[1/3] RISC-V: Don't fail in riscv_of_parent_hartid() for disabled HARTs

Message ID 20231025142820.390238-2-apatel@ventanamicro.com
State New
Headers
Series Linux RISC-V AIA Preparatory Series |

Commit Message

Anup Patel Oct. 25, 2023, 2:28 p.m. UTC
  The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
for HARTs disabled in the DT. This results in the following warning
thrown by the RISC-V INTC driver for the E-core on SiFive boards:

[    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller

The riscv_of_parent_hartid() is only expected to read the hartid from
the DT so we should directly call of_get_cpu_hwid() instead of calling
riscv_of_processor_hartid().

Fixes: ad635e723e17 ("riscv: cpu: Add 64bit hartid support on RV64")
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/kernel/cpu.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)
  

Comments

Thomas Gleixner Oct. 27, 2023, 7:59 a.m. UTC | #1
On Wed, Oct 25 2023 at 19:58, Anup Patel wrote:
> The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
> for HARTs disabled in the DT. This results in the following warning
> thrown by the RISC-V INTC driver for the E-core on SiFive boards:
>
> [    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller
>
> The riscv_of_parent_hartid() is only expected to read the hartid from
> the DT so we should directly call of_get_cpu_hwid() instead of calling

We should? Or maybe not?

Please write precise changelogs and use imperative wording as documented
in Documentation/process.
  
Anup Patel Oct. 27, 2023, 2:38 p.m. UTC | #2
On Fri, Oct 27, 2023 at 1:29 PM Thomas Gleixner <tglx@linutronix.de> wrote:
>
> On Wed, Oct 25 2023 at 19:58, Anup Patel wrote:
> > The riscv_of_processor_hartid() used by riscv_of_parent_hartid() fails
> > for HARTs disabled in the DT. This results in the following warning
> > thrown by the RISC-V INTC driver for the E-core on SiFive boards:
> >
> > [    0.000000] riscv-intc: unable to find hart id for /cpus/cpu@0/interrupt-controller
> >
> > The riscv_of_parent_hartid() is only expected to read the hartid from
> > the DT so we should directly call of_get_cpu_hwid() instead of calling
>
> We should? Or maybe not?
>
> Please write precise changelogs and use imperative wording as documented
> in Documentation/process.

Sure, I will update the wording in the commit description.

Thanks,
Anup
  

Patch

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index c17dacb1141c..157ace8b262c 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -125,13 +125,14 @@  int __init riscv_early_of_processor_hartid(struct device_node *node, unsigned lo
  */
 int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
 {
-	int rc;
-
 	for (; node; node = node->parent) {
 		if (of_device_is_compatible(node, "riscv")) {
-			rc = riscv_of_processor_hartid(node, hartid);
-			if (!rc)
-				return 0;
+			*hartid = (unsigned long)of_get_cpu_hwid(node, 0);
+			if (*hartid == ~0UL) {
+				pr_warn("Found CPU without hart ID\n");
+				return -ENODEV;
+			}
+			return 0;
 		}
 	}