riscv: add compile-time test into is_compat_task()
Currently several places will test for CONFIG_COMPAT before testing
is_compat_task(), probably in order to avoid a run-time test into the task
structure.
Since is_compat_task() is an inlined function, it would be helpful to add a
compile-time test of CONFIG_COMPAT, making sure it always returns zero when
the option is not enabled during the kernel build.
With this, the compiler is able to understand in build-time that
is_compat_task() will always return 0, and optimize-out some of the extra
code introduced by the option.
This will also allow removing a lot #ifdefs that were introduced, and make
the code more clean.
Signed-off-by: Leonardo Bras <leobras@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Reviewed-by: Andy Chiu <andy.chiu@sifive.com>
Link: https://lore.kernel.org/r/20240103160024.70305-5-leobras@redhat.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
diff --git a/arch/riscv/include/asm/compat.h b/arch/riscv/include/asm/compat.h
index 2ac955b..91517b5 100644
--- a/arch/riscv/include/asm/compat.h
+++ b/arch/riscv/include/asm/compat.h
@@ -14,6 +14,9 @@
static inline int is_compat_task(void)
{
+ if (!IS_ENABLED(CONFIG_COMPAT))
+ return 0;
+
return test_thread_flag(TIF_32BIT);
}
diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h
index 59a0836..2e88257 100644
--- a/arch/riscv/include/asm/elf.h
+++ b/arch/riscv/include/asm/elf.h
@@ -53,13 +53,9 @@
#define ELF_ET_DYN_BASE ((DEFAULT_MAP_WINDOW / 3) * 2)
#ifdef CONFIG_64BIT
-#ifdef CONFIG_COMPAT
#define STACK_RND_MASK (is_compat_task() ? \
0x7ff >> (PAGE_SHIFT - 12) : \
0x3ffff >> (PAGE_SHIFT - 12))
-#else
-#define STACK_RND_MASK (0x3ffff >> (PAGE_SHIFT - 12))
-#endif
#endif
/*
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 9a7a92e..f5b5042 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -127,17 +127,11 @@
#define VA_USER_SV48 (UL(1) << (VA_BITS_SV48 - 1))
#define VA_USER_SV57 (UL(1) << (VA_BITS_SV57 - 1))
-#ifdef CONFIG_COMPAT
#define MMAP_VA_BITS_64 ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
#define MMAP_MIN_VA_BITS_64 (VA_BITS_SV39)
#define MMAP_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_VA_BITS_64)
#define MMAP_MIN_VA_BITS (is_compat_task() ? VA_BITS_SV32 : MMAP_MIN_VA_BITS_64)
#else
-#define MMAP_VA_BITS ((VA_BITS >= VA_BITS_SV48) ? VA_BITS_SV48 : VA_BITS)
-#define MMAP_MIN_VA_BITS (VA_BITS_SV39)
-#endif /* CONFIG_COMPAT */
-
-#else
#include <asm/pgtable-32.h>
#endif /* CONFIG_64BIT */
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
index 2278e2a..d2d7ce30 100644
--- a/arch/riscv/include/asm/processor.h
+++ b/arch/riscv/include/asm/processor.h
@@ -28,7 +28,7 @@
({ \
unsigned long mmap_end; \
typeof(addr) _addr = (addr); \
- if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
+ if ((_addr) == 0 || is_compat_task()) \
mmap_end = STACK_TOP_MAX; \
else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
mmap_end = VA_USER_SV57; \
@@ -45,7 +45,7 @@
typeof(addr) _addr = (addr); \
typeof(base) _base = (base); \
unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
- if ((_addr) == 0 || (IS_ENABLED(CONFIG_COMPAT) && is_compat_task())) \
+ if ((_addr) == 0 || is_compat_task()) \
mmap_base = (_base); \
else if (((_addr) >= VA_USER_SV57) && (VA_BITS >= VA_BITS_SV57)) \
mmap_base = VA_USER_SV57 - rnd_gap; \
