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authorAtish Patra <atish.patra@wdc.com>2019-02-22 11:41:40 -0800
committerPalmer Dabbelt <palmer@sifive.com>2019-03-04 10:40:39 -0800
commitfbdc6193dc706c863b70accf2006fa00331a7c3f (patch)
tree78ab70504bf3c09fd306bbf819010faf086e9efa /arch/riscv/kernel/cpufeature.c
parentRISC-V: Compare cpuid with NR_CPUS before mapping. (diff)
downloadlinux-dev-fbdc6193dc706c863b70accf2006fa00331a7c3f.tar.xz
linux-dev-fbdc6193dc706c863b70accf2006fa00331a7c3f.zip
RISC-V: Assign hwcap as per comman capabilities.
Currently, we set hwcap based on first valid hart from DT. This may not be correct always as that hart might not be current booting cpu or may have a different capability. Set hwcap as the capabilities supported by all possible harts with "okay" status. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Anup Patel <anup@brainfault.org> Reviewed-by: Johan Hovold <johan@kernel.org> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to '')
-rw-r--r--arch/riscv/kernel/cpufeature.c41
1 files changed, 22 insertions, 19 deletions
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index e7a4701f0256..bc29b010b722 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -20,6 +20,7 @@
#include <linux/of.h>
#include <asm/processor.h>
#include <asm/hwcap.h>
+#include <asm/smp.h>
unsigned long elf_hwcap __read_mostly;
#ifdef CONFIG_FPU
@@ -42,28 +43,30 @@ void riscv_fill_hwcap(void)
elf_hwcap = 0;
- /*
- * We don't support running Linux on hertergenous ISA systems. For
- * now, we just check the ISA of the first "okay" processor.
- */
for_each_of_cpu_node(node) {
- if (riscv_of_processor_hartid(node) >= 0)
- break;
- }
- if (!node) {
- pr_warn("Unable to find \"cpu\" devicetree entry\n");
- return;
- }
+ unsigned long this_hwcap = 0;
- if (of_property_read_string(node, "riscv,isa", &isa)) {
- pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
- of_node_put(node);
- return;
- }
- of_node_put(node);
+ if (riscv_of_processor_hartid(node) < 0)
+ continue;
- for (i = 0; i < strlen(isa); ++i)
- elf_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
+ if (of_property_read_string(node, "riscv,isa", &isa)) {
+ pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");
+ continue;
+ }
+
+ for (i = 0; i < strlen(isa); ++i)
+ this_hwcap |= isa2hwcap[(unsigned char)(isa[i])];
+
+ /*
+ * All "okay" hart should have same isa. Set HWCAP based on
+ * common capabilities of every "okay" hart, in case they don't
+ * have.
+ */
+ if (elf_hwcap)
+ elf_hwcap &= this_hwcap;
+ else
+ elf_hwcap = this_hwcap;
+ }
/* We don't support systems with F but without D, so mask those out
* here. */