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Commit e765f37b authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Andy Shevchenko
Browse files

platform/x86: ISST: Add Intel Speed Select PUNIT MSR interface 



While using new non arhitectural features using PUNIT Mailbox and MMIO
read/write interface, still there is need to operate using MSRs to
control PUNIT. User space could have used user user-space MSR interface for
this, but when user space MSR access is disabled, then it can't. Here only
limited number of MSRs are allowed using this new interface.

Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent 71b21bd7

drivers/platform/x86/intel_speed_select_if/isst_if_common.c

+59 −0
Original line number Diff line number Diff line
@@ -25,6 +25,11 @@ 


static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX];



static int punit_msr_white_list[] = {

	MSR_TURBO_RATIO_LIMIT,

	MSR_CONFIG_TDP_CONTROL,

};



struct isst_valid_cmd_ranges {

	u16 cmd;

	u16 sub_cmd_beg;
@@ -229,6 +234,54 @@ static long isst_if_proc_phyid_req(u8 *cmd_ptr, int *write_only, int resume) 
	return 0;

}



static bool match_punit_msr_white_list(int msr)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(punit_msr_white_list); ++i) {

		if (punit_msr_white_list[i] == msr)

			return true;

	}



	return false;

}



static long isst_if_msr_cmd_req(u8 *cmd_ptr, int *write_only, int resume)

{

	struct isst_if_msr_cmd *msr_cmd;

	int ret;



	msr_cmd = (struct isst_if_msr_cmd *)cmd_ptr;



	if (!match_punit_msr_white_list(msr_cmd->msr))

		return -EINVAL;



	if (msr_cmd->logical_cpu >= nr_cpu_ids)

		return -EINVAL;



	if (msr_cmd->read_write) {

		if (!capable(CAP_SYS_ADMIN))

			return -EPERM;



		ret = wrmsrl_safe_on_cpu(msr_cmd->logical_cpu,

					 msr_cmd->msr,

					 msr_cmd->data);

		*write_only = 1;

	} else {

		u64 data;



		ret = rdmsrl_safe_on_cpu(msr_cmd->logical_cpu,

					 msr_cmd->msr, &data);

		if (!ret) {

			msr_cmd->data = data;

			*write_only = 0;

		}

	}





	return ret;

}



static long isst_if_exec_multi_cmd(void __user *argp, struct isst_if_cmd_cb *cb)

{

	unsigned char __user *ptr;
@@ -309,6 +362,12 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd, 
		if (cb->registered)

			ret = isst_if_exec_multi_cmd(argp, cb);

		break;

	case ISST_IF_MSR_COMMAND:

		cmd_cb.cmd_size = sizeof(struct isst_if_msr_cmd);

		cmd_cb.offset = offsetof(struct isst_if_msr_cmds, msr_cmd);

		cmd_cb.cmd_callback = isst_if_msr_cmd_req;

		ret = isst_if_exec_multi_cmd(argp, &cmd_cb);

		break;

	default:

		break;

	}

include/uapi/linux/isst_if.h

+32 −0
Original line number Diff line number Diff line
@@ -132,9 +132,41 @@ struct isst_if_mbox_cmds { 
	struct isst_if_mbox_cmd mbox_cmd[1];

};



/**

 * struct isst_if_msr_cmd - Structure to define msr command

 * @read_write:		Value 0: Read, 1: Write

 * @logical_cpu:	Logical CPU number

 * @msr:		MSR number

 * @data:		For write operation, data to write, for read

 *			place holder

 *

 * Structure to specify MSR command related to PUNIT.

 */

struct isst_if_msr_cmd {

	__u32 read_write; /* Read:0, Write:1 */

	__u32 logical_cpu;

	__u64 msr;

	__u64 data;

};



/**

 * struct isst_if_msr_cmds - structure for msr commands

 * @cmd_count:	Number of mailbox commands in msr_cmd[]

 * @msr_cmd[]:	Holds one or more msr commands

 *

 * This structure used with ioctl ISST_IF_MSR_COMMAND to send

 * one or more MSR commands. IOCTL return value indicates number of

 * commands sent or error number if no commands have been sent.

 */

struct isst_if_msr_cmds {

	__u32 cmd_count;

	struct isst_if_msr_cmd msr_cmd[1];

};



#define ISST_IF_MAGIC			0xFE

#define ISST_IF_GET_PLATFORM_INFO	_IOR(ISST_IF_MAGIC, 0, struct isst_if_platform_info *)

#define ISST_IF_GET_PHY_ID		_IOWR(ISST_IF_MAGIC, 1, struct isst_if_cpu_map *)

#define ISST_IF_IO_CMD		_IOW(ISST_IF_MAGIC, 2, struct isst_if_io_regs *)

#define ISST_IF_MBOX_COMMAND	_IOWR(ISST_IF_MAGIC, 3, struct isst_if_mbox_cmds *)

#define ISST_IF_MSR_COMMAND	_IOWR(ISST_IF_MAGIC, 4, struct isst_if_msr_cmds *)

#endif