swiotlb: Remove the swiotlb variable usage
POWERPC doesn't expect it to be used.
This fixes the linux-next build failure reported by
Stephen Rothwell:
lib/swiotlb.c: In function 'setup_io_tlb_npages':
lib/swiotlb.c:114: error: 'swiotlb' undeclared (first use in this function)
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: peterz@infradead.org
LKML-Reference: <20091112000258F.fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index b9e4e20..940f13a 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -9,11 +9,12 @@
#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 f79870e..0b11bf1 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -125,16 +125,13 @@
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 17ce422..a6e5d0f 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -42,16 +42,27 @@
.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 e6755a0..795472d 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -109,10 +109,9 @@
}
if (*str == ',')
++str;
- if (!strcmp(str, "force")) {
+ if (!strcmp(str, "force"))
swiotlb_force = 1;
- swiotlb = 1;
- }
+
return 1;
}
__setup("swiotlb=", setup_io_tlb_npages);