[POWERPC] Virtual DMA support for floppy driver for new powerpc architecture

During ppc64+ppc merge virtual DMA code for floppy driver was not ported. This patch restores virtual DMA support for floppy in new powerpc target. It is necessary at least on Pegasos and AmigaOne machines for the floppy drive to function. ISA DMA controller works incorrectly there due to its addressing limitations. Virtual DMA mode is activated by floppy=nodma option passed to the kernel (or module). There's no automatic switch like on i386. Signed-off-by: Pavel Fedin <sonic_amiga@rambler.ru> Signed-off-by: Paul Mackerras <paulus@samba.org>

[POWERPC] Virtual DMA support for floppy driver for new powerpc architecture
During ppc64+ppc merge virtual DMA code for floppy driver was not ported. This patch restores virtual DMA support for floppy in new powerpc target. It is necessary at least on Pegasos and AmigaOne machines for the floppy drive to function. ISA DMA controller works incorrectly there due to its addressing limitations. Virtual DMA mode is activated by floppy=nodma option passed to the kernel (or module). There's no automatic switch like on i386. Signed-off-by: Pavel Fedin <sonic_amiga@rambler.ru> Signed-off-by: Paul Mackerras <paulus@samba.org>
Pavel Fedin · Paul Mackerras
1 parent cbca567ea5
Showing 1 changed file with 122 additions and 13 deletions Side-by-side Diff
include/asm-powerpc/floppy.h
@@ -17,35 +17,123 @@
 #define fd_outb(value,port)	outb_p(value,port)
  
 #define fd_enable_dma()         enable_dma(FLOPPY_DMA)
-#define fd_disable_dma()        disable_dma(FLOPPY_DMA)
-#define fd_request_dma()        request_dma(FLOPPY_DMA, "floppy")
-#define fd_free_dma()           free_dma(FLOPPY_DMA)
+#define fd_disable_dma()	 fd_ops->_disable_dma(FLOPPY_DMA)
+#define fd_free_dma()           fd_ops->_free_dma(FLOPPY_DMA)
 #define fd_clear_dma_ff()       clear_dma_ff(FLOPPY_DMA)
 #define fd_set_dma_mode(mode)   set_dma_mode(FLOPPY_DMA, mode)
 #define fd_set_dma_count(count) set_dma_count(FLOPPY_DMA, count)
+#define fd_get_dma_residue()    fd_ops->_get_dma_residue(FLOPPY_DMA)
 #define fd_enable_irq()         enable_irq(FLOPPY_IRQ)
 #define fd_disable_irq()        disable_irq(FLOPPY_IRQ)
 #define fd_cacheflush(addr,size) /* nothing */
-#define fd_request_irq()        request_irq(FLOPPY_IRQ, floppy_interrupt, \
-					    IRQF_DISABLED, "floppy", NULL)
 #define fd_free_irq()           free_irq(FLOPPY_IRQ, NULL);
  
-#ifdef CONFIG_PCI
-
 #include <linux/pci.h>
 #include <asm/ppc-pci.h>	/* for ppc64_isabridge_dev */
  
-#define fd_dma_setup(addr,size,mode,io) powerpc_fd_dma_setup(addr,size,mode,io)
+#define fd_dma_setup(addr,size,mode,io) fd_ops->_dma_setup(addr,size,mode,io)
  
-static __inline__ int powerpc_fd_dma_setup(char *addr, unsigned long size,
-					   int mode, int io)
+static int fd_request_dma(void);
+
+struct fd_dma_ops {
+	void (*_disable_dma)(unsigned int dmanr);
+	void (*_free_dma)(unsigned int dmanr);
+	int (*_get_dma_residue)(unsigned int dummy);
+	int (*_dma_setup)(char *addr, unsigned long size, int mode, int io);
+};
+
+static int virtual_dma_count;
+static int virtual_dma_residue;
+static char *virtual_dma_addr;
+static int virtual_dma_mode;
+static int doing_vdma;
+static struct fd_dma_ops *fd_ops;
+
+static irqreturn_t floppy_hardint(int irq, void *dev_id)
 {
+	unsigned char st;
+	int lcount;
+	char *lptr;
+
+	if (!doing_vdma)
+		return floppy_interrupt(irq, dev_id);
+
+
+	st = 1;
+	for (lcount=virtual_dma_count, lptr=virtual_dma_addr;
+	     lcount; lcount--, lptr++) {
+		st=inb(virtual_dma_port+4) & 0xa0 ;
+		if (st != 0xa0)
+			break;
+		if (virtual_dma_mode)
+			outb_p(*lptr, virtual_dma_port+5);
+		else
+			*lptr = inb_p(virtual_dma_port+5);
+	}
+	virtual_dma_count = lcount;
+	virtual_dma_addr = lptr;
+	st = inb(virtual_dma_port+4);
+
+	if (st == 0x20)
+		return IRQ_HANDLED;
+	if (!(st & 0x20)) {
+		virtual_dma_residue += virtual_dma_count;
+		virtual_dma_count=0;
+		doing_vdma = 0;
+		floppy_interrupt(irq, dev_id);
+		return IRQ_HANDLED;
+	}
+	return IRQ_HANDLED;
+}
+
+static void vdma_disable_dma(unsigned int dummy)
+{
+	doing_vdma = 0;
+	virtual_dma_residue += virtual_dma_count;
+	virtual_dma_count=0;
+}
+
+static void vdma_nop(unsigned int dummy)
+{
+}
+
+
+static int vdma_get_dma_residue(unsigned int dummy)
+{
+	return virtual_dma_count + virtual_dma_residue;
+}
+
+
+static int fd_request_irq(void)
+{
+	if (can_use_virtual_dma)
+		return request_irq(FLOPPY_IRQ, floppy_hardint,
+				   IRQF_DISABLED, "floppy", NULL);
+	else
+		return request_irq(FLOPPY_IRQ, floppy_interrupt,
+				   IRQF_DISABLED, "floppy", NULL);
+}
+
+static int vdma_dma_setup(char *addr, unsigned long size, int mode, int io)
+{
+	doing_vdma = 1;
+	virtual_dma_port = io;
+	virtual_dma_mode = (mode  == DMA_MODE_WRITE);
+	virtual_dma_addr = addr;
+	virtual_dma_count = size;
+	virtual_dma_residue = 0;
+	return 0;
+}
+
+static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
+{
 	static unsigned long prev_size;
 	static dma_addr_t bus_addr = 0;
 	static char *prev_addr;
 	static int prev_dir;
 	int dir;
  
+	doing_vdma = 0;
 	dir = (mode == DMA_MODE_READ) ? PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE;
  
 	if (bus_addr 
  
  
@@ -74,11 +162,32 @@
 	return 0;
 }
  
-#endif /* CONFIG_PCI */
+static struct fd_dma_ops real_dma_ops =
+{
+	._disable_dma = disable_dma,
+	._free_dma = free_dma,
+	._get_dma_residue = get_dma_residue,
+	._dma_setup = hard_dma_setup
+};
  
-__inline__ void virtual_dma_init(void)
+static struct fd_dma_ops virt_dma_ops =
 {
-	/* Nothing to do on PowerPC */
+	._disable_dma = vdma_disable_dma,
+	._free_dma = vdma_nop,
+	._get_dma_residue = vdma_get_dma_residue,
+	._dma_setup = vdma_dma_setup
+};
+
+static int fd_request_dma()
+{
+	if (can_use_virtual_dma & 1) {
+		fd_ops = &virt_dma_ops;
+		return 0;
+	}
+	else {
+		fd_ops = &real_dma_ops;
+		return request_dma(FLOPPY_DMA, "floppy");
+	}
 }
  
 static int FDC1 = 0x3f0;
...	...	@@ -17,35 +17,123 @@
17	17	#define fd_outb(value,port) outb_p(value,port)
18	18
19	19	#define fd_enable_dma() enable_dma(FLOPPY_DMA)
20		-#define fd_disable_dma() disable_dma(FLOPPY_DMA)
21		-#define fd_request_dma() request_dma(FLOPPY_DMA, "floppy")
22		-#define fd_free_dma() free_dma(FLOPPY_DMA)
	20	+#define fd_disable_dma() fd_ops->_disable_dma(FLOPPY_DMA)
	21	+#define fd_free_dma() fd_ops->_free_dma(FLOPPY_DMA)
23	22	#define fd_clear_dma_ff() clear_dma_ff(FLOPPY_DMA)
24	23	#define fd_set_dma_mode(mode) set_dma_mode(FLOPPY_DMA, mode)
25	24	#define fd_set_dma_count(count) set_dma_count(FLOPPY_DMA, count)
	25	+#define fd_get_dma_residue() fd_ops->_get_dma_residue(FLOPPY_DMA)
26	26	#define fd_enable_irq() enable_irq(FLOPPY_IRQ)
27	27	#define fd_disable_irq() disable_irq(FLOPPY_IRQ)
28	28	#define fd_cacheflush(addr,size) /* nothing */
29		-#define fd_request_irq() request_irq(FLOPPY_IRQ, floppy_interrupt, \
30		- IRQF_DISABLED, "floppy", NULL)
31	29	#define fd_free_irq() free_irq(FLOPPY_IRQ, NULL);
32	30
33		-#ifdef CONFIG_PCI
34		-
35	31	#include <linux/pci.h>
36	32	#include <asm/ppc-pci.h> /* for ppc64_isabridge_dev */
37	33
38		-#define fd_dma_setup(addr,size,mode,io) powerpc_fd_dma_setup(addr,size,mode,io)
	34	+#define fd_dma_setup(addr,size,mode,io) fd_ops->_dma_setup(addr,size,mode,io)
39	35
40		-static __inline__ int powerpc_fd_dma_setup(char *addr, unsigned long size,
41		- int mode, int io)
	36	+static int fd_request_dma(void);
	37	+
	38	+struct fd_dma_ops {
	39	+ void (*_disable_dma)(unsigned int dmanr);
	40	+ void (*_free_dma)(unsigned int dmanr);
	41	+ int (*_get_dma_residue)(unsigned int dummy);
	42	+ int (_dma_setup)(char addr, unsigned long size, int mode, int io);
	43	+};
	44	+
	45	+static int virtual_dma_count;
	46	+static int virtual_dma_residue;
	47	+static char *virtual_dma_addr;
	48	+static int virtual_dma_mode;
	49	+static int doing_vdma;
	50	+static struct fd_dma_ops *fd_ops;
	51	+
	52	+static irqreturn_t floppy_hardint(int irq, void *dev_id)
42	53	{
	54	+ unsigned char st;
	55	+ int lcount;
	56	+ char *lptr;
	57	+
	58	+ if (!doing_vdma)
	59	+ return floppy_interrupt(irq, dev_id);
	60	+
	61	+
	62	+ st = 1;
	63	+ for (lcount=virtual_dma_count, lptr=virtual_dma_addr;
	64	+ lcount; lcount--, lptr++) {
	65	+ st=inb(virtual_dma_port+4) & 0xa0 ;
	66	+ if (st != 0xa0)
	67	+ break;
	68	+ if (virtual_dma_mode)
	69	+ outb_p(*lptr, virtual_dma_port+5);
	70	+ else
	71	+ *lptr = inb_p(virtual_dma_port+5);
	72	+ }
	73	+ virtual_dma_count = lcount;
	74	+ virtual_dma_addr = lptr;
	75	+ st = inb(virtual_dma_port+4);
	76	+
	77	+ if (st == 0x20)
	78	+ return IRQ_HANDLED;
	79	+ if (!(st & 0x20)) {
	80	+ virtual_dma_residue += virtual_dma_count;
	81	+ virtual_dma_count=0;
	82	+ doing_vdma = 0;
	83	+ floppy_interrupt(irq, dev_id);
	84	+ return IRQ_HANDLED;
	85	+ }
	86	+ return IRQ_HANDLED;
	87	+}
	88	+
	89	+static void vdma_disable_dma(unsigned int dummy)
	90	+{
	91	+ doing_vdma = 0;
	92	+ virtual_dma_residue += virtual_dma_count;
	93	+ virtual_dma_count=0;
	94	+}
	95	+
	96	+static void vdma_nop(unsigned int dummy)
	97	+{
	98	+}
	99	+
	100	+
	101	+static int vdma_get_dma_residue(unsigned int dummy)
	102	+{
	103	+ return virtual_dma_count + virtual_dma_residue;
	104	+}
	105	+
	106	+
	107	+static int fd_request_irq(void)
	108	+{
	109	+ if (can_use_virtual_dma)
	110	+ return request_irq(FLOPPY_IRQ, floppy_hardint,
	111	+ IRQF_DISABLED, "floppy", NULL);
	112	+ else
	113	+ return request_irq(FLOPPY_IRQ, floppy_interrupt,
	114	+ IRQF_DISABLED, "floppy", NULL);
	115	+}
	116	+
	117	+static int vdma_dma_setup(char *addr, unsigned long size, int mode, int io)
	118	+{
	119	+ doing_vdma = 1;
	120	+ virtual_dma_port = io;
	121	+ virtual_dma_mode = (mode == DMA_MODE_WRITE);
	122	+ virtual_dma_addr = addr;
	123	+ virtual_dma_count = size;
	124	+ virtual_dma_residue = 0;
	125	+ return 0;
	126	+}
	127	+
	128	+static int hard_dma_setup(char *addr, unsigned long size, int mode, int io)
	129	+{
43	130	static unsigned long prev_size;
44	131	static dma_addr_t bus_addr = 0;
45	132	static char *prev_addr;
46	133	static int prev_dir;
47	134	int dir;
48	135
	136	+ doing_vdma = 0;
49	137	dir = (mode == DMA_MODE_READ) ? PCI_DMA_FROMDEVICE : PCI_DMA_TODEVICE;
50	138
51	139	if (bus_addr
52	140
53	141
...	...	@@ -74,11 +162,32 @@
74	162	return 0;
75	163	}
76	164
77		-#endif /* CONFIG_PCI */
	165	+static struct fd_dma_ops real_dma_ops =
	166	+{
	167	+ ._disable_dma = disable_dma,
	168	+ ._free_dma = free_dma,
	169	+ ._get_dma_residue = get_dma_residue,
	170	+ ._dma_setup = hard_dma_setup
	171	+};
78	172
79		-__inline__ void virtual_dma_init(void)
	173	+static struct fd_dma_ops virt_dma_ops =
80	174	{
81		- /* Nothing to do on PowerPC */
	175	+ ._disable_dma = vdma_disable_dma,
	176	+ ._free_dma = vdma_nop,
	177	+ ._get_dma_residue = vdma_get_dma_residue,
	178	+ ._dma_setup = vdma_dma_setup
	179	+};
	180	+
	181	+static int fd_request_dma()
	182	+{
	183	+ if (can_use_virtual_dma & 1) {
	184	+ fd_ops = &virt_dma_ops;
	185	+ return 0;
	186	+ }
	187	+ else {
	188	+ fd_ops = &real_dma_ops;
	189	+ return request_dma(FLOPPY_DMA, "floppy");
	190	+ }
82	191	}
83	192
84	193	static int FDC1 = 0x3f0;