[PATCH kernel 4/9] powerpc/powernv/iommu: Add real mode version of xchg()

David Gibson david at gibson.dropbear.id.au
Tue Mar 8 15:50:58 AEDT 2016 

On Mon, Mar 07, 2016 at 06:32:23PM +1100, Alexey Kardashevskiy wrote:
> On 03/07/2016 05:05 PM, David Gibson wrote:
> >On Mon, Mar 07, 2016 at 02:41:12PM +1100, Alexey Kardashevskiy wrote:
> >>In real mode, TCE tables are invalidated using different
> >>cache-inhibited store instructions which is different from
> >>the virtual mode.
> >>
> >>This defines and implements exchange_rm() callback. This does not
> >>define set_rm/clear_rm/flush_rm callbacks as there is no user for those -
> >>exchange/exchange_rm are only to be used by KVM for VFIO.
> >>
> >>The exchange_rm callback is defined for IODA1/IODA2 powernv platforms.
> >>
> >>This replaces list_for_each_entry_rcu with its lockless version as
> >>from now on pnv_pci_ioda2_tce_invalidate() can be called in
> >>the real mode too.
> >>
> >>Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
> >>---
> >>  arch/powerpc/include/asm/iommu.h          |  7 +++++++
> >>  arch/powerpc/kernel/iommu.c               | 15 +++++++++++++++
> >>  arch/powerpc/platforms/powernv/pci-ioda.c | 28 +++++++++++++++++++++++++++-
> >>  3 files changed, 49 insertions(+), 1 deletion(-)
> >>
> >>diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
> >>index 7b87bab..3ca877a 100644
> >>--- a/arch/powerpc/include/asm/iommu.h
> >>+++ b/arch/powerpc/include/asm/iommu.h
> >>@@ -64,6 +64,11 @@ struct iommu_table_ops {
> >>  			long index,
> >>  			unsigned long *hpa,
> >>  			enum dma_data_direction *direction);
> >>+	/* Real mode */
> >>+	int (*exchange_rm)(struct iommu_table *tbl,
> >>+			long index,
> >>+			unsigned long *hpa,
> >>+			enum dma_data_direction *direction);
> >>  #endif
> >>  	void (*clear)(struct iommu_table *tbl,
> >>  			long index, long npages);
> >>@@ -208,6 +213,8 @@ extern void iommu_del_device(struct device *dev);
> >>  extern int __init tce_iommu_bus_notifier_init(void);
> >>  extern long iommu_tce_xchg(struct iommu_table *tbl, unsigned long entry,
> >>  		unsigned long *hpa, enum dma_data_direction *direction);
> >>+extern long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry,
> >>+		unsigned long *hpa, enum dma_data_direction *direction);
> >>  #else
> >>  static inline void iommu_register_group(struct iommu_table_group *table_group,
> >>  					int pci_domain_number,
> >>diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
> >>index a8e3490..2fcc48b 100644
> >>--- a/arch/powerpc/kernel/iommu.c
> >>+++ b/arch/powerpc/kernel/iommu.c
> >>@@ -1062,6 +1062,21 @@ void iommu_release_ownership(struct iommu_table *tbl)
> >>  }
> >>  EXPORT_SYMBOL_GPL(iommu_release_ownership);
> >>
> >>+long iommu_tce_xchg_rm(struct iommu_table *tbl, unsigned long entry,
> >>+		unsigned long *hpa, enum dma_data_direction *direction)
> >>+{
> >>+	long ret;
> >>+
> >>+	ret = tbl->it_ops->exchange_rm(tbl, entry, hpa, direction);
> >>+
> >>+	if (!ret && ((*direction == DMA_FROM_DEVICE) ||
> >>+			(*direction == DMA_BIDIRECTIONAL)))
> >>+		SetPageDirty(realmode_pfn_to_page(*hpa >> PAGE_SHIFT));
> >>+
> >>+	return ret;
> >>+}
> >>+EXPORT_SYMBOL_GPL(iommu_tce_xchg_rm);
> >
> >>  int iommu_add_device(struct device *dev)
> >>  {
> >>  	struct iommu_table *tbl;
> >>diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
> >>index c5baaf3..bed1944 100644
> >>--- a/arch/powerpc/platforms/powernv/pci-ioda.c
> >>+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
> >>@@ -1791,6 +1791,18 @@ static int pnv_ioda1_tce_xchg(struct iommu_table *tbl, long index,
> >>
> >>  	return ret;
> >>  }
> >>+
> >>+static int pnv_ioda1_tce_xchg_rm(struct iommu_table *tbl, long index,
> >>+		unsigned long *hpa, enum dma_data_direction *direction)
> >>+{
> >>+	long ret = pnv_tce_xchg(tbl, index, hpa, direction);
> >>+
> >>+	if (!ret && (tbl->it_type &
> >>+			(TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE)))
> >>+		pnv_pci_ioda1_tce_invalidate(tbl, index, 1, true);
> >>+
> >>+	return ret;
> >>+}
> >>  #endif
> >
> >Both your _rm variants are identical to the non _rm versions.  Why not
> >just set the function poiinter to the same thing, rather than copying
> >the whole function.
> 
> 
> The last parameter - "rm" - to pnv_pci_ioda1_tce_invalidate() is
> different.

Ah, missed that, sorry.

> 
> 
> >
> >>  static void pnv_ioda1_tce_free(struct iommu_table *tbl, long index,
> >>@@ -1806,6 +1818,7 @@ static struct iommu_table_ops pnv_ioda1_iommu_ops = {
> >>  	.set = pnv_ioda1_tce_build,
> >>  #ifdef CONFIG_IOMMU_API
> >>  	.exchange = pnv_ioda1_tce_xchg,
> >>+	.exchange_rm = pnv_ioda1_tce_xchg_rm,
> >>  #endif
> >>  	.clear = pnv_ioda1_tce_free,
> >>  	.get = pnv_tce_get,
> >>@@ -1866,7 +1879,7 @@ static void pnv_pci_ioda2_tce_invalidate(struct iommu_table *tbl,
> >>  {
> >>  	struct iommu_table_group_link *tgl;
> >>
> >>-	list_for_each_entry_rcu(tgl, &tbl->it_group_list, next) {
> >>+	list_for_each_entry_lockless(tgl, &tbl->it_group_list, next) {
> >>  		struct pnv_ioda_pe *npe;
> >>  		struct pnv_ioda_pe *pe = container_of(tgl->table_group,
> >>  				struct pnv_ioda_pe, table_group);
> >>@@ -1918,6 +1931,18 @@ static int pnv_ioda2_tce_xchg(struct iommu_table *tbl, long index,
> >>
> >>  	return ret;
> >>  }
> >>+
> >>+static int pnv_ioda2_tce_xchg_rm(struct iommu_table *tbl, long index,
> >>+		unsigned long *hpa, enum dma_data_direction *direction)
> >>+{
> >>+	long ret = pnv_tce_xchg(tbl, index, hpa, direction);
> >>+
> >>+	if (!ret && (tbl->it_type &
> >>+			(TCE_PCI_SWINV_CREATE | TCE_PCI_SWINV_FREE)))
> >>+		pnv_pci_ioda2_tce_invalidate(tbl, index, 1, true);
> >>+
> >>+	return ret;
> >>+}
> >>  #endif
> >>
> >>  static void pnv_ioda2_tce_free(struct iommu_table *tbl, long index,
> >>@@ -1939,6 +1964,7 @@ static struct iommu_table_ops pnv_ioda2_iommu_ops = {
> >>  	.set = pnv_ioda2_tce_build,
> >>  #ifdef CONFIG_IOMMU_API
> >>  	.exchange = pnv_ioda2_tce_xchg,
> >>+	.exchange_rm = pnv_ioda2_tce_xchg_rm,
> >>  #endif
> >>  	.clear = pnv_ioda2_tce_free,
> >>  	.get = pnv_tce_get,
> >
> 
> 

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20160308/0eef9758/attachment.sig>

More information about the Linuxppc-dev mailing list