[PATCH] PPC64: Fix LPAR IOMMU setup code for p630

[Omkhar Arasaratnam]

Olof Johansson wrote:

>Hi,
>
>Here's a fix to deal with p630 systems in LPAR mode. They're to date
>the only system that in some cases might lack a dma-window property
>for the bus, but contain an overriding property in the device node for
>the specific adapter/slot. This makes the device setup code a bit more
>complex since it needs to do some of the things that the bus setup code
>has already done.
>
>
>Signed-off-by: Olof Johansson <olof at austin.ibm.com>
>
>Index: 2.6/arch/ppc64/kernel/pSeries_iommu.c
>===================================================================
>--- 2.6.orig/arch/ppc64/kernel/pSeries_iommu.c	2005-03-23 13:06:34.000000000 -0600
>+++ 2.6/arch/ppc64/kernel/pSeries_iommu.c	2005-03-23 13:08:50.000000000 -0600
>@@ -401,6 +401,8 @@ static void iommu_bus_setup_pSeriesLP(st
> 	struct device_node *dn, *pdn;
> 	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 */
>@@ -455,6 +457,56 @@ static void iommu_dev_setup_pSeries(stru
> 	}
> }
> 
>+static void iommu_dev_setup_pSeriesLP(struct pci_dev *dev)
>+{
>+	struct device_node *pdn, *dn;
>+	struct iommu_table *tbl;
>+	int *dma_window = NULL;
>+
>+	DBG("iommu_dev_setup_pSeriesLP, dev %p (%s)\n", dev, dev->pretty_name);
>+
>+	/* 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->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) {
>+		/* Fall back to regular (non-LPAR) dev setup */
>+		DBG("No dma window for device, falling back to regular setup\n");
>+		iommu_dev_setup_pSeries(dev);
>+		return;
>+	} else {
>+		DBG("Found DMA window, allocating table\n");
>+	}
>+
>+	if (!pdn->iommu_table) {
>+		/* iommu_table_setparms_lpar needs bussubno. */
>+		pdn->bussubno = pdn->phb->bus->number;
>+
>+		tbl = (struct iommu_table *)kmalloc(sizeof(struct iommu_table),
>+						    GFP_KERNEL);
>+	
>+		iommu_table_setparms_lpar(pdn->phb, pdn, tbl, dma_window);
>+	
>+		pdn->iommu_table = iommu_init_table(tbl);
>+	}
>+
>+	if (pdn != dn)
>+		dn->iommu_table = pdn->iommu_table;
>+}
>+
> static void iommu_bus_setup_null(struct pci_bus *b) { }
> static void iommu_dev_setup_null(struct pci_dev *d) { }
> 
>@@ -479,13 +531,14 @@ void iommu_init_early_pSeries(void)
> 			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;
> 	}
> 
>-	ppc_md.iommu_dev_setup = iommu_dev_setup_pSeries;
> 
> 	pci_iommu_init();
> }
>
>  
>
Olaf - everything works great - anyword on when this will all merge 
upstream?