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LoongArch: Consolidate max_pfn & max_low_pfn calculation

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Now there 5 places which calculate max_pfn & max_low_pfn:
1. in fdt_setup() for FDT systems;
2. in memblock_init() for ACPI systems;
3. in init_numa_memory() for NUMA systems;
4. in arch_mem_init() to recalculate for "mem=" cmdline;
5. in paging_init() to recalculate for NUMA systems.

Since memblock_init() is called both for ACPI and FDT systems, move the
calculation out of the for_each_efi_memory_desc() loop can eliminate the
first case. The last case is very questionable (may be derived from the
MIPS/Loongson code) and breaks the "mem=" cmdline, so should be removed.
And then the NUMA version of paging_init() can be also eliminated.

After consolidation there are 3 places of calculation:
1. in memblock_init() for both ACPI and FDT systems;
2. in init_numa_memory() to recalculate for NUMA systems;
3. in arch_mem_init() to recalculate for the "mem=" cmdline.

For all cases the calculation is:
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);

Cc: stable@vger.kernel.org
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Huacai Chen 2025-11-09 16:02:01 +08:00
parent 43a9e6a10b
commit ce5ad03e45
4 changed files with 7 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/loongarch/kernel/mem.c
View File

@ -13,7 +13,7 @@
void __init memblock_init(void)
{
u32 mem_type;
u64 mem_start, mem_end, mem_size;
u64 mem_start, mem_size;
efi_memory_desc_t *md;
/* Parse memory information */
@ -21,7 +21,6 @@ void __init memblock_init(void)
mem_type = md->type;
mem_start = md->phys_addr;
mem_size = md->num_pages << EFI_PAGE_SHIFT;
mem_end = mem_start + mem_size;
switch (mem_type) {
case EFI_LOADER_CODE:
@ -31,8 +30,6 @@ void __init memblock_init(void)
case EFI_PERSISTENT_MEMORY:
case EFI_CONVENTIONAL_MEMORY:
memblock_add(mem_start, mem_size);
if (max_low_pfn < (mem_end >> PAGE_SHIFT))
max_low_pfn = mem_end >> PAGE_SHIFT;
break;
case EFI_PAL_CODE:
case EFI_UNUSABLE_MEMORY:
@ -49,6 +46,8 @@ void __init memblock_init(void)
}
}
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);
memblock_set_current_limit(PFN_PHYS(max_low_pfn));
/* Reserve the first 2MB */

23
arch/loongarch/kernel/numa.c
View File

@ -272,7 +272,8 @@ int __init init_numa_memory(void)
node_mem_init(node);
node_set_online(node);
}
max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);
setup_nr_node_ids();
loongson_sysconf.nr_nodes = nr_node_ids;
@ -283,26 +284,6 @@ int __init init_numa_memory(void)
#endif
void __init paging_init(void)
{
unsigned int node;
unsigned long zones_size[MAX_NR_ZONES] = {0, };
for_each_online_node(node) {
unsigned long start_pfn, end_pfn;
get_pfn_range_for_nid(node, &start_pfn, &end_pfn);
if (end_pfn > max_low_pfn)
max_low_pfn = end_pfn;
}
#ifdef CONFIG_ZONE_DMA32
zones_size[ZONE_DMA32] = MAX_DMA32_PFN;
#endif
zones_size[ZONE_NORMAL] = max_low_pfn;
free_area_init(zones_size);
}
int pcibus_to_node(struct pci_bus *bus)
{
return dev_to_node(&bus->dev);

5
arch/loongarch/kernel/setup.c
View File

@ -294,8 +294,6 @@ static void __init fdt_setup(void)
early_init_dt_scan(fdt_pointer, __pa(fdt_pointer));
early_init_fdt_reserve_self();
max_low_pfn = PFN_PHYS(memblock_end_of_DRAM());
#endif
}
@ -390,7 +388,8 @@ static void __init check_kernel_sections_mem(void)
static void __init arch_mem_init(char **cmdline_p)
{
/* Recalculate max_low_pfn for "mem=xxx" */
max_pfn = max_low_pfn = PHYS_PFN(memblock_end_of_DRAM());
max_pfn = PFN_DOWN(memblock_end_of_DRAM());
max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);
if (usermem)
pr_info("User-defined physical RAM map overwrite\n");

2
arch/loongarch/mm/init.c
View File

@ -60,7 +60,6 @@ int __ref page_is_ram(unsigned long pfn)
return memblock_is_memory(addr) && !memblock_is_reserved(addr);
}
#ifndef CONFIG_NUMA
void __init paging_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
@ -72,7 +71,6 @@ void __init paging_init(void)
free_area_init(max_zone_pfns);
}
#endif /* !CONFIG_NUMA */
void __ref free_initmem(void)
{