On Thu, Aug 22, 2019 at 10:04:39AM -0600, Logan Gunthorpe wrote:
> This patch implements sparsemem support for risc-v which helps pave the
Please avoid "This patch" in the commit message:
git grep "This patch" Documentation/process/submitting-patches.rst
> way for memory hotplug and eventually P2P support.
>
> We introduce Kconfig options for virtual and physical address bits which
> are used to calculate the size of the vmemmap and set the
> MAX_PHYSMEM_BITS.
>
> The vmemmap is located directly before the VMALLOC region and sized
> such that we can allocate enough pages to populate all the virtual
> address space in the system (similar to the way it's done in arm64).
>
> During initialization, call memblocks_present() and sparse_init(),
> and provide a stub for vmemmap_populate() (all of which is similar to
> arm64).
>
> [greentime...@sifive.com:
> fixed pfn_valid, FIXADDR_TOP and fixed a bug rebasing onto v5.3]
> Signed-off-by: Greentime Hu <greentime...@sifive.com>
> Signed-off-by: Logan Gunthorpe <log...@deltatee.com>
> Reviewed-by: Palmer Dabbelt <pal...@sifive.com>
> Reviewed-by: Christoph Hellwig <h...@lst.de>
> Cc: Albert Ou <a...@eecs.berkeley.edu>
> Cc: Andrew Waterman <and...@sifive.com>
> Cc: Olof Johansson <o...@lixom.net>
> Cc: Michael Clark <michaeljcl...@mac.com>
> Cc: Rob Herring <r...@kernel.org>
> Cc: Zong Li <z...@andestech.com>
> ---
>
> Changes in v5:
> * Rebased onto v5.3-rc5 (required moving the initialization to
> after setup_vm_final() in paging_init())
> * Fixed FIXADDR_TOP value (per Greentime)
> * Use generic pfn_valid() function for sparsemem to fix a bug
> with having holes in memory (also Greentime)
>
> Changes in v4:
> * Rebased onto v5.0-rc1
> * Changed the SECTION_SIZE_BITS to 27, per Nick Kossifidis
>
> Changes in v3 (only sent the common patches):
> * Rebased on v4.20-rc1
> * Minor fixups
> * Collected Ack from Will Deacon
>
> Changes in v2:
> * Rebase on v4.19-rc8
> * Move the STRUCT_PAGE_MAX_SHIFT define into a common header (near
> the definition of struct page). As suggested by Christoph.
> * Clean up the unnecessary nid variable in the memblocks_present()
> function, per Christoph.
> * Collected tags from Palmer and Catalin.
>
> arch/riscv/Kconfig | 20 ++++++++++++++++++++
> arch/riscv/include/asm/fixmap.h | 2 +-
> arch/riscv/include/asm/page.h | 2 ++
> arch/riscv/include/asm/pgtable.h | 21 +++++++++++++++++----
> arch/riscv/include/asm/sparsemem.h | 11 +++++++++++
> arch/riscv/mm/init.c | 10 ++++++++++
> 6 files changed, 61 insertions(+), 5 deletions(-)
> create mode 100644 arch/riscv/include/asm/sparsemem.h
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 59a4727ecd6c..83faa929853c 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -62,12 +62,32 @@ config ZONE_DMA32
> bool
> default y if 64BIT
>
> +config VA_BITS
> + int
> + default 32 if 32BIT
> + default 39 if 64BIT
> +
> +config PA_BITS
> + int
> + default 34 if 32BIT
> + default 56 if 64BIT
> +
> config PAGE_OFFSET
> hex
> default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
> default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
> default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
>
> +config ARCH_FLATMEM_ENABLE
> + def_bool y
> +
> +config ARCH_SPARSEMEM_ENABLE
> + def_bool y
> + select SPARSEMEM_VMEMMAP_ENABLE
This will implicitly select CONFIG_SPARSEMEM_EXTREME=y. Probably for 32-bit
it's overkill.
> +
> +config ARCH_SELECT_MEMORY_MODEL
> + def_bool ARCH_SPARSEMEM_ENABLE
> +
> config ARCH_WANT_GENERAL_HUGETLB
> def_bool y
>
> diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h
> index 9c66033c3a54..7b0259c044c9 100644
> --- a/arch/riscv/include/asm/fixmap.h
> +++ b/arch/riscv/include/asm/fixmap.h
> @@ -31,7 +31,7 @@ enum fixed_addresses {
> };
>
> #define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE)
> -#define FIXADDR_TOP (VMALLOC_START)
> +#define FIXADDR_TOP (VMEMMAP_START)
> #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
>
> #define FIXMAP_PAGE_IO PAGE_KERNEL
> diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h
> index 707e00a8430b..3db261c4810f 100644
> --- a/arch/riscv/include/asm/page.h
> +++ b/arch/riscv/include/asm/page.h
> @@ -110,8 +110,10 @@ extern unsigned long min_low_pfn;
> #define page_to_bus(page) (page_to_phys(page))
> #define phys_to_page(paddr) (pfn_to_page(phys_to_pfn(paddr)))
>
> +#ifdef CONFIG_FLATMEM
> #define pfn_valid(pfn) \
> (((pfn) >= pfn_base) && (((pfn)-pfn_base) < max_mapnr))
> +#endif
>
> #define ARCH_PFN_OFFSET (pfn_base)
>
> diff --git a/arch/riscv/include/asm/pgtable.h
> b/arch/riscv/include/asm/pgtable.h
> index a364aba23d55..dbc19e61ee66 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -83,6 +83,23 @@ 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)
> +
> +/*
> + * 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 (1UL << VMEMMAP_SHIFT)
> +#define VMEMMAP_END (VMALLOC_START - 1)
> +#define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE)
> +
> +#define vmemmap ((struct page *)VMEMMAP_START)
> +
> /*
> * ZERO_PAGE is a global shared page that is always zero,
> * used for zero-mapped memory areas, etc.
> @@ -416,10 +433,6 @@ static inline void pgtable_cache_init(void)
> /* No page table caches to initialize */
> }
>
> -#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
> -#define VMALLOC_END (PAGE_OFFSET - 1)
> -#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
> -
> /*
> * Task size is 0x4000000000 for RV64 or 0xb800000 for RV32.
> * Note that PGDIR_SIZE must evenly divide TASK_SIZE.
> diff --git a/arch/riscv/include/asm/sparsemem.h
> b/arch/riscv/include/asm/sparsemem.h
> new file mode 100644
> index 000000000000..b58ba2d9ed6e
> --- /dev/null
> +++ b/arch/riscv/include/asm/sparsemem.h
> @@ -0,0 +1,11 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef __ASM_SPARSEMEM_H
> +#define __ASM_SPARSEMEM_H
> +
> +#ifdef CONFIG_SPARSEMEM
> +#define MAX_PHYSMEM_BITS CONFIG_PA_BITS
> +#define SECTION_SIZE_BITS 27
> +#endif /* CONFIG_SPARSEMEM */
> +
> +#endif /* __ASM_SPARSEMEM_H */
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index 42bf939693d3..73f40c9d3dee 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -442,6 +442,16 @@ static void __init setup_vm_final(void)
> void __init paging_init(void)
> {
> setup_vm_final();
> + memblocks_present();
> + sparse_init();
> setup_zero_page();
> zone_sizes_init();
> }
> +
> +#ifdef CONFIG_SPARSEMEM
> +int __meminit vmemmap_populate(unsigned long start, unsigned long end, int
> node,
> + struct vmem_altmap *altmap)
> +{
> + return vmemmap_populate_basepages(start, end, node);
> +}
> +#endif
> --
> 2.20.1
>
> _______________________________________________
> linux-riscv mailing list
> linux-ri...@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
--
Sincerely yours,
Mike.
