The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

Possible dependencies:

fc546faa5595 ("powerpc/kexec_file: Count hot-pluggable memory in FDT estimate") 7294194b47e9 ("powerpc/kexec_file: Fix division by zero in extra size estimation") 340a4a9f8773 ("powerpc: Take in account addition CPU node when building kexec FDT")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From fc546faa559538fb312c77e055243ece18ab3288 Mon Sep 17 00:00:00 2001 From: Sourabh Jain sourabhjain@linux.ibm.com Date: Tue, 31 Jan 2023 08:36:15 +0530 Subject: [PATCH] powerpc/kexec_file: Count hot-pluggable memory in FDT estimate

On Systems where online memory is lesser compared to max memory, the kexec_file_load system call may fail to load the kdump kernel with the below errors:

"Failed to update fdt with linux,drconf-usable-memory property" "Error setting up usable-memory property for kdump kernel"

This happens because the size estimation for usable memory properties for the kdump kernel's FDT is based on the online memory whereas the usable memory properties include max memory. In short, the hot-pluggable memory is not accounted for while estimating the size of the usable memory properties.

The issue is addressed by calculating usable memory property size using max hotplug address instead of the last online memory address.

Fixes: 2377c92e37fe ("powerpc/kexec_file: fix FDT size estimation for kdump kernel") Signed-off-by: Sourabh Jain sourabhjain@linux.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20230131030615.729894-1-sourabhjain@linux.ibm.com

diff --git a/arch/powerpc/kexec/file_load_64.c b/arch/powerpc/kexec/file_load_64.c index 19d084682bc2..52085751f5f4 100644 --- a/arch/powerpc/kexec/file_load_64.c +++ b/arch/powerpc/kexec/file_load_64.c @@ -990,7 +990,7 @@ unsigned int kexec_extra_fdt_size_ppc64(struct kimage *image) * number of usable memory entries and use for FDT size estimation. */ if (drmem_lmb_size()) { - usm_entries = ((memblock_end_of_DRAM() / drmem_lmb_size()) + + usm_entries = ((memory_hotplug_max() / drmem_lmb_size()) + (2 * (resource_size(&crashk_res) / drmem_lmb_size()))); extra_size = (unsigned int)(usm_entries * sizeof(u64)); } else {