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-rw-r--r--arch/x86/include/asm/swiotlb.h5
-rw-r--r--arch/x86/kernel/pci-dma.c5
-rw-r--r--arch/x86/kernel/pci-swiotlb.c13
-rw-r--r--lib/swiotlb.c5
4 files changed, 18 insertions, 10 deletions
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index b9e4e20174f..940f13a213f 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -9,11 +9,12 @@ extern int swiotlb_force;
#ifdef CONFIG_SWIOTLB
extern int swiotlb;
-extern void pci_swiotlb_init(void);
+extern int pci_swiotlb_init(void);
#else
#define swiotlb 0
-static inline void pci_swiotlb_init(void)
+static inline int pci_swiotlb_init(void)
{
+ return 0;
}
#endif
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index f79870e8926..0b11bf18f54 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -125,16 +125,13 @@ static void __init dma32_free_bootmem(void)
void __init pci_iommu_alloc(void)
{
- /* swiotlb is forced by the boot option */
- int use_swiotlb = swiotlb;
#ifdef CONFIG_X86_64
/* free the range so iommu could get some range less than 4G */
dma32_free_bootmem();
#else
dma_ops = &nommu_dma_ops;
#endif
- pci_swiotlb_init();
- if (use_swiotlb)
+ if (pci_swiotlb_init())
return;
gart_iommu_hole_init();
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 17ce4221bd0..a6e5d0ffa3a 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,16 +42,27 @@ static struct dma_map_ops swiotlb_dma_ops = {
.dma_supported = NULL,
};
-void __init pci_swiotlb_init(void)
+/*
+ * pci_swiotlb_init - initialize swiotlb if necessary
+ *
+ * This returns non-zero if we are forced to use swiotlb (by the boot
+ * option).
+ */
+int __init pci_swiotlb_init(void)
{
/* don't initialize swiotlb if iommu=off (no_iommu=1) */
#ifdef CONFIG_X86_64
if (!no_iommu && max_pfn > MAX_DMA32_PFN)
swiotlb = 1;
#endif
+ if (swiotlb_force)
+ swiotlb = 1;
+
if (swiotlb) {
swiotlb_init(0);
dma_ops = &swiotlb_dma_ops;
} else
dma_ops = &nommu_dma_ops;
+
+ return swiotlb_force;
}
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index e6755a0574f..795472d8ae2 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -109,10 +109,9 @@ setup_io_tlb_npages(char *str)
}
if (*str == ',')
++str;
- if (!strcmp(str, "force")) {
+ if (!strcmp(str, "force"))
swiotlb_force = 1;
- swiotlb = 1;
- }
+
return 1;
}
__setup("swiotlb=", setup_io_tlb_npages);