[v9,01/14] swiotlb: Refactor swiotlb init functions

Commit Message

Claire Chang June 11, 2021, 3:26 p.m. UTC

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

Signed-off-by: Claire Chang <[e-mail]>
---
 kernel/dma/swiotlb.c | 53 ++++++++++++++++++++++----------------------
 1 file changed, 27 insertions(+), 26 deletions(-)

Comments

Christoph Hellwig June 14, 2021, 6:16 a.m. UTC | #1

On Fri, Jun 11, 2021 at 11:26:46PM +0800, Claire Chang wrote:
> +	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;
> +	}
> +
> +	if (memory_decrypted)
> +		set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> +	memset(vaddr, 0, bytes);

We don't really need to do this call before the memset.  Which means we
can just move it to the callers that care instead of having a bool
argument.

Otherwise looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Claire Chang June 15, 2021, 4:06 a.m. UTC | #2

On Mon, Jun 14, 2021 at 2:16 PM Christoph Hellwig <[e-mail]> wrote:
>
> On Fri, Jun 11, 2021 at 11:26:46PM +0800, Claire Chang wrote:
> > +     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;
> > +     }
> > +
> > +     if (memory_decrypted)
> > +             set_memory_decrypted((unsigned long)vaddr, bytes >> PAGE_SHIFT);
> > +     memset(vaddr, 0, bytes);
>
> We don't really need to do this call before the memset.  Which means we
> can just move it to the callers that care instead of having a bool
> argument.
>
> Otherwise looks good:
>
> Reviewed-by: Christoph Hellwig <[e-mail]>

Thanks for the review. Will wait more days for other reviews and send
v10 to address the comments in this and other patches.

Patch

diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 8ca7d505d61c..1a1208c81e85 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -168,9 +168,32 @@  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,
+				    bool memory_decrypted)
 {
+	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;
+	}
+
+	if (memory_decrypted)
+		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;
 
@@ -186,16 +209,8 @@  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, false);
 
 	io_tlb_default_mem = mem;
 	if (verbose)
@@ -282,7 +297,6 @@  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)
@@ -297,20 +311,7 @@  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, true);
 
 	io_tlb_default_mem = mem;
 	swiotlb_print_info();