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author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-02 13:49:39 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-02 13:49:39 -0700 |
commit | 7ba88a2a09f47e2e4f3e34215677a1d78a9e6a73 (patch) | |
tree | 09ffff5310767631c8e0792098670201a25838e5 /drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c | |
parent | Merge tag 'vfio-v5.15-rc1' of git://github.com/awilliam/linux-vfio (diff) | |
parent | platform/x86: dell-smbios-wmi: Add missing kfree in error-exit from run_smbios_call (diff) | |
download | linux-dev-7ba88a2a09f47e2e4f3e34215677a1d78a9e6a73.tar.xz linux-dev-7ba88a2a09f47e2e4f3e34215677a1d78a9e6a73.zip |
Merge tag 'platform-drivers-x86-v5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86
Pull x86 platform driver updates from Hans de Goede:
"Highlights:
- Move all the Intel drivers into their own subdir(s) (mostly Kate's
work)
- New meraki-mx100 platform driver
- Asus WMI driver enhancements, including support for
/sys/firmware/acpi/platform_profile
- New BIOS SAR driver for Intel M.2 WWAM modems
- Alder Lake support for the Intel PMC driver
- A whole bunch of cleanups + fixes all over the place"
* tag 'platform-drivers-x86-v5.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86: (65 commits)
platform/x86: dell-smbios-wmi: Add missing kfree in error-exit from run_smbios_call
platform/x86: dell-smbios-wmi: Avoid false-positive memcpy() warning
platform/x86: ISST: use semi-colons instead of commas
platform/x86: asus-wmi: Fix "unsigned 'retval' is never less than zero" smatch warning
platform/x86: asus-wmi: Delete impossible condition
platform/x86: hp_accel: Convert to be a platform driver
platform/x86: hp_accel: Remove _INI method call
platform/mellanox: mlxbf-pmc: fix kernel-doc notation
platform/x86/intel: pmc/core: Add GBE Package C10 fix for Alder Lake PCH
platform/x86/intel: pmc/core: Add Alder Lake low power mode support for pmc core
platform/x86/intel: pmc/core: Add Latency Tolerance Reporting (LTR) support to Alder Lake
platform/x86/intel: pmc/core: Add Alderlake support to pmc core driver
platform/x86: intel-wmi-thunderbolt: Move to intel sub-directory
platform/x86: intel-wmi-sbl-fw-update: Move to intel sub-directory
platform/x86: intel-vbtn: Move to intel sub-directory
platform/x86: intel_oaktrail: Move to intel sub-directory
platform/x86: intel_int0002_vgpio: Move to intel sub-directory
platform/x86: intel-hid: Move to intel sub-directory
platform/x86: intel_atomisp2: Move to intel sub-directory
platform/x86: intel_speed_select_if: Move to intel sub-directory
...
Diffstat (limited to 'drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c')
-rw-r--r-- | drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c b/drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c new file mode 100644 index 000000000000..df1fc6c719f3 --- /dev/null +++ b/drivers/platform/x86/intel/speed_select_if/isst_if_mbox_pci.c @@ -0,0 +1,227 @@ +// 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 + +/* + * The average time to complete mailbox commands is less than 40us. Most of + * the commands complete in few micro seconds. But the same firmware handles + * requests from all power management features. + * We can create a scenario where we flood the firmware with requests then + * the mailbox response can be delayed for 100s of micro seconds. So define + * two timeouts. One for average case and one for long. + * If the firmware is taking more than average, just call cond_resched(). + */ +#define OS_MAILBOX_TIMEOUT_AVG_US 40 +#define OS_MAILBOX_TIMEOUT_MAX_US 1000 + +struct isst_if_device { + struct mutex mutex; +}; + +static int isst_if_mbox_cmd(struct pci_dev *pdev, + struct isst_if_mbox_cmd *mbox_cmd) +{ + s64 tm_delta = 0; + ktime_t tm; + u32 data; + int ret; + + /* Poll for rb bit == 0 */ + tm = ktime_get(); + 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; + tm_delta = ktime_us_delta(ktime_get(), tm); + if (tm_delta > OS_MAILBOX_TIMEOUT_AVG_US) + cond_resched(); + continue; + } + ret = 0; + break; + } while (tm_delta < OS_MAILBOX_TIMEOUT_MAX_US); + + 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 */ + tm_delta = 0; + tm = ktime_get(); + 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; + tm_delta = ktime_us_delta(ktime_get(), tm); + if (tm_delta > OS_MAILBOX_TIMEOUT_AVG_US) + cond_resched(); + 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 (tm_delta < OS_MAILBOX_TIMEOUT_MAX_US); + + 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); + if (!ret && !resume && isst_if_mbox_cmd_set_req(mbox_cmd)) + ret = isst_store_cmd(mbox_cmd->command, + mbox_cmd->sub_command, + mbox_cmd->logical_cpu, 1, + mbox_cmd->parameter, + mbox_cmd->req_data); + 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_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CFG_MBOX_DEVID_0)}, + { PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CFG_MBOX_DEVID_1)}, + { 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 int __maybe_unused isst_if_resume(struct device *device) +{ + isst_resume_common(); + return 0; +} + +static SIMPLE_DEV_PM_OPS(isst_if_pm_ops, NULL, isst_if_resume); + +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, + .driver.pm = &isst_if_pm_ops, +}; + +module_pci_driver(isst_if_pci_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Intel speed select interface pci mailbox driver"); |