Unverified Commit 3270bfdb authored by Alexandre Ghiti's avatar Alexandre Ghiti Committed by Palmer Dabbelt
Browse files

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: default avatarAlexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 840125a9

arch/riscv/Kconfig

+0 −10
Original line number Diff line number Diff line
@@ -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

arch/riscv/include/asm/kasan.h

+1 −1
Original line number Diff line number Diff line
@@ -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)

arch/riscv/include/asm/pgtable.h

+8 −2
Original line number Diff line number Diff line
@@ -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

arch/riscv/include/asm/sparsemem.h

+5 −1
Original line number Diff line number Diff line
@@ -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 */