xref: /openbmc/linux/arch/x86/include/asm/floppy.h (revision e7bae9bb)
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/vmalloc.h>
14 
15 /*
16  * The DMA channel used by the floppy controller cannot access data at
17  * addresses >= 16MB
18  *
19  * Went back to the 1MB limit, as some people had problems with the floppy
20  * driver otherwise. It doesn't matter much for performance anyway, as most
21  * floppy accesses go through the track buffer.
22  */
23 #define _CROSS_64KB(a, s, vdma)						\
24 	(!(vdma) &&							\
25 	 ((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(base, reg)		inb_p((base) + (reg))
35 #define fd_outb(value, base, reg)	outb_p(value, (base) + (reg))
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 	unsigned char st;
57 
58 #undef TRACE_FLPY_INT
59 
60 #ifdef TRACE_FLPY_INT
61 	static int calls;
62 	static int bytes;
63 	static int dma_wait;
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 		int lcount;
75 		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 + FD_STATUS);
81 			st &= STATUS_DMA | STATUS_READY;
82 			if (st != (STATUS_DMA | STATUS_READY))
83 				break;
84 			if (virtual_dma_mode)
85 				outb_p(*lptr, virtual_dma_port + FD_DATA);
86 			else
87 				*lptr = inb_p(virtual_dma_port + FD_DATA);
88 		}
89 		virtual_dma_count = lcount;
90 		virtual_dma_addr = lptr;
91 		st = inb(virtual_dma_port + FD_STATUS);
92 	}
93 
94 #ifdef TRACE_FLPY_INT
95 	calls++;
96 #endif
97 	if (st == STATUS_DMA)
98 		return IRQ_HANDLED;
99 	if (!(st & STATUS_DMA)) {
100 		virtual_dma_residue += virtual_dma_count;
101 		virtual_dma_count = 0;
102 #ifdef TRACE_FLPY_INT
103 		printk(KERN_DEBUG "count=%x, residue=%x calls=%d bytes=%d dma_wait=%d\n",
104 		       virtual_dma_count, virtual_dma_residue, calls, bytes,
105 		       dma_wait);
106 		calls = 0;
107 		dma_wait = 0;
108 #endif
109 		doing_pdma = 0;
110 		floppy_interrupt(irq, dev_id);
111 		return IRQ_HANDLED;
112 	}
113 #ifdef TRACE_FLPY_INT
114 	if (!virtual_dma_count)
115 		dma_wait++;
116 #endif
117 	return IRQ_HANDLED;
118 }
119 
120 static void fd_disable_dma(void)
121 {
122 	if (!(can_use_virtual_dma & 1))
123 		disable_dma(FLOPPY_DMA);
124 	doing_pdma = 0;
125 	virtual_dma_residue += virtual_dma_count;
126 	virtual_dma_count = 0;
127 }
128 
129 static int vdma_request_dma(unsigned int dmanr, const char *device_id)
130 {
131 	return 0;
132 }
133 
134 static void vdma_nop(unsigned int dummy)
135 {
136 }
137 
138 
139 static int vdma_get_dma_residue(unsigned int dummy)
140 {
141 	return virtual_dma_count + virtual_dma_residue;
142 }
143 
144 
145 static int fd_request_irq(void)
146 {
147 	if (can_use_virtual_dma)
148 		return request_irq(FLOPPY_IRQ, floppy_hardint,
149 				   0, "floppy", NULL);
150 	else
151 		return request_irq(FLOPPY_IRQ, floppy_interrupt,
152 				   0, "floppy", NULL);
153 }
154 
155 static unsigned long dma_mem_alloc(unsigned long size)
156 {
157 	return __get_dma_pages(GFP_KERNEL|__GFP_NORETRY, 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 long)addr >= (unsigned long)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 long)addr >= (unsigned long)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		= request_dma,
234 		._free_dma		= free_dma,
235 		._get_dma_residue	= get_dma_residue,
236 		._dma_mem_alloc		= dma_mem_alloc,
237 		._dma_setup		= hard_dma_setup
238 	},
239 	{
240 		._request_dma		= vdma_request_dma,
241 		._free_dma		= vdma_nop,
242 		._get_dma_residue	= vdma_get_dma_residue,
243 		._dma_mem_alloc		= vdma_mem_alloc,
244 		._dma_setup		= 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 ({							\
259 	unsigned long flags;				\
260 	unsigned char val;				\
261 	spin_lock_irqsave(&rtc_lock, flags);		\
262 	val = (CMOS_READ(0x10) >> 4) & 15;		\
263 	spin_unlock_irqrestore(&rtc_lock, flags);	\
264 	val;						\
265 })
266 
267 #define FLOPPY1_TYPE					\
268 ({							\
269 	unsigned long flags;				\
270 	unsigned char val;				\
271 	spin_lock_irqsave(&rtc_lock, flags);		\
272 	val = CMOS_READ(0x10) & 15;			\
273 	spin_unlock_irqrestore(&rtc_lock, flags);	\
274 	val;						\
275 })
276 
277 #define N_FDC 2
278 #define N_DRIVE 8
279 
280 #define EXTRA_FLOPPY_PARAMS
281 
282 #endif /* _ASM_X86_FLOPPY_H */
283