[POWERPC] Use 4kB iommu pages even on 64kB-page systems
The 10Gigabit ethernet device drivers appear to be able to chew
up all 256MB of TCE mappings on pSeries systems, as evidenced by
numerous error messages:
iommu_alloc failed, tbl c0000000010d5c48 vaddr c0000000d875eff0 npages 1
Some experimentation indicates that this is essentially because
one 1500 byte ethernet MTU gets mapped as a 64K DMA region when
the large 64K pages are enabled. Thus, it doesn't take much to
exhaust all of the available DMA mappings for a high-speed card.
This patch changes the iommu allocator to work with its own
unique, distinct page size. Although the patch is long, its
actually quite simple: it just #defines a distinct IOMMU_PAGE_SIZE
and then uses this in all the places that matter.
As a side effect, it also dramatically improves network performance
on platforms with H-calls on iommu translation inserts/removes (since
we no longer call it 16 times for a 1500 bytes packet when the iommu HW
is still 4k).
In the future, we might want to make the IOMMU_PAGE_SIZE a variable
in the iommu_table instance, thus allowing support for different HW
page sizes in the iommu itself.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/platforms/iseries/iommu.c b/arch/powerpc/platforms/iseries/iommu.c
index f4cbbcf..218817d 100644
--- a/arch/powerpc/platforms/iseries/iommu.c
+++ b/arch/powerpc/platforms/iseries/iommu.c
@@ -43,9 +43,6 @@
u64 rc;
u64 tce, rpn;
- index <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
while (npages--) {
rpn = virt_to_abs(uaddr) >> TCE_SHIFT;
tce = (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
@@ -75,9 +72,6 @@
{
u64 rc;
- npages <<= TCE_PAGE_FACTOR;
- index <<= TCE_PAGE_FACTOR;
-
while (npages--) {
rc = HvCallXm_setTce((u64)tbl->it_index, (u64)index, 0);
if (rc)
@@ -136,10 +130,9 @@
panic("PCI_DMA: parms->size is zero, parms is 0x%p", parms);
/* itc_size is in pages worth of table, it_size is in # of entries */
- tbl->it_size = ((parms->itc_size * TCE_PAGE_SIZE) /
- TCE_ENTRY_SIZE) >> TCE_PAGE_FACTOR;
+ tbl->it_size = (parms->itc_size * TCE_PAGE_SIZE) / TCE_ENTRY_SIZE;
tbl->it_busno = parms->itc_busno;
- tbl->it_offset = parms->itc_offset >> TCE_PAGE_FACTOR;
+ tbl->it_offset = parms->itc_offset;
tbl->it_index = parms->itc_index;
tbl->it_blocksize = 1;
tbl->it_type = virtbus ? TCE_VB : TCE_PCI;
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index d24ba54..556c279 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -57,9 +57,6 @@
u64 *tcep;
u64 rpn;
- index <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
proto_tce = TCE_PCI_READ; // Read allowed
if (direction != DMA_TO_DEVICE)
@@ -82,9 +79,6 @@
{
u64 *tcep;
- npages <<= TCE_PAGE_FACTOR;
- index <<= TCE_PAGE_FACTOR;
-
tcep = ((u64 *)tbl->it_base) + index;
while (npages--)
@@ -95,7 +89,6 @@
{
u64 *tcep;
- index <<= TCE_PAGE_FACTOR;
tcep = ((u64 *)tbl->it_base) + index;
return *tcep;
@@ -109,9 +102,6 @@
u64 proto_tce, tce;
u64 rpn;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
@@ -146,7 +136,7 @@
u64 rpn;
long l, limit;
- if (TCE_PAGE_FACTOR == 0 && npages == 1)
+ if (npages == 1)
return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
direction);
@@ -164,9 +154,6 @@
__get_cpu_var(tce_page) = tcep;
}
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rpn = (virt_to_abs(uaddr)) >> TCE_SHIFT;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
@@ -207,9 +194,6 @@
{
u64 rc;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
while (npages--) {
rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, 0);
@@ -229,9 +213,6 @@
{
u64 rc;
- tcenum <<= TCE_PAGE_FACTOR;
- npages <<= TCE_PAGE_FACTOR;
-
rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
if (rc && printk_ratelimit()) {
@@ -248,7 +229,6 @@
u64 rc;
unsigned long tce_ret;
- tcenum <<= TCE_PAGE_FACTOR;
rc = plpar_tce_get((u64)tbl->it_index, (u64)tcenum << 12, &tce_ret);
if (rc && printk_ratelimit()) {
@@ -289,7 +269,7 @@
tbl->it_busno = phb->bus->number;
/* Units of tce entries */
- tbl->it_offset = phb->dma_window_base_cur >> PAGE_SHIFT;
+ tbl->it_offset = phb->dma_window_base_cur >> IOMMU_PAGE_SHIFT;
/* Test if we are going over 2GB of DMA space */
if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
@@ -300,7 +280,7 @@
phb->dma_window_base_cur += phb->dma_window_size;
/* Set the tce table size - measured in entries */
- tbl->it_size = phb->dma_window_size >> PAGE_SHIFT;
+ tbl->it_size = phb->dma_window_size >> IOMMU_PAGE_SHIFT;
tbl->it_index = 0;
tbl->it_blocksize = 16;
@@ -325,8 +305,8 @@
tbl->it_base = 0;
tbl->it_blocksize = 16;
tbl->it_type = TCE_PCI;
- tbl->it_offset = offset >> PAGE_SHIFT;
- tbl->it_size = size >> PAGE_SHIFT;
+ tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
+ tbl->it_size = size >> IOMMU_PAGE_SHIFT;
}
static void iommu_bus_setup_pSeries(struct pci_bus *bus)
@@ -522,8 +502,6 @@
const void *dma_window = NULL;
struct pci_dn *pci;
- DBG("iommu_dev_setup_pSeriesLP, dev %p (%s)\n", dev, pci_name(dev));
-
/* dev setup for LPAR is a little tricky, since the device tree might
* contain the dma-window properties per-device and not neccesarily
* for the bus. So we need to search upwards in the tree until we
@@ -532,6 +510,9 @@
*/
dn = pci_device_to_OF_node(dev);
+ DBG("iommu_dev_setup_pSeriesLP, dev %p (%s) %s\n",
+ dev, pci_name(dev), dn->full_name);
+
for (pdn = dn; pdn && PCI_DN(pdn) && !PCI_DN(pdn)->iommu_table;
pdn = pdn->parent) {
dma_window = get_property(pdn, "ibm,dma-window", NULL);