Commit 31a166fe authored by Srinivas Pandruvada's avatar Srinivas Pandruvada Committed by Andy Shevchenko

platform/x86: ISST: Add Intel Speed Select mailbox interface via PCI

Add an IOCTL to send mailbox commands to PUNIT using PUNIT PCI device.
A limited set of mailbox commands can be sent to PUNIT.

This MMIO interface is used by the intel-speed-select tool under
tools/x86/power to enumerate and control Intel Speed Select features.
The MBOX commands ids and semantics of the message can be checked from
the source code of the tool.
Signed-off-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarAndy Shevchenko <andriy.shevchenko@linux.intel.com>
parent d3a23584
...@@ -6,3 +6,4 @@ ...@@ -6,3 +6,4 @@
obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_common.o obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_common.o
obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_mmio.o obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_mmio.o
obj-$(CONFIG_INTEL_SPEED_SELECT_INTERFACE) += isst_if_mbox_pci.o
...@@ -25,6 +25,86 @@ ...@@ -25,6 +25,86 @@
static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX]; static struct isst_if_cmd_cb punit_callbacks[ISST_IF_DEV_MAX];
struct isst_valid_cmd_ranges {
u16 cmd;
u16 sub_cmd_beg;
u16 sub_cmd_end;
};
struct isst_cmd_set_req_type {
u16 cmd;
u16 sub_cmd;
u16 param;
};
static const struct isst_valid_cmd_ranges isst_valid_cmds[] = {
{0xD0, 0x00, 0x03},
{0x7F, 0x00, 0x0B},
{0x7F, 0x10, 0x12},
{0x7F, 0x20, 0x23},
};
static const struct isst_cmd_set_req_type isst_cmd_set_reqs[] = {
{0xD0, 0x00, 0x08},
{0xD0, 0x01, 0x08},
{0xD0, 0x02, 0x08},
{0xD0, 0x03, 0x08},
{0x7F, 0x02, 0x00},
{0x7F, 0x08, 0x00},
};
/**
* isst_if_mbox_cmd_invalid() - Check invalid mailbox commands
* @cmd: Pointer to the command structure to verify.
*
* Invalid command to PUNIT to may result in instability of the platform.
* This function has a whitelist of commands, which are allowed.
*
* Return: Return true if the command is invalid, else false.
*/
bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd)
{
int i;
if (cmd->logical_cpu >= nr_cpu_ids)
return true;
for (i = 0; i < ARRAY_SIZE(isst_valid_cmds); ++i) {
if (cmd->command == isst_valid_cmds[i].cmd &&
(cmd->sub_command >= isst_valid_cmds[i].sub_cmd_beg &&
cmd->sub_command <= isst_valid_cmds[i].sub_cmd_end)) {
return false;
}
}
return true;
}
EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_invalid);
/**
* isst_if_mbox_cmd_set_req() - Check mailbox command is a set request
* @cmd: Pointer to the command structure to verify.
*
* Check if the given mail box level is set request and not a get request.
*
* Return: Return true if the command is set_req, else false.
*/
bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *cmd)
{
int i;
for (i = 0; i < ARRAY_SIZE(isst_cmd_set_reqs); ++i) {
if (cmd->command == isst_cmd_set_reqs[i].cmd &&
cmd->sub_command == isst_cmd_set_reqs[i].sub_cmd &&
cmd->parameter == isst_cmd_set_reqs[i].param) {
return true;
}
}
return false;
}
EXPORT_SYMBOL_GPL(isst_if_mbox_cmd_set_req);
static int isst_if_get_platform_info(void __user *argp) static int isst_if_get_platform_info(void __user *argp)
{ {
struct isst_if_platform_info info; struct isst_if_platform_info info;
...@@ -224,6 +304,11 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd, ...@@ -224,6 +304,11 @@ static long isst_if_def_ioctl(struct file *file, unsigned int cmd,
if (cb->registered) if (cb->registered)
ret = isst_if_exec_multi_cmd(argp, cb); ret = isst_if_exec_multi_cmd(argp, cb);
break; break;
case ISST_IF_MBOX_COMMAND:
cb = &punit_callbacks[ISST_IF_DEV_MBOX];
if (cb->registered)
ret = isst_if_exec_multi_cmd(argp, cb);
break;
default: default:
break; break;
} }
......
...@@ -11,6 +11,7 @@ ...@@ -11,6 +11,7 @@
#define __ISST_IF_COMMON_H #define __ISST_IF_COMMON_H
#define INTEL_RAPL_PRIO_DEVID_0 0x3451 #define INTEL_RAPL_PRIO_DEVID_0 0x3451
#define INTEL_CFG_MBOX_DEVID_0 0x3459
/* /*
* Validate maximum commands in a single request. * Validate maximum commands in a single request.
...@@ -60,4 +61,6 @@ struct isst_if_cmd_cb { ...@@ -60,4 +61,6 @@ struct isst_if_cmd_cb {
int isst_if_cdev_register(int type, struct isst_if_cmd_cb *cb); int isst_if_cdev_register(int type, struct isst_if_cmd_cb *cb);
void isst_if_cdev_unregister(int type); void isst_if_cdev_unregister(int type);
struct pci_dev *isst_if_get_pci_dev(int cpu, int bus, int dev, int fn); struct pci_dev *isst_if_get_pci_dev(int cpu, int bus, int dev, int fn);
bool isst_if_mbox_cmd_set_req(struct isst_if_mbox_cmd *mbox_cmd);
bool isst_if_mbox_cmd_invalid(struct isst_if_mbox_cmd *cmd);
#endif #endif
// SPDX-License-Identifier: GPL-2.0
/*
* Intel Speed Select Interface: Mbox via PCI Interface
* Copyright (c) 2019, Intel Corporation.
* All rights reserved.
*
* Author: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
*/
#include <linux/cpufeature.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/sched/signal.h>
#include <linux/uaccess.h>
#include <uapi/linux/isst_if.h>
#include "isst_if_common.h"
#define PUNIT_MAILBOX_DATA 0xA0
#define PUNIT_MAILBOX_INTERFACE 0xA4
#define PUNIT_MAILBOX_BUSY_BIT 31
/*
* Commands has variable amount of processing time. Most of the commands will
* be done in 0-3 tries, but some takes up to 50.
* The real processing time was observed as 25us for the most of the commands
* at 2GHz. It is possible to optimize this count taking samples on customer
* systems.
*/
#define OS_MAILBOX_RETRY_COUNT 50
struct isst_if_device {
struct mutex mutex;
};
static int isst_if_mbox_cmd(struct pci_dev *pdev,
struct isst_if_mbox_cmd *mbox_cmd)
{
u32 retries, data;
int ret;
/* Poll for rb bit == 0 */
retries = OS_MAILBOX_RETRY_COUNT;
do {
ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE,
&data);
if (ret)
return ret;
if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) {
ret = -EBUSY;
continue;
}
ret = 0;
break;
} while (--retries);
if (ret)
return ret;
/* Write DATA register */
ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_DATA,
mbox_cmd->req_data);
if (ret)
return ret;
/* Write command register */
data = BIT_ULL(PUNIT_MAILBOX_BUSY_BIT) |
(mbox_cmd->parameter & GENMASK_ULL(13, 0)) << 16 |
(mbox_cmd->sub_command << 8) |
mbox_cmd->command;
ret = pci_write_config_dword(pdev, PUNIT_MAILBOX_INTERFACE, data);
if (ret)
return ret;
/* Poll for rb bit == 0 */
retries = OS_MAILBOX_RETRY_COUNT;
do {
ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_INTERFACE,
&data);
if (ret)
return ret;
if (data & BIT_ULL(PUNIT_MAILBOX_BUSY_BIT)) {
ret = -EBUSY;
continue;
}
if (data & 0xff)
return -ENXIO;
ret = pci_read_config_dword(pdev, PUNIT_MAILBOX_DATA, &data);
if (ret)
return ret;
mbox_cmd->resp_data = data;
ret = 0;
break;
} while (--retries);
return ret;
}
static long isst_if_mbox_proc_cmd(u8 *cmd_ptr, int *write_only, int resume)
{
struct isst_if_mbox_cmd *mbox_cmd;
struct isst_if_device *punit_dev;
struct pci_dev *pdev;
int ret;
mbox_cmd = (struct isst_if_mbox_cmd *)cmd_ptr;
if (isst_if_mbox_cmd_invalid(mbox_cmd))
return -EINVAL;
if (isst_if_mbox_cmd_set_req(mbox_cmd) && !capable(CAP_SYS_ADMIN))
return -EPERM;
pdev = isst_if_get_pci_dev(mbox_cmd->logical_cpu, 1, 30, 1);
if (!pdev)
return -EINVAL;
punit_dev = pci_get_drvdata(pdev);
if (!punit_dev)
return -EINVAL;
/*
* Basically we are allowing one complete mailbox transaction on
* a mapped PCI device at a time.
*/
mutex_lock(&punit_dev->mutex);
ret = isst_if_mbox_cmd(pdev, mbox_cmd);
mutex_unlock(&punit_dev->mutex);
if (ret)
return ret;
*write_only = 0;
return 0;
}
static const struct pci_device_id isst_if_mbox_ids[] = {
{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, INTEL_CFG_MBOX_DEVID_0)},
{ 0 },
};
MODULE_DEVICE_TABLE(pci, isst_if_mbox_ids);
static int isst_if_mbox_probe(struct pci_dev *pdev,
const struct pci_device_id *ent)
{
struct isst_if_device *punit_dev;
struct isst_if_cmd_cb cb;
int ret;
punit_dev = devm_kzalloc(&pdev->dev, sizeof(*punit_dev), GFP_KERNEL);
if (!punit_dev)
return -ENOMEM;
ret = pcim_enable_device(pdev);
if (ret)
return ret;
mutex_init(&punit_dev->mutex);
pci_set_drvdata(pdev, punit_dev);
memset(&cb, 0, sizeof(cb));
cb.cmd_size = sizeof(struct isst_if_mbox_cmd);
cb.offset = offsetof(struct isst_if_mbox_cmds, mbox_cmd);
cb.cmd_callback = isst_if_mbox_proc_cmd;
cb.owner = THIS_MODULE;
ret = isst_if_cdev_register(ISST_IF_DEV_MBOX, &cb);
if (ret)
mutex_destroy(&punit_dev->mutex);
return ret;
}
static void isst_if_mbox_remove(struct pci_dev *pdev)
{
struct isst_if_device *punit_dev;
punit_dev = pci_get_drvdata(pdev);
isst_if_cdev_unregister(ISST_IF_DEV_MBOX);
mutex_destroy(&punit_dev->mutex);
}
static struct pci_driver isst_if_pci_driver = {
.name = "isst_if_mbox_pci",
.id_table = isst_if_mbox_ids,
.probe = isst_if_mbox_probe,
.remove = isst_if_mbox_remove,
};
module_pci_driver(isst_if_pci_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Intel speed select interface pci mailbox driver");
...@@ -95,8 +95,46 @@ struct isst_if_io_regs { ...@@ -95,8 +95,46 @@ struct isst_if_io_regs {
struct isst_if_io_reg io_reg[1]; struct isst_if_io_reg io_reg[1];
}; };
/**
* struct isst_if_mbox_cmd - Structure to define mail box command
* @logical_cpu: Logical CPU number to get target PCI device
* @parameter: Mailbox parameter value
* @req_data: Request data for the mailbox
* @resp_data: Response data for mailbox command response
* @command: Mailbox command value
* @sub_command: Mailbox sub command value
* @reserved: Unused, set to 0
*
* Structure to specify mailbox command to be sent to PUNIT.
*/
struct isst_if_mbox_cmd {
__u32 logical_cpu;
__u32 parameter;
__u32 req_data;
__u32 resp_data;
__u16 command;
__u16 sub_command;
__u32 reserved;
};
/**
* struct isst_if_mbox_cmds - structure for mailbox commands
* @cmd_count: Number of mailbox commands in mbox_cmd[]
* @mbox_cmd[]: Holds one or more mbox commands
*
* This structure used with ioctl ISST_IF_MBOX_COMMAND to send
* one or more mailbox commands to PUNIT. Here IOCTL return value
* indicates number of commands sent or error number if no commands have
* been sent.
*/
struct isst_if_mbox_cmds {
__u32 cmd_count;
struct isst_if_mbox_cmd mbox_cmd[1];
};
#define ISST_IF_MAGIC 0xFE #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_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_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_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 *)
#endif #endif
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