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authorZong Li <zong.li@sifive.com>2020-03-12 10:58:35 +0800
committerPalmer Dabbelt <palmerdabbelt@google.com>2020-03-26 09:29:49 -0700
commit59c4da8640ccf4721d54d36835706f3eefb521a4 (patch)
tree598f0449ad9a5643de09202de7b9268f72e33f55 /arch/riscv/include/asm/pgtable.h
parent8fdddb2eae731dd6beb89f9b812e5915d1beb744 (diff)
downloadlinux-59c4da8640ccf4721d54d36835706f3eefb521a4.tar.gz
riscv: Add support to dump the kernel page tables
In a similar manner to arm64, x86, powerpc, etc., it can traverse all page tables, and dump the page table layout with the memory types and permissions. Add a debugfs file at /sys/kernel/debug/kernel_page_tables to export the page table layout to userspace. Signed-off-by: Zong Li <zong.li@sifive.com> Tested-by: Alexandre Ghiti <alex@ghiti.fr> Signed-off-by: Palmer Dabbelt <palmerdabbelt@google.com>
Diffstat (limited to 'arch/riscv/include/asm/pgtable.h')
-rw-r--r--arch/riscv/include/asm/pgtable.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 393f2014dfee..9c188ad2e52d 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -449,6 +449,16 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
/*
+ * In the RV64 Linux scheme, we give the user half of the virtual-address space
+ * and give the kernel the other (upper) half.
+ */
+#ifdef CONFIG_64BIT
+#define KERN_VIRT_START (-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
+#else
+#define KERN_VIRT_START FIXADDR_START
+#endif
+
+/*
* Task size is 0x4000000000 for RV64 or 0x9fc00000 for RV32.
* Note that PGDIR_SIZE must evenly divide TASK_SIZE.
*/