dma-debug: move initialization to common code

Most mainstream architectures are using 65536 entries, so lets stick to
that.  If someone is really desperate to override it that can still be
done through <asm/dma-mapping.h>, but I'd rather see a really good
rationale for that.

dma_debug_init is now called as a core_initcall, which for many
architectures means much earlier, and provides dma-debug functionality
earlier in the boot process.  This should be safe as it only relies
on the memory allocator already being available.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

arch/arm/mm/dma-mapping-nommu.c

@@ -241,12 +241,3 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 void arch_teardown_dma_ops(struct device *dev)
 {
 }
-
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096
-
-static int __init dma_debug_do_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-core_initcall(dma_debug_do_init);

arch/arm/mm/dma-mapping.c

@@ -1165,15 +1165,6 @@ int arm_dma_supported(struct device *dev, u64 mask)
 	return __dma_supported(dev, mask, false);
 }
 
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096
-
-static int __init dma_debug_do_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-core_initcall(dma_debug_do_init);
-
 #ifdef CONFIG_ARM_DMA_USE_IOMMU
 
 static int __dma_info_to_prot(enum dma_data_direction dir, unsigned long attrs)

arch/arm64/mm/dma-mapping.c

@@ -508,16 +508,6 @@ static int __init arm64_dma_init(void)
 }
 arch_initcall(arm64_dma_init);
 
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096
-
-static int __init dma_debug_do_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-fs_initcall(dma_debug_do_init);
-
-
 #ifdef CONFIG_IOMMU_DMA
 #include <linux/dma-iommu.h>
 #include <linux/platform_device.h>

arch/c6x/kernel/dma.c

@@ -136,14 +136,3 @@ const struct dma_map_ops c6x_dma_ops = {
 	.sync_sg_for_cpu	= c6x_dma_sync_sg_for_cpu,
 };
 EXPORT_SYMBOL(c6x_dma_ops);
-
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-	return 0;
-}
-fs_initcall(dma_init);

arch/ia64/kernel/dma-mapping.c

@@ -9,16 +9,6 @@ int iommu_detected __read_mostly;
 const struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-	return 0;
-}
-fs_initcall(dma_init);
-
 const struct dma_map_ops *dma_get_ops(struct device *dev)
 {
 	return dma_ops;

arch/microblaze/kernel/dma.c

@@ -184,14 +184,3 @@ const struct dma_map_ops dma_nommu_ops = {
 	.sync_sg_for_device	= dma_nommu_sync_sg_for_device,
 };
 EXPORT_SYMBOL(dma_nommu_ops);
-
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-	return 0;
-}
-fs_initcall(dma_init);

arch/mips/mm/dma-default.c

@@ -402,13 +402,3 @@ static const struct dma_map_ops mips_default_dma_map_ops = {
 
 const struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 EXPORT_SYMBOL(mips_dma_map_ops);
-
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init mips_dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-	return 0;
-}
-fs_initcall(mips_dma_init);

arch/openrisc/kernel/dma.c

@@ -247,14 +247,3 @@ const struct dma_map_ops or1k_dma_map_ops = {
 	.sync_single_for_device = or1k_sync_single_for_device,
 };
 EXPORT_SYMBOL(or1k_dma_map_ops);
-
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-
-	return 0;
-}
-fs_initcall(dma_init);

arch/powerpc/kernel/dma.c

@@ -309,8 +309,6 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
 }
 EXPORT_SYMBOL(dma_set_coherent_mask);
 
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
 int dma_set_mask(struct device *dev, u64 dma_mask)
 {
 	if (ppc_md.dma_set_mask)
@@ -361,7 +359,6 @@ EXPORT_SYMBOL_GPL(dma_get_required_mask);
 
 static int __init dma_init(void)
 {
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 #ifdef CONFIG_PCI
 	dma_debug_add_bus(&pci_bus_type);
 #endif

arch/s390/pci/pci_dma.c

@@ -668,15 +668,6 @@ void zpci_dma_exit(void)
 	kmem_cache_destroy(dma_region_table_cache);
 }
 
-#define PREALLOC_DMA_DEBUG_ENTRIES	(1 << 16)
-
-static int __init dma_debug_do_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-fs_initcall(dma_debug_do_init);
-
 const struct dma_map_ops s390_pci_dma_ops = {
 	.alloc		= s390_dma_alloc,
 	.free		= s390_dma_free,

arch/sh/mm/consistent.c

@@ -20,18 +20,9 @@
 #include <asm/cacheflush.h>
 #include <asm/addrspace.h>
 
-#define PREALLOC_DMA_DEBUG_ENTRIES	4096
-
 const struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-fs_initcall(dma_init);
-
 void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 				 dma_addr_t *dma_handle, gfp_t gfp,
 				 unsigned long attrs)

arch/sparc/kernel/Makefile

@@ -74,8 +74,6 @@ obj-$(CONFIG_SPARC64)	+= pcr.o
 obj-$(CONFIG_SPARC64)	+= nmi.o
 obj-$(CONFIG_SPARC64_SMP) += cpumap.o
 
-obj-y                     += dma.o
-
 obj-$(CONFIG_PCIC_PCI)    += pcic.o
 obj-$(CONFIG_LEON_PCI)    += leon_pci.o
 obj-$(CONFIG_SPARC_GRPCI2)+= leon_pci_grpci2.o

arch/sparc/kernel/dma.c

@@ -1,13 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <linux/kernel.h>
-#include <linux/dma-mapping.h>
-#include <linux/dma-debug.h>
-
-#define PREALLOC_DMA_DEBUG_ENTRIES       (1 << 15)
-
-static int __init dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-fs_initcall(dma_init);

arch/x86/kernel/pci-dma.c

@@ -55,9 +55,6 @@ struct device x86_dma_fallback_dev = {
 };
 EXPORT_SYMBOL(x86_dma_fallback_dev);
 
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES       65536
-
 void __init pci_iommu_alloc(void)
 {
 	struct iommu_table_entry *p;
@@ -189,7 +186,6 @@ EXPORT_SYMBOL(arch_dma_supported);
 static int __init pci_iommu_init(void)
 {
 	struct iommu_table_entry *p;
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 
 #ifdef CONFIG_PCI
 	dma_debug_add_bus(&pci_bus_type);

arch/xtensa/kernel/pci-dma.c

@@ -261,12 +261,3 @@ const struct dma_map_ops xtensa_dma_map_ops = {
 	.mapping_error = xtensa_dma_mapping_error,
 };
 EXPORT_SYMBOL(xtensa_dma_map_ops);
-
-#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-
-static int __init xtensa_dma_init(void)
-{
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
-	return 0;
-}
-fs_initcall(xtensa_dma_init);

include/linux/dma-debug.h

@@ -30,8 +30,6 @@ struct bus_type;
 
 extern void dma_debug_add_bus(struct bus_type *bus);
 
-extern void dma_debug_init(u32 num_entries);
-
 extern int dma_debug_resize_entries(u32 num_entries);
 
 extern void debug_dma_map_page(struct device *dev, struct page *page,
@@ -100,10 +98,6 @@ static inline void dma_debug_add_bus(struct bus_type *bus)
 {
 }
 
-static inline void dma_debug_init(u32 num_entries)
-{
-}
-
 static inline int dma_debug_resize_entries(u32 num_entries)
 {
 	return 0;

lib/dma-debug.c

@@ -41,6 +41,11 @@
 #define HASH_FN_SHIFT   13
 #define HASH_FN_MASK    (HASH_SIZE - 1)
 
+/* allow architectures to override this if absolutely required */
+#ifndef PREALLOC_DMA_DEBUG_ENTRIES
+#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+#endif
+
 enum {
 	dma_debug_single,
 	dma_debug_page,
@@ -1004,18 +1009,16 @@ void dma_debug_add_bus(struct bus_type *bus)
 	bus_register_notifier(bus, nb);
 }
 
-/*
- * Let the architectures decide how many entries should be preallocated.
- */
-void dma_debug_init(u32 num_entries)
+static int dma_debug_init(void)
 {
+	u32 num_entries;
 	int i;
 
 	/* Do not use dma_debug_initialized here, since we really want to be
 	 * called to set dma_debug_initialized
 	 */
 	if (global_disable)
-		return;
+		return 0;
 
 	for (i = 0; i < HASH_SIZE; ++i) {
 		INIT_LIST_HEAD(&dma_entry_hash[i].list);
@@ -1026,17 +1029,19 @@ void dma_debug_init(u32 num_entries)
 		pr_err("DMA-API: error creating debugfs entries - disabling\n");
 		global_disable = true;
 
-		return;
+		return 0;
 	}
 
 	if (req_entries)
 		num_entries = req_entries;
+	else
+		num_entries = PREALLOC_DMA_DEBUG_ENTRIES;
 
 	if (prealloc_memory(num_entries) != 0) {
 		pr_err("DMA-API: debugging out of memory error - disabled\n");
 		global_disable = true;
 
-		return;
+		return 0;
 	}
 
 	nr_total_entries = num_free_entries;
@@ -1044,7 +1049,9 @@ void dma_debug_init(u32 num_entries)
 	dma_debug_initialized = true;
 
 	pr_info("DMA-API: debugging enabled by kernel config\n");
+	return 0;
 }
+core_initcall(dma_debug_init);
 
 static __init int dma_debug_cmdline(char *str)
 {