[RFC PATCH V2 17/38] riscv: s64ilp32: Adjust TASK_SIZE for s64ilp32 kernel

[guoren]

From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

The RV64ILP32 32-bit Linux kernel uses the same userspace address range
as the 64-bit Linux compat mode, about 2GB. They have no difference from
the hardware view, and all are running ILP32 on a 64-bit ISA. But the
standard 32ilp32 Linux has a slightly bigger userspace address space,
about 2.4GB.

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Signed-off-by: Guo Ren <guoren@xxxxxxxxxx>
---
 arch/riscv/include/asm/pgtable.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 75970ee2bda2..e5e7a929949a 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -839,20 +839,25 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
  * "load and store effective addresses, which are 64bits, must have bits
  * 63–48 all equal to bit 47, or else a page-fault exception will occur."
  */
+#define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
+
 #ifdef CONFIG_64BIT
 #define TASK_SIZE_64	(PGDIR_SIZE * PTRS_PER_PGD / 2)
 #define TASK_SIZE_MIN	(PGDIR_SIZE_L3 * PTRS_PER_PGD / 2)
 
 #ifdef CONFIG_COMPAT
-#define TASK_SIZE_32	(_AC(0x80000000, UL) - PAGE_SIZE)
 #define TASK_SIZE	(test_thread_flag(TIF_32BIT) ? \
 			 TASK_SIZE_32 : TASK_SIZE_64)
 #else
 #define TASK_SIZE	TASK_SIZE_64
 #endif
 
+#else
+#ifdef CONFIG_ARCH_RV64ILP32
+#define TASK_SIZE	TASK_SIZE_32
 #else
 #define TASK_SIZE	FIXADDR_START
+#endif
 #define TASK_SIZE_MIN	TASK_SIZE
 #endif
 
-- 
2.36.1