Re: [PATCH net-next 1/6] platform/x86: intel_pmc_core: Add IPC mailbox accessor function and add SoC register access

[Simon Horman <simon.horman@corigine.com>]

On Thu, Jun 22, 2023 at 12:19:00PM +0800, Choong Yong Liang wrote:
> From: "David E. Box" <david.e.box@linux.intel.com>
> 
> - Exports intel_pmc_core_ipc() for host access to the PMC IPC mailbox
> - Add support to use IPC command allows host to access SoC registers
> through PMC firmware that are otherwise inaccessible to the host due to
> security policies.
> 
> Signed-off-by: David E. Box <david.e.box@linux.intel.com>
> Signed-off-by: Chao Qin <chao.qin@intel.com>
> Signed-off-by: Choong Yong Liang <yong.liang.choong@linux.intel.com>

...

> diff --git a/drivers/platform/x86/intel/pmc/core.c b/drivers/platform/x86/intel/pmc/core.c
> index da6e7206d38b..0d60763c5144 100644
> --- a/drivers/platform/x86/intel/pmc/core.c
> +++ b/drivers/platform/x86/intel/pmc/core.c
> @@ -16,6 +16,7 @@
>  #include <linux/delay.h>
>  #include <linux/dmi.h>
>  #include <linux/io.h>
> +#include <linux/intel_pmc_core.h>
>  #include <linux/module.h>
>  #include <linux/pci.h>
>  #include <linux/slab.h>
> @@ -26,7 +27,9 @@
>  #include <asm/msr.h>
>  #include <asm/tsc.h>
>  
> -#include "core.h"
> +#define PMC_IPCS_PARAM_COUNT           7
> +
> +static const struct x86_cpu_id *pmc_cpu_id;
>  
>  /* Maximum number of modes supported by platfoms that has low power mode capability */
>  const char *pmc_lpm_modes[] = {

Hi Choong Yong Liang,

It looks like pmc_lpm_mode is used in this file and, as of this patch,
has no declaration. Should it be static?

...

> diff --git a/drivers/platform/x86/intel/pmc/core.h b/include/linux/intel_pmc_core.h
> similarity index 95%
> rename from drivers/platform/x86/intel/pmc/core.h
> rename to include/linux/intel_pmc_core.h
> index 9ca9b9746719..82810e8b92a2 100644
> --- a/drivers/platform/x86/intel/pmc/core.h
> +++ b/include/linux/intel_pmc_core.h
> @@ -250,7 +250,16 @@ enum ppfear_regs {
>  #define MTL_LPM_STATUS_OFFSET			0x1700
>  #define MTL_LPM_LIVE_STATUS_OFFSET		0x175C
>  
> -extern const char *pmc_lpm_modes[];
> +#define IPC_SOC_REGISTER_ACCESS			0xAA
> +#define IPC_SOC_SUB_CMD_READ			0x00
> +#define IPC_SOC_SUB_CMD_WRITE			0x01
> +
> +struct pmc_ipc_cmd {
> +	u32 cmd;
> +	u32 sub_cmd;
> +	u32 size;
> +	u32 wbuf[4];
> +};
>  
>  struct pmc_bit_map {
>  	const char *name;

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