By default a pseries guest supports a H_PUT_TCE hypercall which maps
a single IOMMU page in a DMA window. Additionally the hypervisor may
support H_PUT_TCE_INDIRECT/H_STUFF_TCE which update multiple TCEs at once;
this is advertised via the device tree /rtas/ibm,hypertas-functions
property which Linux converts to FW_FEATURE_MULTITCE.
FW_FEATURE_MULTITCE is checked when dma_iommu_ops is used; however
the code managing the huge DMA window (DDW) ignores it and calls
H_PUT_TCE_INDIRECT even if it is explicitly disabled via
the "multitce=off" kernel command line parameter.
This adds FW_FEATURE_MULTITCE checking to the DDW code path.
This changes tce_build_pSeriesLP to take liobn and page size as
the huge window does not have iommu_table descriptor which usually
the place to store these numbers.
Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
---
The idea is then set FW_FEATURE_MULTITCE in init_svm() and have the guest
use H_PUT_TCE without sharing a (temporary) page for H_PUT_TCE_INDIRECT.
---
arch/powerpc/platforms/pseries/iommu.c | 44 ++++++++++++++++++--------
1 file changed, 30 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/iommu.c
b/arch/powerpc/platforms/pseries/iommu.c
index df7db33ca93b..f6e9b87c82fc 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -132,10 +132,10 @@ static unsigned long tce_get_pseries(struct iommu_table
*tbl, long index)
return be64_to_cpu(*tcep);
}
-static void tce_free_pSeriesLP(struct iommu_table*, long, long);
+static void tce_free_pSeriesLP(unsigned long liobn, long, long);
static void tce_freemulti_pSeriesLP(struct iommu_table*, long, long);
-static int tce_build_pSeriesLP(struct iommu_table *tbl, long tcenum,
+static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
long npages, unsigned long uaddr,
enum dma_data_direction direction,
unsigned long attrs)
@@ -146,25 +146,25 @@ static int tce_build_pSeriesLP(struct iommu_table *tbl,
long tcenum,
int ret = 0;
long tcenum_start = tcenum, npages_start = npages;
- rpn = __pa(uaddr) >> TCE_SHIFT;
+ rpn = __pa(uaddr) >> tceshift;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
proto_tce |= TCE_PCI_WRITE;
while (npages--) {
- tce = proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
- rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, tce);
+ tce = proto_tce | (rpn & TCE_RPN_MASK) << tceshift;
+ rc = plpar_tce_put((u64)liobn, (u64)tcenum << tceshift, tce);
if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
ret = (int)rc;
- tce_free_pSeriesLP(tbl, tcenum_start,
+ tce_free_pSeriesLP(liobn, tcenum_start,
(npages_start - (npages + 1)));
break;
}
if (rc && printk_ratelimit()) {
printk("tce_build_pSeriesLP: plpar_tce_put failed.
rc=%lld\n", rc);
- printk("\tindex = 0x%llx\n", (u64)tbl->it_index);
+ printk("\tindex = 0x%llx\n", (u64)liobn);
printk("\ttcenum = 0x%llx\n", (u64)tcenum);
printk("\ttce val = 0x%llx\n", tce );
dump_stack();
@@ -193,7 +193,8 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
unsigned long flags;
if ((npages == 1) || !firmware_has_feature(FW_FEATURE_MULTITCE)) {
- return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
+ return tce_build_pSeriesLP(tbl->it_index, tcenum,
+ tbl->it_page_shift, npages, uaddr,
direction, attrs);
}
@@ -209,8 +210,9 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
/* If allocation fails, fall back to the loop implementation */
if (!tcep) {
local_irq_restore(flags);
- return tce_build_pSeriesLP(tbl, tcenum, npages, uaddr,
- direction, attrs);
+ return tce_build_pSeriesLP(tbl->it_index, tcenum,
+ tbl->it_page_shift,
+ npages, uaddr, direction, attrs);
}
__this_cpu_write(tce_page, tcep);
}
@@ -261,16 +263,16 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table
*tbl, long tcenum,
return ret;
}
-static void tce_free_pSeriesLP(struct iommu_table *tbl, long tcenum, long
npages)
+static void tce_free_pSeriesLP(unsigned long liobn, long tcenum, long npages)
{
u64 rc;
while (npages--) {
- rc = plpar_tce_put((u64)tbl->it_index, (u64)tcenum << 12, 0);
+ rc = plpar_tce_put((u64)liobn, (u64)tcenum << 12, 0);
if (rc && printk_ratelimit()) {
printk("tce_free_pSeriesLP: plpar_tce_put failed.
rc=%lld\n", rc);
- printk("\tindex = 0x%llx\n", (u64)tbl->it_index);
+ printk("\tindex = 0x%llx\n", (u64)liobn);
printk("\ttcenum = 0x%llx\n", (u64)tcenum);
dump_stack();
}
@@ -285,7 +287,7 @@ static void tce_freemulti_pSeriesLP(struct iommu_table
*tbl, long tcenum, long n
u64 rc;
if (!firmware_has_feature(FW_FEATURE_MULTITCE))
- return tce_free_pSeriesLP(tbl, tcenum, npages);
+ return tce_free_pSeriesLP(tbl->it_index, tcenum, npages);
rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
@@ -400,6 +402,20 @@ static int tce_setrange_multi_pSeriesLP(unsigned long
start_pfn,
u64 rc = 0;
long l, limit;
+ if (!firmware_has_feature(FW_FEATURE_MULTITCE)) {
+ unsigned long tceshift = be32_to_cpu(maprange->tce_shift);
+ unsigned long dmastart = (start_pfn << PAGE_SHIFT) +
+ be64_to_cpu(maprange->dma_base);
+ unsigned long tcenum = dmastart >> tceshift;
+ unsigned long npages = num_pfn << PAGE_SHIFT >>
+ be32_to_cpu(maprange->tce_shift);
+ void *uaddr = __va(start_pfn << PAGE_SHIFT);
+
+ return tce_build_pSeriesLP(be32_to_cpu(maprange->liobn),
+ tcenum, tceshift, npages, (unsigned long) uaddr,
+ DMA_BIDIRECTIONAL, 0);
+ }
+
local_irq_disable(); /* to protect tcep and the page behind it */
tcep = __this_cpu_read(tce_page);
--
2.17.1
