[RFC PATCH 10/22] riscv: s64ilp32: Enable user space runtime environment

[guoren at kernel.org]

From: Guo Ren <guoren at linux.alibaba.com>

RV64ILP32 uses the same setting from COMPAT mode for the user
space runtime environment. They all have the same 2GB TASK_SIZE.

Signed-off-by: Guo Ren <guoren at linux.alibaba.com>
Signed-off-by: Guo Ren <guoren at kernel.org>
---
 arch/riscv/include/asm/csr.h     | 2 --
 arch/riscv/include/asm/pgtable.h | 8 +++++++-
 arch/riscv/kernel/process.c      | 4 +++-
 3 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index adc3c866d353..7558e0808af4 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -36,11 +36,9 @@
 #define SR_SD		_AC(0x8000000000000000, ULL) /* FS/XS dirty */
 #endif
 
-#if __riscv_xlen == 64
 #define SR_UXL		_AC(0x300000000, ULL) /* XLEN mask for U-mode */
 #define SR_UXL_32	_AC(0x100000000, ULL) /* XLEN = 32 for U-mode */
 #define SR_UXL_64	_AC(0x200000000, ULL) /* XLEN = 64 for U-mode */
-#endif
 
 /* SATP flags */
 #if __riscv_xlen == 32
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 3303fc03d724..d7b8eff0ade9 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -830,26 +830,32 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte)
  * -     0x9fc00000 (~2.5GB) for RV32.
  * -   0x4000000000 ( 256GB) for RV64 using SV39 mmu
  * - 0x800000000000 ( 128TB) for RV64 using SV48 mmu
+ * -     0x80000000 (   2GB) for COMPAT and RV64ILP32
  *
  * Note that PGDIR_SIZE must evenly divide TASK_SIZE since "RISC-V
  * Instruction Set Manual Volume II: Privileged Architecture" states that
  * "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
 
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index ab01b51a5bb9..e033dbe5b5eb 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -125,13 +125,15 @@ void start_thread(struct pt_regs *regs, unsigned long pc,
 	regs->epc = pc;
 	regs->sp = sp;
 
-#ifdef CONFIG_64BIT
 	regs->status &= ~SR_UXL;
 
+#ifdef CONFIG_64BIT
 	if (is_compat_task())
 		regs->status |= SR_UXL_32;
 	else
 		regs->status |= SR_UXL_64;
+#else
+		regs->status |= SR_UXL_32;
 #endif
 }
 
-- 
2.36.1