powerpc/dma: handle iommu bypass in dma_iommu_ops

Add a new iommu_bypass flag to struct dev_archdata so that the dma_iommu
implementation can handle the direct mapping transparently instead of
switiching ops around.  Setting of this flag is controlled by new
pci_controller_ops method.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christoph Hellwig 2019-02-13 08:01:05 +01:00 committed by Michael Ellerman
parent a20f507f57
commit 8617a5c5bc
5 changed files with 87 additions and 17 deletions

View File

@ -19,6 +19,11 @@ struct iommu_table;
* drivers/macintosh/macio_asic.c
*/
struct dev_archdata {
/*
* Set to %true if the dma_iommu_ops are requested to use a direct
* window instead of dynamically mapping memory.
*/
bool iommu_bypass : 1;
/*
* 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

View File

@ -29,6 +29,14 @@ extern int dma_nommu_mmap_coherent(struct device *dev,
struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle,
size_t size, unsigned long attrs);
int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs);
dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs);
int dma_nommu_dma_supported(struct device *dev, u64 mask);
u64 dma_nommu_get_required_mask(struct device *dev);
#ifdef CONFIG_NOT_COHERENT_CACHE
/*

View File

@ -19,6 +19,8 @@ struct device_node;
struct pci_controller_ops {
void (*dma_dev_setup)(struct pci_dev *pdev);
void (*dma_bus_setup)(struct pci_bus *bus);
bool (*iommu_bypass_supported)(struct pci_dev *pdev,
u64 mask);
int (*probe_mode)(struct pci_bus *bus);

View File

@ -6,12 +6,30 @@
* busses using the iommu infrastructure
*/
#include <linux/dma-direct.h>
#include <linux/pci.h>
#include <asm/iommu.h>
/*
* Generic iommu implementation
*/
/*
* The coherent mask may be smaller than the real mask, check if we can
* really use a direct window.
*/
static inline bool dma_iommu_alloc_bypass(struct device *dev)
{
return dev->archdata.iommu_bypass &&
dma_nommu_dma_supported(dev, dev->coherent_dma_mask);
}
static inline bool dma_iommu_map_bypass(struct device *dev,
unsigned long attrs)
{
return dev->archdata.iommu_bypass;
}
/* Allocates a contiguous real buffer and creates mappings over it.
* Returns the virtual address of the buffer and sets dma_handle
* to the dma address (mapping) of the first page.
@ -20,6 +38,9 @@ static void *dma_iommu_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
unsigned long attrs)
{
if (dma_iommu_alloc_bypass(dev))
return __dma_nommu_alloc_coherent(dev, size, dma_handle, flag,
attrs);
return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
dma_handle, dev->coherent_dma_mask, flag,
dev_to_node(dev));
@ -29,7 +50,11 @@ static void dma_iommu_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
unsigned long attrs)
{
iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle);
if (dma_iommu_alloc_bypass(dev))
__dma_nommu_free_coherent(dev, size, vaddr, dma_handle, attrs);
else
iommu_free_coherent(get_iommu_table_base(dev), size, vaddr,
dma_handle);
}
/* Creates TCEs for a user provided buffer. The user buffer must be
@ -42,6 +67,9 @@ static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page,
enum dma_data_direction direction,
unsigned long attrs)
{
if (dma_iommu_map_bypass(dev, attrs))
return dma_nommu_map_page(dev, page, offset, size, direction,
attrs);
return iommu_map_page(dev, get_iommu_table_base(dev), page, offset,
size, device_to_mask(dev), direction, attrs);
}
@ -51,8 +79,9 @@ static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
size_t size, enum dma_data_direction direction,
unsigned long attrs)
{
iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size, direction,
attrs);
if (!dma_iommu_map_bypass(dev, attrs))
iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size,
direction, attrs);
}
@ -60,6 +89,8 @@ static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction,
unsigned long attrs)
{
if (dma_iommu_map_bypass(dev, attrs))
return dma_nommu_map_sg(dev, sglist, nelems, direction, attrs);
return ppc_iommu_map_sg(dev, get_iommu_table_base(dev), sglist, nelems,
device_to_mask(dev), direction, attrs);
}
@ -68,10 +99,20 @@ static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist,
int nelems, enum dma_data_direction direction,
unsigned long attrs)
{
ppc_iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems,
if (!dma_iommu_map_bypass(dev, attrs))
ppc_iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems,
direction, attrs);
}
static bool dma_iommu_bypass_supported(struct device *dev, u64 mask)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pci_controller *phb = pci_bus_to_host(pdev->bus);
return phb->controller_ops.iommu_bypass_supported &&
phb->controller_ops.iommu_bypass_supported(pdev, mask);
}
/* We support DMA to/from any memory page via the iommu */
int dma_iommu_dma_supported(struct device *dev, u64 mask)
{
@ -83,22 +124,39 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask)
return 0;
}
if (dev_is_pci(dev) && dma_iommu_bypass_supported(dev, mask)) {
dev->archdata.iommu_bypass = true;
dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n");
return 1;
}
if (tbl->it_offset > (mask >> tbl->it_page_shift)) {
dev_info(dev, "Warning: IOMMU offset too big for device mask\n");
dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n",
mask, tbl->it_offset << tbl->it_page_shift);
return 0;
} else
return 1;
}
dev_dbg(dev, "iommu: not 64-bit, using default ops\n");
dev->archdata.iommu_bypass = false;
return 1;
}
u64 dma_iommu_get_required_mask(struct device *dev)
{
struct iommu_table *tbl = get_iommu_table_base(dev);
u64 mask;
if (!tbl)
return 0;
if (dev_is_pci(dev)) {
u64 bypass_mask = dma_nommu_get_required_mask(dev);
if (dma_iommu_bypass_supported(dev, bypass_mask))
return bypass_mask;
}
mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1);
mask += mask - 1;

View File

@ -40,7 +40,7 @@ static u64 __maybe_unused get_pfn_limit(struct device *dev)
return pfn;
}
static int dma_nommu_dma_supported(struct device *dev, u64 mask)
int dma_nommu_dma_supported(struct device *dev, u64 mask)
{
#ifdef CONFIG_PPC64
u64 limit = get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
@ -178,9 +178,9 @@ int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
vma->vm_page_prot);
}
static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
unsigned long attrs)
{
struct scatterlist *sg;
int i;
@ -209,7 +209,7 @@ static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl,
__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
}
static u64 dma_nommu_get_required_mask(struct device *dev)
u64 dma_nommu_get_required_mask(struct device *dev)
{
u64 end, mask;
@ -221,12 +221,9 @@ static u64 dma_nommu_get_required_mask(struct device *dev)
return mask;
}
static inline dma_addr_t dma_nommu_map_page(struct device *dev,
struct page *page,
unsigned long offset,
size_t size,
enum dma_data_direction dir,
unsigned long attrs)
dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size,
enum dma_data_direction dir, unsigned long attrs)
{
if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
__dma_sync_page(page, offset, size, dir);