[PATCH v6] modify the IO_TLB_SEGSIZE and IO_TLB_DEFAULT_SIZE configurable as flexible requirement about SW-IOMMU.
From: Wang Xiaoming
Date: Mon Mar 09 2015 - 04:27:09 EST
The maximum of SW-IOMMU is limited to 2^11*128 = 256K.
And the size of IO_TLB_DEFAULT_SIZE is limited to (64UL<<20) 64M now.
While in different platform and different requirement this seems improper.
So modifing the IO_TLB_SEGSIZE to io_tlb_segsize and IO_TLB_DEFAULT_SIZE
to io_tlb_default_size which can configure by kernel cmdline.
This can meet different requirement.
Signed-off-by: Chuansheng Liu <chuansheng.liu@xxxxxxxxx>
Signed-off-by: Zhang Dongxing <dongxing.zhang@xxxxxxxxx>
Signed-off-by: Wang Xiaoming <xiaoming.wang@xxxxxxxxx>
---
patch v1 make this change at Kconfig
which needs to edit the .config manually.
https://lkml.org/lkml/2015/1/25/571
patch v2 only change IO_TLB_SEGSIZE configurable.
https://lkml.org/lkml/2015/2/5/812
patch v3 parsing io_tlb_segsize and
io_tlb_default_size independently.
https://lkml.org/lkml/2015/2/15/217
patch v4 hasn't validated the data from
command line.
https://lkml.org/lkml/2015/2/17/114
patch v5 fix the postion of 'force'.
https://lkml.org/lkml/2015/3/3/84
Documentation/kernel-parameters.txt | 5 +-
arch/mips/cavium-octeon/dma-octeon.c | 2 +-
arch/mips/netlogic/common/nlm-dma.c | 2 +-
drivers/xen/swiotlb-xen.c | 6 +--
include/linux/swiotlb.h | 8 +--
lib/swiotlb.c | 99 ++++++++++++++++++++++++++--------
6 files changed, 87 insertions(+), 35 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4df73da..8463ef4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -3438,10 +3438,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
it if 0 is given (See Documentation/cgroups/memory.txt)
swiotlb= [ARM,IA-64,PPC,MIPS,X86]
- Format: { <int> | force }
+ Format: { <int>,force,<int>,<int>}
<int> -- Number of I/O TLB slabs
force -- force using of bounce buffers even if they
wouldn't be automatically used by the kernel
+ <int> -- Maximum allowable number of contiguous slabs to map
+ <int> -- The size of SW-MMU mapped.
+ "Use ',' to seperate them."
switches= [HW,M68k]
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index 3778655..a521af6 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -312,7 +312,7 @@ void __init plat_swiotlb_setup(void)
swiotlbsize = 64 * (1<<20);
#endif
swiotlb_nslabs = swiotlbsize >> IO_TLB_SHIFT;
- swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE);
+ swiotlb_nslabs = ALIGN(swiotlb_nslabs, io_tlb_segsize);
swiotlbsize = swiotlb_nslabs << IO_TLB_SHIFT;
octeon_swiotlb = alloc_bootmem_low_pages(swiotlbsize);
diff --git a/arch/mips/netlogic/common/nlm-dma.c b/arch/mips/netlogic/common/nlm-dma.c
index f3d4ae8..eeffa8f 100644
--- a/arch/mips/netlogic/common/nlm-dma.c
+++ b/arch/mips/netlogic/common/nlm-dma.c
@@ -99,7 +99,7 @@ void __init plat_swiotlb_setup(void)
swiotlbsize = 1 << 20; /* 1 MB for now */
swiotlb_nslabs = swiotlbsize >> IO_TLB_SHIFT;
- swiotlb_nslabs = ALIGN(swiotlb_nslabs, IO_TLB_SEGSIZE);
+ swiotlb_nslabs = ALIGN(swiotlb_nslabs, io_tlb_segsize);
swiotlbsize = swiotlb_nslabs << IO_TLB_SHIFT;
nlm_swiotlb = alloc_bootmem_low_pages(swiotlbsize);
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 810ad41..3b3e9fe 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -164,11 +164,11 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
dma_addr_t dma_handle;
phys_addr_t p = virt_to_phys(buf);
- dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
+ dma_bits = get_order(io_tlb_segsize << IO_TLB_SHIFT) + PAGE_SHIFT;
i = 0;
do {
- int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
+ int slabs = min(nslabs - i, (unsigned long)io_tlb_segsize);
do {
rc = xen_create_contiguous_region(
@@ -187,7 +187,7 @@ static unsigned long xen_set_nslabs(unsigned long nr_tbl)
{
if (!nr_tbl) {
xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
- xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
+ xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, io_tlb_segsize);
} else
xen_io_tlb_nslabs = nr_tbl;
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index e7a018e..13506db 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -8,13 +8,7 @@ struct dma_attrs;
struct scatterlist;
extern int swiotlb_force;
-
-/*
- * 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.
- */
-#define IO_TLB_SEGSIZE 128
+extern int io_tlb_segsize;
/*
* log of the size of each IO TLB slab. The number of slabs is command line
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 4abda07..223a45b 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -56,6 +56,25 @@
int swiotlb_force;
/*
+ * default to 128
+ * Maximum allowable number of contiguous slabs to map,
+ * must be a power of 2. What is the appropriate value ?
+ * define io_tlb_segsize as a parameter
+ * which can be changed dynamically in config file
+ * or as a parameter during bootup for special usage.
+ * The complexity of {map,unmap}_single is linearly dependent on this value.
+ */
+#define IO_TLB_SEGSIZE 128
+int io_tlb_segsize = IO_TLB_SEGSIZE;
+
+/* default to 64MB
+ * define io_tlb_default_size as a parameter
+ * which can be changed dynamically in config file for special usage.
+ */
+#define IO_TLB_DEFAULT_SIZE (64UL<<20)
+static unsigned long io_tlb_default_size = IO_TLB_DEFAULT_SIZE;
+
+/*
* Used to do a quick range check in swiotlb_tbl_unmap_single and
* swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
* API.
@@ -96,18 +115,57 @@ static DEFINE_SPINLOCK(io_tlb_lock);
static int late_alloc;
+/*
+ * Example:
+ * BOARD_KERNEL_CMDLINE += swiotlb=32768,force,512,268435456
+ * io_tlb_nslabs=32768, swiotlb_force=1,
+ * io_tlb_segsize=512, io_tlb_default_size=268435456
+ */
static int __init
setup_io_tlb_npages(char *str)
{
- if (isdigit(*str)) {
- io_tlb_nslabs = simple_strtoul(str, &str, 0);
- /* avoid tail segment of size < IO_TLB_SEGSIZE */
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
- }
- if (*str == ',')
+ unsigned long swiotlb_param[3] ={0,0,0};
+ int num_param = 3;
+
+ while (*str) {
+ if (!strncmp(str, "force", 5)) {
+ swiotlb_force = 1;
+ str += 5;
+ if (*str != ',')
+ break;
+ ++str;
+ continue;
+ }
+ if (!num_param)
+ break;
+ if (isdigit(*str)) {
+ swiotlb_param[3 - num_param] = simple_strtoul(str, &str, 0);
+ num_param--;
+ }
+ if (*str != ',')
+ break;
++str;
- if (!strcmp(str, "force"))
- swiotlb_force = 1;
+ }
+
+ if (swiotlb_param[1]) {
+ int n = 0;
+ io_tlb_segsize = (int)swiotlb_param[1];
+ io_tlb_segsize = ALIGN(io_tlb_segsize, IO_TLB_SEGSIZE);
+ while ((io_tlb_segsize - 1) >> n)
+ n++;
+ io_tlb_segsize = (1 << n);
+ }
+
+ if (swiotlb_param[0]) {
+ io_tlb_nslabs = swiotlb_param[0];
+ /* avoid tail segment of size < io_tlb_segsize */
+ io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize);
+ }
+
+ if (swiotlb_param[2]) {
+ io_tlb_default_size = swiotlb_param[2];
+ io_tlb_default_size = ALIGN(io_tlb_default_size, IO_TLB_DEFAULT_SIZE);
+ }
return 0;
}
@@ -120,15 +178,13 @@ unsigned long swiotlb_nr_tbl(void)
}
EXPORT_SYMBOL_GPL(swiotlb_nr_tbl);
-/* default to 64MB */
-#define IO_TLB_DEFAULT_SIZE (64UL<<20)
unsigned long swiotlb_size_or_default(void)
{
unsigned long size;
size = io_tlb_nslabs << IO_TLB_SHIFT;
- return size ? size : (IO_TLB_DEFAULT_SIZE);
+ return size ? size : (io_tlb_default_size);
}
/* Note that this doesn't work with highmem page */
@@ -183,7 +239,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
/*
* Allocate and initialize the free list array. This array is used
- * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
+ * to find contiguous free memory regions of size up to io_tlb_segsize
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = memblock_virt_alloc(
@@ -193,7 +249,7 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
PAGE_ALIGN(io_tlb_nslabs * sizeof(phys_addr_t)),
PAGE_SIZE);
for (i = 0; i < io_tlb_nslabs; i++) {
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+ io_tlb_list[i] = io_tlb_segsize - OFFSET(i, io_tlb_segsize);
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
io_tlb_index = 0;
@@ -211,13 +267,12 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose)
void __init
swiotlb_init(int verbose)
{
- size_t default_size = IO_TLB_DEFAULT_SIZE;
unsigned char *vstart;
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);
+ io_tlb_nslabs = (io_tlb_default_size >> IO_TLB_SHIFT);
+ io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize);
}
bytes = io_tlb_nslabs << IO_TLB_SHIFT;
@@ -249,7 +304,7 @@ swiotlb_late_init_with_default_size(size_t default_size)
if (!io_tlb_nslabs) {
io_tlb_nslabs = (default_size >> IO_TLB_SHIFT);
- io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE);
+ io_tlb_nslabs = ALIGN(io_tlb_nslabs, io_tlb_segsize);
}
/*
@@ -308,7 +363,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
/*
* Allocate and initialize the free list array. This array is used
- * to find contiguous free memory regions of size up to IO_TLB_SEGSIZE
+ * to find contiguous free memory regions of size up to io_tlb_segsize
* between io_tlb_start and io_tlb_end.
*/
io_tlb_list = (unsigned int *)__get_free_pages(GFP_KERNEL,
@@ -324,7 +379,7 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
goto cleanup4;
for (i = 0; i < io_tlb_nslabs; i++) {
- io_tlb_list[i] = IO_TLB_SEGSIZE - OFFSET(i, IO_TLB_SEGSIZE);
+ io_tlb_list[i] = io_tlb_segsize - OFFSET(i, io_tlb_segsize);
io_tlb_orig_addr[i] = INVALID_PHYS_ADDR;
}
io_tlb_index = 0;
@@ -493,7 +548,7 @@ phys_addr_t swiotlb_tbl_map_single(struct device *hwdev,
for (i = index; i < (int) (index + nslots); i++)
io_tlb_list[i] = 0;
- for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE - 1) && io_tlb_list[i]; i--)
+ for (i = index - 1; (OFFSET(i, io_tlb_segsize) != io_tlb_segsize - 1) && io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
tlb_addr = io_tlb_start + (index << IO_TLB_SHIFT);
@@ -571,7 +626,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
*/
spin_lock_irqsave(&io_tlb_lock, flags);
{
- count = ((index + nslots) < ALIGN(index + 1, IO_TLB_SEGSIZE) ?
+ count = ((index + nslots) < ALIGN(index + 1, io_tlb_segsize) ?
io_tlb_list[index + nslots] : 0);
/*
* Step 1: return the slots to the free list, merging the
@@ -585,7 +640,7 @@ void swiotlb_tbl_unmap_single(struct device *hwdev, phys_addr_t tlb_addr,
* Step 2: merge the returned slots with the preceding slots,
* if available (non zero)
*/
- for (i = index - 1; (OFFSET(i, IO_TLB_SEGSIZE) != IO_TLB_SEGSIZE -1) && io_tlb_list[i]; i--)
+ for (i = index - 1; (OFFSET(i, io_tlb_segsize) != io_tlb_segsize -1) && io_tlb_list[i]; i--)
io_tlb_list[i] = ++count;
}
spin_unlock_irqrestore(&io_tlb_lock, flags);
--
1.7.9.5
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