On Wed, Aug 02, 2023 at 08:30:04PM +0530, Anup Patel wrote:
> We add a common riscv_get_intc_hartid() which help device drivers to
> get hartid of the HART associated with a INTC (i.e. local interrupt
> controller) fwnode. This new function is more generic compared to
> the existing riscv_of_parent_hartid() function hence we also replace
> use of riscv_of_parent_hartid() with riscv_get_intc_hartid().
>
> Also, while we are here let us update riscv_of_parent_hartid() to
> always return the hartid irrespective whether the CPU/HART DT node
> is disabled or not.
This change should probably be a separate patch with its own
justification in its commit message.
>
> Signed-off-by: Anup Patel <apatel@xxxxxxxxxxxxxxxx>
> ---
> arch/riscv/include/asm/processor.h | 4 +++-
> arch/riscv/kernel/cpu.c | 26 ++++++++++++++++++++------
> drivers/irqchip/irq-riscv-intc.c | 2 +-
> drivers/irqchip/irq-sifive-plic.c | 3 ++-
> 4 files changed, 26 insertions(+), 9 deletions(-)
>
> diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h
> index c950a8d9edef..662da1e112dd 100644
> --- a/arch/riscv/include/asm/processor.h
> +++ b/arch/riscv/include/asm/processor.h
> @@ -79,7 +79,9 @@ static inline void wait_for_interrupt(void)
> struct device_node;
> int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
> +
> +struct fwnode_handle;
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid);
Do we want a function that is named in a way that appears to be
intc-specific in processor.h?
>
> extern void riscv_fill_hwcap(void);
> extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index a2fc952318e9..c3eaa8a55bbe 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -81,21 +81,35 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har
> * To achieve this, we walk up the DT tree until we find an active
> * RISC-V core (HART) node and extract the cpuid from it.
> */
> -int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
> +static 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);
Shouldn't we still do something like
if (*hartid == ~0UL) {
pr_warn_once("Found CPU without hart ID\n");
return -ENODEV;
}
> + return 0;
> }
> }
>
> return -1;
> }
>
> +/* Find hart ID of the INTC fwnode. */
> +int riscv_get_intc_hartid(struct fwnode_handle *node, unsigned long *hartid)
> +{
> + int rc;
> + u64 temp;
> +
> + if (!is_of_node(node)) {
> + rc = fwnode_property_read_u64_array(node, "hartid", &temp, 1);
This fwnode property read call seems premature, since we don't have any
way to know that "hartid" will be a property of the intc since it's not a
property documented in the DT binding. (I know Sunil has a series in
progress which will introduce "hartid" for ACPI, but, even then, it seems
like we need some documentation to point at that says '"hartid" is the
name to use'.
> + if (!rc)
> + *hartid = temp;
> + } else
> + rc = riscv_of_parent_hartid(to_of_node(node), hartid);
> +
> + return rc;
> +}
> +
> DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
>
> unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
> diff --git a/drivers/irqchip/irq-riscv-intc.c b/drivers/irqchip/irq-riscv-intc.c
> index 4adeee1bc391..65f4a2afb381 100644
> --- a/drivers/irqchip/irq-riscv-intc.c
> +++ b/drivers/irqchip/irq-riscv-intc.c
> @@ -143,7 +143,7 @@ static int __init riscv_intc_init(struct device_node *node,
> int rc;
> unsigned long hartid;
>
> - rc = riscv_of_parent_hartid(node, &hartid);
> + rc = riscv_get_intc_hartid(of_fwnode_handle(node), &hartid);
> if (rc < 0) {
> pr_warn("unable to find hart id for %pOF\n", node);
> return 0;
> diff --git a/drivers/irqchip/irq-sifive-plic.c b/drivers/irqchip/irq-sifive-plic.c
> index e1484905b7bd..56b0544b1f27 100644
> --- a/drivers/irqchip/irq-sifive-plic.c
> +++ b/drivers/irqchip/irq-sifive-plic.c
> @@ -477,7 +477,8 @@ static int __init __plic_init(struct device_node *node,
> continue;
> }
>
> - error = riscv_of_parent_hartid(parent.np, &hartid);
> + error = riscv_get_intc_hartid(of_fwnode_handle(parent.np),
> + &hartid);
> if (error < 0) {
> pr_warn("failed to parse hart ID for context %d.\n", i);
> continue;
> --
> 2.34.1
>
Thanks,
drew
