Re: [PATCH v9 01/14] swiotlb: Refactor swiotlb init functions

[Claire Chang]

On Mon, Jun 14, 2021 at 2:16 PM Christoph Hellwig  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 

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

Re: [PATCH v9 01/14] swiotlb: Refactor swiotlb init functions

[Christoph Hellwig]

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 

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

[Claire Chang]

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 
---
 kernel/dma/swiotlb.c | 53 ++--
 1 file changed, 27 insertions(+), 26 deletions(-)

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();
-- 
2.32.0.272.g935e593368-goog