swiotlb: Defer swiotlb init printing, export swiotlb_print_info()

This enables us to avoid printing swiotlb memory info when we
initialize swiotlb. After swiotlb initialization, we could find
that we don't need swiotlb.

This patch removes the code to print swiotlb memory info in
swiotlb_init() and exports the function to do that.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: chrisw@sous-sol.org
Cc: dwmw2@infradead.org
Cc: joerg.roedel@amd.com
Cc: muli@il.ibm.com
Cc: tony.luck@intel.com
Cc: benh@kernel.crashing.org
LKML-Reference: <1257849980-22640-9-git-send-email-fujita.tomonori@lab.ntt.co.jp>
[ -v2: merge up conflict ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

arch/ia64/kernel/pci-swiotlb.c

@@ -41,7 +41,7 @@ struct dma_map_ops swiotlb_dma_ops = {
 void __init swiotlb_dma_init(void)
 {
 	dma_ops = &swiotlb_dma_ops;
-	swiotlb_init();
+	swiotlb_init(1);
 }
 
 void __init pci_swiotlb_init(void)
@@ -51,7 +51,7 @@ void __init pci_swiotlb_init(void)
 		swiotlb = 1;
 		printk(KERN_INFO "PCI-DMA: Re-initialize machine vector.\n");
 		machvec_init("dig");
-		swiotlb_init();
+		swiotlb_init(1);
 		dma_ops = &swiotlb_dma_ops;
 #else
 		panic("Unable to find Intel IOMMU");

arch/powerpc/kernel/setup_32.c

@@ -345,7 +345,7 @@ void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_SWIOTLB
 	if (ppc_swiotlb_enable)
-		swiotlb_init();
+		swiotlb_init(1);
 #endif
 
 	paging_init();

arch/powerpc/kernel/setup_64.c

@@ -550,7 +550,7 @@ void __init setup_arch(char **cmdline_p)
 
 #ifdef CONFIG_SWIOTLB
 	if (ppc_swiotlb_enable)
-		swiotlb_init();
+		swiotlb_init(1);
 #endif
 
 	paging_init();

arch/x86/kernel/pci-swiotlb.c

@@ -52,8 +52,7 @@ void __init pci_swiotlb_init(void)
 	if (swiotlb_force)
 		swiotlb = 1;
 	if (swiotlb) {
-		printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
-		swiotlb_init();
+		swiotlb_init(0);
 		dma_ops = &swiotlb_dma_ops;
 	}
 }

include/linux/swiotlb.h

@@ -20,8 +20,7 @@ struct scatterlist;
  */
 #define IO_TLB_SHIFT 11
 
-extern void
-swiotlb_init(void);
+extern void swiotlb_init(int verbose);
 
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
@@ -94,4 +93,5 @@ extern void __init swiotlb_free(void);
 static inline void swiotlb_free(void) { }
 #endif
 
+extern void swiotlb_print_info(void);
 #endif /* __LINUX_SWIOTLB_H */

lib/swiotlb.c

@@ -123,8 +123,9 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
 	return phys_to_dma(hwdev, virt_to_phys(address));
 }
 
-static void swiotlb_print_info(unsigned long bytes)
+void swiotlb_print_info(void)
 {
+	unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
 	phys_addr_t pstart, pend;
 
 	pstart = virt_to_phys(io_tlb_start);
@@ -142,7 +143,7 @@ static void swiotlb_print_info(unsigned long bytes)
  * structures for the software IO TLB used to implement the DMA API.
  */
 void __init
-swiotlb_init_with_default_size(size_t default_size)
+swiotlb_init_with_default_size(size_t default_size, int verbose)
 {
 	unsigned long i, bytes;
 
@@ -178,14 +179,14 @@ swiotlb_init_with_default_size(size_t default_size)
 	io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
 	if (!io_tlb_overflow_buffer)
 		panic("Cannot allocate SWIOTLB overflow buffer!\n");
-
-	swiotlb_print_info(bytes);
+	if (verbose)
+		swiotlb_print_info();
 }
 
 void __init
-swiotlb_init(void)
+swiotlb_init(int verbose)
 {
-	swiotlb_init_with_default_size(64 * (1<<20));	/* default to 64MB */
+	swiotlb_init_with_default_size(64 * (1<<20), verbose);	/* default to 64MB */
 }
 
 /*
@@ -262,7 +263,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
 	if (!io_tlb_overflow_buffer)
 		goto cleanup4;
 
-	swiotlb_print_info(bytes);
+	swiotlb_print_info();
 
 	late_alloc = 1;