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powerpc/pseries/iommu: Replace hard-coded page shift
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Some functions assume IOMMU page size can only be 4K (pageshift == 12).
Update them to accept any page size passed, so we can use 64K pages.

In the process, some defines like TCE_SHIFT were made obsolete, and then
removed.

IODA3 Revision 3.0_prd1 (OpenPowerFoundation), Figures 3.4 and 3.5 show
a RPN of 52-bit, and considers a 12-bit pageshift, so there should be
no need of using TCE_RPN_MASK, which masks out any bit after 40 in rpn.
It's usage removed from tce_build_pSeries(), tce_build_pSeriesLP(), and
tce_buildmulti_pSeriesLP().

Most places had a tbl struct, so using tbl->it_page_shift was simple.
tce_free_pSeriesLP() was a special case, since callers not always have a
tbl struct, so adding a tceshift parameter seems the right thing to do.

Signed-off-by: Leonardo Bras <leobras.c@gmail.com>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210817063929.38701-2-leobras.c@gmail.com
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Leonardo Bras authored and Michael Ellerman committed Aug 26, 2021
1 parent 9a245d0 commit 0c634ba
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Showing 2 changed files with 23 additions and 24 deletions.
8 changes: 0 additions & 8 deletions arch/powerpc/include/asm/tce.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -19,15 +19,7 @@
#define TCE_VB 0
#define TCE_PCI 1

/* TCE page size is 4096 bytes (1 << 12) */

#define TCE_SHIFT 12
#define TCE_PAGE_SIZE (1 << TCE_SHIFT)

#define TCE_ENTRY_SIZE 8 /* each TCE is 64 bits */

#define TCE_RPN_MASK 0xfffffffffful /* 40-bit RPN (4K pages) */
#define TCE_RPN_SHIFT 12
#define TCE_VALID 0x800 /* TCE valid */
#define TCE_ALLIO 0x400 /* TCE valid for all lpars */
#define TCE_PCI_WRITE 0x2 /* write from PCI allowed */
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39 changes: 23 additions & 16 deletions arch/powerpc/platforms/pseries/iommu.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -107,6 +107,8 @@ static int tce_build_pSeries(struct iommu_table *tbl, long index,
u64 proto_tce;
__be64 *tcep;
u64 rpn;
const unsigned long tceshift = tbl->it_page_shift;
const unsigned long pagesize = IOMMU_PAGE_SIZE(tbl);

proto_tce = TCE_PCI_READ; // Read allowed

Expand All @@ -117,10 +119,10 @@ static int tce_build_pSeries(struct iommu_table *tbl, long index,

while (npages--) {
/* can't move this out since we might cross MEMBLOCK boundary */
rpn = __pa(uaddr) >> TCE_SHIFT;
*tcep = cpu_to_be64(proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT);
rpn = __pa(uaddr) >> tceshift;
*tcep = cpu_to_be64(proto_tce | rpn << tceshift);

uaddr += TCE_PAGE_SIZE;
uaddr += pagesize;
tcep++;
}
return 0;
Expand All @@ -146,7 +148,7 @@ static unsigned long tce_get_pseries(struct iommu_table *tbl, long index)
return be64_to_cpu(*tcep);
}

static void tce_free_pSeriesLP(unsigned long liobn, long, long);
static void tce_free_pSeriesLP(unsigned long liobn, long, long, long);
static void tce_freemulti_pSeriesLP(struct iommu_table*, long, long);

static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
Expand All @@ -166,12 +168,12 @@ static int tce_build_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
proto_tce |= TCE_PCI_WRITE;

while (npages--) {
tce = proto_tce | (rpn & TCE_RPN_MASK) << tceshift;
tce = proto_tce | rpn << tceshift;
rc = plpar_tce_put((u64)liobn, (u64)tcenum << tceshift, tce);

if (unlikely(rc == H_NOT_ENOUGH_RESOURCES)) {
ret = (int)rc;
tce_free_pSeriesLP(liobn, tcenum_start,
tce_free_pSeriesLP(liobn, tcenum_start, tceshift,
(npages_start - (npages + 1)));
break;
}
Expand Down Expand Up @@ -205,10 +207,11 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
long tcenum_start = tcenum, npages_start = npages;
int ret = 0;
unsigned long flags;
const unsigned long tceshift = tbl->it_page_shift;

if ((npages == 1) || !firmware_has_feature(FW_FEATURE_PUT_TCE_IND)) {
return tce_build_pSeriesLP(tbl->it_index, tcenum,
tbl->it_page_shift, npages, uaddr,
tceshift, npages, uaddr,
direction, attrs);
}

Expand All @@ -225,13 +228,13 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
if (!tcep) {
local_irq_restore(flags);
return tce_build_pSeriesLP(tbl->it_index, tcenum,
tbl->it_page_shift,
tceshift,
npages, uaddr, direction, attrs);
}
__this_cpu_write(tce_page, tcep);
}

rpn = __pa(uaddr) >> TCE_SHIFT;
rpn = __pa(uaddr) >> tceshift;
proto_tce = TCE_PCI_READ;
if (direction != DMA_TO_DEVICE)
proto_tce |= TCE_PCI_WRITE;
Expand All @@ -245,12 +248,12 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
limit = min_t(long, npages, 4096/TCE_ENTRY_SIZE);

for (l = 0; l < limit; l++) {
tcep[l] = cpu_to_be64(proto_tce | (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT);
tcep[l] = cpu_to_be64(proto_tce | rpn << tceshift);
rpn++;
}

rc = plpar_tce_put_indirect((u64)tbl->it_index,
(u64)tcenum << 12,
(u64)tcenum << tceshift,
(u64)__pa(tcep),
limit);

Expand All @@ -277,12 +280,13 @@ static int tce_buildmulti_pSeriesLP(struct iommu_table *tbl, long tcenum,
return ret;
}

static void tce_free_pSeriesLP(unsigned long liobn, long tcenum, long npages)
static void tce_free_pSeriesLP(unsigned long liobn, long tcenum, long tceshift,
long npages)
{
u64 rc;

while (npages--) {
rc = plpar_tce_put((u64)liobn, (u64)tcenum << 12, 0);
rc = plpar_tce_put((u64)liobn, (u64)tcenum << tceshift, 0);

if (rc && printk_ratelimit()) {
printk("tce_free_pSeriesLP: plpar_tce_put failed. rc=%lld\n", rc);
Expand All @@ -301,9 +305,11 @@ static void tce_freemulti_pSeriesLP(struct iommu_table *tbl, long tcenum, long n
u64 rc;

if (!firmware_has_feature(FW_FEATURE_STUFF_TCE))
return tce_free_pSeriesLP(tbl->it_index, tcenum, npages);
return tce_free_pSeriesLP(tbl->it_index, tcenum,
tbl->it_page_shift, npages);

rc = plpar_tce_stuff((u64)tbl->it_index, (u64)tcenum << 12, 0, npages);
rc = plpar_tce_stuff((u64)tbl->it_index,
(u64)tcenum << tbl->it_page_shift, 0, npages);

if (rc && printk_ratelimit()) {
printk("tce_freemulti_pSeriesLP: plpar_tce_stuff failed\n");
Expand All @@ -319,7 +325,8 @@ static unsigned long tce_get_pSeriesLP(struct iommu_table *tbl, long tcenum)
u64 rc;
unsigned long tce_ret;

rc = plpar_tce_get((u64)tbl->it_index, (u64)tcenum << 12, &tce_ret);
rc = plpar_tce_get((u64)tbl->it_index,
(u64)tcenum << tbl->it_page_shift, &tce_ret);

if (rc && printk_ratelimit()) {
printk("tce_get_pSeriesLP: plpar_tce_get failed. rc=%lld\n", rc);
Expand Down

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