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Subject[PATCH 4.9 109/116] powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW
Date
From: Alexey Kardashevskiy <aik@ozlabs.ru>

commit 7559d3d295f3365ea7ac0c0274c05e633fe4f594 upstream.

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.

Fixes: 4e8b0cf46b25 ("powerpc/pseries: Add support for dynamic dma windows")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191216041924.42318-3-aik@ozlabs.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/powerpc/platforms/pseries/iommu.c | 43 ++++++++++++++++++++++-----------
1 file changed, 29 insertions(+), 14 deletions(-)

--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -167,10 +167,10 @@ static unsigned long tce_get_pseries(str
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)
@@ -181,25 +181,25 @@ static int tce_build_pSeriesLP(struct io
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();
@@ -228,7 +228,8 @@ static int tce_buildmulti_pSeriesLP(stru
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);
}

@@ -244,8 +245,9 @@ static int tce_buildmulti_pSeriesLP(stru
/* 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);
}
@@ -296,16 +298,16 @@ static int tce_buildmulti_pSeriesLP(stru
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();
}
@@ -320,7 +322,7 @@ static void tce_freemulti_pSeriesLP(stru
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);

@@ -435,6 +437,19 @@ static int tce_setrange_multi_pSeriesLP(
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 >> tceshift;
+ 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);


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