Unverified Commit fbdc6193 authored by Atish Patra's avatar Atish Patra Committed by Palmer Dabbelt
Browse files

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: default avatarAtish Patra <atish.patra@wdc.com>
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Reviewed-by: default avatarJohan Hovold <johan@kernel.org>
Signed-off-by: default avatarPalmer Dabbelt <palmer@sifive.com>
parent 291debb3

arch/riscv/kernel/cpufeature.c

+22 −19
Original line number Diff line number Diff line
@@ -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 (riscv_of_processor_hartid(node) < 0)

			continue;



		if (of_property_read_string(node, "riscv,isa", &isa)) {

			pr_warn("Unable to find \"riscv,isa\" devicetree entry\n");

		of_node_put(node);

		return;

			continue;

		}

	of_node_put(node);



		for (i = 0; i < strlen(isa); ++i)

		elf_hwcap |= isa2hwcap[(unsigned char)(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. */