[PATCH 18/24] x86/calgary: remove the mapping_error dma_map_ops method

Christoph Hellwig
2018-11-22T14:03:14Z

Return DMA_MAPPING_ERROR instead of the magic bad_dma_addr on a dma
mapping failure and let the core dma-mapping code handle the rest.

Remove the magic EMERGENCY_PAGES that the bad_dma_addr gets redirected to.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
arch/x86/kernel/pci-calgary_64.c | 29 +++++++----------------------
1 file changed, 7 insertions(+), 22 deletions(-)

diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index bbfc8b1e9104..e76ec1b8ed1f 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -51,8 +51,6 @@
#include <asm/x86_init.h>
#include <asm/iommu_table.h>

-#define CALGARY_MAPPING_ERROR 0
-
#ifdef CONFIG_CALGARY_IOMMU_ENABLED_BY_DEFAULT
int use_calgary __read_mostly = 1;
#else
@@ -157,8 +155,6 @@ static const unsigned long phb_debug_offsets[] = {

#define PHB_DEBUG_STUFF_OFFSET 0x0020

-#define EMERGENCY_PAGES 32 /* = 128KB */
-
unsigned int specified_table_size = TCE_TABLE_SIZE_UNSPECIFIED;
static int translate_empty_slots __read_mostly = 0;
static int calgary_detected __read_mostly = 0;
@@ -255,7 +251,7 @@ static unsigned long iommu_range_alloc(struct device *dev,
if (panic_on_overflow)
panic("Calgary: fix the allocator.\n");
else
- return CALGARY_MAPPING_ERROR;
+ return DMA_MAPPING_ERROR;
}
}

@@ -274,11 +270,10 @@ static dma_addr_t iommu_alloc(struct device *dev, struct iommu_table *tbl,
dma_addr_t ret;

entry = iommu_range_alloc(dev, tbl, npages);
-
- if (unlikely(entry = CALGARY_MAPPING_ERROR)) {
+ if (unlikely(entry = DMA_MAPPING_ERROR)) {
pr_warn("failed to allocate %u pages in iommu %p\n",
npages, tbl);
- return CALGARY_MAPPING_ERROR;
+ return DMA_MAPPING_ERROR;
}

/* set the return dma address */
@@ -298,8 +293,7 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr,
unsigned long flags;

/* were we called with bad_dma_address? */
- badend = CALGARY_MAPPING_ERROR + (EMERGENCY_PAGES * PAGE_SIZE);
- if (unlikely(dma_addr < badend)) {
+ if (unlikely(dma_addr = DMA_MAPPING_ERROR)) {
WARN(1, KERN_ERR "Calgary: driver tried unmapping bad DMA "
"address 0x%Lx\n", dma_addr);
return;
@@ -383,7 +377,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
npages = iommu_num_pages(vaddr, s->length, PAGE_SIZE);

entry = iommu_range_alloc(dev, tbl, npages);
- if (entry = CALGARY_MAPPING_ERROR) {
+ if (entry = DMA_MAPPING_ERROR) {
/* makes sure unmap knows to stop */
s->dma_length = 0;
goto error;
@@ -401,7 +395,7 @@ static int calgary_map_sg(struct device *dev, struct scatterlist *sg,
error:
calgary_unmap_sg(dev, sg, nelems, dir, 0);
for_each_sg(sg, s, nelems, i) {
- sg->dma_address = CALGARY_MAPPING_ERROR;
+ sg->dma_address = DMA_MAPPING_ERROR;
sg->dma_length = 0;
}
return 0;
@@ -454,7 +448,7 @@ static void* calgary_alloc_coherent(struct device *dev, size_t size,

/* set up tces to cover the allocated range */
mapping = iommu_alloc(dev, tbl, ret, npages, DMA_BIDIRECTIONAL);
- if (mapping = CALGARY_MAPPING_ERROR)
+ if (mapping = DMA_MAPPING_ERROR)
goto free;
*dma_handle = mapping;
return ret;
@@ -479,11 +473,6 @@ static void calgary_free_coherent(struct device *dev, size_t size,
free_pages((unsigned long)vaddr, get_order(size));
}

-static int calgary_mapping_error(struct device *dev, dma_addr_t dma_addr)
-{
- return dma_addr = CALGARY_MAPPING_ERROR;
-}
-
static const struct dma_map_ops calgary_dma_ops = {
.alloc = calgary_alloc_coherent,
.free = calgary_free_coherent,
@@ -491,7 +480,6 @@ static const struct dma_map_ops calgary_dma_ops = {
.unmap_sg = calgary_unmap_sg,
.map_page = calgary_map_page,
.unmap_page = calgary_unmap_page,
- .mapping_error = calgary_mapping_error,
.dma_supported = dma_direct_supported,
};

@@ -739,9 +727,6 @@ static void __init calgary_reserve_regions(struct pci_dev *dev)
u64 start;
struct iommu_table *tbl = pci_iommu(dev->bus);

- /* reserve EMERGENCY_PAGES from bad_dma_address and up */
- iommu_range_reserve(tbl, CALGARY_MAPPING_ERROR, EMERGENCY_PAGES);
-
/* avoid the BIOS/VGA first 640KB-1MB region */
/* for CalIOC2 - avoid the entire first MB */
if (is_calgary(dev->device)) {
--
2.19.1