Re: [PATCH v2] RISC-V: Add address map dumper

[Anup Patel]

On Mon, Nov 18, 2019 at 11:28 AM Yash Shah <yash.shah@xxxxxxxxxx> wrote:
>
> Add support for dumping the kernel address space layout to the console.
> User can enable CONFIG_DEBUG_VM to dump the virtual memory region into
> dmesg buffer during boot-up.
>
> Signed-off-by: Yash Shah <yash.shah@xxxxxxxxxx>
> ---
> This patch is based on Linux 5.4-rc6 and tested on SiFive HiFive
> Unleashed board.
>
> Changes in v2:
> - Avoid #ifdefs inside functions
> - Helper functions instead of macros
> - Drop newly added CONFIG_DEBUG_VM_LAYOUT, instead use CONFIG_DEBUG_VM
> ---
>  arch/riscv/mm/init.c | 36 ++++++++++++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
>
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 573463d..7828136 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -45,6 +45,41 @@ void setup_zero_page(void)
>         memset((void *)empty_zero_page, 0, PAGE_SIZE);
>  }
>
> +#ifdef CONFIG_DEBUG_VM
> +static inline void print_mlk(char *name, unsigned long b, unsigned long t)
> +{
> +       pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
> +                 (((t) - (b)) >> 10));
> +}
> +
> +static inline void print_mlm(char *name, unsigned long b, unsigned long t)
> +{
> +       pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
> +                 (((t) - (b)) >> 20));
> +}
> +
> +static void print_vm_layout(void)
> +{
> +       pr_notice("Virtual kernel memory layout:\n");
> +       print_mlk("fixmap", (unsigned long)FIXADDR_START,
> +                 (unsigned long)FIXADDR_TOP);
> +       print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
> +                 (unsigned long)VMEMMAP_END);
> +       print_mlm("vmalloc", (unsigned long)VMALLOC_START,
> +                 (unsigned long)VMALLOC_END);
> +       print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
> +                 (unsigned long)high_memory);
> +       print_mlk(".init", (unsigned long)__init_begin,
> +                 (unsigned long)__init_end);
> +       print_mlk(".text", (unsigned long)_text, (unsigned long)_etext);
> +       print_mlk(".data", (unsigned long)_sdata, (unsigned long)_edata);
> +       print_mlk(".bss", (unsigned long)__bss_start,
> +                 (unsigned long)__bss_stop);
> +}
> +#else
> +static void print_vm_layout(void) { }
> +#endif /* CONFIG_DEBUG_VM */
> +
>  void __init mem_init(void)
>  {
>  #ifdef CONFIG_FLATMEM
> @@ -55,6 +90,7 @@ void __init mem_init(void)
>         memblock_free_all();
>
>         mem_init_print_info(NULL);
> +       print_vm_layout();
>  }
>
>  #ifdef CONFIG_BLK_DEV_INITRD
> --
> 2.7.4
>

LGTM.

Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>

Regards,
Anup