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

Message ID 20230622041905.629430-2-yong.liang.choong@linux.intel.com
State New
Headers
Series TSN auto negotiation between 1G and 2.5G |

Commit Message

Choong Yong Liang June 22, 2023, 4:19 a.m. UTC
  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>
---
 MAINTAINERS                                   |  1 +
 drivers/platform/x86/intel/pmc/adl.c          |  2 +-
 drivers/platform/x86/intel/pmc/cnp.c          |  2 +-
 drivers/platform/x86/intel/pmc/core.c         | 63 ++++++++++++++++++-
 drivers/platform/x86/intel/pmc/icl.c          |  2 +-
 drivers/platform/x86/intel/pmc/mtl.c          |  2 +-
 drivers/platform/x86/intel/pmc/spt.c          |  2 +-
 drivers/platform/x86/intel/pmc/tgl.c          |  2 +-
 .../core.h => include/linux/intel_pmc_core.h  | 27 +++++++-
 9 files changed, 95 insertions(+), 8 deletions(-)
 rename drivers/platform/x86/intel/pmc/core.h => include/linux/intel_pmc_core.h (95%)
  

Comments

Hans de Goede June 22, 2023, 8:18 a.m. UTC | #1
Hi,

On 6/22/23 06:19, 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>

This seem to be 2 patches in 1:

1. Move core.h to include/linux/intel_pmc_core.h
2. The actual adding of IPC mailbox accessor function and add SoC register access

I wonder if you really need to move the entire core.h ?

IMHO it would be better to just add a new header with just the bits
which you actually need to export the desired functionality.

If you do believe that you really need to move core.h please split
this into 2 separate patches and please place the header in a x86
specific place, e.g. : include/linux/platform_data/x86/



Also note that a somewhat big refactor, to add support for
multiple PMCs for Meteor Lake is on its way to linux-next.

Currently this is available in my review-hans branch:

https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans

Please base a next version of this on this.

There also is the question of how to merge this. Assuming this is
ready for merging once 6.5-rc1 is out then I can merge this intel_pmc_core
change into an immutable branch and send a pull-req to the net folks
for this.

Regards,

Hans






> ---
>  MAINTAINERS                                   |  1 +
>  drivers/platform/x86/intel/pmc/adl.c          |  2 +-
>  drivers/platform/x86/intel/pmc/cnp.c          |  2 +-
>  drivers/platform/x86/intel/pmc/core.c         | 63 ++++++++++++++++++-
>  drivers/platform/x86/intel/pmc/icl.c          |  2 +-
>  drivers/platform/x86/intel/pmc/mtl.c          |  2 +-
>  drivers/platform/x86/intel/pmc/spt.c          |  2 +-
>  drivers/platform/x86/intel/pmc/tgl.c          |  2 +-
>  .../core.h => include/linux/intel_pmc_core.h  | 27 +++++++-
>  9 files changed, 95 insertions(+), 8 deletions(-)
>  rename drivers/platform/x86/intel/pmc/core.h => include/linux/intel_pmc_core.h (95%)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index cb14589d14ab..bdb08a79a5f8 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10581,6 +10581,7 @@ L:	platform-driver-x86@vger.kernel.org
>  S:	Maintained
>  F:	Documentation/ABI/testing/sysfs-platform-intel-pmc
>  F:	drivers/platform/x86/intel/pmc/
> +F:	include/linux/intel_pmc_core*
>  
>  INTEL PMIC GPIO DRIVERS
>  M:	Andy Shevchenko <andy@kernel.org>
> diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
> index 5cbd40979f2a..b6a376c536c0 100644
> --- a/drivers/platform/x86/intel/pmc/adl.c
> +++ b/drivers/platform/x86/intel/pmc/adl.c
> @@ -8,7 +8,7 @@
>   *
>   */
>  
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  /* Alder Lake: PGD PFET Enable Ack Status Register(s) bitmap */
>  const struct pmc_bit_map adl_pfear_map[] = {
> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
> index 7fb38815c4eb..504034cc5ec3 100644
> --- a/drivers/platform/x86/intel/pmc/cnp.c
> +++ b/drivers/platform/x86/intel/pmc/cnp.c
> @@ -8,7 +8,7 @@
>   *
>   */
>  
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
>  const struct pmc_bit_map cnp_pfear_map[] = {
> 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[] = {
> @@ -53,6 +56,63 @@ const struct pmc_bit_map msr_map[] = {
>  	{}
>  };
>  
> +int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
> +{
> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> +	union acpi_object params[PMC_IPCS_PARAM_COUNT] = {
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +		{.type = ACPI_TYPE_INTEGER,},
> +	};
> +	struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
> +	union acpi_object *obj;
> +	int status;
> +
> +	if (!pmc_cpu_id || !ipc_cmd || !rbuf)
> +		return -EINVAL;
> +
> +	/*
> +	 * 0: IPC Command
> +	 * 1: IPC Sub Command
> +	 * 2: Size
> +	 * 3-6: Write Buffer for offset
> +	 */
> +	params[0].integer.value = ipc_cmd->cmd;
> +	params[1].integer.value = ipc_cmd->sub_cmd;
> +	params[2].integer.value = ipc_cmd->size;
> +	params[3].integer.value = ipc_cmd->wbuf[0];
> +	params[4].integer.value = ipc_cmd->wbuf[1];
> +	params[5].integer.value = ipc_cmd->wbuf[2];
> +	params[6].integer.value = ipc_cmd->wbuf[3];
> +
> +	status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	obj = buffer.pointer;
> +	/* Check if the number of elements in package is 5 */
> +	if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
> +		const union acpi_object *objs = obj->package.elements;
> +
> +		if ((u8)objs[0].integer.value != 0)
> +			return -EINVAL;
> +
> +		rbuf[0] = objs[1].integer.value;
> +		rbuf[1] = objs[2].integer.value;
> +		rbuf[2] = objs[3].integer.value;
> +		rbuf[3] = objs[4].integer.value;
> +	} else {
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +EXPORT_SYMBOL(intel_pmc_core_ipc);
> +
>  static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
>  {
>  	return readl(pmcdev->regbase + reg_offset);
> @@ -1130,6 +1190,7 @@ static int pmc_core_probe(struct platform_device *pdev)
>  	mutex_init(&pmcdev->lock);
>  	core_init(pmcdev);
>  
> +	pmc_cpu_id = cpu_id;
>  
>  	if (lpit_read_residency_count_address(&slp_s0_addr)) {
>  		pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
> diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
> index 2f11b1a6daeb..f18048ff9382 100644
> --- a/drivers/platform/x86/intel/pmc/icl.c
> +++ b/drivers/platform/x86/intel/pmc/icl.c
> @@ -8,7 +8,7 @@
>   *
>   */
>  
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  const struct pmc_bit_map icl_pfear_map[] = {
>  	{"RES_65",		BIT(0)},
> diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
> index e8cc156412ce..7897f5fe9881 100644
> --- a/drivers/platform/x86/intel/pmc/mtl.c
> +++ b/drivers/platform/x86/intel/pmc/mtl.c
> @@ -9,7 +9,7 @@
>   */
>  
>  #include <linux/pci.h>
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  const struct pmc_reg_map mtl_reg_map = {
>  	.pfear_sts = ext_tgl_pfear_map,
> diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
> index e16982236778..95ce490cf5d6 100644
> --- a/drivers/platform/x86/intel/pmc/spt.c
> +++ b/drivers/platform/x86/intel/pmc/spt.c
> @@ -8,7 +8,7 @@
>   *
>   */
>  
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  const struct pmc_bit_map spt_pll_map[] = {
>  	{"MIPI PLL",			SPT_PMC_BIT_MPHY_CMN_LANE0},
> diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
> index c245ada849d0..a1719d809497 100644
> --- a/drivers/platform/x86/intel/pmc/tgl.c
> +++ b/drivers/platform/x86/intel/pmc/tgl.c
> @@ -8,7 +8,7 @@
>   *
>   */
>  
> -#include "core.h"
> +#include <linux/intel_pmc_core.h>
>  
>  #define ACPI_S0IX_DSM_UUID		"57a6512e-3979-4e9d-9708-ff13b2508972"
>  #define ACPI_GET_LOW_MODE_REGISTERS	1
> 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;
> @@ -427,4 +436,20 @@ static const struct file_operations __name ## _fops = {			\
>  	.release	= single_release,				\
>  }
>  
> +#if IS_ENABLED(CONFIG_INTEL_PMC_CORE)
> +/**
> + * intel_pmc_core_ipc() - PMC IPC Mailbox accessor
> + * @ipc_cmd:  struct pmc_ipc_cmd prepared with input to send
> + * @rbuf:     Allocated u32[4] array for returned IPC data
> + *
> + * Return: 0 on success. Non-zero on mailbox error
> + */
> +int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf);
> +#else
> +static inline int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
> +{
> +	return -ENODEV;
> +}
> +#endif /* CONFIG_INTEL_PMC_CORE */
> +
>  #endif /* PMC_CORE_H */
  
Simon Horman June 22, 2023, 2:41 p.m. UTC | #2
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;

...
  
Choong Yong Liang June 23, 2023, 5:52 a.m. UTC | #3
Hi Hans,

I will discuss it with David but currently he is on vacation. It might take 
some time to get the final output. Thank you.

On 22/6/2023 4:18 pm, Hans de Goede wrote:
> Hi,
> 
> On 6/22/23 06:19, 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>
> 
> This seem to be 2 patches in 1:
> 
> 1. Move core.h to include/linux/intel_pmc_core.h
> 2. The actual adding of IPC mailbox accessor function and add SoC register access
> 
> I wonder if you really need to move the entire core.h ?
> 
> IMHO it would be better to just add a new header with just the bits
> which you actually need to export the desired functionality.
> 
> If you do believe that you really need to move core.h please split
> this into 2 separate patches and please place the header in a x86
> specific place, e.g. : include/linux/platform_data/x86/
> 
> 
> 
> Also note that a somewhat big refactor, to add support for
> multiple PMCs for Meteor Lake is on its way to linux-next.
> 
> Currently this is available in my review-hans branch:
> 
> https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
> 
> Please base a next version of this on this.
> 
> There also is the question of how to merge this. Assuming this is
> ready for merging once 6.5-rc1 is out then I can merge this intel_pmc_core
> change into an immutable branch and send a pull-req to the net folks
> for this.
> 
> Regards,
> 
> Hans
> 
> 
> 
> 
> 
> 
>> ---
>>   MAINTAINERS                                   |  1 +
>>   drivers/platform/x86/intel/pmc/adl.c          |  2 +-
>>   drivers/platform/x86/intel/pmc/cnp.c          |  2 +-
>>   drivers/platform/x86/intel/pmc/core.c         | 63 ++++++++++++++++++-
>>   drivers/platform/x86/intel/pmc/icl.c          |  2 +-
>>   drivers/platform/x86/intel/pmc/mtl.c          |  2 +-
>>   drivers/platform/x86/intel/pmc/spt.c          |  2 +-
>>   drivers/platform/x86/intel/pmc/tgl.c          |  2 +-
>>   .../core.h => include/linux/intel_pmc_core.h  | 27 +++++++-
>>   9 files changed, 95 insertions(+), 8 deletions(-)
>>   rename drivers/platform/x86/intel/pmc/core.h => include/linux/intel_pmc_core.h (95%)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index cb14589d14ab..bdb08a79a5f8 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10581,6 +10581,7 @@ L:	platform-driver-x86@vger.kernel.org
>>   S:	Maintained
>>   F:	Documentation/ABI/testing/sysfs-platform-intel-pmc
>>   F:	drivers/platform/x86/intel/pmc/
>> +F:	include/linux/intel_pmc_core*
>>   
>>   INTEL PMIC GPIO DRIVERS
>>   M:	Andy Shevchenko <andy@kernel.org>
>> diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
>> index 5cbd40979f2a..b6a376c536c0 100644
>> --- a/drivers/platform/x86/intel/pmc/adl.c
>> +++ b/drivers/platform/x86/intel/pmc/adl.c
>> @@ -8,7 +8,7 @@
>>    *
>>    */
>>   
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   /* Alder Lake: PGD PFET Enable Ack Status Register(s) bitmap */
>>   const struct pmc_bit_map adl_pfear_map[] = {
>> diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
>> index 7fb38815c4eb..504034cc5ec3 100644
>> --- a/drivers/platform/x86/intel/pmc/cnp.c
>> +++ b/drivers/platform/x86/intel/pmc/cnp.c
>> @@ -8,7 +8,7 @@
>>    *
>>    */
>>   
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
>>   const struct pmc_bit_map cnp_pfear_map[] = {
>> 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[] = {
>> @@ -53,6 +56,63 @@ const struct pmc_bit_map msr_map[] = {
>>   	{}
>>   };
>>   
>> +int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
>> +{
>> +	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
>> +	union acpi_object params[PMC_IPCS_PARAM_COUNT] = {
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +		{.type = ACPI_TYPE_INTEGER,},
>> +	};
>> +	struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
>> +	union acpi_object *obj;
>> +	int status;
>> +
>> +	if (!pmc_cpu_id || !ipc_cmd || !rbuf)
>> +		return -EINVAL;
>> +
>> +	/*
>> +	 * 0: IPC Command
>> +	 * 1: IPC Sub Command
>> +	 * 2: Size
>> +	 * 3-6: Write Buffer for offset
>> +	 */
>> +	params[0].integer.value = ipc_cmd->cmd;
>> +	params[1].integer.value = ipc_cmd->sub_cmd;
>> +	params[2].integer.value = ipc_cmd->size;
>> +	params[3].integer.value = ipc_cmd->wbuf[0];
>> +	params[4].integer.value = ipc_cmd->wbuf[1];
>> +	params[5].integer.value = ipc_cmd->wbuf[2];
>> +	params[6].integer.value = ipc_cmd->wbuf[3];
>> +
>> +	status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer);
>> +	if (ACPI_FAILURE(status))
>> +		return -ENODEV;
>> +
>> +	obj = buffer.pointer;
>> +	/* Check if the number of elements in package is 5 */
>> +	if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
>> +		const union acpi_object *objs = obj->package.elements;
>> +
>> +		if ((u8)objs[0].integer.value != 0)
>> +			return -EINVAL;
>> +
>> +		rbuf[0] = objs[1].integer.value;
>> +		rbuf[1] = objs[2].integer.value;
>> +		rbuf[2] = objs[3].integer.value;
>> +		rbuf[3] = objs[4].integer.value;
>> +	} else {
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +EXPORT_SYMBOL(intel_pmc_core_ipc);
>> +
>>   static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
>>   {
>>   	return readl(pmcdev->regbase + reg_offset);
>> @@ -1130,6 +1190,7 @@ static int pmc_core_probe(struct platform_device *pdev)
>>   	mutex_init(&pmcdev->lock);
>>   	core_init(pmcdev);
>>   
>> +	pmc_cpu_id = cpu_id;
>>   
>>   	if (lpit_read_residency_count_address(&slp_s0_addr)) {
>>   		pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
>> diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
>> index 2f11b1a6daeb..f18048ff9382 100644
>> --- a/drivers/platform/x86/intel/pmc/icl.c
>> +++ b/drivers/platform/x86/intel/pmc/icl.c
>> @@ -8,7 +8,7 @@
>>    *
>>    */
>>   
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   const struct pmc_bit_map icl_pfear_map[] = {
>>   	{"RES_65",		BIT(0)},
>> diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
>> index e8cc156412ce..7897f5fe9881 100644
>> --- a/drivers/platform/x86/intel/pmc/mtl.c
>> +++ b/drivers/platform/x86/intel/pmc/mtl.c
>> @@ -9,7 +9,7 @@
>>    */
>>   
>>   #include <linux/pci.h>
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   const struct pmc_reg_map mtl_reg_map = {
>>   	.pfear_sts = ext_tgl_pfear_map,
>> diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
>> index e16982236778..95ce490cf5d6 100644
>> --- a/drivers/platform/x86/intel/pmc/spt.c
>> +++ b/drivers/platform/x86/intel/pmc/spt.c
>> @@ -8,7 +8,7 @@
>>    *
>>    */
>>   
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   const struct pmc_bit_map spt_pll_map[] = {
>>   	{"MIPI PLL",			SPT_PMC_BIT_MPHY_CMN_LANE0},
>> diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
>> index c245ada849d0..a1719d809497 100644
>> --- a/drivers/platform/x86/intel/pmc/tgl.c
>> +++ b/drivers/platform/x86/intel/pmc/tgl.c
>> @@ -8,7 +8,7 @@
>>    *
>>    */
>>   
>> -#include "core.h"
>> +#include <linux/intel_pmc_core.h>
>>   
>>   #define ACPI_S0IX_DSM_UUID		"57a6512e-3979-4e9d-9708-ff13b2508972"
>>   #define ACPI_GET_LOW_MODE_REGISTERS	1
>> 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;
>> @@ -427,4 +436,20 @@ static const struct file_operations __name ## _fops = {			\
>>   	.release	= single_release,				\
>>   }
>>   
>> +#if IS_ENABLED(CONFIG_INTEL_PMC_CORE)
>> +/**
>> + * intel_pmc_core_ipc() - PMC IPC Mailbox accessor
>> + * @ipc_cmd:  struct pmc_ipc_cmd prepared with input to send
>> + * @rbuf:     Allocated u32[4] array for returned IPC data
>> + *
>> + * Return: 0 on success. Non-zero on mailbox error
>> + */
>> +int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf);
>> +#else
>> +static inline int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
>> +{
>> +	return -ENODEV;
>> +}
>> +#endif /* CONFIG_INTEL_PMC_CORE */
>> +
>>   #endif /* PMC_CORE_H */
>
  
Choong Yong Liang June 23, 2023, 5:54 a.m. UTC | #4
Hi Simon,

Yes, you are right. I will add static in v2. Thank you.

On 22/6/2023 10:41 pm, Simon Horman wrote:
> 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;
> 
> ...
  
Wong Vee Khee June 23, 2023, 12:44 p.m. UTC | #5
On Fri, Jun 23, 2023 at 01:52:49PM +0800, Choong Yong Liang wrote:
> Hi Hans,
> 
> I will discuss it with David but currently he is on vacation. It might take
> some time to get the final output. Thank you.
>

Please remember not to top post on ML.

Regards,
 Vee Khee
  

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index cb14589d14ab..bdb08a79a5f8 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10581,6 +10581,7 @@  L:	platform-driver-x86@vger.kernel.org
 S:	Maintained
 F:	Documentation/ABI/testing/sysfs-platform-intel-pmc
 F:	drivers/platform/x86/intel/pmc/
+F:	include/linux/intel_pmc_core*
 
 INTEL PMIC GPIO DRIVERS
 M:	Andy Shevchenko <andy@kernel.org>
diff --git a/drivers/platform/x86/intel/pmc/adl.c b/drivers/platform/x86/intel/pmc/adl.c
index 5cbd40979f2a..b6a376c536c0 100644
--- a/drivers/platform/x86/intel/pmc/adl.c
+++ b/drivers/platform/x86/intel/pmc/adl.c
@@ -8,7 +8,7 @@ 
  *
  */
 
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 /* Alder Lake: PGD PFET Enable Ack Status Register(s) bitmap */
 const struct pmc_bit_map adl_pfear_map[] = {
diff --git a/drivers/platform/x86/intel/pmc/cnp.c b/drivers/platform/x86/intel/pmc/cnp.c
index 7fb38815c4eb..504034cc5ec3 100644
--- a/drivers/platform/x86/intel/pmc/cnp.c
+++ b/drivers/platform/x86/intel/pmc/cnp.c
@@ -8,7 +8,7 @@ 
  *
  */
 
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 /* Cannon Lake: PGD PFET Enable Ack Status Register(s) bitmap */
 const struct pmc_bit_map cnp_pfear_map[] = {
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[] = {
@@ -53,6 +56,63 @@  const struct pmc_bit_map msr_map[] = {
 	{}
 };
 
+int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
+{
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+	union acpi_object params[PMC_IPCS_PARAM_COUNT] = {
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+		{.type = ACPI_TYPE_INTEGER,},
+	};
+	struct acpi_object_list arg_list = { PMC_IPCS_PARAM_COUNT, params };
+	union acpi_object *obj;
+	int status;
+
+	if (!pmc_cpu_id || !ipc_cmd || !rbuf)
+		return -EINVAL;
+
+	/*
+	 * 0: IPC Command
+	 * 1: IPC Sub Command
+	 * 2: Size
+	 * 3-6: Write Buffer for offset
+	 */
+	params[0].integer.value = ipc_cmd->cmd;
+	params[1].integer.value = ipc_cmd->sub_cmd;
+	params[2].integer.value = ipc_cmd->size;
+	params[3].integer.value = ipc_cmd->wbuf[0];
+	params[4].integer.value = ipc_cmd->wbuf[1];
+	params[5].integer.value = ipc_cmd->wbuf[2];
+	params[6].integer.value = ipc_cmd->wbuf[3];
+
+	status = acpi_evaluate_object(NULL, "\\IPCS", &arg_list, &buffer);
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	obj = buffer.pointer;
+	/* Check if the number of elements in package is 5 */
+	if (obj && obj->type == ACPI_TYPE_PACKAGE && obj->package.count == 5) {
+		const union acpi_object *objs = obj->package.elements;
+
+		if ((u8)objs[0].integer.value != 0)
+			return -EINVAL;
+
+		rbuf[0] = objs[1].integer.value;
+		rbuf[1] = objs[2].integer.value;
+		rbuf[2] = objs[3].integer.value;
+		rbuf[3] = objs[4].integer.value;
+	} else {
+		return -EINVAL;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(intel_pmc_core_ipc);
+
 static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
 {
 	return readl(pmcdev->regbase + reg_offset);
@@ -1130,6 +1190,7 @@  static int pmc_core_probe(struct platform_device *pdev)
 	mutex_init(&pmcdev->lock);
 	core_init(pmcdev);
 
+	pmc_cpu_id = cpu_id;
 
 	if (lpit_read_residency_count_address(&slp_s0_addr)) {
 		pmcdev->base_addr = PMC_BASE_ADDR_DEFAULT;
diff --git a/drivers/platform/x86/intel/pmc/icl.c b/drivers/platform/x86/intel/pmc/icl.c
index 2f11b1a6daeb..f18048ff9382 100644
--- a/drivers/platform/x86/intel/pmc/icl.c
+++ b/drivers/platform/x86/intel/pmc/icl.c
@@ -8,7 +8,7 @@ 
  *
  */
 
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 const struct pmc_bit_map icl_pfear_map[] = {
 	{"RES_65",		BIT(0)},
diff --git a/drivers/platform/x86/intel/pmc/mtl.c b/drivers/platform/x86/intel/pmc/mtl.c
index e8cc156412ce..7897f5fe9881 100644
--- a/drivers/platform/x86/intel/pmc/mtl.c
+++ b/drivers/platform/x86/intel/pmc/mtl.c
@@ -9,7 +9,7 @@ 
  */
 
 #include <linux/pci.h>
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 const struct pmc_reg_map mtl_reg_map = {
 	.pfear_sts = ext_tgl_pfear_map,
diff --git a/drivers/platform/x86/intel/pmc/spt.c b/drivers/platform/x86/intel/pmc/spt.c
index e16982236778..95ce490cf5d6 100644
--- a/drivers/platform/x86/intel/pmc/spt.c
+++ b/drivers/platform/x86/intel/pmc/spt.c
@@ -8,7 +8,7 @@ 
  *
  */
 
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 const struct pmc_bit_map spt_pll_map[] = {
 	{"MIPI PLL",			SPT_PMC_BIT_MPHY_CMN_LANE0},
diff --git a/drivers/platform/x86/intel/pmc/tgl.c b/drivers/platform/x86/intel/pmc/tgl.c
index c245ada849d0..a1719d809497 100644
--- a/drivers/platform/x86/intel/pmc/tgl.c
+++ b/drivers/platform/x86/intel/pmc/tgl.c
@@ -8,7 +8,7 @@ 
  *
  */
 
-#include "core.h"
+#include <linux/intel_pmc_core.h>
 
 #define ACPI_S0IX_DSM_UUID		"57a6512e-3979-4e9d-9708-ff13b2508972"
 #define ACPI_GET_LOW_MODE_REGISTERS	1
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;
@@ -427,4 +436,20 @@  static const struct file_operations __name ## _fops = {			\
 	.release	= single_release,				\
 }
 
+#if IS_ENABLED(CONFIG_INTEL_PMC_CORE)
+/**
+ * intel_pmc_core_ipc() - PMC IPC Mailbox accessor
+ * @ipc_cmd:  struct pmc_ipc_cmd prepared with input to send
+ * @rbuf:     Allocated u32[4] array for returned IPC data
+ *
+ * Return: 0 on success. Non-zero on mailbox error
+ */
+int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf);
+#else
+static inline int intel_pmc_core_ipc(struct pmc_ipc_cmd *ipc_cmd, u32 *rbuf)
+{
+	return -ENODEV;
+}
+#endif /* CONFIG_INTEL_PMC_CORE */
+
 #endif /* PMC_CORE_H */