xref: /linux/arch/x86/include/asm/floppy.h (revision 40286d6379aacfcc053253ef78dc78b09addffda)
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_X86_FLOPPY_H
11 #define _ASM_X86_FLOPPY_H
12 
13 #include <linux/sizes.h>
14 #include <linux/vmalloc.h>
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) &&							\
26 	 ((unsigned long)(a) / SZ_64K != ((unsigned long)(a) + (s) - 1) / SZ_64K))
27 
28 #define SW fd_routine[use_virtual_dma & 1]
29 #define CSW fd_routine[can_use_virtual_dma & 1]
30 
31 
32 #define fd_request_dma()	CSW._request_dma(FLOPPY_DMA, "floppy")
33 #define fd_free_dma()		CSW._free_dma(FLOPPY_DMA)
34 #define fd_enable_irq()		enable_irq(FLOPPY_IRQ)
35 #define fd_disable_irq()	disable_irq(FLOPPY_IRQ)
36 #define fd_free_irq()		free_irq(FLOPPY_IRQ, NULL)
37 #define fd_get_dma_residue()	SW._get_dma_residue(FLOPPY_DMA)
38 #define fd_dma_mem_alloc(size)	SW._dma_mem_alloc(size)
39 #define fd_dma_setup(addr, size, mode, io) SW._dma_setup(addr, size, mode, io)
40 
41 #define FLOPPY_CAN_FALLBACK_ON_NODMA
42 
43 static int virtual_dma_count;
44 static int virtual_dma_residue;
45 static char *virtual_dma_addr;
46 static int virtual_dma_mode;
47 static int doing_pdma;
48 
49 static inline u8 fd_inb(u16 base, u16 reg)
50 {
51 	u8 ret = inb_p(base + reg);
52 
53 	native_io_delay();
54 	native_io_delay();
55 	native_io_delay();
56 
57 	return ret;
58 }
59 
60 static inline void fd_outb(u8 value, u16 base, u16 reg)
61 {
62 	outb_p(value, base + reg);
63 
64 	native_io_delay();
65 	native_io_delay();
66 	native_io_delay();
67 }
68 
69 static irqreturn_t floppy_hardint(int irq, void *dev_id)
70 {
71 	unsigned char st;
72 
73 #undef TRACE_FLPY_INT
74 
75 #ifdef TRACE_FLPY_INT
76 	static int calls;
77 	static int bytes;
78 	static int dma_wait;
79 #endif
80 	if (!doing_pdma)
81 		return floppy_interrupt(irq, dev_id);
82 
83 #ifdef TRACE_FLPY_INT
84 	if (!calls)
85 		bytes = virtual_dma_count;
86 #endif
87 
88 	{
89 		int lcount;
90 		char *lptr;
91 
92 		for (lcount = virtual_dma_count, lptr = virtual_dma_addr;
93 		     lcount; lcount--, lptr++) {
94 			st = inb(virtual_dma_port + FD_STATUS);
95 			st &= STATUS_DMA | STATUS_READY;
96 			if (st != (STATUS_DMA | STATUS_READY))
97 				break;
98 			if (virtual_dma_mode)
99 				fd_outb(*lptr, virtual_dma_port, FD_DATA);
100 			else
101 				*lptr = fd_inb(virtual_dma_port, FD_DATA);
102 		}
103 		virtual_dma_count = lcount;
104 		virtual_dma_addr = lptr;
105 		st = inb(virtual_dma_port + FD_STATUS);
106 	}
107 
108 #ifdef TRACE_FLPY_INT
109 	calls++;
110 #endif
111 	if (st == STATUS_DMA)
112 		return IRQ_HANDLED;
113 	if (!(st & STATUS_DMA)) {
114 		virtual_dma_residue += virtual_dma_count;
115 		virtual_dma_count = 0;
116 #ifdef TRACE_FLPY_INT
117 		printk(KERN_DEBUG "count=%x, residue=%x calls=%d bytes=%d dma_wait=%d\n",
118 		       virtual_dma_count, virtual_dma_residue, calls, bytes,
119 		       dma_wait);
120 		calls = 0;
121 		dma_wait = 0;
122 #endif
123 		doing_pdma = 0;
124 		floppy_interrupt(irq, dev_id);
125 		return IRQ_HANDLED;
126 	}
127 #ifdef TRACE_FLPY_INT
128 	if (!virtual_dma_count)
129 		dma_wait++;
130 #endif
131 	return IRQ_HANDLED;
132 }
133 
134 static void fd_disable_dma(void)
135 {
136 	if (!(can_use_virtual_dma & 1))
137 		disable_dma(FLOPPY_DMA);
138 	doing_pdma = 0;
139 	virtual_dma_residue += virtual_dma_count;
140 	virtual_dma_count = 0;
141 }
142 
143 static int vdma_request_dma(unsigned int dmanr, const char *device_id)
144 {
145 	return 0;
146 }
147 
148 static void vdma_nop(unsigned int dummy)
149 {
150 }
151 
152 
153 static int vdma_get_dma_residue(unsigned int dummy)
154 {
155 	return virtual_dma_count + virtual_dma_residue;
156 }
157 
158 
159 static int fd_request_irq(void)
160 {
161 	if (can_use_virtual_dma)
162 		return request_irq(FLOPPY_IRQ, floppy_hardint,
163 				   0, "floppy", NULL);
164 	else
165 		return request_irq(FLOPPY_IRQ, floppy_interrupt,
166 				   0, "floppy", NULL);
167 }
168 
169 static unsigned long dma_mem_alloc(unsigned long size)
170 {
171 	return __get_dma_pages(GFP_KERNEL|__GFP_NORETRY, get_order(size));
172 }
173 
174 
175 static unsigned long vdma_mem_alloc(unsigned long size)
176 {
177 	return (unsigned long)vmalloc(size);
178 
179 }
180 
181 #define nodma_mem_alloc(size) vdma_mem_alloc(size)
182 
183 static void _fd_dma_mem_free(unsigned long addr, unsigned long size)
184 {
185 	if ((unsigned long)addr >= (unsigned long)high_memory)
186 		vfree((void *)addr);
187 	else
188 		free_pages(addr, get_order(size));
189 }
190 
191 #define fd_dma_mem_free(addr, size)  _fd_dma_mem_free(addr, size)
192 
193 static void _fd_chose_dma_mode(char *addr, unsigned long size)
194 {
195 	if (can_use_virtual_dma == 2) {
196 		if ((unsigned long)addr >= (unsigned long)high_memory ||
197 		    isa_virt_to_bus(addr) >= 0x1000000 ||
198 		    _CROSS_64KB(addr, size, 0))
199 			use_virtual_dma = 1;
200 		else
201 			use_virtual_dma = 0;
202 	} else {
203 		use_virtual_dma = can_use_virtual_dma & 1;
204 	}
205 }
206 
207 #define fd_chose_dma_mode(addr, size) _fd_chose_dma_mode(addr, size)
208 
209 
210 static int vdma_dma_setup(char *addr, unsigned long size, int mode, int io)
211 {
212 	doing_pdma = 1;
213 	virtual_dma_port = io;
214 	virtual_dma_mode = (mode == DMA_MODE_WRITE);
215 	virtual_dma_addr = addr;
216 	virtual_dma_count = size;
217 	virtual_dma_residue = 0;
218 	return 0;
219 }
220 
221 static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
222 {
223 #ifdef FLOPPY_SANITY_CHECK
224 	if (_CROSS_64KB(addr, size, use_virtual_dma & 1)) {
225 		printk("DMA crossing 64-K boundary %p-%p\n", addr, addr+size);
226 		return -1;
227 	}
228 #endif
229 	/* actual, physical DMA */
230 	doing_pdma = 0;
231 	clear_dma_ff(FLOPPY_DMA);
232 	set_dma_mode(FLOPPY_DMA, mode);
233 	set_dma_addr(FLOPPY_DMA, isa_virt_to_bus(addr));
234 	set_dma_count(FLOPPY_DMA, size);
235 	enable_dma(FLOPPY_DMA);
236 	return 0;
237 }
238 
239 static struct fd_routine_l {
240 	int (*_request_dma)(unsigned int dmanr, const char *device_id);
241 	void (*_free_dma)(unsigned int dmanr);
242 	int (*_get_dma_residue)(unsigned int dummy);
243 	unsigned long (*_dma_mem_alloc)(unsigned long size);
244 	int (*_dma_setup)(char *addr, unsigned long size, int mode, int io);
245 } fd_routine[] = {
246 	{
247 		._request_dma		= request_dma,
248 		._free_dma		= free_dma,
249 		._get_dma_residue	= get_dma_residue,
250 		._dma_mem_alloc		= dma_mem_alloc,
251 		._dma_setup		= hard_dma_setup
252 	},
253 	{
254 		._request_dma		= vdma_request_dma,
255 		._free_dma		= vdma_nop,
256 		._get_dma_residue	= vdma_get_dma_residue,
257 		._dma_mem_alloc		= vdma_mem_alloc,
258 		._dma_setup		= vdma_dma_setup
259 	}
260 };
261 
262 
263 static int FDC1 = 0x3f0;
264 static int FDC2 = -1;
265 
266 /*
267  * Floppy types are stored in the rtc's CMOS RAM and so rtc_lock
268  * is needed to prevent corrupted CMOS RAM in case "insmod floppy"
269  * coincides with another rtc CMOS user.		Paul G.
270  */
271 #define FLOPPY0_TYPE					\
272 ({							\
273 	unsigned long flags;				\
274 	unsigned char val;				\
275 	spin_lock_irqsave(&rtc_lock, flags);		\
276 	val = (CMOS_READ(0x10) >> 4) & 15;		\
277 	spin_unlock_irqrestore(&rtc_lock, flags);	\
278 	val;						\
279 })
280 
281 #define FLOPPY1_TYPE					\
282 ({							\
283 	unsigned long flags;				\
284 	unsigned char val;				\
285 	spin_lock_irqsave(&rtc_lock, flags);		\
286 	val = CMOS_READ(0x10) & 15;			\
287 	spin_unlock_irqrestore(&rtc_lock, flags);	\
288 	val;						\
289 })
290 
291 #define N_FDC 2
292 #define N_DRIVE 8
293 
294 #define EXTRA_FLOPPY_PARAMS
295 
296 #endif /* _ASM_X86_FLOPPY_H */
297