[PATCH v12] PPC: POWERNV: move iommu_add_device earlier

From: Alexey Kardashevskiy
Date: Tue Dec 17 2013 - 23:17:46 EST


The current implementation of IOMMU on sPAPR does not use iommu_ops
and therefore does not call IOMMU API's bus_set_iommu() which
1) sets iommu_ops for a bus
2) registers a bus notifier
Instead, PCI devices are added to IOMMU groups from
subsys_initcall_sync(tce_iommu_init) which does basically the same
thing without using iommu_ops callbacks.

However Freescale PAMU driver (https://lkml.org/lkml/2013/7/1/158)
implements iommu_ops and when tce_iommu_init is called, every PCI device
is already added to some group so there is a conflict.

This patch does 2 things:
1. removes the loop in which PCI devices were added to groups and
adds explicit iommu_add_device() calls to add devices as soon as they get
the iommu_table pointer assigned to them.
2. moves a bus notifier to powernv code in order to avoid conflict with
the notifier from Freescale driver.

iommu_add_device() and iommu_del_device() are public now.

Signed-off-by: Alexey Kardashevskiy <aik@xxxxxxxxx>
---
Changes:
v12:
* removed redundant bus notifier from common POWERPC code

v11:
* rebased on upstream

v10:
* fixed linker error when IOMMU_API is not enabled

v9:
* removed "KVM" from the subject as it is not really a KVM patch so
PPC mainainter (hi Ben!) can review/include it into his tree

v8:
* added the check for iommu_group!=NULL before removing device from a group
as suggested by Wei Yang <weiyang@xxxxxxxxxxxxxxxxxx>

v2:
* added a helper - set_iommu_table_base_and_group - which does
set_iommu_table_base() and iommu_add_device()
---
arch/powerpc/include/asm/iommu.h | 26 ++++++++++++++++++
arch/powerpc/kernel/iommu.c | 41 +++--------------------------
arch/powerpc/platforms/powernv/pci-ioda.c | 8 +++---
arch/powerpc/platforms/powernv/pci-p5ioc2.c | 2 +-
arch/powerpc/platforms/powernv/pci.c | 31 +++++++++++++++++++++-
arch/powerpc/platforms/pseries/iommu.c | 8 +++---
6 files changed, 70 insertions(+), 46 deletions(-)

diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index c34656a..774fa27 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -101,8 +101,34 @@ extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
*/
extern struct iommu_table *iommu_init_table(struct iommu_table * tbl,
int nid);
+#ifdef CONFIG_IOMMU_API
extern void iommu_register_group(struct iommu_table *tbl,
int pci_domain_number, unsigned long pe_num);
+extern int iommu_add_device(struct device *dev);
+extern void iommu_del_device(struct device *dev);
+#else
+static inline void iommu_register_group(struct iommu_table *tbl,
+ int pci_domain_number,
+ unsigned long pe_num)
+{
+}
+
+static inline int iommu_add_device(struct device *dev)
+{
+ return 0;
+}
+
+static inline void iommu_del_device(struct device *dev)
+{
+}
+#endif /* !CONFIG_IOMMU_API */
+
+static inline void set_iommu_table_base_and_group(struct device *dev,
+ void *base)
+{
+ set_iommu_table_base(dev, base);
+ iommu_add_device(dev);
+}

extern int iommu_map_sg(struct device *dev, struct iommu_table *tbl,
struct scatterlist *sglist, int nelems,
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 572bb5b..ecbf468 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1105,7 +1105,7 @@ void iommu_release_ownership(struct iommu_table *tbl)
}
EXPORT_SYMBOL_GPL(iommu_release_ownership);

-static int iommu_add_device(struct device *dev)
+int iommu_add_device(struct device *dev)
{
struct iommu_table *tbl;
int ret = 0;
@@ -1134,46 +1134,13 @@ static int iommu_add_device(struct device *dev)

return ret;
}
+EXPORT_SYMBOL_GPL(iommu_add_device);

-static void iommu_del_device(struct device *dev)
+void iommu_del_device(struct device *dev)
{
iommu_group_remove_device(dev);
}
-
-static int iommu_bus_notifier(struct notifier_block *nb,
- unsigned long action, void *data)
-{
- struct device *dev = data;
-
- switch (action) {
- case BUS_NOTIFY_ADD_DEVICE:
- return iommu_add_device(dev);
- case BUS_NOTIFY_DEL_DEVICE:
- iommu_del_device(dev);
- return 0;
- default:
- return 0;
- }
-}
-
-static struct notifier_block tce_iommu_bus_nb = {
- .notifier_call = iommu_bus_notifier,
-};
-
-static int __init tce_iommu_init(void)
-{
- struct pci_dev *pdev = NULL;
-
- BUILD_BUG_ON(PAGE_SIZE < IOMMU_PAGE_SIZE);
-
- for_each_pci_dev(pdev)
- iommu_add_device(&pdev->dev);
-
- bus_register_notifier(&pci_bus_type, &tce_iommu_bus_nb);
- return 0;
-}
-
-subsys_initcall_sync(tce_iommu_init);
+EXPORT_SYMBOL_GPL(iommu_del_device);

#else

diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 2c6d173..f0e6871 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -460,7 +460,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
return;

pe = &phb->ioda.pe_array[pdn->pe_number];
- set_iommu_table_base(&pdev->dev, &pe->tce32_table);
+ set_iommu_table_base_and_group(&pdev->dev, &pe->tce32_table);
}

static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
@@ -468,7 +468,7 @@ static void pnv_ioda_setup_bus_dma(struct pnv_ioda_pe *pe, struct pci_bus *bus)
struct pci_dev *dev;

list_for_each_entry(dev, &bus->devices, bus_list) {
- set_iommu_table_base(&dev->dev, &pe->tce32_table);
+ set_iommu_table_base_and_group(&dev->dev, &pe->tce32_table);
if (dev->subordinate)
pnv_ioda_setup_bus_dma(pe, dev->subordinate);
}
@@ -644,7 +644,7 @@ static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
iommu_register_group(tbl, pci_domain_nr(pe->pbus), pe->pe_number);

if (pe->pdev)
- set_iommu_table_base(&pe->pdev->dev, tbl);
+ set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
else
pnv_ioda_setup_bus_dma(pe, pe->pbus);

@@ -723,7 +723,7 @@ static void pnv_pci_ioda2_setup_dma_pe(struct pnv_phb *phb,
iommu_register_group(tbl, pci_domain_nr(pe->pbus), pe->pe_number);

if (pe->pdev)
- set_iommu_table_base(&pe->pdev->dev, tbl);
+ set_iommu_table_base_and_group(&pe->pdev->dev, tbl);
else
pnv_ioda_setup_bus_dma(pe, pe->pbus);

diff --git a/arch/powerpc/platforms/powernv/pci-p5ioc2.c b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
index f8b4bd8..e3807d6 100644
--- a/arch/powerpc/platforms/powernv/pci-p5ioc2.c
+++ b/arch/powerpc/platforms/powernv/pci-p5ioc2.c
@@ -92,7 +92,7 @@ static void pnv_pci_p5ioc2_dma_dev_setup(struct pnv_phb *phb,
pci_domain_nr(phb->hose->bus), phb->opal_id);
}

- set_iommu_table_base(&pdev->dev, &phb->p5ioc2.iommu_table);
+ set_iommu_table_base_and_group(&pdev->dev, &phb->p5ioc2.iommu_table);
}

static void __init pnv_pci_init_p5ioc2_phb(struct device_node *np, u64 hub_id,
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index 4eb33a9..362b8ac 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -536,7 +536,7 @@ static void pnv_pci_dma_fallback_setup(struct pci_controller *hose,
pdn->iommu_table = pnv_pci_setup_bml_iommu(hose);
if (!pdn->iommu_table)
return;
- set_iommu_table_base(&pdev->dev, pdn->iommu_table);
+ set_iommu_table_base_and_group(&pdev->dev, pdn->iommu_table);
}

static void pnv_pci_dma_dev_setup(struct pci_dev *pdev)
@@ -657,3 +657,32 @@ void __init pnv_pci_init(void)
ppc_md.teardown_msi_irqs = pnv_teardown_msi_irqs;
#endif
}
+
+static int pnv_iommu_bus_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct device *dev = data;
+
+ switch (action) {
+ case BUS_NOTIFY_ADD_DEVICE:
+ return iommu_add_device(dev);
+ case BUS_NOTIFY_DEL_DEVICE:
+ if (dev->iommu_group)
+ iommu_del_device(dev);
+ return 0;
+ default:
+ return 0;
+ }
+}
+
+static struct notifier_block pnv_iommu_bus_nb = {
+ .notifier_call = pnv_iommu_bus_notifier,
+};
+
+static int __init pnv_iommu_bus_notifier_init(void)
+{
+ bus_register_notifier(&pci_bus_type, &pnv_iommu_bus_nb);
+ return 0;
+}
+
+subsys_initcall_sync(pnv_iommu_bus_notifier_init);
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index f253361..a80af6c 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -687,7 +687,8 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
iommu_table_setparms(phb, dn, tbl);
PCI_DN(dn)->iommu_table = iommu_init_table(tbl, phb->node);
iommu_register_group(tbl, pci_domain_nr(phb->bus), 0);
- set_iommu_table_base(&dev->dev, PCI_DN(dn)->iommu_table);
+ set_iommu_table_base_and_group(&dev->dev,
+ PCI_DN(dn)->iommu_table);
return;
}

@@ -699,7 +700,8 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
dn = dn->parent;

if (dn && PCI_DN(dn))
- set_iommu_table_base(&dev->dev, PCI_DN(dn)->iommu_table);
+ set_iommu_table_base_and_group(&dev->dev,
+ PCI_DN(dn)->iommu_table);
else
printk(KERN_WARNING "iommu: Device %s has no iommu table\n",
pci_name(dev));
@@ -1193,7 +1195,7 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
pr_debug(" found DMA window, table: %p\n", pci->iommu_table);
}

- set_iommu_table_base(&dev->dev, pci->iommu_table);
+ set_iommu_table_base_and_group(&dev->dev, pci->iommu_table);
}

static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
--
1.8.4.rc4

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