powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent...

This reverts commit 54fc3c681ded9437e4548e2501dc1136b23cfa9a
which does not allow 1:1 mapping even for the system RAM which
is usually possible.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211108040320.3857636-2-aik@ozlabs.ru

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 49b401536d297428da3e54fcfd5deac7aa63731a..64385d6f33c2eeab27ea9802677615994ba2ad52 100644 (file)
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1094,15 +1094,6 @@ static phys_addr_t ddw_memory_hotplug_max(void)
        phys_addr_t max_addr = memory_hotplug_max();
        struct device_node *memory;
 
-       /*
-        * The "ibm,pmemory" can appear anywhere in the address space.
-        * Assuming it is still backed by page structs, set the upper limit
-        * for the huge DMA window as MAX_PHYSMEM_BITS.
-        */
-       if (of_find_node_by_type(NULL, "ibm,pmemory"))
-               return (sizeof(phys_addr_t) * 8 <= MAX_PHYSMEM_BITS) ?
-                       (phys_addr_t) -1 : (1ULL << MAX_PHYSMEM_BITS);
-
        for_each_node_by_type(memory, "memory") {
                unsigned long start, size;
                int n_mem_addr_cells, n_mem_size_cells, len;