[PATCH v4 04/14] swiotlb: Refactor swiotlb_late_init_with_tbl

[Claire Chang]

Refactor swiotlb_late_init_with_tbl to make the code reusable for
restricted DMA pool initialization.

Signed-off-by: Claire Chang <tientzu at chromium.org>
---
 kernel/dma/swiotlb.c | 65 ++++++++++++++++++++++++++++----------------
 1 file changed, 42 insertions(+), 23 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 28b7bfe7a2a8..dc37951c6924 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -353,20 +353,21 @@ static void swiotlb_cleanup(void)
 	max_segment = 0;
 }
 
-int
-swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
+static int swiotlb_init_tlb_pool(struct swiotlb *swiotlb, phys_addr_t start,
+				size_t size)
 {
-	struct swiotlb *swiotlb = &default_swiotlb;
-	unsigned long i, bytes;
+	unsigned long i;
+	void *vaddr = phys_to_virt(start);
 
-	bytes = nslabs << IO_TLB_SHIFT;
+	size = ALIGN(size, 1 << IO_TLB_SHIFT);
+	swiotlb->nslabs = size >> IO_TLB_SHIFT;
+	swiotlb->nslabs = ALIGN(swiotlb->nslabs, IO_TLB_SEGSIZE);
 
-	swiotlb->nslabs = nslabs;
-	swiotlb->start = virt_to_phys(tlb);
-	swiotlb->end = swiotlb->start + bytes;
+	swiotlb->start = start;
+	swiotlb->end = swiotlb->start + size;
 
-	set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
-	memset(tlb, 0, bytes);
+	set_memory_decrypted((unsigned long)vaddr, size >> PAGE_SHIFT);
+	memset(vaddr, 0, size);
 
 	/*
 	 * Allocate and initialize the free list array.  This array is used
@@ -390,13 +391,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 		swiotlb->orig_addr[i] = INVALID_PHYS_ADDR;
 	}
 	swiotlb->index = 0;
-	no_iotlb_memory = false;
-
-	swiotlb_print_info();
 
-	late_alloc = 1;
-
-	swiotlb_set_max_segment(swiotlb->nslabs << IO_TLB_SHIFT);
 	spin_lock_init(&swiotlb->lock);
 
 	return 0;
@@ -410,6 +405,27 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 	return -ENOMEM;
 }
 
+int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
+{
+	struct swiotlb *swiotlb = &default_swiotlb;
+	unsigned long bytes = nslabs << IO_TLB_SHIFT;
+	int ret;
+
+	ret = swiotlb_init_tlb_pool(swiotlb, virt_to_phys(tlb), bytes);
+	if (ret)
+		return ret;
+
+	no_iotlb_memory = false;
+
+	swiotlb_print_info();
+
+	late_alloc = 1;
+
+	swiotlb_set_max_segment(bytes);
+
+	return 0;
+}
+
 void __init swiotlb_exit(void)
 {
 	struct swiotlb *swiotlb = &default_swiotlb;
@@ -747,17 +763,20 @@ phys_addr_t get_swiotlb_start(void)
 }
 
 #ifdef CONFIG_DEBUG_FS
-
-static int __init swiotlb_create_debugfs(void)
+static void swiotlb_create_debugfs(struct swiotlb *swiotlb, const char *name,
+				   struct dentry *node)
 {
-	struct swiotlb *swiotlb = &default_swiotlb;
-
-	swiotlb->debugfs = debugfs_create_dir("swiotlb", NULL);
+	swiotlb->debugfs = debugfs_create_dir(name, node);
 	debugfs_create_ulong("io_tlb_nslabs", 0400, swiotlb->debugfs, &swiotlb->nslabs);
 	debugfs_create_ulong("io_tlb_used", 0400, swiotlb->debugfs, &swiotlb->used);
-	return 0;
 }
 
-late_initcall(swiotlb_create_debugfs);
+static int __init swiotlb_create_default_debugfs(void)
+{
+	swiotlb_create_debugfs(&default_swiotlb, "swiotlb", NULL);
+
+	return 0;
+}
 
+late_initcall(swiotlb_create_default_debugfs);
 #endif
-- 
2.30.0.478.g8a0d178c01-goog