[PATCH 25/25] swiotlb: Use page alignment for early buffer allocation

From: Yinghai Lu
Date: Tue Jun 22 2010 - 13:30:53 EST


for 2.6.34

We could call free_bootmem_late() if swiotlb is not used, and
it will shrink to page alignement.

So alloc them with page alignment at first, to avoid lose two pages

before patch:
[ 0.000000] lmb_reserve_range: [00d3600000, 00d7600000] swiotlb buffer
[ 0.000000] lmb_reserve_range: [00d7e7ef40, 00d7e9ef40] swiotlb list
[ 0.000000] lmb_reserve_range: [00d7e3ef40, 00d7e7ef40] swiotlb orig_ad
[ 0.000000] lmb_reserve_range: [000008a000, 0000092000] swiotlb overflo

after patch will get
[ 0.000000] lmb_reserve_range: [00d3600000, 00d7600000] swiotlb buffer
[ 0.000000] lmb_reserve_range: [00d7e7e000, 00d7e9e000] swiotlb list
[ 0.000000] lmb_reserve_range: [00d7e3e000, 00d7e7e000] swiotlb orig_ad
[ 0.000000] lmb_reserve_range: [000008a000, 0000092000] swiotlb overflo

Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
Cc: Becky Bruce <beckyb@xxxxxxxxxxxxxxxxxxx>
---
lib/swiotlb.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index a009055..ecfab7f 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -159,7 +159,7 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
/*
* Get IO TLB memory from the low pages
*/
- io_tlb_start = alloc_bootmem_low_pages(bytes);
+ io_tlb_start = alloc_bootmem_low_pages(PAGE_ALIGN(bytes));
if (!io_tlb_start)
panic("Cannot allocate SWIOTLB buffer");
io_tlb_end = io_tlb_start + bytes;
@@ -169,16 +169,16 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
* to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
* between io_tlb_start and io_tlb_end.
*/
- io_tlb_list = alloc_bootmem(io_tlb_nslabs * sizeof(int));
+ io_tlb_list = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
for (i = 0; i < io_tlb_nslabs; i++)
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_index = 0;
- io_tlb_orig_addr = alloc_bootmem(io_tlb_nslabs * sizeof(phys_addr_t));
+ io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));

/*
* Get the overflow emergency buffer
*/
- io_tlb_overflow_buffer = alloc_bootmem_low(io_tlb_overflow);
+ io_tlb_overflow_buffer = alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
if (!io_tlb_overflow_buffer)
panic("Cannot allocate SWIOTLB overflow buffer!\n");
if (verbose)
@@ -304,13 +304,13 @@ void __init swiotlb_free(void)
get_order(io_tlb_nslabs << IO_TLB_SHIFT));
} else {
free_bootmem_late(__pa(io_tlb_overflow_buffer),
- io_tlb_overflow);
+ PAGE_ALIGN(io_tlb_overflow));
free_bootmem_late(__pa(io_tlb_orig_addr),
- io_tlb_nslabs * sizeof(phys_addr_t));
+ PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
free_bootmem_late(__pa(io_tlb_list),
- io_tlb_nslabs * sizeof(int));
+ PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
free_bootmem_late(__pa(io_tlb_start),
- io_tlb_nslabs << IO_TLB_SHIFT);
+ PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
}
}

--
1.6.4.2

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