From: Prarit Bhargava <prarit@redhat.com>
Date: Wed, 3 Dec 2008 17:37:06 -0500
Subject: [x86_64] Calgary IOMMU sysdata fixes
Message-id: 20081203223706.32135.31422.sendpatchset@prarit.bos.redhat.com
O-Subject: [RHEL5.3 PATCH]: Calgary IOMMU sysdata fixes
Bugzilla: 474047
RH-Acked-by: Pete Zaitcev <zaitcev@redhat.com>
RH-Acked-by: Jeff Garzik <jgarzik@redhat.com>
RH-Acked-by: Alan Cox <alan@redhat.com>

Backport of 2.6.27's pci_iommu().

PCI domain and Calgary IOMMU both attempt to use the sysdata pointer.  This
leads to a panic on IBM Calgary IOMMU enabled systems.

Tested* and compiled by me.

Resolves BZ 474047.

* Testing yielded another problem with the mpt driver.  AFAICT, this new issue
is independent of PCI domain support and BZ 474047.  I have opened a new BZ
to track the new issue.

diff --git a/arch/x86_64/kernel/pci-calgary.c b/arch/x86_64/kernel/pci-calgary.c
index a79e968..bb71924 100644
--- a/arch/x86_64/kernel/pci-calgary.c
+++ b/arch/x86_64/kernel/pci-calgary.c
@@ -383,7 +383,7 @@ static inline struct iommu_table *find_iommu_table(struct device *dev)
 		pbus = pbus->parent;
 
 	if (pbus->self)
-		tbl = pbus->self->sysdata;
+		tbl = pci_iommu(pbus);
 	else
 		tbl = NULL;
 
@@ -807,7 +807,7 @@ static void __init calgary_reserve_mem_region(struct pci_dev *dev, u64 start,
 	limit++;
 
 	numpages = ((limit - start) >> PAGE_SHIFT);
-	iommu_range_reserve(dev->sysdata, start, numpages);
+	iommu_range_reserve(pci_iommu(dev->bus), start, numpages);
 }
 
 static void __init calgary_reserve_peripheral_mem_1(struct pci_dev *dev)
@@ -815,7 +815,7 @@ static void __init calgary_reserve_peripheral_mem_1(struct pci_dev *dev)
 	void __iomem *target;
 	u64 low, high, sizelow;
 	u64 start, limit;
-	struct iommu_table *tbl = dev->sysdata;
+	struct iommu_table *tbl = pci_iommu(dev->bus);
 	unsigned char busnum = dev->bus->number;
 	void __iomem *bbar = tbl->bbar;
 
@@ -839,7 +839,7 @@ static void __init calgary_reserve_peripheral_mem_2(struct pci_dev *dev)
 	u32 val32;
 	u64 low, high, sizelow, sizehigh;
 	u64 start, limit;
-	struct iommu_table *tbl = dev->sysdata;
+	struct iommu_table *tbl = pci_iommu(dev->bus);
 	unsigned char busnum = dev->bus->number;
 	void __iomem *bbar = tbl->bbar;
 
@@ -875,7 +875,7 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
 {
 	unsigned int npages;
 	u64 start;
-	struct iommu_table *tbl = dev->sysdata;
+	struct iommu_table *tbl = pci_iommu(dev->bus);
 
 	/* reserve EMERGENCY_PAGES from bad_dma_address and up */
 	iommu_range_reserve(tbl, bad_dma_address, EMERGENCY_PAGES);
@@ -915,7 +915,7 @@ static int __init calgary_setup_tar(struct pci_dev *dev, void __iomem *bbar)
 	if (ret)
 		return ret;
 
-	tbl = dev->sysdata;
+	tbl = pci_iommu(dev->bus);
 	tbl->it_base = (unsigned long)bus_info[dev->bus->number].tce_space;
 
 	if (is_kdump_kernel())
@@ -956,7 +956,7 @@ static int __init calgary_setup_tar(struct pci_dev *dev, void __iomem *bbar)
 static void __init calgary_free_bus(struct pci_dev *dev)
 {
 	u64 val64;
-	struct iommu_table *tbl = dev->sysdata;
+	struct iommu_table *tbl = pci_iommu(dev->bus);
 	void __iomem *target;
 	unsigned int bitmapsz;
 
@@ -972,7 +972,7 @@ static void __init calgary_free_bus(struct pci_dev *dev)
 
 	kfree(tbl);
 
-	dev->sysdata = NULL;
+	set_pci_iommu(dev->bus, NULL);
 
 	/* Can't free bootmem allocated memory after system is up :-( */
 	bus_info[dev->bus->number].tce_space = NULL;
@@ -1045,7 +1045,7 @@ static void calioc2_dump_error_regs(struct iommu_table *tbl)
 static void calgary_watchdog(unsigned long data)
 {
 	struct pci_dev *dev = (struct pci_dev *)data;
-	struct iommu_table *tbl = dev->sysdata;
+	struct iommu_table *tbl = pci_iommu(dev->bus);
 	void __iomem *bbar = tbl->bbar;
 	u32 val32;
 	void __iomem *target;
@@ -1143,7 +1143,7 @@ static void __init calgary_enable_translation(struct pci_dev *dev)
 	struct iommu_table *tbl;
 
 	busnum = dev->bus->number;
-	tbl = dev->sysdata;
+	tbl = pci_iommu(dev->bus);
 	bbar = tbl->bbar;
 
 	/* enable TCE in PHB Config Register */
@@ -1175,7 +1175,7 @@ static void __init calgary_disable_translation(struct pci_dev *dev)
 	struct iommu_table *tbl;
 
 	busnum = dev->bus->number;
-	tbl = dev->sysdata;
+	tbl = pci_iommu(dev->bus);
 	bbar = tbl->bbar;
 
 	/* disable TCE in PHB Config Register */
@@ -1193,7 +1193,7 @@ static void __init calgary_disable_translation(struct pci_dev *dev)
 static void __init calgary_init_one_nontraslated(struct pci_dev *dev)
 {
 	pci_dev_get(dev);
-	dev->sysdata = NULL;
+	set_pci_iommu(dev->bus, NULL);
 
 	/* is the device behind a bridge? */
 	if (dev->bus->parent)
@@ -1225,7 +1225,7 @@ static int __init calgary_init_one(struct pci_dev *dev)
 	} else
 		dev->bus->self = dev;
 
-	tbl = dev->sysdata;
+	tbl = pci_iommu(dev->bus);
 	tbl->chip_ops->handle_quirks(tbl, dev);
 
 	calgary_enable_translation(dev);
@@ -1689,7 +1689,7 @@ static void __init calgary_fixup_one_tce_space(struct pci_dev *dev)
 	unsigned int npages;
 	int i;
 
-	tbl = dev->sysdata;
+	tbl = pci_iommu(dev->bus);
 
 	for (i = 0; i < 4; i++) {
 		struct resource *r = &dev->resource[PCI_BRIDGE_RESOURCES + i];
diff --git a/arch/x86_64/kernel/tce.c b/arch/x86_64/kernel/tce.c
index e979fc2..67076c3 100644
--- a/arch/x86_64/kernel/tce.c
+++ b/arch/x86_64/kernel/tce.c
@@ -136,9 +136,9 @@ int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
 	struct iommu_table *tbl;
 	int ret;
 
-	if (dev->sysdata) {
+	if (pci_iommu(dev->bus)) {
 		printk(KERN_ERR "Calgary: dev %p has sysdata %p\n",
-		       dev, dev->sysdata);
+		       dev, pci_iommu(dev->bus));
 		BUG();
 	}
 
@@ -159,7 +159,7 @@ int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
 	 * NUMA is already using the bus's sysdata pointer, so we use
 	 * the bus's pci_dev's sysdata instead.
 	 */
-	dev->sysdata = tbl;
+	set_pci_iommu(dev->bus, tbl);
 
 	return 0;
 
diff --git a/include/asm-x86_64/pci.h b/include/asm-x86_64/pci.h
index f2ca179..e0af482 100644
--- a/include/asm-x86_64/pci.h
+++ b/include/asm-x86_64/pci.h
@@ -8,7 +8,11 @@
 struct pci_sysdata {
 	int		domain;		/* PCI domain */
 	int		node;		/* NUMA node */
+#ifdef CONFIG_X86_64
+	void		*iommu;		/*IOMMU private data*/
+#endif
 };
+
 extern struct pci_sysdata pci_default_sysdata;
 
 #ifdef CONFIG_PCI_DOMAINS
@@ -24,6 +28,20 @@ static inline int pci_proc_domain(struct pci_bus *bus)
 }
 #endif /* CONFIG_PCI_DOMAINS */
 
+#ifdef CONFIG_CALGARY_IOMMU
+static inline void *pci_iommu(struct pci_bus *bus)
+{
+	struct pci_sysdata *sd = bus->sysdata;
+	return sd->iommu;
+}
+
+static inline void set_pci_iommu(struct pci_bus *bus, void *val)
+{
+	struct pci_sysdata *sd = bus->sysdata;
+	sd->iommu = val;
+}
+#endif /* CONFIG_CALGARY_IOMMU */
+
 #include <linux/mm.h> /* for struct page */
 
 /* Can be used to override the logic in pci_scan_bus for skipping