swiotlb: add the late swiotlb initialization function with iotlb memory
This enables the caller to initialize swiotlb with its own iotlb
memory late in the bootup.
See git commit eb605a5754d050a25a9f00d718fb173f24c486ef
"swiotlb: add swiotlb_tbl_map_single library function" which will
explain the full details of what it can be used for.
CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
[v1: Fold in smatch warning]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index e872526..8d08b3e 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -25,6 +25,7 @@
extern void swiotlb_init(int verbose);
extern void swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose);
extern unsigned long swiotlb_nr_tbl(void);
+extern int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs);
/*
* Enumeration for sync targets
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 45bc1f8..f114bf6 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -170,7 +170,7 @@
* Statically reserve bounce buffer space and initialize bounce buffer data
* structures for the software IO TLB used to implement the DMA API.
*/
-void __init
+static void __init
swiotlb_init_with_default_size(size_t default_size, int verbose)
{
unsigned long bytes;
@@ -206,8 +206,9 @@
int
swiotlb_late_init_with_default_size(size_t default_size)
{
- unsigned long i, bytes, req_nslabs = io_tlb_nslabs;
+ unsigned long bytes, req_nslabs = io_tlb_nslabs;
unsigned int order;
+ int rc = 0;
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
@@ -229,16 +230,32 @@
order--;
}
- if (!io_tlb_start)
- goto cleanup1;
-
+ if (!io_tlb_start) {
+ io_tlb_nslabs = req_nslabs;
+ return -ENOMEM;
+ }
if (order != get_order(bytes)) {
printk(KERN_WARNING "Warning: only able to allocate %ld MB "
"for software IO TLB\n", (PAGE_SIZE << order) >> 20);
io_tlb_nslabs = SLABS_PER_PAGE << order;
- bytes = io_tlb_nslabs << IO_TLB_SHIFT;
}
+ rc = swiotlb_late_init_with_tbl(io_tlb_start, io_tlb_nslabs);
+ if (rc)
+ free_pages((unsigned long)io_tlb_start, order);
+ return rc;
+}
+
+int
+swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
+{
+ unsigned long i, bytes;
+
+ bytes = nslabs << IO_TLB_SHIFT;
+
+ io_tlb_nslabs = nslabs;
+ io_tlb_start = tlb;
io_tlb_end = io_tlb_start + bytes;
+
memset(io_tlb_start, 0, bytes);
/*
@@ -288,10 +305,8 @@
io_tlb_list = NULL;
cleanup2:
io_tlb_end = NULL;
- free_pages((unsigned long)io_tlb_start, order);
io_tlb_start = NULL;
-cleanup1:
- io_tlb_nslabs = req_nslabs;
+ io_tlb_nslabs = 0;
return -ENOMEM;
}