triton.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

		/* Consult the list of known "good" drives */
		list = good_dma_drives;
		while (*list) {
			if (!strcmp(*list++,id->model)) {
				drive->using_dma = 1;
				return 0;	/* DMA enabled */
			}
		}
	}
	return 1;	/* DMA not enabled */
}

/*
 * triton_dmaproc() initiates/aborts DMA read/write operations on a drive.
 *
 * The caller is assumed to have selected the drive and programmed the drive's
 * sector address using CHS or LBA.  All that remains is to prepare for DMA
 * and then issue the actual read/write DMA/PIO command to the drive.
 *
 * For ATAPI devices, we just prepare for DMA and return. The caller should
 * then issue the packet command to the drive and call us again with
 * ide_dma_begin afterwards.
 *
 * Returns 0 if all went well.
 * Returns 1 if DMA read/write could not be started, in which case
 * the caller should revert to PIO for the current request.
 */
static int triton_dmaproc (ide_dma_action_t func, ide_drive_t *drive)
{
	unsigned long dma_base = HWIF(drive)->dma_base;
	unsigned int reading = (1 << 3);

	switch (func) {
		case ide_dma_abort:
			outb(inb(dma_base)&~1, dma_base);	/* stop DMA */
			return 0;
		case ide_dma_check:
			return config_drive_for_dma (drive);
		case ide_dma_write:
			reading = 0;
		case ide_dma_read:
			break;
		case ide_dma_status_bad:
			return ((inb(dma_base+2) & 7) != 4);	/* verify good DMA status */
		case ide_dma_transferred:
#if 0
			return (number of bytes actually transferred);
#else
			return (0);
#endif
		case ide_dma_begin:
			outb(inb(dma_base)|1, dma_base);	/* begin DMA */
			return 0;
		default:
			printk("triton_dmaproc: unsupported func: %d\n", func);
			return 1;
	}
	if (build_dmatable (drive))
		return 1;
	outl(virt_to_bus (HWIF(drive)->dmatable), dma_base + 4); /* PRD table */
	outb(reading, dma_base);			/* specify r/w */
	outb(inb(dma_base+2)|0x06, dma_base+2);		/* clear status bits */
#ifdef CONFIG_BLK_DEV_IDEATAPI
	if (drive->media != ide_disk)
		return 0;
#endif /* CONFIG_BLK_DEV_IDEATAPI */	
	ide_set_handler(drive, &dma_intr, WAIT_CMD);	/* issue cmd to drive */
	OUT_BYTE(reading ? WIN_READDMA : WIN_WRITEDMA, IDE_COMMAND_REG);
	outb(inb(dma_base)|1, dma_base);		/* begin DMA */
	return 0;
}

#ifdef DISPLAY_TRITON_TIMINGS
/*
 * print_triton_drive_flags() displays the currently programmed options
 * in the i82371 (Triton) for a given drive.
 *
 *	If fastDMA  is "no", then slow ISA timings are used for DMA data xfers.
 *	If fastPIO  is "no", then slow ISA timings are used for PIO data xfers.
 *	If IORDY    is "no", then IORDY is assumed to always be asserted.
 *	If PreFetch is "no", then data pre-fetch/post are not used.
 *
 * When "fastPIO" and/or "fastDMA" are "yes", then faster PCI timings and
 * back-to-back 16-bit data transfers are enabled, using the sample_CLKs
 * and recovery_CLKs (PCI clock cycles) timing parameters for that interface.
 */
static void print_triton_drive_flags (unsigned int unit, byte flags)
{
	printk("         %s ", unit ? "slave :" : "master:");
	printk( "fastDMA=%s",	(flags&9)	? "on " : "off");
	printk(" PreFetch=%s",	(flags&4)	? "on " : "off");
	printk(" IORDY=%s",	(flags&2)	? "on " : "off");
	printk(" fastPIO=%s\n",	((flags&9)==1)	? "on " : "off");
}
#endif /* DISPLAY_TRITON_TIMINGS */

static void init_triton_dma (ide_hwif_t *hwif, unsigned short base)
{
	static unsigned long dmatable = 0;

	printk("    %s: BM-DMA at 0x%04x-0x%04x", hwif->name, base, base+7);
	if (check_region(base, 8)) {
		printk(" -- ERROR, PORTS ALREADY IN USE");
	} else {
		request_region(base, 8, "IDE DMA");
		hwif->dma_base = base;
		if (!dmatable) {
			/*
			 * The BM-DMA uses a full 32-bits, so we can
			 * safely use __get_free_page() here instead
			 * of __get_dma_pages() -- no ISA limitations.
			 */
			dmatable = __get_free_pages(GFP_KERNEL, 1, 0);
		}
		if (dmatable) {
			hwif->dmatable = (unsigned long *) dmatable;
			dmatable += (PRD_ENTRIES * PRD_BYTES);
			outl(virt_to_bus(hwif->dmatable), base + 4);
			hwif->dmaproc  = &triton_dmaproc;
		}
	}
	printk("\n");
}

/*
 * ide_init_triton() prepares the IDE driver for DMA operation.
 * This routine is called once, from ide.c during driver initialization,
 * for each triton chipset which is found (unlikely to be more than one).
 */
void ide_init_triton (byte bus, byte fn)
{
	int rc = 0, h;
	int dma_enabled = 0;
	unsigned short pcicmd;
	unsigned int bmiba, timings;

	printk("ide: i82371 PIIX (Triton) on PCI bus %d function %d\n", bus, fn);
	/*
	 * See if IDE and BM-DMA features are enabled:
	 */
	if ((rc = pcibios_read_config_word(bus, fn, 0x04, &pcicmd)))
		goto quit;
	if ((pcicmd & 1) == 0)  {
		printk("ide: ports are not enabled (BIOS)\n");
		goto quit;
	}
	if ((pcicmd & 4) == 0) {
		printk("ide: BM-DMA feature is not enabled (BIOS)\n");
	} else {
		/*
		 * Get the bmiba base address
		 */
		int try_again = 1;
		do {
			if ((rc = pcibios_read_config_dword(bus, fn, 0x20, &bmiba)))
				goto quit;
			bmiba &= 0xfff0;	/* extract port base address */
			if (bmiba) {
				dma_enabled = 1;
				break;
			} else {
				printk("ide: BM-DMA base register is invalid (0x%04x, PnP BIOS problem)\n", bmiba);
				if (inb(DEFAULT_BMIBA) != 0xff || !try_again)
					break;
				printk("ide: setting BM-DMA base register to 0x%04x\n", DEFAULT_BMIBA);
				if ((rc = pcibios_write_config_word(bus, fn, 0x04, pcicmd&~1)))
					goto quit;
				rc = pcibios_write_config_dword(bus, fn, 0x20, DEFAULT_BMIBA|1);
				if (pcibios_write_config_word(bus, fn, 0x04, pcicmd|5) || rc)
					goto quit;
			}
		} while (try_again--);
	}

	/*
	 * See if ide port(s) are enabled
	 */
	if ((rc = pcibios_read_config_dword(bus, fn, 0x40, &timings)))
		goto quit;
	if (!(timings & 0x80008000)) {
		printk("ide: neither port is enabled\n");
		goto quit;
	}

	/*
	 * Save the dma_base port addr for each interface
	 */
	for (h = 0; h < MAX_HWIFS; ++h) {
#ifdef DISPLAY_TRITON_TIMINGS
		byte s_clks, r_clks;
		unsigned short devid;
#endif /* DISPLAY_TRITON_TIMINGS */
		ide_hwif_t *hwif = &ide_hwifs[h];
		unsigned short time;
		if (hwif->io_base == 0x1f0) {
			time = timings & 0xffff;
			if ((time & 0x8000) == 0)	/* interface enabled? */
				continue;
			hwif->chipset = ide_triton;
			if (dma_enabled)
				init_triton_dma(hwif, bmiba);
		} else if (hwif->io_base == 0x170) {
			time = timings >> 16;
			if ((time & 0x8000) == 0)	/* interface enabled? */
				continue;
			hwif->chipset = ide_triton;
			if (dma_enabled)
				init_triton_dma(hwif, bmiba + 8);
		} else
			continue;
#ifdef DISPLAY_TRITON_TIMINGS
		s_clks = ((~time >> 12) & 3) + 2;
		r_clks = ((~time >>  8) & 3) + 1;
		printk("    %s timing: (0x%04x) sample_CLKs=%d, recovery_CLKs=%d\n",
		 hwif->name, time, s_clks, r_clks);
		if ((time & 0x40) && !pcibios_read_config_word(bus, fn, 0x02, &devid)
		 && devid == PCI_DEVICE_ID_INTEL_82371SB_1)
		{
			byte stime;
			if (pcibios_read_config_byte(bus, fn, 0x44, &stime)) {
				if (hwif->io_base == 0x1f0) {
					s_clks = ~stime >> 6;
					r_clks = ~stime >> 4;
				} else {
					s_clks = ~stime >> 2;
					r_clks = ~stime;
				}
				s_clks = (s_clks & 3) + 2;
				r_clks = (r_clks & 3) + 1;
				printk("                   slave: sample_CLKs=%d, recovery_CLKs=%d\n",
		 			s_clks, r_clks);
			}
		}
		print_triton_drive_flags (0, time & 0xf);
		print_triton_drive_flags (1, (time >> 4) & 0xf);
#endif /* DISPLAY_TRITON_TIMINGS */
	}

quit: if (rc) printk("ide: pcibios access failed - %s\n", pcibios_strerror(rc));
}

void ide_init_promise (byte bus, byte fn, ide_hwif_t *hwif0, ide_hwif_t *hwif1, unsigned short dma)
{
	int rc;
	unsigned short pcicmd;
	unsigned int bmiba = 0;

	printk("ide: Enabling DMA for Promise Technology IDE Ultra-DMA 33 on PCI bus %d function %d, port 0x%04x\n", bus, fn, dma);
	if ((rc = pcibios_read_config_word(bus, fn, 0x04, &pcicmd)) || (pcicmd & 1) == 0 || (pcicmd & 4) == 0)
		goto abort;
	if ((rc = pcibios_read_config_dword(bus, fn, 0x20, &bmiba)))
		goto abort;
	bmiba &= 0xfff0;	/* extract port base address */
	if (bmiba != dma || !bmiba)
		goto abort;
	hwif0->chipset = ide_promise_udma;
	hwif1->chipset = ide_promise_udma;
	init_triton_dma(hwif0, bmiba);
	init_triton_dma(hwif1, bmiba + 0x08);
	return;
abort:
	printk(KERN_WARNING "ide: Promise/33 not configured correctly (BIOS)\n");
}