Hi Lukas
> From: Lukas Auer [mailto:lukas.a...@aisec.fraunhofer.de]
> Sent: Wednesday, December 04, 2019 5:40 AM
> To: u-boot@lists.denx.de
> Cc: Rick Jian-Zhi Chen(陳建志); Anup Patel; Bin Meng; Lukas Auer; Anup Patel;
> Atish Patra
> Subject: [PATCH 2/4] riscv: add functions for reading the IPI status
>
> Add the function riscv_get_ipi() for reading the pending status of IPIs.
> The supported controllers are Andes' Platform Level Interrupt Controller
> (PLIC), the Supervisor Binary Interface (SBI), and SiFive's Core Local
> Interruptor (CLINT).
>
> Signed-off-by: Lukas Auer <lukas.a...@aisec.fraunhofer.de>
> ---
> I do not have access to the datasheet of the Andes PLIC. The
> riscv_clear_ipi() implementation seems to read the IPI status from the claim
> register before writing back the results to clear them. Based on this, I also
> used the claim register. Rick, please let me know if that is ok or if I
> should use the pending register instead.
Yes.
Please use pending register instead of claim register.
Thanks
Rick
>
> arch/riscv/lib/andes_plic.c | 9 +++++++++
> arch/riscv/lib/sbi_ipi.c | 11 +++++++++++
> arch/riscv/lib/sifive_clint.c | 9 +++++++++
> arch/riscv/lib/smp.c | 12 ++++++++++++
> 4 files changed, 41 insertions(+)
>
> diff --git a/arch/riscv/lib/andes_plic.c b/arch/riscv/lib/andes_plic.c index
> 28568e4e2b..731ac3a148 100644
> --- a/arch/riscv/lib/andes_plic.c
> +++ b/arch/riscv/lib/andes_plic.c
> @@ -114,6 +114,15 @@ int riscv_clear_ipi(int hart)
> return 0;
> }
>
> +int riscv_get_ipi(int hart, int *pending) {
> + PLIC_BASE_GET();
> +
> + *pending = !!readl((void __iomem *)CLAIM_REG(gd->arch.plic, hart));
> +
> + return 0;
> +}
> +
> static const struct udevice_id andes_plic_ids[] = {
> { .compatible = "riscv,plic1", .data = RISCV_SYSCON_PLIC },
> { }
> diff --git a/arch/riscv/lib/sbi_ipi.c b/arch/riscv/lib/sbi_ipi.c index
> 170346da68..9a698ce74e 100644
> --- a/arch/riscv/lib/sbi_ipi.c
> +++ b/arch/riscv/lib/sbi_ipi.c
> @@ -23,3 +23,14 @@ int riscv_clear_ipi(int hart)
>
> return 0;
> }
> +
> +int riscv_get_ipi(int hart, int *pending) {
> + /*
> + * The SBI does not support reading the IPI status. We always return 0
> + * to indicate that no IPI is pending.
> + */
> + *pending = 0;
> +
> + return 0;
> +}
> diff --git a/arch/riscv/lib/sifive_clint.c b/arch/riscv/lib/sifive_clint.c
> index d24e0d585b..d7899d16d7 100644
> --- a/arch/riscv/lib/sifive_clint.c
> +++ b/arch/riscv/lib/sifive_clint.c
> @@ -71,6 +71,15 @@ int riscv_clear_ipi(int hart)
> return 0;
> }
>
> +int riscv_get_ipi(int hart, int *pending) {
> + CLINT_BASE_GET();
> +
> + *pending = readl((void __iomem *)MSIP_REG(gd->arch.clint, hart));
> +
> + return 0;
> +}
> +
> static const struct udevice_id sifive_clint_ids[] = {
> { .compatible = "riscv,clint0", .data = RISCV_SYSCON_CLINT },
> { }
> diff --git a/arch/riscv/lib/smp.c b/arch/riscv/lib/smp.c index
> cc66f15567..6ff0de4b74 100644
> --- a/arch/riscv/lib/smp.c
> +++ b/arch/riscv/lib/smp.c
> @@ -31,6 +31,18 @@ extern int riscv_send_ipi(int hart);
> */
> extern int riscv_clear_ipi(int hart);
>
> +/**
> + * riscv_get_ipi() - Get status of inter-processor interrupt (IPI)
> + *
> + * Platform code must provide this function.
> + *
> + * @hart: Hart ID of hart to be checked
> + * @pending: Pointer to variable with result of the check,
> + * 1 if IPI is pending, 0 otherwise
> + * @return 0 if OK, -ve on error
> + */
> +extern int riscv_get_ipi(int hart, int *pending);
> +
> static int send_ipi_many(struct ipi_data *ipi) {
> ofnode node, cpus;
> --
> 2.21.0
>
