riscv: Allow to dynamically define VA_BITS

With 4-level page table folding at runtime, we don't know at compile time
the size of the virtual address space so we must set VA_BITS dynamically
so that sparsemem reserves the right amount of memory for struct pages.

Signed-off-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 7f8aea3..7945bac 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -146,16 +146,6 @@ config MMU
          Select if you want MMU-based virtualised addressing space
          support by paged memory management. If unsure, say 'Y'.
 
-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

diff --git a/arch/riscv/include/asm/kasan.h b/arch/riscv/include/asm/kasan.h
index 2788e2c..743e6ff 100644 (file)
--- a/arch/riscv/include/asm/kasan.h
+++ b/arch/riscv/include/asm/kasan.h
@@ -27,7 +27,7 @@
  */
 #define KASAN_SHADOW_SCALE_SHIFT       3
 
-#define KASAN_SHADOW_SIZE      (UL(1) << ((CONFIG_VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
+#define KASAN_SHADOW_SIZE      (UL(1) << ((VA_BITS - 1) - KASAN_SHADOW_SCALE_SHIFT))
 #define KASAN_SHADOW_START     (KASAN_SHADOW_END - KASAN_SHADOW_SIZE)
 #define KASAN_SHADOW_END       MODULES_LOWEST_VADDR
 #define KASAN_SHADOW_OFFSET    _AC(CONFIG_KASAN_SHADOW_OFFSET, UL)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index fa400b2..23c7c66 100644 (file)
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -61,8 +61,14 @@
  * struct pages to map half the virtual address space. Then
  * position vmemmap directly below the VMALLOC region.
  */
+#ifdef CONFIG_64BIT
+#define VA_BITS                39
+#else
+#define VA_BITS                32
+#endif
+
 #define VMEMMAP_SHIFT \
-       (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT)
+       (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)
@@ -661,7 +667,7 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma,
  * and give the kernel the other (upper) half.
  */
 #ifdef CONFIG_64BIT
-#define KERN_VIRT_START        (-(BIT(CONFIG_VA_BITS)) + TASK_SIZE)
+#define KERN_VIRT_START        (-(BIT(VA_BITS)) + TASK_SIZE)
 #else
 #define KERN_VIRT_START        FIXADDR_START
 #endif

diff --git a/arch/riscv/include/asm/sparsemem.h b/arch/riscv/include/asm/sparsemem.h
index 45a7018..63acaec 100644 (file)
--- a/arch/riscv/include/asm/sparsemem.h
+++ b/arch/riscv/include/asm/sparsemem.h
@@ -4,7 +4,11 @@
 #define _ASM_RISCV_SPARSEMEM_H
 
 #ifdef CONFIG_SPARSEMEM
-#define MAX_PHYSMEM_BITS       CONFIG_PA_BITS
+#ifdef CONFIG_64BIT
+#define MAX_PHYSMEM_BITS       56
+#else
+#define MAX_PHYSMEM_BITS       34
+#endif /* CONFIG_64BIT */
 #define SECTION_SIZE_BITS      27
 #endif /* CONFIG_SPARSEMEM */