From 1aa866931b8026a0dd636e9ef7b5c5dfb4cc5ce8 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Fri, 24 Mar 2023 10:05:38 +0000 Subject: RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely() The has_fpu() check, which in turn calls riscv_has_extension_likely(), relies on alternatives to figure out whether the system has an FPU. As a result, it will malfunction on XIP kernels, as they do not support the alternatives mechanism. When alternatives support is not present, fall back to using __riscv_isa_extension_available() in riscv_has_extension_[un]likely() instead stead, which handily takes the same argument, so that kernels that do not support alternatives can accurately report the presence of FPU support. Fixes: 702e64550b12 ("riscv: fpu: switch has_fpu() to riscv_has_extension_likely()") Link: https://lore.kernel.org/all/ad445951-3d13-4644-94d9-e0989cda39c3@spud/ Signed-off-by: Conor Dooley Reviewed-by: Andrew Jones Reviewed-by: Jason A. Donenfeld Link: https://lore.kernel.org/r/20230324100538.3514663-2-conor.dooley@microchip.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/hwcap.h | 50 +++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 20 deletions(-) (limited to 'arch') diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e3021b2590de..6263a0de1c6a 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -57,18 +57,31 @@ struct riscv_isa_ext_data { unsigned int isa_ext_id; }; +unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); + +#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext) + +bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit); +#define riscv_isa_extension_available(isa_bitmap, ext) \ + __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext) + static __always_inline bool riscv_has_extension_likely(const unsigned long ext) { compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX"); - asm_volatile_goto( - ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1) - : - : [ext] "i" (ext) - : - : l_no); + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + asm_volatile_goto( + ALTERNATIVE("j %l[l_no]", "nop", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_no); + } else { + if (!__riscv_isa_extension_available(NULL, ext)) + goto l_no; + } return true; l_no: @@ -81,26 +94,23 @@ riscv_has_extension_unlikely(const unsigned long ext) compiletime_assert(ext < RISCV_ISA_EXT_MAX, "ext must be < RISCV_ISA_EXT_MAX"); - asm_volatile_goto( - ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1) - : - : [ext] "i" (ext) - : - : l_yes); + if (IS_ENABLED(CONFIG_RISCV_ALTERNATIVE)) { + asm_volatile_goto( + ALTERNATIVE("nop", "j %l[l_yes]", 0, %[ext], 1) + : + : [ext] "i" (ext) + : + : l_yes); + } else { + if (__riscv_isa_extension_available(NULL, ext)) + goto l_yes; + } return false; l_yes: return true; } -unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); - -#define riscv_isa_extension_mask(ext) BIT_MASK(RISCV_ISA_EXT_##ext) - -bool __riscv_isa_extension_available(const unsigned long *isa_bitmap, int bit); -#define riscv_isa_extension_available(isa_bitmap, ext) \ - __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_##ext) - #endif #endif /* _ASM_RISCV_HWCAP_H */ -- cgit v1.2.3