[PATCH v2] ACPI: ARM Performance Monitoring Unit Table (APMT) initial support

[Will Deacon]

On Wed, Sep 28, 2022 at 07:28:34PM -0500, Besar Wicaksono wrote:
> diff --git a/drivers/acpi/arm64/apmt.c b/drivers/acpi/arm64/apmt.c
> new file mode 100644
> index 000000000000..f55167ca51e7
> --- /dev/null
> +++ b/drivers/acpi/arm64/apmt.c
> @@ -0,0 +1,177 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * ARM APMT table support.
> + * Design document number: ARM DEN0117.
> + *
> + * Copyright (c) 2022, NVIDIA CORPORATION & AFFILIATES.
> + *
> + */
> +
> +#define pr_fmt(fmt)	"ACPI: APMT: " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/acpi_apmt.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +
> +#define DEV_NAME "arm-cs-arch-pmu"
> +
> +/* There can be up to 3 resources: page 0 and 1 address, and interrupt. */
> +#define DEV_MAX_RESOURCE_COUNT 3
> +
> +/* Root pointer to the mapped APMT table */
> +static struct acpi_table_header *apmt_table;
> +
> +static int __init apmt_init_resources(struct resource *res,
> +					      struct acpi_apmt_node *node)
> +{
> +	int irq, trigger;
> +	int num_res = 0;
> +
> +	res[num_res].start = node->base_address0;
> +	res[num_res].end = node->base_address0 + SZ_4K - 1;
> +	res[num_res].flags = IORESOURCE_MEM;
> +
> +	num_res++;
> +
> +	res[num_res].start = node->base_address1;
> +	res[num_res].end = node->base_address1 + SZ_4K - 1;
> +	res[num_res].flags = IORESOURCE_MEM;
> +
> +	num_res++;
> +
> +	if (node->ovflw_irq != 0) {
> +		trigger = (node->ovflw_irq_flags & ACPI_APMT_OVFLW_IRQ_FLAGS_MODE);
> +		trigger = (trigger == ACPI_APMT_OVFLW_IRQ_FLAGS_MODE_LEVEL) ?
> +			ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
> +		irq = acpi_register_gsi(NULL, node->ovflw_irq, trigger,
> +						ACPI_ACTIVE_HIGH);
> +
> +		if (irq <= 0) {
> +			pr_warn("APMT could not register gsi hwirq %d\n", irq);
> +			return num_res;
> +		}
> +
> +		res[num_res].start = irq;
> +		res[num_res].end = irq;
> +		res[num_res].flags = IORESOURCE_IRQ;
> +
> +		num_res++;
> +	}
> +
> +	return num_res;
> +}
> +
> +/**
> + * apmt_add_platform_device() - Allocate a platform device for APMT node
> + * @node: Pointer to device ACPI APMT node
> + *
> + * Returns: 0 on success, <0 failure
> + */
> +static int __init apmt_add_platform_device(struct acpi_apmt_node *node,
> +							struct fwnode_handle *fwnode)

I queued this already, but my testing kicked up a nit that 'fwnode' is not
described in the kerneldoc. Please can you send a follow-up fix for that,
based on for-next/acpi? The indentation is also pretty weird with extra
parameter.

Will