diff mbox series

[v3,3/7] RISC-V: validate riscv,isa at boot, not during ISA string parsing

Message ID 20230607-guts-blurry-67e711acf328@spud (mailing list archive)
State Accepted
Commit 069b0d51707721d5ab2001df866b66b82e4c1c35
Headers show
Series ISA string parser cleanups | expand

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conchuod/cover_letter success Series has a cover letter
conchuod/tree_selection success Guessed tree name to be for-next at HEAD 748462b59f90
conchuod/fixes_present success Fixes tag not required for -next series
conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 0 this patch: 0
conchuod/build_rv64_clang_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/module_param success Was 0 now: 0
conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 9 this patch: 9
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch success total: 0 errors, 0 warnings, 0 checks, 33 lines checked
conchuod/build_rv64_nommu_k210_defconfig success Build OK
conchuod/verify_fixes success No Fixes tag
conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

Conor Dooley June 7, 2023, 8:28 p.m. UTC
From: Conor Dooley <conor.dooley@microchip.com>

Since riscv_fill_hwcap() now only iterates over possible cpus, the
basic validation of whether riscv,isa contains "rv<width>" 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 <ajones@ventanamicro.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
---
 arch/riscv/kernel/cpu.c        |  8 +++++---
 arch/riscv/kernel/cpufeature.c | 12 ++++++------
 2 files changed, 11 insertions(+), 9 deletions(-)

Comments

Sunil V L June 12, 2023, 7:33 a.m. UTC | #1
On Wed, Jun 07, 2023 at 09:28:27PM +0100, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley@microchip.com>
> 
> Since riscv_fill_hwcap() now only iterates over possible cpus, the
> basic validation of whether riscv,isa contains "rv<width>" 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 <ajones@ventanamicro.com>
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> ---

Reviewed-by: Sunil V L <sunilvl@ventanamicro.com>
diff mbox series

Patch

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 8025de06edb7..dfb4a2a61050 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 c8635211fc18..c3851c8cfa9c 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);