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authorLogan Gunthorpe <logang@deltatee.com>2019-08-28 15:40:54 -0600
committerPaul Walmsley <paul.walmsley@sifive.com>2019-08-30 11:10:37 -0700
commitd95f1a542c3df396137afa217ef9bd39cb8931ca (patch)
treec3589a3d0c784429b607bb7ceac24db04e31c1d7 /arch/riscv/include/asm/pgtable.h
parent4f3f90084673fa1d7f8e81b9dbee652d2fae3092 (diff)
downloadlinux-d95f1a542c3df396137afa217ef9bd39cb8931ca.tar.gz
RISC-V: Implement sparsemem
Implement sparsemem support for Risc-v which helps pave the way for memory hotplug and eventually P2P support. 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.hu@sifive.com: fixed pfn_valid, FIXADDR_TOP and fixed a bug rebasing onto v5.3] Signed-off-by: Greentime Hu <greentime.hu@sifive.com> Signed-off-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Palmer Dabbelt <palmer@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Andrew Waterman <andrew@sifive.com> Cc: Olof Johansson <olof@lixom.net> Cc: Michael Clark <michaeljclark@mac.com> Cc: Rob Herring <robh@kernel.org> Cc: Zong Li <zong@andestech.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> [paul.walmsley@sifive.com: updated to apply; minor commit message reformat] Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Diffstat (limited to 'arch/riscv/include/asm/pgtable.h')
-rw-r--r--arch/riscv/include/asm/pgtable.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index c24a083b3e12..80905b27ee98 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -84,6 +84,19 @@ extern pgd_t swapper_pg_dir[];
#define __S111 PAGE_SHARED_EXEC
/*
+ * 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 ((struct page *)VMEMMAP_START)
+
+/*
* ZERO_PAGE is a global shared page that is always zero,
* used for zero-mapped memory areas, etc.
*/