@@ -3190,6 +3190,9 @@
Note that even when enabled, there are a few cases where
the feature is not effective.
+ memory_block_size=size [PPC]
+ Use this parameter to configure the memory block size value.
+
memtest= [KNL,X86,ARM,M68K,PPC,RISCV] Enable memtest
Format: <integer>
default : 0 <disable>
@@ -885,13 +885,40 @@ void __init setup_per_cpu_areas(void)
#endif
#ifdef CONFIG_MEMORY_HOTPLUG
+static unsigned long set_mem_block_size;
unsigned long memory_block_size_bytes(void)
{
+ if (set_mem_block_size)
+ return set_mem_block_size;
+
if (ppc_md.memory_block_size)
return ppc_md.memory_block_size();
return MIN_MEMORY_BLOCK_SIZE;
}
+
+/*
+ * Restrict to a power of 2 value for memblock which is larger than
+ * section size
+ */
+static int __init parse_mem_block_size(char *ptr)
+{
+ unsigned int order;
+ unsigned long size = memparse(ptr, NULL);
+
+ order = fls64(size);
+ if (!order)
+ return 0;
+
+ order--;
+ if (order < SECTION_SIZE_BITS)
+ return 0;
+
+ set_mem_block_size = 1UL << order;
+
+ return 0;
+}
+early_param("memory_block_size", parse_mem_block_size);
#endif
#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO)
Certain devices can possess non-standard memory capacities, not constrained to multiples of 1GB. Provide a kernel parameter so that we can map the device memory completely on memory hotplug. Restrict memory_block_size value to a power of 2 value similar to LMB size. The memory block size should also be more than the section size. Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> --- .../admin-guide/kernel-parameters.txt | 3 +++ arch/powerpc/kernel/setup_64.c | 27 +++++++++++++++++++ 2 files changed, 30 insertions(+)