iommu.c

linux-2.6.15.6

 *
 * ToDo: properly interpret the ibm,dma-window property.  The definition is:
 *	logical-bus-number	(1 word)
 *	phys-address		(#address-cells words)
 *	size			(#cell-size words)
 *
 * Currently we hard code these sizes (more or less).
 */
static void iommu_table_setparms_lpar(struct pci_controller *phb,
				      struct device_node *dn,
				      struct iommu_table *tbl,
				      unsigned int *dma_window)
{
	tbl->it_busno  = PCI_DN(dn)->bussubno;

	/* TODO: Parse field size properties properly. */
	tbl->it_size   = (((unsigned long)dma_window[4] << 32) |
			   (unsigned long)dma_window[5]) >> PAGE_SHIFT;
	tbl->it_offset = (((unsigned long)dma_window[2] << 32) |
			   (unsigned long)dma_window[3]) >> PAGE_SHIFT;
	tbl->it_base   = 0;
	tbl->it_index  = dma_window[0];
	tbl->it_blocksize  = 16;
	tbl->it_type = TCE_PCI;
}

static void iommu_bus_setup_pSeries(struct pci_bus *bus)
{
	struct device_node *dn;
	struct iommu_table *tbl;
	struct device_node *isa_dn, *isa_dn_orig;
	struct device_node *tmp;
	struct pci_dn *pci;
	int children;

	DBG("iommu_bus_setup_pSeries, bus %p, bus->self %p\n", bus, bus->self);

	dn = pci_bus_to_OF_node(bus);
	pci = PCI_DN(dn);

	if (bus->self) {
		/* This is not a root bus, any setup will be done for the
		 * device-side of the bridge in iommu_dev_setup_pSeries().
		 */
		return;
	}

	/* Check if the ISA bus on the system is under
	 * this PHB.
	 */
	isa_dn = isa_dn_orig = of_find_node_by_type(NULL, "isa");

	while (isa_dn && isa_dn != dn)
		isa_dn = isa_dn->parent;

	if (isa_dn_orig)
		of_node_put(isa_dn_orig);

	/* Count number of direct PCI children of the PHB.
	 * All PCI device nodes have class-code property, so it's
	 * an easy way to find them.
	 */
	for (children = 0, tmp = dn->child; tmp; tmp = tmp->sibling)
		if (get_property(tmp, "class-code", NULL))
			children++;

	DBG("Children: %d\n", children);

	/* Calculate amount of DMA window per slot. Each window must be
	 * a power of two (due to pci_alloc_consistent requirements).
	 *
	 * Keep 256MB aside for PHBs with ISA.
	 */

	if (!isa_dn) {
		/* No ISA/IDE - just set window size and return */
		pci->phb->dma_window_size = 0x80000000ul; /* To be divided */

		while (pci->phb->dma_window_size * children > 0x80000000ul)
			pci->phb->dma_window_size >>= 1;
		DBG("No ISA/IDE, window size is 0x%lx\n",
			pci->phb->dma_window_size);
		pci->phb->dma_window_base_cur = 0;

		return;
	}

	/* If we have ISA, then we probably have an IDE
	 * controller too. Allocate a 128MB table but
	 * skip the first 128MB to avoid stepping on ISA
	 * space.
	 */
	pci->phb->dma_window_size = 0x8000000ul;
	pci->phb->dma_window_base_cur = 0x8000000ul;

	tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);

	iommu_table_setparms(pci->phb, dn, tbl);
	pci->iommu_table = iommu_init_table(tbl);

	/* Divide the rest (1.75GB) among the children */
	pci->phb->dma_window_size = 0x80000000ul;
	while (pci->phb->dma_window_size * children > 0x70000000ul)
		pci->phb->dma_window_size >>= 1;

	DBG("ISA/IDE, window size is 0x%lx\n", pci->phb->dma_window_size);

}


static void iommu_bus_setup_pSeriesLP(struct pci_bus *bus)
{
	struct iommu_table *tbl;
	struct device_node *dn, *pdn;
	struct pci_dn *ppci;
	unsigned int *dma_window = NULL;

	DBG("iommu_bus_setup_pSeriesLP, bus %p, bus->self %p\n", bus, bus->self);

	dn = pci_bus_to_OF_node(bus);

	/* Find nearest ibm,dma-window, walking up the device tree */
	for (pdn = dn; pdn != NULL; pdn = pdn->parent) {
		dma_window = (unsigned int *)get_property(pdn, "ibm,dma-window", NULL);
		if (dma_window != NULL)
			break;
	}

	if (dma_window == NULL) {
		DBG("iommu_bus_setup_pSeriesLP: bus %s seems to have no ibm,dma-window property\n", dn->full_name);
		return;
	}

	ppci = pdn->data;
	if (!ppci->iommu_table) {
		/* Bussubno hasn't been copied yet.
		 * Do it now because iommu_table_setparms_lpar needs it.
		 */

		ppci->bussubno = bus->number;

		tbl = (struct iommu_table *)kmalloc(sizeof(struct iommu_table),
						    GFP_KERNEL);
	
		iommu_table_setparms_lpar(ppci->phb, pdn, tbl, dma_window);

		ppci->iommu_table = iommu_init_table(tbl);
	}

	if (pdn != dn)
		PCI_DN(dn)->iommu_table = ppci->iommu_table;
}


static void iommu_dev_setup_pSeries(struct pci_dev *dev)
{
	struct device_node *dn, *mydn;
	struct iommu_table *tbl;

	DBG("iommu_dev_setup_pSeries, dev %p (%s)\n", dev, pci_name(dev));

	mydn = dn = pci_device_to_OF_node(dev);

	/* If we're the direct child of a root bus, then we need to allocate
	 * an iommu table ourselves. The bus setup code should have setup
	 * the window sizes already.
	 */
	if (!dev->bus->self) {
		DBG(" --> first child, no bridge. Allocating iommu table.\n");
		tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
		iommu_table_setparms(PCI_DN(dn)->phb, dn, tbl);
		PCI_DN(mydn)->iommu_table = iommu_init_table(tbl);

		return;
	}

	/* If this device is further down the bus tree, search upwards until
	 * an already allocated iommu table is found and use that.
	 */

	while (dn && dn->data && PCI_DN(dn)->iommu_table == NULL)
		dn = dn->parent;

	if (dn && dn->data) {
		PCI_DN(mydn)->iommu_table = PCI_DN(dn)->iommu_table;
	} else {
		DBG("iommu_dev_setup_pSeries, dev %p (%s) has no iommu table\n", dev, pci_name(dev));
	}
}

static int iommu_reconfig_notifier(struct notifier_block *nb, unsigned long action, void *node)
{
	int err = NOTIFY_OK;
	struct device_node *np = node;
	struct pci_dn *pci = np->data;

	switch (action) {
	case PSERIES_RECONFIG_REMOVE:
		if (pci && pci->iommu_table &&
		    get_property(np, "ibm,dma-window", NULL))
			iommu_free_table(np);
		break;
	default:
		err = NOTIFY_DONE;
		break;
	}
	return err;
}

static struct notifier_block iommu_reconfig_nb = {
	.notifier_call = iommu_reconfig_notifier,
};

static void iommu_dev_setup_pSeriesLP(struct pci_dev *dev)
{
	struct device_node *pdn, *dn;
	struct iommu_table *tbl;
	int *dma_window = NULL;
	struct pci_dn *pci;

	DBG("iommu_dev_setup_pSeriesLP, dev %p (%s)\n", dev, pci_name(dev));

	/* dev setup for LPAR is a little tricky, since the device tree might
	 * contain the dma-window properties per-device and not neccesarily
	 * for the bus. So we need to search upwards in the tree until we
	 * either hit a dma-window property, OR find a parent with a table
	 * already allocated.
	 */
	dn = pci_device_to_OF_node(dev);

	for (pdn = dn; pdn && pdn->data && !PCI_DN(pdn)->iommu_table;
	     pdn = pdn->parent) {
		dma_window = (unsigned int *)
			get_property(pdn, "ibm,dma-window", NULL);
		if (dma_window)
			break;
	}

	/* Check for parent == NULL so we don't try to setup the empty EADS
	 * slots on POWER4 machines.
	 */
	if (dma_window == NULL || pdn->parent == NULL) {
		DBG("No dma window for device, linking to parent\n");
		PCI_DN(dn)->iommu_table = PCI_DN(pdn)->iommu_table;
		return;
	} else {
		DBG("Found DMA window, allocating table\n");
	}

	pci = pdn->data;
	if (!pci->iommu_table) {
		/* iommu_table_setparms_lpar needs bussubno. */
		pci->bussubno = pci->phb->bus->number;

		tbl = (struct iommu_table *)kmalloc(sizeof(struct iommu_table),
						    GFP_KERNEL);

		iommu_table_setparms_lpar(pci->phb, pdn, tbl, dma_window);

		pci->iommu_table = iommu_init_table(tbl);
	}

	if (pdn != dn)
		PCI_DN(dn)->iommu_table = pci->iommu_table;
}

static void iommu_bus_setup_null(struct pci_bus *b) { }
static void iommu_dev_setup_null(struct pci_dev *d) { }

/* These are called very early. */
void iommu_init_early_pSeries(void)
{
	if (of_chosen && get_property(of_chosen, "linux,iommu-off", NULL)) {
		/* Direct I/O, IOMMU off */
		ppc_md.iommu_dev_setup = iommu_dev_setup_null;
		ppc_md.iommu_bus_setup = iommu_bus_setup_null;
		pci_direct_iommu_init();

		return;
	}

	if (platform_is_lpar()) {
		if (firmware_has_feature(FW_FEATURE_MULTITCE)) {
			ppc_md.tce_build = tce_buildmulti_pSeriesLP;
			ppc_md.tce_free	 = tce_freemulti_pSeriesLP;
		} else {
			ppc_md.tce_build = tce_build_pSeriesLP;
			ppc_md.tce_free	 = tce_free_pSeriesLP;
		}
		ppc_md.iommu_bus_setup = iommu_bus_setup_pSeriesLP;
		ppc_md.iommu_dev_setup = iommu_dev_setup_pSeriesLP;
	} else {
		ppc_md.tce_build = tce_build_pSeries;
		ppc_md.tce_free  = tce_free_pSeries;
		ppc_md.iommu_bus_setup = iommu_bus_setup_pSeries;
		ppc_md.iommu_dev_setup = iommu_dev_setup_pSeries;
	}


	pSeries_reconfig_notifier_register(&iommu_reconfig_nb);

	pci_iommu_init();
}