powerpc/pseries/iommu: Replace hard-coded page shift

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

diff --git a/arch/powerpc/include/asm/tce.h b/arch/powerpc/include/asm/tce.h
index db5fc2f2262d8de2b2a430291e0f0eb3b0886e6a..0c34d2756d92177032e3fac0d017536f6686697e 100644 (file)
--- a/arch/powerpc/include/asm/tce.h
+++ b/arch/powerpc/include/asm/tce.h
@@ -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 */

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 0c55b991f665b56c3473c91dc7924d9256bacb7f..b1b8d12bab39e67e0ff49486cc6600a252bfc939 100644 (file)
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -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
 
@@ -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;
@@ -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,
@@ -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;
                }
@@ -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);
        }
 
@@ -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;
@@ -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);
 
@@ -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);
@@ -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");
@@ -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);