USB: prevent char device open/deregister race
[linux-2.6] / include / asm-i386 / floppy.h
1 /*
2  * Architecture specific parts of the Floppy driver
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 1995
9  */
10 #ifndef __ASM_I386_FLOPPY_H
11 #define __ASM_I386_FLOPPY_H
12
13 #include <linux/vmalloc.h>
14
15
16 /*
17  * The DMA channel used by the floppy controller cannot access data at
18  * addresses >= 16MB
19  *
20  * Went back to the 1MB limit, as some people had problems with the floppy
21  * driver otherwise. It doesn't matter much for performance anyway, as most
22  * floppy accesses go through the track buffer.
23  */
24 #define _CROSS_64KB(a,s,vdma) \
25 (!(vdma) && ((unsigned long)(a)/K_64 != ((unsigned long)(a) + (s) - 1) / K_64))
26
27 #define CROSS_64KB(a,s) _CROSS_64KB(a,s,use_virtual_dma & 1)
28
29
30 #define SW fd_routine[use_virtual_dma&1]
31 #define CSW fd_routine[can_use_virtual_dma & 1]
32
33
34 #define fd_inb(port)                    inb_p(port)
35 #define fd_outb(value,port)             outb_p(value,port)
36
37 #define fd_request_dma()        CSW._request_dma(FLOPPY_DMA,"floppy")
38 #define fd_free_dma()           CSW._free_dma(FLOPPY_DMA)
39 #define fd_enable_irq()         enable_irq(FLOPPY_IRQ)
40 #define fd_disable_irq()        disable_irq(FLOPPY_IRQ)
41 #define fd_free_irq()           free_irq(FLOPPY_IRQ, NULL)
42 #define fd_get_dma_residue()    SW._get_dma_residue(FLOPPY_DMA)
43 #define fd_dma_mem_alloc(size)  SW._dma_mem_alloc(size)
44 #define fd_dma_setup(addr, size, mode, io) SW._dma_setup(addr, size, mode, io)
45
46 #define FLOPPY_CAN_FALLBACK_ON_NODMA
47
48 static int virtual_dma_count;
49 static int virtual_dma_residue;
50 static char *virtual_dma_addr;
51 static int virtual_dma_mode;
52 static int doing_pdma;
53
54 static irqreturn_t floppy_hardint(int irq, void *dev_id)
55 {
56         register unsigned char st;
57
58 #undef TRACE_FLPY_INT
59
60 #ifdef TRACE_FLPY_INT
61         static int calls=0;
62         static int bytes=0;
63         static int dma_wait=0;
64 #endif
65         if (!doing_pdma)
66                 return floppy_interrupt(irq, dev_id);
67
68 #ifdef TRACE_FLPY_INT
69         if(!calls)
70                 bytes = virtual_dma_count;
71 #endif
72
73         {
74                 register int lcount;
75                 register char *lptr;
76
77                 st = 1;
78                 for(lcount=virtual_dma_count, lptr=virtual_dma_addr; 
79                     lcount; lcount--, lptr++) {
80                         st=inb(virtual_dma_port+4) & 0xa0 ;
81                         if(st != 0xa0) 
82                                 break;
83                         if(virtual_dma_mode)
84                                 outb_p(*lptr, virtual_dma_port+5);
85                         else
86                                 *lptr = inb_p(virtual_dma_port+5);
87                 }
88                 virtual_dma_count = lcount;
89                 virtual_dma_addr = lptr;
90                 st = inb(virtual_dma_port+4);
91         }
92
93 #ifdef TRACE_FLPY_INT
94         calls++;
95 #endif
96         if(st == 0x20)
97                 return IRQ_HANDLED;
98         if(!(st & 0x20)) {
99                 virtual_dma_residue += virtual_dma_count;
100                 virtual_dma_count=0;
101 #ifdef TRACE_FLPY_INT
102                 printk("count=%x, residue=%x calls=%d bytes=%d dma_wait=%d\n", 
103                        virtual_dma_count, virtual_dma_residue, calls, bytes,
104                        dma_wait);
105                 calls = 0;
106                 dma_wait=0;
107 #endif
108                 doing_pdma = 0;
109                 floppy_interrupt(irq, dev_id);
110                 return IRQ_HANDLED;
111         }
112 #ifdef TRACE_FLPY_INT
113         if(!virtual_dma_count)
114                 dma_wait++;
115 #endif
116         return IRQ_HANDLED;
117 }
118
119 static void fd_disable_dma(void)
120 {
121         if(! (can_use_virtual_dma & 1))
122                 disable_dma(FLOPPY_DMA);
123         doing_pdma = 0;
124         virtual_dma_residue += virtual_dma_count;
125         virtual_dma_count=0;
126 }
127
128 static int vdma_request_dma(unsigned int dmanr, const char * device_id)
129 {
130         return 0;
131 }
132
133 static void vdma_nop(unsigned int dummy)
134 {
135 }
136
137
138 static int vdma_get_dma_residue(unsigned int dummy)
139 {
140         return virtual_dma_count + virtual_dma_residue;
141 }
142
143
144 static int fd_request_irq(void)
145 {
146         if(can_use_virtual_dma)
147                 return request_irq(FLOPPY_IRQ, floppy_hardint,
148                                    IRQF_DISABLED, "floppy", NULL);
149         else
150                 return request_irq(FLOPPY_IRQ, floppy_interrupt,
151                                    IRQF_DISABLED, "floppy", NULL);
152
153 }
154
155 static unsigned long dma_mem_alloc(unsigned long size)
156 {
157         return __get_dma_pages(GFP_KERNEL,get_order(size));
158 }
159
160
161 static unsigned long vdma_mem_alloc(unsigned long size)
162 {
163         return (unsigned long) vmalloc(size);
164
165 }
166
167 #define nodma_mem_alloc(size) vdma_mem_alloc(size)
168
169 static void _fd_dma_mem_free(unsigned long addr, unsigned long size)
170 {
171         if((unsigned int) addr >= (unsigned int) high_memory)
172                 vfree((void *)addr);
173         else
174                 free_pages(addr, get_order(size));              
175 }
176
177 #define fd_dma_mem_free(addr, size)  _fd_dma_mem_free(addr, size) 
178
179 static void _fd_chose_dma_mode(char *addr, unsigned long size)
180 {
181         if(can_use_virtual_dma == 2) {
182                 if((unsigned int) addr >= (unsigned int) high_memory ||
183                    isa_virt_to_bus(addr) >= 0x1000000 ||
184                    _CROSS_64KB(addr, size, 0))
185                         use_virtual_dma = 1;
186                 else
187                         use_virtual_dma = 0;
188         } else {
189                 use_virtual_dma = can_use_virtual_dma & 1;
190         }
191 }
192
193 #define fd_chose_dma_mode(addr, size) _fd_chose_dma_mode(addr, size)
194
195
196 static int vdma_dma_setup(char *addr, unsigned long size, int mode, int io)
197 {
198         doing_pdma = 1;
199         virtual_dma_port = io;
200         virtual_dma_mode = (mode  == DMA_MODE_WRITE);
201         virtual_dma_addr = addr;
202         virtual_dma_count = size;
203         virtual_dma_residue = 0;
204         return 0;
205 }
206
207 static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
208 {
209 #ifdef FLOPPY_SANITY_CHECK
210         if (CROSS_64KB(addr, size)) {
211                 printk("DMA crossing 64-K boundary %p-%p\n", addr, addr+size);
212                 return -1;
213         }
214 #endif
215         /* actual, physical DMA */
216         doing_pdma = 0;
217         clear_dma_ff(FLOPPY_DMA);
218         set_dma_mode(FLOPPY_DMA,mode);
219         set_dma_addr(FLOPPY_DMA,isa_virt_to_bus(addr));
220         set_dma_count(FLOPPY_DMA,size);
221         enable_dma(FLOPPY_DMA);
222         return 0;
223 }
224
225 static struct fd_routine_l {
226         int (*_request_dma)(unsigned int dmanr, const char * device_id);
227         void (*_free_dma)(unsigned int dmanr);
228         int (*_get_dma_residue)(unsigned int dummy);
229         unsigned long (*_dma_mem_alloc) (unsigned long size);
230         int (*_dma_setup)(char *addr, unsigned long size, int mode, int io);
231 } fd_routine[] = {
232         {
233                 request_dma,
234                 free_dma,
235                 get_dma_residue,
236                 dma_mem_alloc,
237                 hard_dma_setup
238         },
239         {
240                 vdma_request_dma,
241                 vdma_nop,
242                 vdma_get_dma_residue,
243                 vdma_mem_alloc,
244                 vdma_dma_setup
245         }
246 };
247
248
249 static int FDC1 = 0x3f0;
250 static int FDC2 = -1;
251
252 /*
253  * Floppy types are stored in the rtc's CMOS RAM and so rtc_lock
254  * is needed to prevent corrupted CMOS RAM in case "insmod floppy"
255  * coincides with another rtc CMOS user.                Paul G.
256  */
257 #define FLOPPY0_TYPE    ({                              \
258         unsigned long flags;                            \
259         unsigned char val;                              \
260         spin_lock_irqsave(&rtc_lock, flags);            \
261         val = (CMOS_READ(0x10) >> 4) & 15;              \
262         spin_unlock_irqrestore(&rtc_lock, flags);       \
263         val;                                            \
264 })
265
266 #define FLOPPY1_TYPE    ({                              \
267         unsigned long flags;                            \
268         unsigned char val;                              \
269         spin_lock_irqsave(&rtc_lock, flags);            \
270         val = CMOS_READ(0x10) & 15;                     \
271         spin_unlock_irqrestore(&rtc_lock, flags);       \
272         val;                                            \
273 })
274
275 #define N_FDC 2
276 #define N_DRIVE 8
277
278 #define FLOPPY_MOTOR_MASK 0xf0
279
280 #define AUTO_DMA
281
282 #define EXTRA_FLOPPY_PARAMS
283
284 #endif /* __ASM_I386_FLOPPY_H */