powerpc/pseries: Allow not having ibm, hypertas-functions::hcall-multi-tce for DDW

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>

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 3e8865b..17b322e 100644 (file)
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -202,10 +202,10 @@ 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,
                                struct dma_attrs *attrs)
@@ -216,25 +216,25 @@ 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();
@@ -263,7 +263,8 @@ 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);
        }
 
@@ -279,8 +280,9 @@ 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);
        }
@@ -331,16 +333,16 @@ 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();
                }
@@ -355,7 +357,7 @@ 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);
 
@@ -470,6 +472,19 @@ 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 >> 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);