Re: [PATCH] RISC-V: Move all address space definition macros to one place

[Anup Patel <anup@brainfault.org>]

On Tue, Feb 25, 2020 at 1:04 AM Atish Patra <atish.patra@wdc.com> wrote:
>
> If both CONFIG_KASAN and CONFIG_SPARSEMEM_VMEMMAP are set, we get the
> following compilation error.
>
> ---------------------------------------------------------------
> ./arch/riscv/include/asm/pgtable-64.h: In function ‘pud_page’:
> ./include/asm-generic/memory_model.h:54:29: error: ‘vmemmap’ undeclared
> (first use in this function); did you mean ‘mem_map’?
>  #define __pfn_to_page(pfn) (vmemmap + (pfn))
>                              ^~~~~~~
> ./include/asm-generic/memory_model.h:82:21: note: in expansion of
> macro ‘__pfn_to_page’
>
>  #define pfn_to_page __pfn_to_page
>                      ^~~~~~~~~~~~~
> ./arch/riscv/include/asm/pgtable-64.h:70:9: note: in expansion of macro
> ‘pfn_to_page’
>   return pfn_to_page(pud_val(pud) >> _PAGE_PFN_SHIFT);
> ---------------------------------------------------------------
>
> Fix the compliation errors by moving all the address space definition
> macros before including pgtable-64.h.
>
> Cc: stable@vger.kernel.org
> Fixes: 8ad8b72721d0 (riscv: Add KASAN support)
>
> Signed-off-by: Atish Patra <atish.patra@wdc.com>
> ---
>  arch/riscv/include/asm/pgtable.h | 78 +++++++++++++++++---------------
>  1 file changed, 41 insertions(+), 37 deletions(-)
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 453afb0a570a..4f6ee48a42e8 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -19,6 +19,47 @@
>  #include <asm/tlbflush.h>
>  #include <linux/mm_types.h>
>
> +#ifdef CONFIG_MMU
> +
> +#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
> +#define VMALLOC_END      (PAGE_OFFSET - 1)
> +#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
> +
> +#define BPF_JIT_REGION_SIZE    (SZ_128M)
> +#define BPF_JIT_REGION_START   (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
> +#define BPF_JIT_REGION_END     (VMALLOC_END)
> +
> +/*
> + * Roughly size the vmemmap space to be large enough to fit enough
> + * struct pages to map half the virtual address space. Then
> + * position vmemmap directly below the VMALLOC region.
> + */
> +#define VMEMMAP_SHIFT \
> +       (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
> +#define VMEMMAP_SIZE   BIT(VMEMMAP_SHIFT)
> +#define VMEMMAP_END    (VMALLOC_START - 1)
> +#define VMEMMAP_START  (VMALLOC_START - VMEMMAP_SIZE)
> +
> +/*
> + * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
> + * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
> + */
> +#define vmemmap                ((struct page *)VMEMMAP_START)
> +
> +#define PCI_IO_SIZE      SZ_16M
> +#define PCI_IO_END       VMEMMAP_START
> +#define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
> +
> +#define FIXADDR_TOP      PCI_IO_START
> +#ifdef CONFIG_64BIT
> +#define FIXADDR_SIZE     PMD_SIZE
> +#else
> +#define FIXADDR_SIZE     PGDIR_SIZE
> +#endif
> +#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
> +
> +#endif
> +
>  #ifdef CONFIG_64BIT
>  #include <asm/pgtable-64.h>
>  #else
> @@ -90,31 +131,6 @@ extern pgd_t swapper_pg_dir[];
>  #define __S110 PAGE_SHARED_EXEC
>  #define __S111 PAGE_SHARED_EXEC
>
> -#define VMALLOC_SIZE     (KERN_VIRT_SIZE >> 1)
> -#define VMALLOC_END      (PAGE_OFFSET - 1)
> -#define VMALLOC_START    (PAGE_OFFSET - VMALLOC_SIZE)
> -
> -#define BPF_JIT_REGION_SIZE    (SZ_128M)
> -#define BPF_JIT_REGION_START   (PAGE_OFFSET - BPF_JIT_REGION_SIZE)
> -#define BPF_JIT_REGION_END     (VMALLOC_END)
> -
> -/*
> - * Roughly size the vmemmap space to be large enough to fit enough
> - * struct pages to map half the virtual address space. Then
> - * position vmemmap directly below the VMALLOC region.
> - */
> -#define VMEMMAP_SHIFT \
> -       (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
> -#define VMEMMAP_SIZE   BIT(VMEMMAP_SHIFT)
> -#define VMEMMAP_END    (VMALLOC_START - 1)
> -#define VMEMMAP_START  (VMALLOC_START - VMEMMAP_SIZE)
> -
> -/*
> - * Define vmemmap for pfn_to_page & page_to_pfn calls. Needed if kernel
> - * is configured with CONFIG_SPARSEMEM_VMEMMAP enabled.
> - */
> -#define vmemmap                ((struct page *)VMEMMAP_START)
> -
>  static inline int pmd_present(pmd_t pmd)
>  {
>         return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
> @@ -452,18 +468,6 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
>  #define __pte_to_swp_entry(pte)        ((swp_entry_t) { pte_val(pte) })
>  #define __swp_entry_to_pte(x)  ((pte_t) { (x).val })
>
> -#define PCI_IO_SIZE      SZ_16M
> -#define PCI_IO_END       VMEMMAP_START
> -#define PCI_IO_START     (PCI_IO_END - PCI_IO_SIZE)
> -
> -#define FIXADDR_TOP      PCI_IO_START
> -#ifdef CONFIG_64BIT
> -#define FIXADDR_SIZE     PMD_SIZE
> -#else
> -#define FIXADDR_SIZE     PGDIR_SIZE
> -#endif
> -#define FIXADDR_START    (FIXADDR_TOP - FIXADDR_SIZE)
> -
>  /*
>   * Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
>   * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
> --
> 2.25.0
>

Looks good to me. At least now all virtual memory layout related
defines are in one place.

Reviewed-by: Anup Patel <anup@brainfault.org>

Regards,
Anup