This is a note to let you know that I've just added the patch titled powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent memory" to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: powerpc-pseries-ddw-revert-extend-upper-limit-for-hu.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c883a2f5e4dff39e7b600bf51530596dfd6a750a Author: Alexey Kardashevskiy <aik@xxxxxxxxx> Date: Mon Nov 8 15:03:17 2021 +1100 powerpc/pseries/ddw: Revert "Extend upper limit for huge DMA window for persistent memory" [ Upstream commit 2d33f5504490a9d90924476dbccd4a5349ee1ad0 ] 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@xxxxxxxxx> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211108040320.3857636-2-aik@xxxxxxxxx Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c index a52af8fbf5711..ad96d6e13d1f6 100644 --- a/arch/powerpc/platforms/pseries/iommu.c +++ b/arch/powerpc/platforms/pseries/iommu.c @@ -1092,15 +1092,6 @@ 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;