[PATCH v5 02/16] swiotlb: Refactor swiotlb init functions

[Claire Chang <tientzu@xxxxxxxxxxxx>]

Add a new function, swiotlb_init_io_tlb_mem, for the io_tlb_mem struct
initialization to make the code reusable.

Note that we now also call set_memory_decrypted in swiotlb_init_with_tbl.

Signed-off-by: Claire Chang <tientzu@xxxxxxxxxxxx>
---
 kernel/dma/swiotlb.c | 51 ++++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 26 deletions(-)

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 8635a57f88e9..3f1adee35097 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -166,9 +166,30 @@ void __init swiotlb_update_mem_attributes(void)
 	memset(vaddr, 0, bytes);
 }
 
-int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start,
+				    unsigned long nslabs, bool late_alloc)
 {
+	void *vaddr = phys_to_virt(start);
 	unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
+
+	mem->nslabs = nslabs;
+	mem->start = start;
+	mem->end = mem->start + bytes;
+	mem->index = 0;
+	mem->late_alloc = late_alloc;
+	spin_lock_init(&mem->lock);
+	for (i = 0; i < mem->nslabs; i++) {
+		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
+		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
+		mem->slots[i].alloc_size = 0;
+	}
+
+	set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
+	memset(vaddr, 0, bytes);
+}
+
+int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
+{
 	struct io_tlb_mem *mem;
 	size_t alloc_size;
 
@@ -184,16 +205,8 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
 	if (!mem)
 		panic("%s: Failed to allocate %zu bytes align=0x%lx\n",
 		      __func__, alloc_size, PAGE_SIZE);
-	mem->nslabs = nslabs;
-	mem->start = __pa(tlb);
-	mem->end = mem->start + bytes;
-	mem->index = 0;
-	spin_lock_init(&mem->lock);
-	for (i = 0; i < mem->nslabs; i++) {
-		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
-		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
-		mem->slots[i].alloc_size = 0;
-	}
+
+	swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false);
 
 	io_tlb_default_mem = mem;
 	if (verbose)
@@ -280,7 +293,6 @@ swiotlb_late_init_with_default_size(size_t default_size)
 int
 swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 {
-	unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
 	struct io_tlb_mem *mem;
 
 	if (swiotlb_force == SWIOTLB_NO_FORCE)
@@ -295,20 +307,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
 	if (!mem)
 		return -ENOMEM;
 
-	mem->nslabs = nslabs;
-	mem->start = virt_to_phys(tlb);
-	mem->end = mem->start + bytes;
-	mem->index = 0;
-	mem->late_alloc = 1;
-	spin_lock_init(&mem->lock);
-	for (i = 0; i < mem->nslabs; i++) {
-		mem->slots[i].list = IO_TLB_SEGSIZE - io_tlb_offset(i);
-		mem->slots[i].orig_addr = INVALID_PHYS_ADDR;
-		mem->slots[i].alloc_size = 0;
-	}
-
-	set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT);
-	memset(tlb, 0, bytes);
+	swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true);
 
 	io_tlb_default_mem = mem;
 	swiotlb_print_info();
-- 

I'm not 100% sure if set_memory_decrypted is safe to call in
swiotlb_init_with_tbl, but I didn't hit any issue booting with this.

2.31.1.368.gbe11c130af-goog