powerpc/mm: Cleanup memory block size probing

Parse the device tree in early init to find the memory block size to be
used by the kernel. Consolidate the memory block size device tree parsing
to one helper and use that on both powernv and pseries. We still want to
use machine-specific callback because on all machine types other than
powernv and pseries we continue to return MIN_MEMORY_BLOCK_SIZE.

pseries_memory_block_size used to look for the second memory
block (memory@x) to determine the memory_block_size value. This patch
changed that to look at all memory blocks and make sure we can map them all
correctly using the computed memory block size value.

Add workaround to force 256MB memory block size if device driver managed
memory such as GPU memory is present. This helps to add GPU memory
that is not aligned to 1G.

Co-developed-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230801044447.11275-1-aneesh.kumar@linux.ibm.com

1 files changed, 1 insertions, 64 deletions

diff --git a/arch/powerpc/mm/book3s64/radix_pgtable.c b/arch/powerpc/mm/book3s64/radix_pgtable.c
index e7ea492ac510..b5102491b50f 100644
--- a/arch/powerpc/mm/book3s64/radix_pgtable.c
+++ b/arch/powerpc/mm/book3s64/radix_pgtable.c
@@ -37,7 +37,6 @@
 #include <mm/mmu_decl.h>
 
 unsigned int mmu_base_pid;
-unsigned long radix_mem_block_size __ro_after_init;
 
 static __ref void *early_alloc_pgtable(unsigned long size, int nid,
 			unsigned long region_start, unsigned long region_end)
@@ -300,7 +299,7 @@ static int __meminit create_physical_mapping(unsigned long start,
 	bool prev_exec, exec = false;
 	pgprot_t prot;
 	int psize;
-	unsigned long max_mapping_size = radix_mem_block_size;
+	unsigned long max_mapping_size = memory_block_size;
 
 	if (debug_pagealloc_enabled_or_kfence())
 		max_mapping_size = PAGE_SIZE;
@@ -502,58 +501,6 @@ static int __init radix_dt_scan_page_sizes(unsigned long node,
 	return 1;
 }
 
-#ifdef CONFIG_MEMORY_HOTPLUG
-static int __init probe_memory_block_size(unsigned long node, const char *uname, int
-					  depth, void *data)
-{
-	unsigned long *mem_block_size = (unsigned long *)data;
-	const __be32 *prop;
-	int len;
-
-	if (depth != 1)
-		return 0;
-
-	if (strcmp(uname, "ibm,dynamic-reconfiguration-memory"))
-		return 0;
-
-	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
-
-	if (!prop || len < dt_root_size_cells * sizeof(__be32))
-		/*
-		 * Nothing in the device tree
-		 */
-		*mem_block_size = MIN_MEMORY_BLOCK_SIZE;
-	else
-		*mem_block_size = of_read_number(prop, dt_root_size_cells);
-	return 1;
-}
-
-static unsigned long __init radix_memory_block_size(void)
-{
-	unsigned long mem_block_size = MIN_MEMORY_BLOCK_SIZE;
-
-	/*
-	 * OPAL firmware feature is set by now. Hence we are ok
-	 * to test OPAL feature.
-	 */
-	if (firmware_has_feature(FW_FEATURE_OPAL))
-		mem_block_size = 1UL * 1024 * 1024 * 1024;
-	else
-		of_scan_flat_dt(probe_memory_block_size, &mem_block_size);
-
-	return mem_block_size;
-}
-
-#else   /* CONFIG_MEMORY_HOTPLUG */
-
-static unsigned long __init radix_memory_block_size(void)
-{
-	return 1UL * 1024 * 1024 * 1024;
-}
-
-#endif /* CONFIG_MEMORY_HOTPLUG */
-
-
 void __init radix__early_init_devtree(void)
 {
 	int rc;
@@ -577,16 +524,6 @@ void __init radix__early_init_devtree(void)
 		mmu_psize_defs[MMU_PAGE_64K].h_rpt_pgsize =
 			psize_to_rpti_pgsize(MMU_PAGE_64K);
 	}
-
-	/*
-	 * Max mapping size used when mapping pages. We don't use
-	 * ppc_md.memory_block_size() here because this get called
-	 * early and we don't have machine probe called yet. Also
-	 * the pseries implementation only check for ibm,lmb-size.
-	 * All hypervisor supporting radix do expose that device
-	 * tree node.
-	 */
-	radix_mem_block_size = radix_memory_block_size();
 	return;
 }