On Wed, Jan 25, 2023 at 09:12:13AM +0100, Alexandre Ghiti wrote: > Use directly phys_ram_base instead, riscv_pfn_base is just the pfn of > the address contained in phys_ram_base. > > Even if there is no functional change intended in this patch, actually > setting phys_ram_base that early changes the behaviour of > kernel_mapping_pa_to_va during the early boot: phys_ram_base used to be > zero before this patch and now it is set to the physical start address of > the kernel. But it does not break the conversion of a kernel physical > address into a virtual address since kernel_mapping_pa_to_va should only > be used on kernel physical addresses, i.e. addresses greater than the > physical start address of the kernel. afaict, only CONFIG_XIP_KERNEL kernels use phys_ram_base prior to setup_bootmem() and, for them, this change only redundantly sets phys_ram_base to the same thing, so I believe this is a no functional change patch. > > Signed-off-by: Alexandre Ghiti <alexghiti@xxxxxxxxxxxx> > --- > arch/riscv/include/asm/page.h | 3 +-- > arch/riscv/mm/init.c | 6 +----- > 2 files changed, 2 insertions(+), 7 deletions(-) > > diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h > index 9f432c1b5289..728eee53152a 100644 > --- a/arch/riscv/include/asm/page.h > +++ b/arch/riscv/include/asm/page.h > @@ -91,8 +91,7 @@ typedef struct page *pgtable_t; > #endif > > #ifdef CONFIG_MMU > -extern unsigned long riscv_pfn_base; > -#define ARCH_PFN_OFFSET (riscv_pfn_base) > +#define ARCH_PFN_OFFSET (PFN_DOWN(phys_ram_base)) > #else > #define ARCH_PFN_OFFSET (PAGE_OFFSET >> PAGE_SHIFT) > #endif /* CONFIG_MMU */ > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 478d6763a01a..225a7d2b65cc 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -271,9 +271,6 @@ static void __init setup_bootmem(void) > #ifdef CONFIG_MMU > struct pt_alloc_ops pt_ops __initdata; > > -unsigned long riscv_pfn_base __ro_after_init; > -EXPORT_SYMBOL(riscv_pfn_base); > - > pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; > pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss; > static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; > @@ -285,7 +282,6 @@ static pmd_t __maybe_unused early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAG > > #ifdef CONFIG_XIP_KERNEL > #define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&pt_ops)) > -#define riscv_pfn_base (*(unsigned long *)XIP_FIXUP(&riscv_pfn_base)) > #define trampoline_pg_dir ((pgd_t *)XIP_FIXUP(trampoline_pg_dir)) > #define fixmap_pte ((pte_t *)XIP_FIXUP(fixmap_pte)) > #define early_pg_dir ((pgd_t *)XIP_FIXUP(early_pg_dir)) > @@ -985,7 +981,7 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr; > kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr; > > - riscv_pfn_base = PFN_DOWN(kernel_map.phys_addr); > + phys_ram_base = kernel_map.phys_addr; nit: I'd put this in the #else part of the #ifdef CONFIG_XIP_KERNEL above to have some consistency with that #ifdef arm and also avoid the redundant assignment of phys_ram_base for CONFIG_XIP_KERNEL. > > /* > * The default maximal physical memory size is KERN_VIRT_SIZE for 32-bit > -- > 2.37.2 > Otherwise, Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> Thanks, drew
