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swiotlb: add the late swiotlb initialization function with iotlb memory

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This enables the caller to initialize swiotlb with its own iotlb
memory late in the bootup.

See git commit eb605a5754
"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>
This commit is contained in:
Konrad Rzeszutek Wilk 2012-07-27 20:55:27 -04:00
parent fc2341df9e
commit 74838b7537
2 changed files with 25 additions and 9 deletions
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1
include/linux/swiotlb.h
View file

@ -25,6 +25,7 @@ extern int swiotlb_force;
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

33
lib/swiotlb.c
View file

@ -170,7 +170,7 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
* 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 @@ swiotlb_init(int verbose)
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 @@ swiotlb_late_init_with_default_size(size_t default_size)
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 @@ swiotlb_late_init_with_default_size(size_t default_size)
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;
}