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RISC-V: Assign hwcap as per comman capabilities.

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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>
This commit is contained in:
Atish Patra 2019-02-22 11:41:40 -08:00 committed by Palmer Dabbelt
parent 291debb38d
commit fbdc6193dc
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GPG Key ID: EF4CA1502CCBAB41
1 changed files with 22 additions and 19 deletions
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41
arch/riscv/kernel/cpufeature.c
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@ -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. */