__, var->xres, var->yres, var->bits_per_pixel, 419 __func__, var->xres, var->yres, var->bits_per_pixel,
@@ -453,18 +454,20 @@ static int sm501fb_set_par_common(struct fb_info *info,
453 454
454 /* allocate fb memory within 501 */ 455 /* allocate fb memory within 501 */
455 info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8; 456 info->fix.line_length = (var->xres_virtual * var->bits_per_pixel)/8;
456 info->fix.smem_len = info->fix.line_length * var->yres_virtual; 457 smem_len = info->fix.line_length * var->yres_virtual;
457 458
458 dev_dbg(fbi->dev, "%s: line length = %u\n", __func__, 459 dev_dbg(fbi->dev, "%s: line length = %u\n", __func__,
459 info->fix.line_length); 460 info->fix.line_length);
460 461
461 if (sm501_alloc_mem(fbi, &par->screen, mem_type, 462 if (sm501_alloc_mem(fbi, &par->screen, mem_type, smem_len, smem_len)) {
462 info->fix.smem_len)) {
463 dev_err(fbi->dev, "no memory available\n"); 463 dev_err(fbi->dev, "no memory available\n");
464 return -ENOMEM; 464 return -ENOMEM;
465 } 465 }
466 466
467 mutex_lock(&info->mm_lock);
467 info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr; 468 info->fix.smem_start = fbi->fbmem_res->start + par->screen.sm_addr;
469 info->fix.smem_len = smem_len;
470 mutex_unlock(&info->mm_lock);
468 471
469 info->screen_base = fbi->fbmem + par->screen.sm_addr; 472 info->screen_base = fbi->fbmem + par->screen.sm_addr;
470 info->screen_size = info->fix.smem_len; 473 info->screen_size = info->fix.smem_len;
@@ -637,7 +640,8 @@ static int sm501fb_set_par_crt(struct fb_info *info)
637 if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) { 640 if ((control & SM501_DC_CRT_CONTROL_SEL) == 0) {
638 /* the head is displaying panel data... */ 641 /* the head is displaying panel data... */
639 642
640 sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0); 643 sm501_alloc_mem(fbi, &par->screen, SM501_MEMF_CRT, 0,
644 info->fix.smem_len);
641 goto out_update; 645 goto out_update;
642 } 646 }
643 647
@@ -1289,7 +1293,8 @@ static int sm501_init_cursor(struct fb_info *fbi, unsigned int reg_base)
1289 1293
1290 par->cursor_regs = info->regs + reg_base; 1294 par->cursor_regs = info->regs + reg_base;
1291 1295
1292 ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024); 1296 ret = sm501_alloc_mem(info, &par->cursor, SM501_MEMF_CURSOR, 1024,
1297 fbi->fix.smem_len);
1293 if (ret < 0) 1298 if (ret < 0)
1294 return ret; 1299 return ret;
1295 1300