lkml.org 
[lkml]   [2011]   [Jun]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] swiotlb: Export io_tlb_nslabs as swiotlb_nslabs and use it.
Date
By default the io_tlb_nslabs is set to zero, and gets set to
whatever value is passed in via swiotlb_init_with_tbl function.
The default value passed in is 64MB. However, if the user provides
the 'swiotlb=<nslabs>' the default value is ignored and
the value provided by the user is used... Except when the SWIOTLB
is used under Xen - there the default value of 64MB is used and
the Xen-SWIOTLB has no mechanism to get the 'io_tlb_nslabs' filled
out by setup_io_tlb_npages functions. This patch exports the
value that is potentially set by setup_io_tlb_npages and renames
it to swiotlb_nslabs.

CC: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
drivers/xen/swiotlb-xen.c | 7 +++-
include/linux/swiotlb.h | 5 +++
lib/swiotlb.c | 78 ++++++++++++++++++++++----------------------
3 files changed, 49 insertions(+), 41 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 54469c3..20b0a54 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -148,8 +148,11 @@ void __init xen_swiotlb_init(int verbose)
unsigned long bytes;
int rc;

- xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
- xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
+ if (!swiotlb_nslabs) {
+ xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
+ xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
+ } else
+ xen_io_tlb_nslabs = swiotlb_nslabs;

bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;

diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 8c0e349..c373c23 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -10,6 +10,11 @@ struct scatterlist;
extern int swiotlb_force;

/*
+ * The amount of slabs set by swiotlb=<pages> argument.
+ * It is multiple of 128Kb chunks.
+ */
+extern unsigned long swiotlb_nslabs;
+/*
* Maximum allowable number of contiguous slabs to map,
* must be a power of 2. What is the appropriate value ?
* The complexity of {map,unmap}_single is linearly dependent on this value.
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 93ca08b..0822fec 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -63,7 +63,7 @@ static char *io_tlb_start, *io_tlb_end;
* The number of IO TLB blocks (in groups of 64) between io_tlb_start and
* io_tlb_end. This is command line adjustable via setup_io_tlb_npages.
*/
-static unsigned long io_tlb_nslabs;
+unsigned long swiotlb_nslabs;

/*
* When the IOMMU overflows we return a fallback buffer. This sets the size.
@@ -96,9 +96,9 @@ static int __init
setup_io_tlb_npages(char *str)
{
if (isdigit(*str)) {
- io_tlb_nslabs = simple_strtoul(str, &str, 0);
+ swiotlb_nslabs = simple_strtoul(str, &str, 0);
/* avoid tail segment of size < IO_TLB_SEGSIZE */
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+ swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE);
}
if (*str == ',')
++str;
@@ -119,7 +119,7 @@ static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,

void swiotlb_print_info(void)
{
- unsigned long bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+ unsigned long bytes = swiotlb_nslabs << IO_TLB_SHIFT;
phys_addr_t pstart, pend;

pstart = virt_to_phys(io_tlb_start);
@@ -138,7 +138,7 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)

bytes = nslabs << IO_TLB_SHIFT;

- io_tlb_nslabs = nslabs;
+ swiotlb_nslabs = nslabs;
io_tlb_start = tlb;
io_tlb_end = io_tlb_start + bytes;

@@ -147,11 +147,11 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, 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_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
- for (i = 0; i < io_tlb_nslabs; i++)
+ io_tlb_list = alloc_bootmem_pages(PAGE_ALIGN(swiotlb_nslabs * sizeof(int)));
+ for (i = 0; i < swiotlb_nslabs; i++)
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_index = 0;
- io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
+ io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(swiotlb_nslabs * sizeof(phys_addr_t)));

/*
* Get the overflow emergency buffer
@@ -172,12 +172,12 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
{
unsigned long bytes;

- if (!io_tlb_nslabs) {
- io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+ if (!swiotlb_nslabs) {
+ swiotlb_nslabs = (default_size >> IO_TLB_SHIFT);
+ swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE);
}

- bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+ bytes = swiotlb_nslabs << IO_TLB_SHIFT;

/*
* Get IO TLB memory from the low pages
@@ -186,7 +186,7 @@ swiotlb_init_with_default_size(size_t default_size, int verbose)
if (!io_tlb_start)
panic("Cannot allocate SWIOTLB buffer");

- swiotlb_init_with_tbl(io_tlb_start, io_tlb_nslabs, verbose);
+ swiotlb_init_with_tbl(io_tlb_start, swiotlb_nslabs, verbose);
}

void __init
@@ -203,20 +203,20 @@ 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 i, bytes, req_nslabs = swiotlb_nslabs;
unsigned int order;

- if (!io_tlb_nslabs) {
- io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+ if (!swiotlb_nslabs) {
+ swiotlb_nslabs = (default_size >> IO_TLB_SHIFT);
+ swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE);
}

/*
* Get IO TLB memory from the low pages
*/
- order = get_order(io_tlb_nslabs << IO_TLB_SHIFT);
- io_tlb_nslabs = SLABS_PER_PAGE << order;
- bytes = io_tlb_nslabs << IO_TLB_SHIFT;
+ order = get_order(swiotlb_nslabs << IO_TLB_SHIFT);
+ swiotlb_nslabs = SLABS_PER_PAGE << order;
+ bytes = swiotlb_nslabs << IO_TLB_SHIFT;

while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
io_tlb_start = (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN,
@@ -232,8 +232,8 @@ swiotlb_late_init_with_default_size(size_t default_size)
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;
+ swiotlb_nslabs = SLABS_PER_PAGE << order;
+ bytes = swiotlb_nslabs << IO_TLB_SHIFT;
}
io_tlb_end = io_tlb_start + bytes;
memset(io_tlb_start, 0, bytes);
@@ -244,22 +244,22 @@ swiotlb_late_init_with_default_size(size_t default_size)
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
- get_order(io_tlb_nslabs * sizeof(int)));
+ get_order(swiotlb_nslabs * sizeof(int)));
if (!io_tlb_list)
goto cleanup2;

- for (i = 0; i < io_tlb_nslabs; i++)
+ for (i = 0; i < swiotlb_nslabs; i++)
io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
io_tlb_index = 0;

io_tlb_orig_addr = (phys_addr_t *)
__get_free_pages(GFP_KERNEL,
- get_order(io_tlb_nslabs *
+ get_order(swiotlb_nslabs *
sizeof(phys_addr_t)));
if (!io_tlb_orig_addr)
goto cleanup3;

- memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
+ memset(io_tlb_orig_addr, 0, swiotlb_nslabs * sizeof(phys_addr_t));

/*
* Get the overflow emergency buffer
@@ -277,10 +277,10 @@ swiotlb_late_init_with_default_size(size_t default_size)

cleanup4:
free_pages((unsigned long)io_tlb_orig_addr,
- get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
+ get_order(swiotlb_nslabs * sizeof(phys_addr_t)));
io_tlb_orig_addr = NULL;
cleanup3:
- free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
+ free_pages((unsigned long)io_tlb_list, get_order(swiotlb_nslabs *
sizeof(int)));
io_tlb_list = NULL;
cleanup2:
@@ -288,7 +288,7 @@ cleanup2:
free_pages((unsigned long)io_tlb_start, order);
io_tlb_start = NULL;
cleanup1:
- io_tlb_nslabs = req_nslabs;
+ swiotlb_nslabs = req_nslabs;
return -ENOMEM;
}

@@ -301,20 +301,20 @@ void __init swiotlb_free(void)
free_pages((unsigned long)io_tlb_overflow_buffer,
get_order(io_tlb_overflow));
free_pages((unsigned long)io_tlb_orig_addr,
- get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
- free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
+ get_order(swiotlb_nslabs * sizeof(phys_addr_t)));
+ free_pages((unsigned long)io_tlb_list, get_order(swiotlb_nslabs *
sizeof(int)));
free_pages((unsigned long)io_tlb_start,
- get_order(io_tlb_nslabs << IO_TLB_SHIFT));
+ get_order(swiotlb_nslabs << IO_TLB_SHIFT));
} else {
free_bootmem_late(__pa(io_tlb_overflow_buffer),
PAGE_ALIGN(io_tlb_overflow));
free_bootmem_late(__pa(io_tlb_orig_addr),
- PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)));
+ PAGE_ALIGN(swiotlb_nslabs * sizeof(phys_addr_t)));
free_bootmem_late(__pa(io_tlb_list),
- PAGE_ALIGN(io_tlb_nslabs * sizeof(int)));
+ PAGE_ALIGN(swiotlb_nslabs * sizeof(int)));
free_bootmem_late(__pa(io_tlb_start),
- PAGE_ALIGN(io_tlb_nslabs << IO_TLB_SHIFT));
+ PAGE_ALIGN(swiotlb_nslabs << IO_TLB_SHIFT));
}
}

@@ -409,7 +409,7 @@ void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
*/
spin_lock_irqsave(&io_tlb_lock, flags);
index = ALIGN(io_tlb_index, stride);
- if (index >= io_tlb_nslabs)
+ if (index >= swiotlb_nslabs)
index = 0;
wrap = index;

@@ -417,7 +417,7 @@ void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
while (iommu_is_span_boundary(index, nslots, offset_slots,
max_slots)) {
index += stride;
- if (index >= io_tlb_nslabs)
+ if (index >= swiotlb_nslabs)
index = 0;
if (index == wrap)
goto not_found;
@@ -441,13 +441,13 @@ void *swiotlb_tbl_map_single(struct device *hwdev, dma_addr_t tbl_dma_addr,
* Update the indices to avoid searching in the next
* round.
*/
- io_tlb_index = ((index + nslots) < io_tlb_nslabs
+ io_tlb_index = ((index + nslots) < swiotlb_nslabs
? (index + nslots) : 0);

goto found;
}
index += stride;
- if (index >= io_tlb_nslabs)
+ if (index >= swiotlb_nslabs)
index = 0;
} while (index != wrap);

--
1.7.4.1


\
 
 \ /
  Last update: 2011-06-01 18:45    [from the cache]
©2003-2011 Jasper Spaans