sbus.c

讲述linux的初始化过程

				len = sg->length;
				if (((tmp ^ pteval) >> PAGE_SHIFT) != 0UL) {
					pteval = tmp & PAGE_MASK;
					offset = tmp & (PAGE_SIZE - 1UL);
					break;
				}
				if (((tmp ^ (tmp + len - 1UL)) >> PAGE_SHIFT) != 0UL) {
					pteval = (tmp + PAGE_SIZE) & PAGE_MASK;
					offset = 0UL;
					len -= (PAGE_SIZE - (tmp & (PAGE_SIZE - 1UL)));
					break;
				}
				sg++;
			}

			pteval = ((pteval & IOPTE_PAGE) | iopte_bits);
			while (len > 0) {
				*iopte++ = __iopte(pteval);
				pteval += PAGE_SIZE;
				len -= (PAGE_SIZE - offset);
				offset = 0;
				dma_npages--;
			}

			pteval = (pteval & IOPTE_PAGE) + len;
			sg++;

			/* Skip over any tail mappings we've fully mapped,
			 * adjusting pteval along the way.  Stop when we
			 * detect a page crossing event.
			 */
			while ((pteval << (64 - PAGE_SHIFT)) != 0UL &&
			       pteval == __pa(sg->address) &&
			       ((pteval ^
				 (__pa(sg->address) + sg->length - 1UL)) >> PAGE_SHIFT) == 0UL) {
				pteval += sg->length;
				sg++;
			}
			if ((pteval << (64 - PAGE_SHIFT)) == 0UL)
				pteval = ~0UL;
		} while (dma_npages != 0);
		dma_sg++;
	}
}

int sbus_map_sg(struct sbus_dev *sdev, struct scatterlist *sg, int nents, int dir)
{
	struct sbus_iommu *iommu = sdev->bus->iommu;
	unsigned long flags, npages;
	iopte_t *iopte;
	u32 dma_base;
	struct scatterlist *sgtmp;
	int used;
	unsigned long iopte_bits;

	if (dir == SBUS_DMA_NONE)
		BUG();

	/* Fast path single entry scatterlists. */
	if (nents == 1) {
		sg->dvma_address = sbus_map_single(sdev, sg->address, sg->length, dir);
		sg->dvma_length = sg->length;
		return 1;
	}

	npages = prepare_sg(sg, nents);

	spin_lock_irqsave(&iommu->lock, flags);
	iopte = alloc_streaming_cluster(iommu, npages);
	dma_base = MAP_BASE + ((iopte - iommu->page_table) << PAGE_SHIFT);

	/* Normalize DVMA addresses. */
	sgtmp = sg;
	used = nents;

	while (used && sgtmp->dvma_length) {
		sgtmp->dvma_address += dma_base;
		sgtmp++;
		used--;
	}
	used = nents - used;

	iopte_bits = IOPTE_VALID | IOPTE_STBUF | IOPTE_CACHE;
	if (dir != SBUS_DMA_TODEVICE)
		iopte_bits |= IOPTE_WRITE;

	fill_sg(iopte, sg, used, iopte_bits);
#ifdef VERIFY_SG
	verify_sglist(sg, nents, iopte, npages);
#endif
	spin_unlock_irqrestore(&iommu->lock, flags);

	return used;
}

void sbus_unmap_sg(struct sbus_dev *sdev, struct scatterlist *sg, int nents, int direction)
{
	unsigned long size, flags;
	struct sbus_iommu *iommu;
	u32 dvma_base;
	int i;

	/* Fast path single entry scatterlists. */
	if (nents == 1) {
		sbus_unmap_single(sdev, sg->dvma_address, sg->dvma_length, direction);
		return;
	}

	dvma_base = sg[0].dvma_address & PAGE_MASK;
	for (i = 0; i < nents; i++) {
		if (sg[i].dvma_length == 0)
			break;
	}
	i--;
	size = PAGE_ALIGN(sg[i].dvma_address + sg[i].dvma_length) - dvma_base;

	iommu = sdev->bus->iommu;
	spin_lock_irqsave(&iommu->lock, flags);
	free_streaming_cluster(iommu, dvma_base, size >> PAGE_SHIFT);
	strbuf_flush(iommu, dvma_base, size >> PAGE_SHIFT);
	spin_unlock_irqrestore(&iommu->lock, flags);
}

void sbus_dma_sync_single(struct sbus_dev *sdev, dma_addr_t base, size_t size, int direction)
{
	struct sbus_iommu *iommu = sdev->bus->iommu;
	unsigned long flags;

	size = (PAGE_ALIGN(base + size) - (base & PAGE_MASK));

	spin_lock_irqsave(&iommu->lock, flags);
	strbuf_flush(iommu, base & PAGE_MASK, size >> PAGE_SHIFT);
	spin_unlock_irqrestore(&iommu->lock, flags);
}

void sbus_dma_sync_sg(struct sbus_dev *sdev, struct scatterlist *sg, int nents, int direction)
{
	struct sbus_iommu *iommu = sdev->bus->iommu;
	unsigned long flags, size;
	u32 base;
	int i;

	base = sg[0].dvma_address & PAGE_MASK;
	for (i = 0; i < nents; i++) {
		if (sg[i].dvma_length == 0)
			break;
	}
	i--;
	size = PAGE_ALIGN(sg[i].dvma_address + sg[i].dvma_length) - base;

	spin_lock_irqsave(&iommu->lock, flags);
	strbuf_flush(iommu, base, size >> PAGE_SHIFT);
	spin_unlock_irqrestore(&iommu->lock, flags);
}

/* Enable 64-bit DVMA mode for the given device. */
void sbus_set_sbus64(struct sbus_dev *sdev, int bursts)
{
	struct sbus_iommu *iommu = sdev->bus->iommu;
	int slot = sdev->slot;
	unsigned long cfg_reg;
	u64 val;

	cfg_reg = iommu->sbus_control_reg;
	switch (slot) {
	case 0:
		cfg_reg += 0x20UL;
		break;
	case 1:
		cfg_reg += 0x28UL;
		break;
	case 2:
		cfg_reg += 0x30UL;
		break;
	case 3:
		cfg_reg += 0x38UL;
		break;
	case 13:
		cfg_reg += 0x40UL;
		break;
	case 14:
		cfg_reg += 0x48UL;
		break;
	case 15:
		cfg_reg += 0x50UL;
		break;

	default:
		return;
	};

	val = upa_readq(cfg_reg);
	if (val & (1UL << 14UL)) {
		/* Extended transfer mode already enabled. */
		return;
	}

	val |= (1UL << 14UL);

	if (bursts & DMA_BURST8)
		val |= (1UL << 1UL);
	if (bursts & DMA_BURST16)
		val |= (1UL << 2UL);
	if (bursts & DMA_BURST32)
		val |= (1UL << 3UL);
	if (bursts & DMA_BURST64)
		val |= (1UL << 4UL);
	upa_writeq(val, cfg_reg);
}

/* SBUS SYSIO INO number to Sparc PIL level. */
static unsigned char sysio_ino_to_pil[] = {
	0, 1, 2, 7, 5, 7, 8, 9,		/* SBUS slot 0 */
	0, 1, 2, 7, 5, 7, 8, 9,		/* SBUS slot 1 */
	0, 1, 2, 7, 5, 7, 8, 9,		/* SBUS slot 2 */
	0, 1, 2, 7, 5, 7, 8, 9,		/* SBUS slot 3 */
	3, /* Onboard SCSI */
	5, /* Onboard Ethernet */
/*XXX*/	8, /* Onboard BPP */
	0, /* Bogon */
       13, /* Audio */
/*XXX*/15, /* PowerFail */
	0, /* Bogon */
	0, /* Bogon */
       12, /* Zilog Serial Channels (incl. Keyboard/Mouse lines) */
       11, /* Floppy */
	0, /* Spare Hardware (bogon for now) */
	0, /* Keyboard (bogon for now) */
	0, /* Mouse (bogon for now) */
	0, /* Serial (bogon for now) */
     0, 0, /* Bogon, Bogon */
       10, /* Timer 0 */
       11, /* Timer 1 */
     0, 0, /* Bogon, Bogon */
       15, /* Uncorrectable SBUS Error */
       15, /* Correctable SBUS Error */
       15, /* SBUS Error */
/*XXX*/ 0, /* Power Management (bogon for now) */
};

/* INO number to IMAP register offset for SYSIO external IRQ's.
 * This should conform to both Sunfire/Wildfire server and Fusion
 * desktop designs.
 */
#define SYSIO_IMAP_SLOT0	0x2c04UL
#define SYSIO_IMAP_SLOT1	0x2c0cUL
#define SYSIO_IMAP_SLOT2	0x2c14UL
#define SYSIO_IMAP_SLOT3	0x2c1cUL
#define SYSIO_IMAP_SCSI		0x3004UL
#define SYSIO_IMAP_ETH		0x300cUL
#define SYSIO_IMAP_BPP		0x3014UL
#define SYSIO_IMAP_AUDIO	0x301cUL
#define SYSIO_IMAP_PFAIL	0x3024UL
#define SYSIO_IMAP_KMS		0x302cUL
#define SYSIO_IMAP_FLPY		0x3034UL
#define SYSIO_IMAP_SHW		0x303cUL
#define SYSIO_IMAP_KBD		0x3044UL
#define SYSIO_IMAP_MS		0x304cUL
#define SYSIO_IMAP_SER		0x3054UL
#define SYSIO_IMAP_TIM0		0x3064UL
#define SYSIO_IMAP_TIM1		0x306cUL
#define SYSIO_IMAP_UE		0x3074UL
#define SYSIO_IMAP_CE		0x307cUL
#define SYSIO_IMAP_SBERR	0x3084UL
#define SYSIO_IMAP_PMGMT	0x308cUL
#define SYSIO_IMAP_GFX		0x3094UL
#define SYSIO_IMAP_EUPA		0x309cUL

#define bogon     ((unsigned long) -1)
static unsigned long sysio_irq_offsets[] = {
	/* SBUS Slot 0 --> 3, level 1 --> 7 */
	SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0,
	SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0, SYSIO_IMAP_SLOT0,
	SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1,
	SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1, SYSIO_IMAP_SLOT1,
	SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2,
	SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2, SYSIO_IMAP_SLOT2,
	SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3,
	SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3, SYSIO_IMAP_SLOT3,

	/* Onboard devices (not relevant/used on SunFire). */
	SYSIO_IMAP_SCSI,
	SYSIO_IMAP_ETH,
	SYSIO_IMAP_BPP,
	bogon,
	SYSIO_IMAP_AUDIO,
	SYSIO_IMAP_PFAIL,
	bogon,
	bogon,
	SYSIO_IMAP_KMS,
	SYSIO_IMAP_FLPY,
	SYSIO_IMAP_SHW,
	SYSIO_IMAP_KBD,
	SYSIO_IMAP_MS,
	SYSIO_IMAP_SER,
	bogon,
	bogon,
	SYSIO_IMAP_TIM0,
	SYSIO_IMAP_TIM1,
	bogon,
	bogon,
	SYSIO_IMAP_UE,
	SYSIO_IMAP_CE,
	SYSIO_IMAP_SBERR,
	SYSIO_IMAP_PMGMT,
};

#undef bogon

#define NUM_SYSIO_OFFSETS (sizeof(sysio_irq_offsets) / sizeof(sysio_irq_offsets[0]))

/* Convert Interrupt Mapping register pointer to assosciated
 * Interrupt Clear register pointer, SYSIO specific version.
 */
#define SYSIO_ICLR_UNUSED0	0x3400UL
#define SYSIO_ICLR_SLOT0	0x340cUL
#define SYSIO_ICLR_SLOT1	0x344cUL
#define SYSIO_ICLR_SLOT2	0x348cUL
#define SYSIO_ICLR_SLOT3	0x34ccUL
static unsigned long sysio_imap_to_iclr(unsigned long imap)
{
	unsigned long diff = SYSIO_ICLR_UNUSED0 - SYSIO_IMAP_SLOT0;
	return imap + diff;
}

unsigned int sbus_build_irq(void *buscookie, unsigned int ino)
{
	struct sbus_bus *sbus = (struct sbus_bus *)buscookie;
	struct sbus_iommu *iommu = sbus->iommu;
	unsigned long reg_base = iommu->sbus_control_reg - 0x2000UL;
	unsigned long imap, iclr;
	int pil, sbus_level = 0;

	pil = sysio_ino_to_pil[ino];
	if (!pil) {
		printk("sbus_irq_build: Bad SYSIO INO[%x]\n", ino);
		panic("Bad SYSIO IRQ translations...");
	}
	imap = sysio_irq_offsets[ino];
	if (imap == ((unsigned long)-1)) {
		prom_printf("get_irq_translations: Bad SYSIO INO[%x] cpu[%d]\n",
			    ino, pil);
		prom_halt();
	}
	imap += reg_base;

	/* SYSIO inconsistancy.  For external SLOTS, we have to select
	 * the right ICLR register based upon the lower SBUS irq level
	 * bits.
	 */
	if (ino >= 0x20) {
		iclr = sysio_imap_to_iclr(imap);
	} else {
		int sbus_slot = (ino & 0x18)>>3;
		
		sbus_level = ino & 0x7;

		switch(sbus_slot) {
		case 0:
			iclr = reg_base + SYSIO_ICLR_SLOT0;
			break;
		case 1:
			iclr = reg_base + SYSIO_ICLR_SLOT1;
			break;
		case 2:
			iclr = reg_base + SYSIO_ICLR_SLOT2;
			break;
		default:
		case 3:
			iclr = reg_base + SYSIO_ICLR_SLOT3;
			break;
		};

		iclr += ((unsigned long)sbus_level - 1UL) * 8UL;
	}
	return build_irq(pil, sbus_level, iclr, imap);
}

/* Error interrupt handling. */
#define SYSIO_UE_AFSR	0x0030UL
#define SYSIO_UE_AFAR	0x0038UL
#define  SYSIO_UEAFSR_PPIO	0x8000000000000000 /* Primary PIO is cause         */
#define  SYSIO_UEAFSR_PDRD	0x4000000000000000 /* Primary DVMA read is cause   */
#define  SYSIO_UEAFSR_PDWR	0x2000000000000000 /* Primary DVMA write is cause  */
#define  SYSIO_UEAFSR_SPIO	0x1000000000000000 /* Secondary PIO is cause       */
#define  SYSIO_UEAFSR_SDRD	0x0800000000000000 /* Secondary DVMA read is cause */
#define  SYSIO_UEAFSR_SDWR	0x0400000000000000 /* Secondary DVMA write is cause*/
#define  SYSIO_UEAFSR_RESV1	0x03ff000000000000 /* Reserved                     */