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authorKeith Wansbrough <keith@lochan.org>2008-09-22 17:57:17 -0400
committerJens Axboe <jens.axboe@oracle.com>2008-10-09 02:56:19 -0400
commit9e49184c82e9ec3ab4d45f9ea5a17ccaf43869f0 (patch)
tree532d70e75854e1f7c070d4818f3b44cefe528d3e /drivers/block
parent061837bc8687edc2739ef02f721b7ae0b8076390 (diff)
floppy: support arbitrary first-sector numbers
The current floppy_struct allows floppies to number sectors starting from 0 or 1. This patch allows arbitrary first-sector numbers - for example, 0xC1 for Amstrad CPC disks. This extends the existing 1-bit field (FD_ZEROBASED, bit 2 of stretch) to 8 bits (FD_SECTMASK, bits 2 to 9). Currently 0x00 denotes a first sector number of 1, and 0x01 denotes a first sector number of 0. We extend this by interpreting FD_SECTMASK as the first sector number with the LSB flipped. Signed-off-by: Keith Wansbrough <keith@lochan.org> Cc: Alain Knaff <alain@linux.lu> Cc: Michael Kerrisk <mtk.manpages@googlemail.com> Cc: Karel Zak <kzak@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'drivers/block')
-rw-r--r--drivers/block/floppy.c23
1 files changed, 15 insertions, 8 deletions
diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 9c0b494f5e87..cf64ddf5d839 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -423,8 +423,15 @@ static struct floppy_raw_cmd *raw_cmd, default_raw_cmd;
423 * 1581's logical side 0 is on physical side 1, whereas the Sharp's logical 423 * 1581's logical side 0 is on physical side 1, whereas the Sharp's logical
424 * side 0 is on physical side 0 (but with the misnamed sector IDs). 424 * side 0 is on physical side 0 (but with the misnamed sector IDs).
425 * 'stretch' should probably be renamed to something more general, like 425 * 'stretch' should probably be renamed to something more general, like
426 * 'options'. Other parameters should be self-explanatory (see also 426 * 'options'.
427 * setfdprm(8)). 427 *
428 * Bits 2 through 9 of 'stretch' tell the number of the first sector.
429 * The LSB (bit 2) is flipped. For most disks, the first sector
430 * is 1 (represented by 0x00<<2). For some CP/M and music sampler
431 * disks (such as Ensoniq EPS 16plus) it is 0 (represented as 0x01<<2).
432 * For Amstrad CPC disks it is 0xC1 (represented as 0xC0<<2).
433 *
434 * Other parameters should be self-explanatory (see also setfdprm(8)).
428 */ 435 */
429/* 436/*
430 Size 437 Size
@@ -2236,9 +2243,9 @@ static void setup_format_params(int track)
2236 } 2243 }
2237 } 2244 }
2238 } 2245 }
2239 if (_floppy->stretch & FD_ZEROBASED) { 2246 if (_floppy->stretch & FD_SECTBASEMASK) {
2240 for (count = 0; count < F_SECT_PER_TRACK; count++) 2247 for (count = 0; count < F_SECT_PER_TRACK; count++)
2241 here[count].sect--; 2248 here[count].sect += FD_SECTBASE(_floppy) - 1;
2242 } 2249 }
2243} 2250}
2244 2251
@@ -2649,7 +2656,7 @@ static int make_raw_rw_request(void)
2649 } 2656 }
2650 HEAD = fsector_t / _floppy->sect; 2657 HEAD = fsector_t / _floppy->sect;
2651 2658
2652 if (((_floppy->stretch & (FD_SWAPSIDES | FD_ZEROBASED)) || 2659 if (((_floppy->stretch & (FD_SWAPSIDES | FD_SECTBASEMASK)) ||
2653 TESTF(FD_NEED_TWADDLE)) && fsector_t < _floppy->sect) 2660 TESTF(FD_NEED_TWADDLE)) && fsector_t < _floppy->sect)
2654 max_sector = _floppy->sect; 2661 max_sector = _floppy->sect;
2655 2662
@@ -2679,7 +2686,7 @@ static int make_raw_rw_request(void)
2679 CODE2SIZE; 2686 CODE2SIZE;
2680 SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE; 2687 SECT_PER_TRACK = _floppy->sect << 2 >> SIZECODE;
2681 SECTOR = ((fsector_t % _floppy->sect) << 2 >> SIZECODE) + 2688 SECTOR = ((fsector_t % _floppy->sect) << 2 >> SIZECODE) +
2682 ((_floppy->stretch & FD_ZEROBASED) ? 0 : 1); 2689 FD_SECTBASE(_floppy);
2683 2690
2684 /* tracksize describes the size which can be filled up with sectors 2691 /* tracksize describes the size which can be filled up with sectors
2685 * of size ssize. 2692 * of size ssize.
@@ -3311,7 +3318,7 @@ static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
3311 g->head <= 0 || 3318 g->head <= 0 ||
3312 g->track <= 0 || g->track > UDP->tracks >> STRETCH(g) || 3319 g->track <= 0 || g->track > UDP->tracks >> STRETCH(g) ||
3313 /* check if reserved bits are set */ 3320 /* check if reserved bits are set */
3314 (g->stretch & ~(FD_STRETCH | FD_SWAPSIDES | FD_ZEROBASED)) != 0) 3321 (g->stretch & ~(FD_STRETCH | FD_SWAPSIDES | FD_SECTBASEMASK)) != 0)
3315 return -EINVAL; 3322 return -EINVAL;
3316 if (type) { 3323 if (type) {
3317 if (!capable(CAP_SYS_ADMIN)) 3324 if (!capable(CAP_SYS_ADMIN))
@@ -3356,7 +3363,7 @@ static inline int set_geometry(unsigned int cmd, struct floppy_struct *g,
3356 if (DRS->maxblock > user_params[drive].sect || 3363 if (DRS->maxblock > user_params[drive].sect ||
3357 DRS->maxtrack || 3364 DRS->maxtrack ||
3358 ((user_params[drive].sect ^ oldStretch) & 3365 ((user_params[drive].sect ^ oldStretch) &
3359 (FD_SWAPSIDES | FD_ZEROBASED))) 3366 (FD_SWAPSIDES | FD_SECTBASEMASK)))
3360 invalidate_drive(bdev); 3367 invalidate_drive(bdev);
3361 else 3368 else
3362 process_fd_request(); 3369 process_fd_request();