Re: [PATCH v4 1/3] ACPI/APEI: Add hest_parse_pcie_aer()

Yazen Ghannam
2024-12-11T19:21:10Z

On Thu, Dec 05, 2024 at 07:40:46PM +0800, LeoLiu-oc wrote:
> From: LeoLiuoc <LeoLiu-oc@zhaoxin.com>
>
> The purpose of the function apei_hest_parse_aer() is used to parse and
> extract register value from HEST PCIe AER structures. This applies to
> all hardware platforms that has a PCI Express AER structure in HEST.
>
> Signed-off-by: LeoLiuoc <LeoLiu-oc@zhaoxin.com>
> ---
> drivers/acpi/apei/hest.c | 77 ++++++++++++++++++++++++++++++++++++++--
> include/acpi/apei.h | 17 +++++++++
> 2 files changed, 92 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/acpi/apei/hest.c b/drivers/acpi/apei/hest.c
> index 20d757687e3d..13075f5aea25 100644
> --- a/drivers/acpi/apei/hest.c
> +++ b/drivers/acpi/apei/hest.c
> @@ -22,6 +22,7 @@
> #include <linux/kdebug.h>
> #include <linux/highmem.h>
> #include <linux/io.h>
> +#include <linux/pci.h>
> #include <linux/platform_device.h>
> #include <acpi/apei.h>
> #include <acpi/ghes.h>
> @@ -132,9 +133,81 @@ static bool is_ghes_assist_struct(struct acpi_hest_header *hest_hdr)
> return false;
> }
>
> -typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
> +#ifdef CONFIG_ACPI_APEI

Why is this needed? The entire hest.c file is only built if
CONFIG_ACPI_APEI is enabled.

> +static bool hest_match_pci_devfn(struct acpi_hest_aer_common *p,
> + struct pci_dev *dev)
> +{
> + return ACPI_HEST_SEGMENT(p->bus) == pci_domain_nr(dev->bus) &&
> + ACPI_HEST_BUS(p->bus) == dev->bus->number &&
> + p->device == PCI_SLOT(dev->devfn) &&
> + p->function == PCI_FUNC(dev->devfn);

It may be nice to align all these lines on the "==".

> +}
> +
> +static bool hest_source_is_pcie_aer(struct acpi_hest_header *hest_hdr,
> + struct pci_dev *dev)
> +{
> + u16 hest_type = hest_hdr->type;
> + u8 pcie_type = pci_pcie_type(dev);
> + struct acpi_hest_aer_common *common;
> +
> + common = (struct acpi_hest_aer_common *)(hest_hdr + 1);
> +
> + switch (hest_type) {
> + case ACPI_HEST_TYPE_AER_ROOT_PORT:
> + if (pcie_type != PCI_EXP_TYPE_ROOT_PORT)
> + return false;
> + break;

The breaks should be indented to the "if". Same for the rest of the
file.

> + case ACPI_HEST_TYPE_AER_ENDPOINT:
> + if (pcie_type != PCI_EXP_TYPE_ENDPOINT)
> + return false;
> + break;
> + case ACPI_HEST_TYPE_AER_BRIDGE:
> + if (pcie_type != PCI_EXP_TYPE_PCI_BRIDGE &&
> + pcie_type != PCI_EXP_TYPE_PCIE_BRIDGE)
> + return false;
> + break;
> + default:
> + return false;
> + break;
> + }
> +
> + if (common->flags & ACPI_HEST_GLOBAL)
> + return true;
> +
> + if (hest_match_pci_devfn(common, dev))
> + return true;
> +
> + return false;
> +}
> +
> +int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data)
> +{
> + struct hest_parse_aer_info *info = data;
> +
> + if (!hest_source_is_pcie_aer(hest_hdr, info->pci_dev))
> + return 0;
> +
> + switch (hest_hdr->type) {
> + case ACPI_HEST_TYPE_AER_ROOT_PORT:
> + info->hest_aer_root_port = (struct acpi_hest_aer_root *)hest_hdr;
> + return 1;
> + break;
> + case ACPI_HEST_TYPE_AER_ENDPOINT:
> + info->hest_aer_endpoint = (struct acpi_hest_aer *)hest_hdr;
> + return 1;
> + break;
> + case ACPI_HEST_TYPE_AER_BRIDGE:
> + info->hest_aer_bridge = (struct acpi_hest_aer_bridge *)hest_hdr;
> + return 1;
> + break;
> + default:
> + return 0;
> + break;
> + }
> +}
> +#endif
>
> -static int apei_hest_parse(apei_hest_func_t func, void *data)
> +int apei_hest_parse(apei_hest_func_t func, void *data)
> {
> struct acpi_hest_header *hest_hdr;
> int i, rc, len;
> diff --git a/include/acpi/apei.h b/include/acpi/apei.h
> index dc60f7db5524..82d3cdf53e22 100644
> --- a/include/acpi/apei.h
> +++ b/include/acpi/apei.h
> @@ -23,6 +23,15 @@ enum hest_status {
> HEST_NOT_FOUND,
> };
>
> +#ifdef CONFIG_ACPI_APEI
> +struct hest_parse_aer_info {
> + struct pci_dev *pci_dev;
> + struct acpi_hest_aer *hest_aer_endpoint;
> + struct acpi_hest_aer_root *hest_aer_root_port;
> + struct acpi_hest_aer_bridge *hest_aer_bridge;

These three pointers are mutually exclusive. Can you save just one
pointer and then cast it when checking the "port_type" in patch 3?

> +};
> +#endif

I think the #ifdef is not needed, because this is not declaring an
instance of the struct.

> +
> extern int hest_disable;
> extern int erst_disable;
> #ifdef CONFIG_ACPI_APEI_GHES
> @@ -33,10 +42,18 @@ void __init acpi_ghes_init(void);
> static inline void acpi_ghes_init(void) { }
> #endif
>
> +typedef int (*apei_hest_func_t)(struct acpi_hest_header *hest_hdr, void *data);
> +int apei_hest_parse(apei_hest_func_t func, void *data);
> +

Minor nit: this could be done as a separate patch.

Patch 1: Move apei_hest_parse() to apei.h
Patch 2: Add new hest_parse_pcie_aer()

> #ifdef CONFIG_ACPI_APEI
> void __init acpi_hest_init(void);
> +int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data);
> #else
> static inline void acpi_hest_init(void) { }
> +static inline int hest_parse_pcie_aer(struct acpi_hest_header *hest_hdr, void *data)
> +{
> + return 0;
> +}
> #endif
>
> int erst_write(const struct cper_record_header *record);
> --

Thanks,
Yazen