This patch adds the ability to the DMA direct ops to fallback to the IOMMU
ops for coherent alloc/free if the coherent mask of the device isn't
suitable for accessing the direct DMA space and the device also happens
to have an active IOMMU table.
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
---
v2: Implement a custom dma_set_coherent_mask() to work around the fact
that dma_supported() will fail otherwise.
v3: Add missing symbol export
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 22b0940..cd46474 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -82,6 +82,9 @@ config GENERIC_HWEIGHT
bool
default y
+config ARCH_HAS_DMA_SET_COHERENT_MASK
+ bool
+
config PPC
bool
default y
@@ -152,6 +155,7 @@ config PPC
select DCACHE_WORD_ACCESS if PPC64 && CPU_LITTLE_ENDIAN
select NO_BOOTMEM
select HAVE_GENERIC_RCU_GUP
+ select ARCH_HAS_DMA_SET_COHERENT_MASK
config GENERIC_CSUM
def_bool CPU_LITTLE_ENDIAN
diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 9f1371b..9ce2199 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -10,6 +10,7 @@ struct dma_map_ops;
struct device_node;
#ifdef CONFIG_PPC64
struct pci_dn;
+struct iommu_table;
#endif
/*
@@ -23,13 +24,15 @@ struct dev_archdata {
struct dma_map_ops *dma_ops;
/*
- * When an iommu is in use, dma_data is used as a ptr to the base of the
- * iommu_table. Otherwise, it is a simple numerical offset.
+ * These two used to be a union. However, with the hybrid ops we need
+ * both so here we store both a DMA offset for direct mappings and
+ * an iommu_table for remapped DMA.
*/
- union {
- dma_addr_t dma_offset;
- void *iommu_table_base;
- } dma_data;
+ dma_addr_t dma_offset;
+
+#ifdef CONFIG_PPC64
+ struct iommu_table *iommu_table_base;
+#endif
#ifdef CONFIG_IOMMU_API
void *iommu_domain;
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 894d538..2e12366 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -21,12 +21,12 @@
#define DMA_ERROR_CODE (~(dma_addr_t)0x0)
/* Some dma direct funcs must be visible for use in other dma_ops */
-extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag,
+extern void *__dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag,
+ struct dma_attrs *attrs);
+extern void __dma_direct_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs);
-extern void dma_direct_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_handle,
- struct dma_attrs *attrs);
extern int dma_direct_mmap_coherent(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle,
@@ -106,7 +106,7 @@ static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
static inline dma_addr_t get_dma_offset(struct device *dev)
{
if (dev)
- return dev->archdata.dma_data.dma_offset;
+ return dev->archdata.dma_offset;
return PCI_DRAM_OFFSET;
}
@@ -114,7 +114,7 @@ static inline dma_addr_t get_dma_offset(struct device *dev)
static inline void set_dma_offset(struct device *dev, dma_addr_t off)
{
if (dev)
- dev->archdata.dma_data.dma_offset = off;
+ dev->archdata.dma_offset = off;
}
/* this will be removed soon */
diff --git a/arch/powerpc/include/asm/iommu.h b/arch/powerpc/include/asm/iommu.h
index e2abbe8..e67e678 100644
--- a/arch/powerpc/include/asm/iommu.h
+++ b/arch/powerpc/include/asm/iommu.h
@@ -2,17 +2,17 @@
* Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
* Rewrite, cleanup:
* Copyright (C) 2004 Olof Johansson <olof@xxxxxxxxx>, IBM Corporation
- *
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
- *
+ *
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
+ *
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
@@ -93,16 +93,21 @@ int get_iommu_order(unsigned long size, struct iommu_table *tbl)
struct scatterlist;
-static inline void set_iommu_table_base(struct device *dev, void *base)
+#ifdef CONFIG_PPC64
+
+static inline void set_iommu_table_base(struct device *dev,
+ struct iommu_table *base)
{
- dev->archdata.dma_data.iommu_table_base = base;
+ dev->archdata.iommu_table_base = base;
}
static inline void *get_iommu_table_base(struct device *dev)
{
- return dev->archdata.dma_data.iommu_table_base;
+ return dev->archdata.iommu_table_base;
}
+extern int dma_iommu_dma_supported(struct device *dev, u64 mask);
+
/* Frees table for an individual device node */
extern void iommu_free_table(struct iommu_table *tbl, const char *node_name);
@@ -146,6 +151,20 @@ static inline void set_iommu_table_base_and_group(struct device *dev,
iommu_add_device(dev);
}
+#else
+
+static inline void *get_iommu_table_base(struct device *dev)
+{
+ return NULL;
+}
+
+static inline int dma_iommu_dma_supported(struct device *dev, u64 mask)
+{
+ return 0;
+}
+
+#endif /* CONFIG_PPC64 */
+
extern int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl,
struct scatterlist *sglist, int nelems,
unsigned long mask,
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 4c68bfe..41a7d9d 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -73,7 +73,7 @@ static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
}
/* We support DMA to/from any memory page via the iommu */
-static int dma_iommu_dma_supported(struct device *dev, u64 mask)
+int dma_iommu_dma_supported(struct device *dev, u64 mask)
{
struct iommu_table *tbl = get_iommu_table_base(dev);
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index 7359797..81b81cd 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -47,8 +47,8 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
* for everything else.
*/
struct dma_map_ops swiotlb_dma_ops = {
- .alloc = dma_direct_alloc_coherent,
- .free = dma_direct_free_coherent,
+ .alloc = __dma_direct_alloc_coherent,
+ .free = __dma_direct_free_coherent,
.mmap = dma_direct_mmap_coherent,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 484b2d4..b0c4faa 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -16,6 +16,7 @@
#include <asm/bug.h>
#include <asm/machdep.h>
#include <asm/swiotlb.h>
+#include <asm/iommu.h>
/*
* Generic direct DMA implementation
@@ -39,9 +40,31 @@ static u64 __maybe_unused get_pfn_limit(struct device *dev)
return pfn;
}
-void *dma_direct_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t flag,
- struct dma_attrs *attrs)
+static int dma_direct_dma_supported(struct device *dev, u64 mask)
+{
+#ifdef CONFIG_PPC64
+ u64 limit = get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
+
+ /* Limit fits in the mask, we are good */
+ if (mask >= limit)
+ return 1;
+
+#ifdef CONFIG_FSL_SOC
+ /* Freescale gets another chance via ZONE_DMA/ZONE_DMA32, however
+ * that will have to be refined if/when they support iommus
+ */
+ return 1;
+#endif
+ /* Sorry ... */
+ return 0;
+#else
+ return 1;
+#endif
+}
+
+void *__dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag,
+ struct dma_attrs *attrs)
{
void *ret;
#ifdef CONFIG_NOT_COHERENT_CACHE
@@ -96,9 +119,9 @@ void *dma_direct_alloc_coherent(struct device *dev, size_t size,
#endif
}
-void dma_direct_free_coherent(struct device *dev, size_t size,
- void *vaddr, dma_addr_t dma_handle,
- struct dma_attrs *attrs)
+void __dma_direct_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
{
#ifdef CONFIG_NOT_COHERENT_CACHE
__dma_free_coherent(size, vaddr);
@@ -107,6 +130,51 @@ void dma_direct_free_coherent(struct device *dev, size_t size,
#endif
}
+static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag,
+ struct dma_attrs *attrs)
+{
+ struct iommu_table *iommu;
+
+ /* The coherent mask may be smaller than the real mask, check if
+ * we can really use the direct ops
+ */
+ if (dma_direct_dma_supported(dev, dev->coherent_dma_mask))
+ return __dma_direct_alloc_coherent(dev, size, dma_handle,
+ flag, attrs);
+
+ /* Ok we can't ... do we have an iommu ? If not, fail */
+ iommu = get_iommu_table_base(dev);
+ if (!iommu)
+ return NULL;
+
+ /* Try to use the iommu */
+ return iommu_alloc_coherent(dev, iommu, size, dma_handle,
+ dev->coherent_dma_mask, flag,
+ dev_to_node(dev));
+}
+
+static void dma_direct_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
+{
+ struct iommu_table *iommu;
+
+ /* See comments in dma_direct_alloc_coherent() */
+ if (dma_direct_dma_supported(dev, dev->coherent_dma_mask))
+ return __dma_direct_free_coherent(dev, size, vaddr, dma_handle,
+ attrs);
+ /* Maybe we used an iommu ... */
+ iommu = get_iommu_table_base(dev);
+
+ /* If we hit that we should have never allocated in the first
+ * place so how come we are freeing ?
+ */
+ if (WARN_ON(!iommu))
+ return;
+ iommu_free_coherent(iommu, size, vaddr, dma_handle);
+}
+
int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size,
struct dma_attrs *attrs)
@@ -147,18 +215,6 @@ static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
{
}
-static int dma_direct_dma_supported(struct device *dev, u64 mask)
-{
-#ifdef CONFIG_PPC64
- /* Could be improved so platforms can set the limit in case
- * they have limited DMA windows
- */
- return mask >= get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
-#else
- return 1;
-#endif
-}
-
static u64 dma_direct_get_required_mask(struct device *dev)
{
u64 end, mask;
@@ -230,6 +286,25 @@ struct dma_map_ops dma_direct_ops = {
};
EXPORT_SYMBOL(dma_direct_ops);
+int dma_set_coherent_mask(struct device *dev, u64 mask)
+{
+ if (!dma_supported(dev, mask)) {
+ /*
+ * We need to special case the direct DMA ops which can
+ * support a fallback for coherent allocations. There
+ * is no dma_op->set_coherent_mask() so we have to do
+ * things the hard way:
+ */
+ if (get_dma_ops(dev) != &dma_direct_ops ||
+ get_iommu_table_base(dev) == NULL ||
+ !dma_iommu_dma_supported(dev, mask))
+ return -EIO;
+ }
+ dev->coherent_dma_mask = mask;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dma_set_coherent_mask);
+
#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
int __dma_set_mask(struct device *dev, u64 dma_mask)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 5ac7c60..fcff6fa 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1625,7 +1625,6 @@ static int pnv_pci_ioda_dma_set_mask(struct pnv_phb *phb,
} else {
dev_info(&pdev->dev, "Using 32-bit DMA via iommu\n");
set_dma_ops(&pdev->dev, &dma_iommu_ops);
- set_iommu_table_base(&pdev->dev, pe->tce32_table);
}
*pdev->dev.dma_mask = dma_mask;
return 0;
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 7803a19..0acab86 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1161,11 +1161,10 @@ static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
}
}
- /* fall back on iommu ops, restore table pointer with ops */
+ /* fall back on iommu ops */
if (!ddw_enabled && get_dma_ops(dev) != &dma_iommu_ops) {
dev_info(dev, "Restoring 32-bit DMA via iommu\n");
set_dma_ops(dev, &dma_iommu_ops);
- pci_dma_dev_setup_pSeriesLP(pdev);
}
check_mask:
diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 9e5353f..6cf033d 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -306,20 +306,11 @@ static void iommu_table_dart_setup(void)
set_bit(iommu_table_dart.it_size - 1, iommu_table_dart.it_map);
}
-static void dma_dev_setup_dart(struct device *dev)
-{
- /* We only have one iommu table on the mac for now, which makes
- * things simple. Setup all PCI devices to point to this table
- */
- if (get_dma_ops(dev) == &dma_direct_ops)
- set_dma_offset(dev, DART_U4_BYPASS_BASE);
- else
- set_iommu_table_base(dev, &iommu_table_dart);
-}
-
static void pci_dma_dev_setup_dart(struct pci_dev *dev)
{
- dma_dev_setup_dart(&dev->dev);
+ if (dart_is_u4)
+ set_dma_offset(&dev->dev, DART_U4_BYPASS_BASE);
+ set_iommu_table_base(&dev->dev, &iommu_table_dart);
}
static void pci_dma_bus_setup_dart(struct pci_bus *bus)
@@ -363,7 +354,6 @@ static int dart_dma_set_mask(struct device *dev, u64 dma_mask)
dev_info(dev, "Using 32-bit DMA via iommu\n");
set_dma_ops(dev, &dma_iommu_ops);
}
- dma_dev_setup_dart(dev);
*dev->dma_mask = dma_mask;
return 0;
--
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