[PATCH 5/8] powerpc: add real mode support for dma operations on powernv

Alexey Kardashevskiy aik at ozlabs.ru
Sun Jul 7 01:07:04 EST 2013


The existing TCE machine calls (tce_build and tce_free) only support
virtual mode as they call __raw_writeq for TCE invalidation what
fails in real mode.

This introduces tce_build_rm and tce_free_rm real mode versions
which do mostly the same but use "Store Doubleword Caching Inhibited
Indexed" instruction for TCE invalidation.

This new feature is going to be utilized by real mode support of VFIO.

Signed-off-by: Alexey Kardashevskiy <aik at ozlabs.ru>
---
 arch/powerpc/include/asm/machdep.h        | 12 ++++++++++
 arch/powerpc/platforms/powernv/pci-ioda.c | 26 +++++++++++++++------
 arch/powerpc/platforms/powernv/pci.c      | 38 ++++++++++++++++++++++++++-----
 arch/powerpc/platforms/powernv/pci.h      |  2 +-
 4 files changed, 64 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 92386fc..0c19eef 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -75,6 +75,18 @@ struct machdep_calls {
 				    long index);
 	void		(*tce_flush)(struct iommu_table *tbl);
 
+	/* _rm versions are for real mode use only */
+	int		(*tce_build_rm)(struct iommu_table *tbl,
+				     long index,
+				     long npages,
+				     unsigned long uaddr,
+				     enum dma_data_direction direction,
+				     struct dma_attrs *attrs);
+	void		(*tce_free_rm)(struct iommu_table *tbl,
+				    long index,
+				    long npages);
+	void		(*tce_flush_rm)(struct iommu_table *tbl);
+
 	void __iomem *	(*ioremap)(phys_addr_t addr, unsigned long size,
 				   unsigned long flags, void *caller);
 	void		(*iounmap)(volatile void __iomem *token);
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 2931d97..2797dec 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -68,6 +68,12 @@ define_pe_printk_level(pe_err, KERN_ERR);
 define_pe_printk_level(pe_warn, KERN_WARNING);
 define_pe_printk_level(pe_info, KERN_INFO);
 
+static inline void rm_writed(unsigned long paddr, u64 val)
+{
+	__asm__ __volatile__("sync; stdcix %0,0,%1"
+		: : "r" (val), "r" (paddr) : "memory");
+}
+
 static int pnv_ioda_alloc_pe(struct pnv_phb *phb)
 {
 	unsigned long pe;
@@ -442,7 +448,7 @@ static void pnv_pci_ioda_dma_dev_setup(struct pnv_phb *phb, struct pci_dev *pdev
 }
 
 static void pnv_pci_ioda1_tce_invalidate(struct iommu_table *tbl,
-					 u64 *startp, u64 *endp)
+					 u64 *startp, u64 *endp, bool rm)
 {
 	u64 __iomem *invalidate = (u64 __iomem *)tbl->it_index;
 	unsigned long start, end, inc;
@@ -471,7 +477,10 @@ static void pnv_pci_ioda1_tce_invalidate(struct iommu_table *tbl,
 
         mb(); /* Ensure above stores are visible */
         while (start <= end) {
-                __raw_writeq(start, invalidate);
+		if (rm)
+			rm_writed((unsigned long) invalidate, start);
+		else
+			__raw_writeq(start, invalidate);
                 start += inc;
         }
 
@@ -483,7 +492,7 @@ static void pnv_pci_ioda1_tce_invalidate(struct iommu_table *tbl,
 
 static void pnv_pci_ioda2_tce_invalidate(struct pnv_ioda_pe *pe,
 					 struct iommu_table *tbl,
-					 u64 *startp, u64 *endp)
+					 u64 *startp, u64 *endp, bool rm)
 {
 	unsigned long start, end, inc;
 	u64 __iomem *invalidate = (u64 __iomem *)tbl->it_index;
@@ -502,22 +511,25 @@ static void pnv_pci_ioda2_tce_invalidate(struct pnv_ioda_pe *pe,
 	mb();
 
 	while (start <= end) {
-		__raw_writeq(start, invalidate);
+		if (rm)
+			rm_writed((unsigned long) invalidate, start);
+		else
+			__raw_writeq(start, invalidate);
 		start += inc;
 	}
 }
 
 void pnv_pci_ioda_tce_invalidate(struct iommu_table *tbl,
-				 u64 *startp, u64 *endp)
+				 u64 *startp, u64 *endp, bool rm)
 {
 	struct pnv_ioda_pe *pe = container_of(tbl, struct pnv_ioda_pe,
 					      tce32_table);
 	struct pnv_phb *phb = pe->phb;
 
 	if (phb->type == PNV_PHB_IODA1)
-		pnv_pci_ioda1_tce_invalidate(tbl, startp, endp);
+		pnv_pci_ioda1_tce_invalidate(tbl, startp, endp, rm);
 	else
-		pnv_pci_ioda2_tce_invalidate(pe, tbl, startp, endp);
+		pnv_pci_ioda2_tce_invalidate(pe, tbl, startp, endp, rm);
 }
 
 static void pnv_pci_ioda_setup_dma_pe(struct pnv_phb *phb,
diff --git a/arch/powerpc/platforms/powernv/pci.c b/arch/powerpc/platforms/powernv/pci.c
index e16b729..280f614 100644
--- a/arch/powerpc/platforms/powernv/pci.c
+++ b/arch/powerpc/platforms/powernv/pci.c
@@ -336,7 +336,7 @@ struct pci_ops pnv_pci_ops = {
 
 static int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
 			 unsigned long uaddr, enum dma_data_direction direction,
-			 struct dma_attrs *attrs)
+			 struct dma_attrs *attrs, bool rm)
 {
 	u64 proto_tce;
 	u64 *tcep, *tces;
@@ -358,12 +358,19 @@ static int pnv_tce_build(struct iommu_table *tbl, long index, long npages,
 	 * of flags if that becomes the case
 	 */
 	if (tbl->it_type & TCE_PCI_SWINV_CREATE)
-		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1);
+		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1, rm);
 
 	return 0;
 }
 
-static void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
+static int pnv_tce_build_vm(struct iommu_table *tbl, long index, long npages,
+			    unsigned long uaddr, enum dma_data_direction direction,
+			    struct dma_attrs *attrs)
+{
+	return pnv_tce_build(tbl, index, npages, uaddr, direction, attrs, false);
+}
+
+static void pnv_tce_free(struct iommu_table *tbl, long index, long npages, bool rm)
 {
 	u64 *tcep, *tces;
 
@@ -373,7 +380,12 @@ static void pnv_tce_free(struct iommu_table *tbl, long index, long npages)
 		*(tcep++) = 0;
 
 	if (tbl->it_type & TCE_PCI_SWINV_FREE)
-		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1);
+		pnv_pci_ioda_tce_invalidate(tbl, tces, tcep - 1, rm);
+}
+
+static void pnv_tce_free_vm(struct iommu_table *tbl, long index, long npages)
+{
+	pnv_tce_free(tbl, index, npages, false);
 }
 
 static unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
@@ -381,6 +393,18 @@ static unsigned long pnv_tce_get(struct iommu_table *tbl, long index)
 	return ((u64 *)tbl->it_base)[index - tbl->it_offset];
 }
 
+static int pnv_tce_build_rm(struct iommu_table *tbl, long index, long npages,
+			    unsigned long uaddr, enum dma_data_direction direction,
+			    struct dma_attrs *attrs)
+{
+	return pnv_tce_build(tbl, index, npages, uaddr, direction, attrs, true);
+}
+
+static void pnv_tce_free_rm(struct iommu_table *tbl, long index, long npages)
+{
+	pnv_tce_free(tbl, index, npages, true);
+}
+
 void pnv_pci_setup_iommu_table(struct iommu_table *tbl,
 			       void *tce_mem, u64 tce_size,
 			       u64 dma_offset)
@@ -545,8 +569,10 @@ void __init pnv_pci_init(void)
 
 	/* Configure IOMMU DMA hooks */
 	ppc_md.pci_dma_dev_setup = pnv_pci_dma_dev_setup;
-	ppc_md.tce_build = pnv_tce_build;
-	ppc_md.tce_free = pnv_tce_free;
+	ppc_md.tce_build = pnv_tce_build_vm;
+	ppc_md.tce_free = pnv_tce_free_vm;
+	ppc_md.tce_build_rm = pnv_tce_build_rm;
+	ppc_md.tce_free_rm = pnv_tce_free_rm;
 	ppc_md.tce_get = pnv_tce_get;
 	ppc_md.pci_probe_mode = pnv_pci_probe_mode;
 	set_pci_dma_ops(&dma_iommu_ops);
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 25d76c4..6799374 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -158,6 +158,6 @@ extern void pnv_pci_init_p5ioc2_hub(struct device_node *np);
 extern void pnv_pci_init_ioda_hub(struct device_node *np);
 extern void pnv_pci_init_ioda2_phb(struct device_node *np);
 extern void pnv_pci_ioda_tce_invalidate(struct iommu_table *tbl,
-					u64 *startp, u64 *endp);
+					u64 *startp, u64 *endp, bool rm);
 
 #endif /* __POWERNV_PCI_H */
-- 
1.8.3.2



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