Messages in this thread | | | Date | Tue, 7 Dec 2021 00:10:30 +0800 | From | Jisheng Zhang <> | Subject | Re: [PATCH 2/5] riscv: mm: init: try best to IS_ENABLED(CONFIG_64BIT) instead of #ifdef |
| |
On Fri, 3 Dec 2021 09:33:12 +0100 Alexandre ghiti <alex@ghiti.fr> wrote:
> On 12/3/21 06:03, Jisheng Zhang wrote: > > Try our best to replace the conditional compilation using > > "#ifdef CONFIG_64BIT" by a check for "IS_ENABLED(CONFIG_64BIT)", to > > simplify the code and to increase compile coverage. > > > > Signed-off-by: Jisheng Zhang <jszhang@kernel.org> > > --- > > arch/riscv/mm/init.c | 38 +++++++++++++++++--------------------- > > 1 file changed, 17 insertions(+), 21 deletions(-) > > > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > > index 745f26a3b02e..bd445ac778a8 100644 > > --- a/arch/riscv/mm/init.c > > +++ b/arch/riscv/mm/init.c > > @@ -102,10 +102,9 @@ static void __init print_vm_layout(void) > > (unsigned long)VMALLOC_END); > > print_mlm("lowmem", (unsigned long)PAGE_OFFSET, > > (unsigned long)high_memory); > > -#ifdef CONFIG_64BIT > > - print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR, > > - (unsigned long)ADDRESS_SPACE_END); > > -#endif > > + if (IS_ENABLED(CONFIG_64BIT)) > > + print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR, > > + (unsigned long)ADDRESS_SPACE_END); > > } > > #else > > static void print_vm_layout(void) { } > > @@ -172,17 +171,16 @@ static void __init setup_bootmem(void) > > > > memblock_enforce_memory_limit(memory_limit); > > > > - /* > > - * Reserve from the start of the kernel to the end of the kernel > > - */ > > -#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX) > > /* > > * Make sure we align the reservation on PMD_SIZE since we will > > * map the kernel in the linear mapping as read-only: we do not want > > * any allocation to happen between _end and the next pmd aligned page. > > */ > > - vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK; > > -#endif > > + if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) > > + vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK; > > + /* > > + * Reserve from the start of the kernel to the end of the kernel > > + */ > > memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); > > > > > > @@ -190,7 +188,6 @@ static void __init setup_bootmem(void) > > #ifndef CONFIG_XIP_KERNEL > > phys_ram_base = memblock_start_of_DRAM(); > > #endif > > -#ifndef CONFIG_64BIT > > /* > > * memblock allocator is not aware of the fact that last 4K bytes of > > * the addressable memory can not be mapped because of IS_ERR_VALUE > > @@ -200,10 +197,11 @@ static void __init setup_bootmem(void) > > * address space is occupied by the kernel mapping then this check must > > * be done as soon as the kernel mapping base address is determined. > > */ > > - max_mapped_addr = __pa(~(ulong)0); > > - if (max_mapped_addr == (phys_ram_end - 1)) > > - memblock_set_current_limit(max_mapped_addr - 4096); > > -#endif > > + if (!IS_ENABLED(CONFIG_64BIT)) { > > + max_mapped_addr = __pa(~(ulong)0); > > + if (max_mapped_addr == (phys_ram_end - 1)) > > + memblock_set_current_limit(max_mapped_addr - 4096); > > + } > > > > min_low_pfn = PFN_UP(phys_ram_base); > > max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end); > > @@ -616,13 +614,12 @@ asmlinkage void __init setup_vm(uintptr_t dtb_pa) > > BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); > > BUG_ON((kernel_map.phys_addr % PMD_SIZE) != 0); > > > > -#ifdef CONFIG_64BIT > > /* > > * The last 4K bytes of the addressable memory can not be mapped because > > * of IS_ERR_VALUE macro. > > */ > > - BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); > > -#endif > > + if (IS_ENABLED(CONFIG_64BIT)) > > + BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K); > > > For this one, I think we can just get rid of the condition since this is > true for every kernel actually.
Thanks for pointing out this out. Addressed in v2
> > > > > > pt_ops.alloc_pte = alloc_pte_early; > > pt_ops.get_pte_virt = get_pte_virt_early; > > @@ -735,10 +732,9 @@ static void __init setup_vm_final(void) > > } > > } > > > > -#ifdef CONFIG_64BIT > > /* Map the kernel */ > > - create_kernel_page_table(swapper_pg_dir, false); > > -#endif > > + if (IS_ENABLED(CONFIG_64BIT)) > > + create_kernel_page_table(swapper_pg_dir, false); > > > Wouldn't it be better to introduce a create_kernel_page_table function > that does nothing for !CONFIG_64BIT? >
If so, we will have something as: #ifdef CONFIG_64BIT create_kernel_page_table() { ... } #else create_kernel_page_table() { } #endif
Since we already have different create_kernel_page_table() version for XIP and !XIP, the code would be more complex.
Thanks for your code review
| |