From 069b0d51707721d5ab2001df866b66b82e4c1c35 Mon Sep 17 00:00:00 2001 From: Conor Dooley Date: Wed, 7 Jun 2023 21:28:27 +0100 Subject: [PATCH] RISC-V: validate riscv,isa at boot, not during ISA string parsing Since riscv_fill_hwcap() now only iterates over possible cpus, the basic validation of whether riscv,isa contains "rv" can be moved to riscv_early_of_processor_hartid(). Further, "ima" support is required by the kernel, so reject any CPU not fitting the bill. Reviewed-by: Andrew Jones Signed-off-by: Conor Dooley Reviewed-by: Sunil V L Link: https://lore.kernel.org/r/20230607-guts-blurry-67e711acf328@spud Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpu.c | 8 +++++--- arch/riscv/kernel/cpufeature.c | 12 ++++++------ 2 files changed, 11 insertions(+), 9 deletions(-) diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 8025de0..dfb4a2a 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -65,10 +65,12 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har pr_warn("CPU with hartid=%lu has no \"riscv,isa\" property\n", *hart); return -ENODEV; } - if (tolower(isa[0]) != 'r' || tolower(isa[1]) != 'v') { - pr_warn("CPU with hartid=%lu has an invalid ISA of \"%s\"\n", *hart, isa); + + if (IS_ENABLED(CONFIG_32BIT) && strncasecmp(isa, "rv32ima", 7)) + return -ENODEV; + + if (IS_ENABLED(CONFIG_64BIT) && strncasecmp(isa, "rv64ima", 7)) return -ENODEV; - } return 0; } diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index c863521..c3851c8 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -148,12 +148,12 @@ void __init riscv_fill_hwcap(void) } } - if (IS_ENABLED(CONFIG_32BIT) && strncasecmp(isa, "rv32", 4)) - continue; - - if (IS_ENABLED(CONFIG_64BIT) && strncasecmp(isa, "rv64", 4)) - continue; - + /* + * For all possible cpus, we have already validated in + * the boot process that they at least contain "rv" and + * whichever of "32"/"64" this kernel supports, and so this + * section can be skipped. + */ isa += 4; bitmap_zero(this_isa, RISCV_ISA_EXT_MAX); -- 2.7.4