tioca_provider.c

linux 内核源代码

	if (node_upper > 64) {
		printk(KERN_ERR "%s:  coretalk addr 0x%p node id out "
		       "of range\n", __FUNCTION__, (void *)ct_addr);
		return 0;
	}

	agp_dma_extn = __sn_readq_relaxed(&ca_base->ca_agp_dma_addr_extn);
	if (node_upper != (agp_dma_extn >> CA_AGP_DMA_NODE_ID_SHFT)) {
		printk(KERN_ERR "%s:  coretalk upper node (%u) "
		       "mismatch with ca_agp_dma_addr_extn (%lu)\n",
		       __FUNCTION__,
		       node_upper, (agp_dma_extn >> CA_AGP_DMA_NODE_ID_SHFT));
		return 0;
	}

	return bus_addr;
}

/**
 * tioca_dma_mapped - create a DMA mapping using a CA GART 
 * @pdev: linux pci_dev representing the function
 * @paddr: host physical address to map
 * @req_size: len (bytes) to map
 *
 * Map @paddr into CA address space using the GART mechanism.  The mapped
 * dma_addr_t is guaranteed to be contiguous in CA bus space.
 */
static dma_addr_t
tioca_dma_mapped(struct pci_dev *pdev, u64 paddr, size_t req_size)
{
	int i, ps, ps_shift, entry, entries, mapsize, last_entry;
	u64 xio_addr, end_xio_addr;
	struct tioca_common *tioca_common;
	struct tioca_kernel *tioca_kern;
	dma_addr_t bus_addr = 0;
	struct tioca_dmamap *ca_dmamap;
	void *map;
	unsigned long flags;
	struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(pdev);

	tioca_common = (struct tioca_common *)pcidev_info->pdi_pcibus_info;
	tioca_kern = (struct tioca_kernel *)tioca_common->ca_kernel_private;

	xio_addr = PHYS_TO_TIODMA(paddr);
	if (!xio_addr)
		return 0;

	spin_lock_irqsave(&tioca_kern->ca_lock, flags);

	/*
	 * allocate a map struct
	 */

	ca_dmamap = kzalloc(sizeof(struct tioca_dmamap), GFP_ATOMIC);
	if (!ca_dmamap)
		goto map_return;

	/*
	 * Locate free entries that can hold req_size.  Account for
	 * unaligned start/length when allocating.
	 */

	ps = tioca_kern->ca_ap_pagesize;	/* will be power of 2 */
	ps_shift = ffs(ps) - 1;
	end_xio_addr = xio_addr + req_size - 1;

	entries = (end_xio_addr >> ps_shift) - (xio_addr >> ps_shift) + 1;

	map = tioca_kern->ca_pcigart_pagemap;
	mapsize = tioca_kern->ca_pcigart_entries;

	entry = find_first_zero_bit(map, mapsize);
	while (entry < mapsize) {
		last_entry = find_next_bit(map, mapsize, entry);

		if (last_entry - entry >= entries)
			break;

		entry = find_next_zero_bit(map, mapsize, last_entry);
	}

	if (entry > mapsize)
		goto map_return;

	for (i = 0; i < entries; i++)
		set_bit(entry + i, map);

	bus_addr = tioca_kern->ca_pciap_base + (entry * ps);

	ca_dmamap->cad_dma_addr = bus_addr;
	ca_dmamap->cad_gart_size = entries;
	ca_dmamap->cad_gart_entry = entry;
	list_add(&ca_dmamap->cad_list, &tioca_kern->ca_dmamaps);

	if (xio_addr % ps) {
		tioca_kern->ca_pcigart[entry] = tioca_paddr_to_gart(xio_addr);
		bus_addr += xio_addr & (ps - 1);
		xio_addr &= ~(ps - 1);
		xio_addr += ps;
		entry++;
	}

	while (xio_addr < end_xio_addr) {
		tioca_kern->ca_pcigart[entry] = tioca_paddr_to_gart(xio_addr);
		xio_addr += ps;
		entry++;
	}

	tioca_tlbflush(tioca_kern);

map_return:
	spin_unlock_irqrestore(&tioca_kern->ca_lock, flags);
	return bus_addr;
}

/**
 * tioca_dma_unmap - release CA mapping resources
 * @pdev: linux pci_dev representing the function
 * @bus_addr: bus address returned by an earlier tioca_dma_map
 * @dir: mapping direction (unused)
 *
 * Locate mapping resources associated with @bus_addr and release them.
 * For mappings created using the direct modes (64 or 48) there are no
 * resources to release.
 */
static void
tioca_dma_unmap(struct pci_dev *pdev, dma_addr_t bus_addr, int dir)
{
	int i, entry;
	struct tioca_common *tioca_common;
	struct tioca_kernel *tioca_kern;
	struct tioca_dmamap *map;
	struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(pdev);
	unsigned long flags;

	tioca_common = (struct tioca_common *)pcidev_info->pdi_pcibus_info;
	tioca_kern = (struct tioca_kernel *)tioca_common->ca_kernel_private;

	/* return straight away if this isn't be a mapped address */

	if (bus_addr < tioca_kern->ca_pciap_base ||
	    bus_addr >= (tioca_kern->ca_pciap_base + tioca_kern->ca_pciap_size))
		return;

	spin_lock_irqsave(&tioca_kern->ca_lock, flags);

	list_for_each_entry(map, &tioca_kern->ca_dmamaps, cad_list)
	    if (map->cad_dma_addr == bus_addr)
		break;

	BUG_ON(map == NULL);

	entry = map->cad_gart_entry;

	for (i = 0; i < map->cad_gart_size; i++, entry++) {
		clear_bit(entry, tioca_kern->ca_pcigart_pagemap);
		tioca_kern->ca_pcigart[entry] = 0;
	}
	tioca_tlbflush(tioca_kern);

	list_del(&map->cad_list);
	spin_unlock_irqrestore(&tioca_kern->ca_lock, flags);
	kfree(map);
}

/**
 * tioca_dma_map - map pages for PCI DMA
 * @pdev: linux pci_dev representing the function
 * @paddr: host physical address to map
 * @byte_count: bytes to map
 *
 * This is the main wrapper for mapping host physical pages to CA PCI space.
 * The mapping mode used is based on the devices dma_mask.  As a last resort
 * use the GART mapped mode.
 */
static u64
tioca_dma_map(struct pci_dev *pdev, u64 paddr, size_t byte_count, int dma_flags)
{
	u64 mapaddr;

	/*
	 * Not supported for now ...
	 */
	if (dma_flags & SN_DMA_MSI)
		return 0;

	/*
	 * If card is 64 or 48 bit addressable, use a direct mapping.  32
	 * bit direct is so restrictive w.r.t. where the memory resides that
	 * we don't use it even though CA has some support.
	 */

	if (pdev->dma_mask == ~0UL)
		mapaddr = tioca_dma_d64(paddr);
	else if (pdev->dma_mask == 0xffffffffffffUL)
		mapaddr = tioca_dma_d48(pdev, paddr);
	else
		mapaddr = 0;

	/* Last resort ... use PCI portion of CA GART */

	if (mapaddr == 0)
		mapaddr = tioca_dma_mapped(pdev, paddr, byte_count);

	return mapaddr;
}

/**
 * tioca_error_intr_handler - SGI TIO CA error interrupt handler
 * @irq: unused
 * @arg: pointer to tioca_common struct for the given CA
 *
 * Handle a CA error interrupt.  Simply a wrapper around a SAL call which
 * defers processing to the SGI prom.
 */
static irqreturn_t
tioca_error_intr_handler(int irq, void *arg)
{
	struct tioca_common *soft = arg;
	struct ia64_sal_retval ret_stuff;
	u64 segment;
	u64 busnum;
	ret_stuff.status = 0;
	ret_stuff.v0 = 0;

	segment = soft->ca_common.bs_persist_segment;
	busnum = soft->ca_common.bs_persist_busnum;

	SAL_CALL_NOLOCK(ret_stuff,
			(u64) SN_SAL_IOIF_ERROR_INTERRUPT,
			segment, busnum, 0, 0, 0, 0, 0);

	return IRQ_HANDLED;
}

/**
 * tioca_bus_fixup - perform final PCI fixup for a TIO CA bus
 * @prom_bussoft: Common prom/kernel struct representing the bus
 *
 * Replicates the tioca_common pointed to by @prom_bussoft in kernel
 * space.  Allocates and initializes a kernel-only area for a given CA,
 * and sets up an irq for handling CA error interrupts.
 *
 * On successful setup, returns the kernel version of tioca_common back to
 * the caller.
 */
static void *
tioca_bus_fixup(struct pcibus_bussoft *prom_bussoft, struct pci_controller *controller)
{
	struct tioca_common *tioca_common;
	struct tioca_kernel *tioca_kern;
	struct pci_bus *bus;

	/* sanity check prom rev */

	if (is_shub1() && sn_sal_rev() < 0x0406) {
		printk
		    (KERN_ERR "%s:  SGI prom rev 4.06 or greater required "
		     "for tioca support\n", __FUNCTION__);
		return NULL;
	}

	/*
	 * Allocate kernel bus soft and copy from prom.
	 */

	tioca_common = kzalloc(sizeof(struct tioca_common), GFP_KERNEL);
	if (!tioca_common)
		return NULL;

	memcpy(tioca_common, prom_bussoft, sizeof(struct tioca_common));
	tioca_common->ca_common.bs_base = (unsigned long)
		ioremap(REGION_OFFSET(tioca_common->ca_common.bs_base),
			sizeof(struct tioca_common));

	/* init kernel-private area */

	tioca_kern = kzalloc(sizeof(struct tioca_kernel), GFP_KERNEL);
	if (!tioca_kern) {
		kfree(tioca_common);
		return NULL;
	}

	tioca_kern->ca_common = tioca_common;
	spin_lock_init(&tioca_kern->ca_lock);
	INIT_LIST_HEAD(&tioca_kern->ca_dmamaps);
	tioca_kern->ca_closest_node =
	    nasid_to_cnodeid(tioca_common->ca_closest_nasid);
	tioca_common->ca_kernel_private = (u64) tioca_kern;

	bus = pci_find_bus(tioca_common->ca_common.bs_persist_segment,
		tioca_common->ca_common.bs_persist_busnum);
	BUG_ON(!bus);
	tioca_kern->ca_devices = &bus->devices;

	/* init GART */

	if (tioca_gart_init(tioca_kern) < 0) {
		kfree(tioca_kern);
		kfree(tioca_common);
		return NULL;
	}

	tioca_gart_found++;
	list_add(&tioca_kern->ca_list, &tioca_list);

	if (request_irq(SGI_TIOCA_ERROR,
			tioca_error_intr_handler,
			IRQF_SHARED, "TIOCA error", (void *)tioca_common))
		printk(KERN_WARNING
		       "%s:  Unable to get irq %d.  "
		       "Error interrupts won't be routed for TIOCA bus %d\n",
		       __FUNCTION__, SGI_TIOCA_ERROR,
		       (int)tioca_common->ca_common.bs_persist_busnum);

	sn_set_err_irq_affinity(SGI_TIOCA_ERROR);

	/* Setup locality information */
	controller->node = tioca_kern->ca_closest_node;
	return tioca_common;
}

static struct sn_pcibus_provider tioca_pci_interfaces = {
	.dma_map = tioca_dma_map,
	.dma_map_consistent = tioca_dma_map,
	.dma_unmap = tioca_dma_unmap,
	.bus_fixup = tioca_bus_fixup,
	.force_interrupt = NULL,
	.target_interrupt = NULL
};

/**
 * tioca_init_provider - init SN PCI provider ops for TIO CA
 */
int
tioca_init_provider(void)
{
	sn_pci_provider[PCIIO_ASIC_TYPE_TIOCA] = &tioca_pci_interfaces;
	return 0;
}