[PATCH 1/2] riscv: Register System RAM as iomem resources

From: Zong Li
Date: Tue Jun 16 2020 - 03:46:00 EST


Add System RAM to /proc/iomem, various tools expect it such as kdump.
It is also needed for page_is_ram API which checks the specified address
whether registered as System RAM in iomem_resource list.

Signed-off-by: Zong Li <zong.li@xxxxxxxxxx>
---
arch/riscv/mm/init.c | 22 ++++++++++++++++++++++
1 file changed, 22 insertions(+)

diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index f4adb3684f3d..bbe816e03b2f 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -517,6 +517,27 @@ void mark_rodata_ro(void)
}
#endif

+void __init resource_init(void)
+{
+ struct memblock_region *region;
+
+ for_each_memblock(memory, region) {
+ struct resource *res;
+
+ res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
+ if (!res)
+ panic("%s: Failed to allocate %zu bytes\n", __func__,
+ sizeof(struct resource));
+
+ res->name = "System RAM";
+ res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
+ res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
+ res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
+
+ request_resource(&iomem_resource, res);
+ }
+}
+
void __init paging_init(void)
{
setup_vm_final();
@@ -524,6 +545,7 @@ void __init paging_init(void)
sparse_init();
setup_zero_page();
zone_sizes_init();
+ resource_init();
}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
--
2.27.0