[PATCH 07/31] alpha/pci_iommu: handle page-less SG entries

Christoph Hellwig
2015-08-12T07:05:26Z

Use sg_phys() instead of virt_to_phys(sg_virt(sg)) so that we don't
require a kernel virtual address, and switch a few debug printfs to
print physical instead of virtual addresses.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/alpha/kernel/pci_iommu.c | 36 +++++++++++++++---------------------
1 file changed, 15 insertions(+), 21 deletions(-)

diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c
index eddee77..5d46b49 100644
--- a/arch/alpha/kernel/pci_iommu.c
+++ b/arch/alpha/kernel/pci_iommu.c
@@ -248,20 +248,17 @@ static int pci_dac_dma_supported(struct pci_dev *dev, u64 mask)
until either pci_unmap_single or pci_dma_sync_single is performed. */

static dma_addr_t
-pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
+pci_map_single_1(struct pci_dev *pdev, unsigned long paddr, size_t size,
int dac_allowed)
{
struct pci_controller *hose = pdev ? pdev->sysdata : pci_isa_hose;
dma_addr_t max_dma = pdev ? pdev->dma_mask : ISA_DMA_MASK;
struct pci_iommu_arena *arena;
long npages, dma_ofs, i;
- unsigned long paddr;
dma_addr_t ret;
unsigned int align = 0;
struct device *dev = pdev ? &pdev->dev : NULL;

- paddr = __pa(cpu_addr);
-
#if !DEBUG_NODIRECT
/* First check to see if we can use the direct map window. */
if (paddr + size + __direct_map_base - 1 <= max_dma
@@ -269,7 +266,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
ret = paddr + __direct_map_base;

DBGA2("pci_map_single: [%p,%zx] -> direct %llx from %pf\n",
- cpu_addr, size, ret, __builtin_return_address(0));
+ paddr, size, ret, __builtin_return_address(0));

return ret;
}
@@ -280,7 +277,7 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
ret = paddr + alpha_mv.pci_dac_offset;

DBGA2("pci_map_single: [%p,%zx] -> DAC %llx from %pf\n",
- cpu_addr, size, ret, __builtin_return_address(0));
+ paddr, size, ret, __builtin_return_address(0));

return ret;
}
@@ -309,15 +306,15 @@ pci_map_single_1(struct pci_dev *pdev, void *cpu_addr, size_t size,
return 0;
}

+ offset = paddr & ~PAGE_MASK;
paddr &= PAGE_MASK;
for (i = 0; i < npages; ++i, paddr += PAGE_SIZE)
arena->ptes[i + dma_ofs] = mk_iommu_pte(paddr);

- ret = arena->dma_base + dma_ofs * PAGE_SIZE;
- ret += (unsigned long)cpu_addr & ~PAGE_MASK;
+ ret = arena->dma_base + dma_ofs * PAGE_SIZE + offset;

DBGA2("pci_map_single: [%p,%zx] np %ld -> sg %llx from %pf\n",
- cpu_addr, size, npages, ret, __builtin_return_address(0));
+ paddr, size, npages, ret, __builtin_return_address(0));

return ret;
}
@@ -357,7 +354,7 @@ static dma_addr_t alpha_pci_map_page(struct device *dev, struct page *page,
BUG_ON(dir = PCI_DMA_NONE);

dac_allowed = pdev ? pci_dac_dma_supported(pdev, pdev->dma_mask) : 0;
- return pci_map_single_1(pdev, (char *)page_address(page) + offset,
+ return pci_map_single_1(pdev, page_to_phys(page) + offset,
size, dac_allowed);
}

@@ -453,7 +450,7 @@ try_again:
}
memset(cpu_addr, 0, size);

- *dma_addrp = pci_map_single_1(pdev, cpu_addr, size, 0);
+ *dma_addrp = pci_map_single_1(pdev, __pa(cpu_addr), size, 0);
if (*dma_addrp = 0) {
free_pages((unsigned long)cpu_addr, order);
if (alpha_mv.mv_pci_tbi || (gfp & GFP_DMA))
@@ -497,9 +494,6 @@ static void alpha_pci_free_coherent(struct device *dev, size_t size,
Write dma_length of each leader with the combined lengths of
the mergable followers. */

-#define SG_ENT_VIRT_ADDRESS(SG) (sg_virt((SG)))
-#define SG_ENT_PHYS_ADDRESS(SG) __pa(SG_ENT_VIRT_ADDRESS(SG))
-
static void
sg_classify(struct device *dev, struct scatterlist *sg, struct scatterlist *end,
int virt_ok)
@@ -512,13 +506,13 @@ sg_classify(struct device *dev, struct scatterlist *sg, struct scatterlist *end,
leader = sg;
leader_flag = 0;
leader_length = leader->length;
- next_paddr = SG_ENT_PHYS_ADDRESS(leader) + leader_length;
+ next_paddr = sg_phys(leader) + leader_length;

/* we will not marge sg without device. */
max_seg_size = dev ? dma_get_max_seg_size(dev) : 0;
for (++sg; sg < end; ++sg) {
unsigned long addr, len;
- addr = SG_ENT_PHYS_ADDRESS(sg);
+ addr = sg_phys(sg);
len = sg->length;

if (leader_length + len > max_seg_size)
@@ -555,7 +549,7 @@ sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,
struct scatterlist *out, struct pci_iommu_arena *arena,
dma_addr_t max_dma, int dac_allowed)
{
- unsigned long paddr = SG_ENT_PHYS_ADDRESS(leader);
+ unsigned long paddr = sg_phys(leader);
long size = leader->dma_length;
struct scatterlist *sg;
unsigned long *ptes;
@@ -621,7 +615,7 @@ sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,
#endif

size = sg->length;
- paddr = SG_ENT_PHYS_ADDRESS(sg);
+ paddr = sg_phys(sg);

while (sg+1 < end && (int) sg[1].dma_address = -1) {
size += sg[1].length;
@@ -636,11 +630,11 @@ sg_fill(struct device *dev, struct scatterlist *leader, struct scatterlist *end,

#if DEBUG_ALLOC > 0
DBGA(" (%ld) [%p,%x] np %ld\n",
- last_sg - leader, SG_ENT_VIRT_ADDRESS(last_sg),
+ last_sg - leader, sg_phys(last_sg),
last_sg->length, npages);
while (++last_sg <= sg) {
DBGA(" (%ld) [%p,%x] cont\n",
- last_sg - leader, SG_ENT_VIRT_ADDRESS(last_sg),
+ last_sg - leader, sg_phys(last_sg),
last_sg->length);
}
#endif
@@ -668,7 +662,7 @@ static int alpha_pci_map_sg(struct device *dev, struct scatterlist *sg,
if (nents = 1) {
sg->dma_length = sg->length;
sg->dma_address
- = pci_map_single_1(pdev, SG_ENT_VIRT_ADDRESS(sg),
+ = pci_map_single_1(pdev, sg_phys(sg),
sg->length, dac_allowed);
return sg->dma_address != 0;
}
--
1.9.1