Re: [PATCH v2] riscv: fix the global name pfn_base confliction error

From: Palmer Dabbelt
Date: Sat Aug 14 2021 - 01:23:40 EST

On Wed, 28 Jul 2021 00:15:57 PDT (-0700), wrote:
From: Kenneth Lee <liguozhu@xxxxxxxxxxxxx>

RISCV uses a global variable pfn_base for page/pfn translation. But this
is a common name and will be used elsewhere. In those cases, the
page-pfn macros which refer to this name will be referred to the
local/input variable instead. (such as in vfio_pin_pages_remote). This
make everything wrong.

This patch changes the name from pfn_base to riscv_pfn_base to fix
this problem

Chagne from V1:
use riscv_pfn_base instead of riscv_global_pfn_base.

Signed-off-by: Kenneth Lee <liguozhu@xxxxxxxxxxxxx>
arch/riscv/include/asm/page.h | 4 ++--
arch/riscv/mm/init.c | 6 +++---
2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
index cca8764aed83..c690e83bde23 100644
--- a/arch/riscv/include/asm/page.h
+++ b/arch/riscv/include/asm/page.h
@@ -79,8 +79,8 @@ typedef struct page *pgtable_t;

-extern unsigned long pfn_base;
-#define ARCH_PFN_OFFSET (pfn_base)
+extern unsigned long riscv_pfn_base;
+#define ARCH_PFN_OFFSET (riscv_pfn_base)
#endif /* CONFIG_MMU */
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index a14bf3910eec..788f12bb586b 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -228,8 +228,8 @@ static struct pt_alloc_ops _pt_ops __initdata;
#define pt_ops _pt_ops

-unsigned long pfn_base __ro_after_init;
+unsigned long riscv_pfn_base __ro_after_init;

pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
@@ -572,7 +572,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa)
kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;

- pfn_base = PFN_DOWN(kernel_map.phys_addr);
+ riscv_pfn_base = PFN_DOWN(kernel_map.phys_addr);

* Enforce boot alignment requirements of RV32 and

Thanks, this is on for-next.