Similar to the situation in commit 9049572fb145 ("hwmon: Remove amd_energy
driver"), access to power information can be used as the basis for a side-
channel attack. Removing unprivileged access to monitoring information
would effectively make the driver useless, so simply remove the driver.
Fixes: ed42cfa881e1 ("hwmon: Add xgene hwmon driver")
Signed-off-by: D Scott Phillips <[email protected]>
Cc: [email protected]
---
I've put a cc: stable here, though I see that wasn't done for the removal
of the amd_energy driver. I'm assuming that removing a driver wouldn't
normally be sent to stable, but should it be if it's being removed for a
security issue?
drivers/hwmon/Kconfig | 7 -
drivers/hwmon/Makefile | 1 -
drivers/hwmon/xgene-hwmon.c | 792 ------------------------------------
3 files changed, 800 deletions(-)
delete mode 100644 drivers/hwmon/xgene-hwmon.c
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 590d3d550acb..382157c7f681 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -2280,13 +2280,6 @@ config SENSORS_ULTRA45
This driver provides support for the Ultra45 workstation environmental
sensors.
-config SENSORS_XGENE
- tristate "APM X-Gene SoC hardware monitoring driver"
- depends on XGENE_SLIMPRO_MBOX || PCC
- help
- If you say yes here you get support for the temperature
- and power sensors for APM X-Gene SoC.
-
config SENSORS_INTEL_M10_BMC_HWMON
tristate "Intel MAX10 BMC Hardware Monitoring"
depends on MFD_INTEL_M10_BMC
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 007e829d1d0d..fe8fa99f3960 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -212,7 +212,6 @@ obj-$(CONFIG_SENSORS_W83L785TS) += w83l785ts.o
obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o
obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o
-obj-$(CONFIG_SENSORS_XGENE) += xgene-hwmon.o
obj-$(CONFIG_SENSORS_OCC) += occ/
obj-$(CONFIG_SENSORS_PECI) += peci/
diff --git a/drivers/hwmon/xgene-hwmon.c b/drivers/hwmon/xgene-hwmon.c
deleted file mode 100644
index 5cde837bfd09..000000000000
--- a/drivers/hwmon/xgene-hwmon.c
+++ /dev/null
@@ -1,792 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-or-later
-/*
- * APM X-Gene SoC Hardware Monitoring Driver
- *
- * Copyright (c) 2016, Applied Micro Circuits Corporation
- * Author: Loc Ho <[email protected]>
- * Hoan Tran <[email protected]>
- *
- * This driver provides the following features:
- * - Retrieve CPU total power (uW)
- * - Retrieve IO total power (uW)
- * - Retrieve SoC temperature (milli-degree C) and alarm
- */
-#include <linux/acpi.h>
-#include <linux/dma-mapping.h>
-#include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
-#include <linux/io.h>
-#include <linux/interrupt.h>
-#include <linux/kfifo.h>
-#include <linux/mailbox_controller.h>
-#include <linux/mailbox_client.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-
-#include <acpi/pcc.h>
-
-/* SLIMpro message defines */
-#define MSG_TYPE_DBG 0
-#define MSG_TYPE_ERR 7
-#define MSG_TYPE_PWRMGMT 9
-
-#define MSG_TYPE(v) (((v) & 0xF0000000) >> 28)
-#define MSG_TYPE_SET(v) (((v) << 28) & 0xF0000000)
-#define MSG_SUBTYPE(v) (((v) & 0x0F000000) >> 24)
-#define MSG_SUBTYPE_SET(v) (((v) << 24) & 0x0F000000)
-
-#define DBG_SUBTYPE_SENSOR_READ 4
-#define SENSOR_RD_MSG 0x04FFE902
-#define SENSOR_RD_EN_ADDR(a) ((a) & 0x000FFFFF)
-#define PMD_PWR_REG 0x20
-#define PMD_PWR_MW_REG 0x26
-#define SOC_PWR_REG 0x21
-#define SOC_PWR_MW_REG 0x27
-#define SOC_TEMP_REG 0x10
-
-#define TEMP_NEGATIVE_BIT 8
-#define SENSOR_INVALID_DATA BIT(15)
-
-#define PWRMGMT_SUBTYPE_TPC 1
-#define TPC_ALARM 2
-#define TPC_GET_ALARM 3
-#define TPC_CMD(v) (((v) & 0x00FF0000) >> 16)
-#define TPC_CMD_SET(v) (((v) << 16) & 0x00FF0000)
-#define TPC_EN_MSG(hndl, cmd, type) \
- (MSG_TYPE_SET(MSG_TYPE_PWRMGMT) | \
- MSG_SUBTYPE_SET(hndl) | TPC_CMD_SET(cmd) | type)
-
-/* PCC defines */
-#define PCC_SIGNATURE_MASK 0x50424300
-#define PCCC_GENERATE_DB_INT BIT(15)
-#define PCCS_CMD_COMPLETE BIT(0)
-#define PCCS_SCI_DOORBEL BIT(1)
-#define PCCS_PLATFORM_NOTIFICATION BIT(3)
-/*
- * Arbitrary retries in case the remote processor is slow to respond
- * to PCC commands
- */
-#define PCC_NUM_RETRIES 500
-
-#define ASYNC_MSG_FIFO_SIZE 16
-#define MBOX_OP_TIMEOUTMS 1000
-
-#define WATT_TO_mWATT(x) ((x) * 1000)
-#define mWATT_TO_uWATT(x) ((x) * 1000)
-#define CELSIUS_TO_mCELSIUS(x) ((x) * 1000)
-
-#define to_xgene_hwmon_dev(cl) \
- container_of(cl, struct xgene_hwmon_dev, mbox_client)
-
-enum xgene_hwmon_version {
- XGENE_HWMON_V1 = 0,
- XGENE_HWMON_V2 = 1,
-};
-
-struct slimpro_resp_msg {
- u32 msg;
- u32 param1;
- u32 param2;
-} __packed;
-
-struct xgene_hwmon_dev {
- struct device *dev;
- struct mbox_chan *mbox_chan;
- struct pcc_mbox_chan *pcc_chan;
- struct mbox_client mbox_client;
- int mbox_idx;
-
- spinlock_t kfifo_lock;
- struct mutex rd_mutex;
- struct completion rd_complete;
- int resp_pending;
- struct slimpro_resp_msg sync_msg;
-
- struct work_struct workq;
- struct kfifo_rec_ptr_1 async_msg_fifo;
-
- struct device *hwmon_dev;
- bool temp_critical_alarm;
-
- phys_addr_t comm_base_addr;
- void *pcc_comm_addr;
- u64 usecs_lat;
-};
-
-/*
- * This function tests and clears a bitmask then returns its old value
- */
-static u16 xgene_word_tst_and_clr(u16 *addr, u16 mask)
-{
- u16 ret, val;
-
- val = le16_to_cpu(READ_ONCE(*addr));
- ret = val & mask;
- val &= ~mask;
- WRITE_ONCE(*addr, cpu_to_le16(val));
-
- return ret;
-}
-
-static int xgene_hwmon_pcc_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
-{
- struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
- u32 *ptr = (void *)(generic_comm_base + 1);
- int rc, i;
- u16 val;
-
- mutex_lock(&ctx->rd_mutex);
- init_completion(&ctx->rd_complete);
- ctx->resp_pending = true;
-
- /* Write signature for subspace */
- WRITE_ONCE(generic_comm_base->signature,
- cpu_to_le32(PCC_SIGNATURE_MASK | ctx->mbox_idx));
-
- /* Write to the shared command region */
- WRITE_ONCE(generic_comm_base->command,
- cpu_to_le16(MSG_TYPE(msg[0]) | PCCC_GENERATE_DB_INT));
-
- /* Flip CMD COMPLETE bit */
- val = le16_to_cpu(READ_ONCE(generic_comm_base->status));
- val &= ~PCCS_CMD_COMPLETE;
- WRITE_ONCE(generic_comm_base->status, cpu_to_le16(val));
-
- /* Copy the message to the PCC comm space */
- for (i = 0; i < sizeof(struct slimpro_resp_msg) / 4; i++)
- WRITE_ONCE(ptr[i], cpu_to_le32(msg[i]));
-
- /* Ring the doorbell */
- rc = mbox_send_message(ctx->mbox_chan, msg);
- if (rc < 0) {
- dev_err(ctx->dev, "Mailbox send error %d\n", rc);
- goto err;
- }
- if (!wait_for_completion_timeout(&ctx->rd_complete,
- usecs_to_jiffies(ctx->usecs_lat))) {
- dev_err(ctx->dev, "Mailbox operation timed out\n");
- rc = -ETIMEDOUT;
- goto err;
- }
-
- /* Check for error message */
- if (MSG_TYPE(ctx->sync_msg.msg) == MSG_TYPE_ERR) {
- rc = -EINVAL;
- goto err;
- }
-
- msg[0] = ctx->sync_msg.msg;
- msg[1] = ctx->sync_msg.param1;
- msg[2] = ctx->sync_msg.param2;
-
-err:
- mbox_chan_txdone(ctx->mbox_chan, 0);
- ctx->resp_pending = false;
- mutex_unlock(&ctx->rd_mutex);
- return rc;
-}
-
-static int xgene_hwmon_rd(struct xgene_hwmon_dev *ctx, u32 *msg)
-{
- int rc;
-
- mutex_lock(&ctx->rd_mutex);
- init_completion(&ctx->rd_complete);
- ctx->resp_pending = true;
-
- rc = mbox_send_message(ctx->mbox_chan, msg);
- if (rc < 0) {
- dev_err(ctx->dev, "Mailbox send error %d\n", rc);
- goto err;
- }
-
- if (!wait_for_completion_timeout(&ctx->rd_complete,
- msecs_to_jiffies(MBOX_OP_TIMEOUTMS))) {
- dev_err(ctx->dev, "Mailbox operation timed out\n");
- rc = -ETIMEDOUT;
- goto err;
- }
-
- /* Check for error message */
- if (MSG_TYPE(ctx->sync_msg.msg) == MSG_TYPE_ERR) {
- rc = -EINVAL;
- goto err;
- }
-
- msg[0] = ctx->sync_msg.msg;
- msg[1] = ctx->sync_msg.param1;
- msg[2] = ctx->sync_msg.param2;
-
-err:
- ctx->resp_pending = false;
- mutex_unlock(&ctx->rd_mutex);
- return rc;
-}
-
-static int xgene_hwmon_reg_map_rd(struct xgene_hwmon_dev *ctx, u32 addr,
- u32 *data)
-{
- u32 msg[3];
- int rc;
-
- msg[0] = SENSOR_RD_MSG;
- msg[1] = SENSOR_RD_EN_ADDR(addr);
- msg[2] = 0;
-
- if (acpi_disabled)
- rc = xgene_hwmon_rd(ctx, msg);
- else
- rc = xgene_hwmon_pcc_rd(ctx, msg);
-
- if (rc < 0)
- return rc;
-
- /*
- * Check if sensor data is valid.
- */
- if (msg[1] & SENSOR_INVALID_DATA)
- return -ENODATA;
-
- *data = msg[1];
-
- return rc;
-}
-
-static int xgene_hwmon_get_notification_msg(struct xgene_hwmon_dev *ctx,
- u32 *amsg)
-{
- u32 msg[3];
- int rc;
-
- msg[0] = TPC_EN_MSG(PWRMGMT_SUBTYPE_TPC, TPC_GET_ALARM, 0);
- msg[1] = 0;
- msg[2] = 0;
-
- rc = xgene_hwmon_pcc_rd(ctx, msg);
- if (rc < 0)
- return rc;
-
- amsg[0] = msg[0];
- amsg[1] = msg[1];
- amsg[2] = msg[2];
-
- return rc;
-}
-
-static int xgene_hwmon_get_cpu_pwr(struct xgene_hwmon_dev *ctx, u32 *val)
-{
- u32 watt, mwatt;
- int rc;
-
- rc = xgene_hwmon_reg_map_rd(ctx, PMD_PWR_REG, &watt);
- if (rc < 0)
- return rc;
-
- rc = xgene_hwmon_reg_map_rd(ctx, PMD_PWR_MW_REG, &mwatt);
- if (rc < 0)
- return rc;
-
- *val = WATT_TO_mWATT(watt) + mwatt;
- return 0;
-}
-
-static int xgene_hwmon_get_io_pwr(struct xgene_hwmon_dev *ctx, u32 *val)
-{
- u32 watt, mwatt;
- int rc;
-
- rc = xgene_hwmon_reg_map_rd(ctx, SOC_PWR_REG, &watt);
- if (rc < 0)
- return rc;
-
- rc = xgene_hwmon_reg_map_rd(ctx, SOC_PWR_MW_REG, &mwatt);
- if (rc < 0)
- return rc;
-
- *val = WATT_TO_mWATT(watt) + mwatt;
- return 0;
-}
-
-static int xgene_hwmon_get_temp(struct xgene_hwmon_dev *ctx, u32 *val)
-{
- return xgene_hwmon_reg_map_rd(ctx, SOC_TEMP_REG, val);
-}
-
-/*
- * Sensor temperature/power functions
- */
-static ssize_t temp1_input_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
- int rc, temp;
- u32 val;
-
- rc = xgene_hwmon_get_temp(ctx, &val);
- if (rc < 0)
- return rc;
-
- temp = sign_extend32(val, TEMP_NEGATIVE_BIT);
-
- return sysfs_emit(buf, "%d\n", CELSIUS_TO_mCELSIUS(temp));
-}
-
-static ssize_t temp1_label_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sysfs_emit(buf, "SoC Temperature\n");
-}
-
-static ssize_t temp1_critical_alarm_show(struct device *dev,
- struct device_attribute *devattr,
- char *buf)
-{
- struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
-
- return sysfs_emit(buf, "%d\n", ctx->temp_critical_alarm);
-}
-
-static ssize_t power1_label_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sysfs_emit(buf, "CPU power\n");
-}
-
-static ssize_t power2_label_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- return sysfs_emit(buf, "IO power\n");
-}
-
-static ssize_t power1_input_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
- u32 val;
- int rc;
-
- rc = xgene_hwmon_get_cpu_pwr(ctx, &val);
- if (rc < 0)
- return rc;
-
- return sysfs_emit(buf, "%u\n", mWATT_TO_uWATT(val));
-}
-
-static ssize_t power2_input_show(struct device *dev,
- struct device_attribute *attr,
- char *buf)
-{
- struct xgene_hwmon_dev *ctx = dev_get_drvdata(dev);
- u32 val;
- int rc;
-
- rc = xgene_hwmon_get_io_pwr(ctx, &val);
- if (rc < 0)
- return rc;
-
- return sysfs_emit(buf, "%u\n", mWATT_TO_uWATT(val));
-}
-
-static DEVICE_ATTR_RO(temp1_label);
-static DEVICE_ATTR_RO(temp1_input);
-static DEVICE_ATTR_RO(temp1_critical_alarm);
-static DEVICE_ATTR_RO(power1_label);
-static DEVICE_ATTR_RO(power1_input);
-static DEVICE_ATTR_RO(power2_label);
-static DEVICE_ATTR_RO(power2_input);
-
-static struct attribute *xgene_hwmon_attrs[] = {
- &dev_attr_temp1_label.attr,
- &dev_attr_temp1_input.attr,
- &dev_attr_temp1_critical_alarm.attr,
- &dev_attr_power1_label.attr,
- &dev_attr_power1_input.attr,
- &dev_attr_power2_label.attr,
- &dev_attr_power2_input.attr,
- NULL,
-};
-
-ATTRIBUTE_GROUPS(xgene_hwmon);
-
-static int xgene_hwmon_tpc_alarm(struct xgene_hwmon_dev *ctx,
- struct slimpro_resp_msg *amsg)
-{
- ctx->temp_critical_alarm = !!amsg->param2;
- sysfs_notify(&ctx->dev->kobj, NULL, "temp1_critical_alarm");
-
- return 0;
-}
-
-static void xgene_hwmon_process_pwrmsg(struct xgene_hwmon_dev *ctx,
- struct slimpro_resp_msg *amsg)
-{
- if ((MSG_SUBTYPE(amsg->msg) == PWRMGMT_SUBTYPE_TPC) &&
- (TPC_CMD(amsg->msg) == TPC_ALARM))
- xgene_hwmon_tpc_alarm(ctx, amsg);
-}
-
-/*
- * This function is called to process async work queue
- */
-static void xgene_hwmon_evt_work(struct work_struct *work)
-{
- struct slimpro_resp_msg amsg;
- struct xgene_hwmon_dev *ctx;
- int ret;
-
- ctx = container_of(work, struct xgene_hwmon_dev, workq);
- while (kfifo_out_spinlocked(&ctx->async_msg_fifo, &amsg,
- sizeof(struct slimpro_resp_msg),
- &ctx->kfifo_lock)) {
- /*
- * If PCC, send a consumer command to Platform to get info
- * If Slimpro Mailbox, get message from specific FIFO
- */
- if (!acpi_disabled) {
- ret = xgene_hwmon_get_notification_msg(ctx,
- (u32 *)&amsg);
- if (ret < 0)
- continue;
- }
-
- if (MSG_TYPE(amsg.msg) == MSG_TYPE_PWRMGMT)
- xgene_hwmon_process_pwrmsg(ctx, &amsg);
- }
-}
-
-static int xgene_hwmon_rx_ready(struct xgene_hwmon_dev *ctx, void *msg)
-{
- if (IS_ERR_OR_NULL(ctx->hwmon_dev) && !ctx->resp_pending) {
- /* Enqueue to the FIFO */
- kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
- sizeof(struct slimpro_resp_msg),
- &ctx->kfifo_lock);
- return -ENODEV;
- }
-
- return 0;
-}
-
-/*
- * This function is called when the SLIMpro Mailbox received a message
- */
-static void xgene_hwmon_rx_cb(struct mbox_client *cl, void *msg)
-{
- struct xgene_hwmon_dev *ctx = to_xgene_hwmon_dev(cl);
-
- /*
- * While the driver registers with the mailbox framework, an interrupt
- * can be pending before the probe function completes its
- * initialization. If such condition occurs, just queue up the message
- * as the driver is not ready for servicing the callback.
- */
- if (xgene_hwmon_rx_ready(ctx, msg) < 0)
- return;
-
- /*
- * Response message format:
- * msg[0] is the return code of the operation
- * msg[1] is the first parameter word
- * msg[2] is the second parameter word
- *
- * As message only supports dword size, just assign it.
- */
-
- /* Check for sync query */
- if (ctx->resp_pending &&
- ((MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_ERR) ||
- (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_DBG &&
- MSG_SUBTYPE(((u32 *)msg)[0]) == DBG_SUBTYPE_SENSOR_READ) ||
- (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_PWRMGMT &&
- MSG_SUBTYPE(((u32 *)msg)[0]) == PWRMGMT_SUBTYPE_TPC &&
- TPC_CMD(((u32 *)msg)[0]) == TPC_ALARM))) {
- ctx->sync_msg.msg = ((u32 *)msg)[0];
- ctx->sync_msg.param1 = ((u32 *)msg)[1];
- ctx->sync_msg.param2 = ((u32 *)msg)[2];
-
- /* Operation waiting for response */
- complete(&ctx->rd_complete);
-
- return;
- }
-
- /* Enqueue to the FIFO */
- kfifo_in_spinlocked(&ctx->async_msg_fifo, msg,
- sizeof(struct slimpro_resp_msg), &ctx->kfifo_lock);
- /* Schedule the bottom handler */
- schedule_work(&ctx->workq);
-}
-
-/*
- * This function is called when the PCC Mailbox received a message
- */
-static void xgene_hwmon_pcc_rx_cb(struct mbox_client *cl, void *msg)
-{
- struct xgene_hwmon_dev *ctx = to_xgene_hwmon_dev(cl);
- struct acpi_pcct_shared_memory *generic_comm_base = ctx->pcc_comm_addr;
- struct slimpro_resp_msg amsg;
-
- /*
- * While the driver registers with the mailbox framework, an interrupt
- * can be pending before the probe function completes its
- * initialization. If such condition occurs, just queue up the message
- * as the driver is not ready for servicing the callback.
- */
- if (xgene_hwmon_rx_ready(ctx, &amsg) < 0)
- return;
-
- msg = generic_comm_base + 1;
- /* Check if platform sends interrupt */
- if (!xgene_word_tst_and_clr(&generic_comm_base->status,
- PCCS_SCI_DOORBEL))
- return;
-
- /*
- * Response message format:
- * msg[0] is the return code of the operation
- * msg[1] is the first parameter word
- * msg[2] is the second parameter word
- *
- * As message only supports dword size, just assign it.
- */
-
- /* Check for sync query */
- if (ctx->resp_pending &&
- ((MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_ERR) ||
- (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_DBG &&
- MSG_SUBTYPE(((u32 *)msg)[0]) == DBG_SUBTYPE_SENSOR_READ) ||
- (MSG_TYPE(((u32 *)msg)[0]) == MSG_TYPE_PWRMGMT &&
- MSG_SUBTYPE(((u32 *)msg)[0]) == PWRMGMT_SUBTYPE_TPC &&
- TPC_CMD(((u32 *)msg)[0]) == TPC_ALARM))) {
- /* Check if platform completes command */
- if (xgene_word_tst_and_clr(&generic_comm_base->status,
- PCCS_CMD_COMPLETE)) {
- ctx->sync_msg.msg = ((u32 *)msg)[0];
- ctx->sync_msg.param1 = ((u32 *)msg)[1];
- ctx->sync_msg.param2 = ((u32 *)msg)[2];
-
- /* Operation waiting for response */
- complete(&ctx->rd_complete);
-
- return;
- }
- }
-
- /*
- * Platform notifies interrupt to OSPM.
- * OPSM schedules a consumer command to get this information
- * in a workqueue. Platform must wait until OSPM has issued
- * a consumer command that serves this notification.
- */
-
- /* Enqueue to the FIFO */
- kfifo_in_spinlocked(&ctx->async_msg_fifo, &amsg,
- sizeof(struct slimpro_resp_msg), &ctx->kfifo_lock);
- /* Schedule the bottom handler */
- schedule_work(&ctx->workq);
-}
-
-static void xgene_hwmon_tx_done(struct mbox_client *cl, void *msg, int ret)
-{
- if (ret) {
- dev_dbg(cl->dev, "TX did not complete: CMD sent:%x, ret:%d\n",
- *(u16 *)msg, ret);
- } else {
- dev_dbg(cl->dev, "TX completed. CMD sent:%x, ret:%d\n",
- *(u16 *)msg, ret);
- }
-}
-
-#ifdef CONFIG_ACPI
-static const struct acpi_device_id xgene_hwmon_acpi_match[] = {
- {"APMC0D29", XGENE_HWMON_V1},
- {"APMC0D8A", XGENE_HWMON_V2},
- {},
-};
-MODULE_DEVICE_TABLE(acpi, xgene_hwmon_acpi_match);
-#endif
-
-static int xgene_hwmon_probe(struct platform_device *pdev)
-{
- struct xgene_hwmon_dev *ctx;
- struct mbox_client *cl;
- int rc;
-
- ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
- if (!ctx)
- return -ENOMEM;
-
- ctx->dev = &pdev->dev;
- platform_set_drvdata(pdev, ctx);
- cl = &ctx->mbox_client;
-
- spin_lock_init(&ctx->kfifo_lock);
- mutex_init(&ctx->rd_mutex);
-
- rc = kfifo_alloc(&ctx->async_msg_fifo,
- sizeof(struct slimpro_resp_msg) * ASYNC_MSG_FIFO_SIZE,
- GFP_KERNEL);
- if (rc)
- return -ENOMEM;
-
- INIT_WORK(&ctx->workq, xgene_hwmon_evt_work);
-
- /* Request mailbox channel */
- cl->dev = &pdev->dev;
- cl->tx_done = xgene_hwmon_tx_done;
- cl->tx_block = false;
- cl->tx_tout = MBOX_OP_TIMEOUTMS;
- cl->knows_txdone = false;
- if (acpi_disabled) {
- cl->rx_callback = xgene_hwmon_rx_cb;
- ctx->mbox_chan = mbox_request_channel(cl, 0);
- if (IS_ERR(ctx->mbox_chan)) {
- dev_err(&pdev->dev,
- "SLIMpro mailbox channel request failed\n");
- rc = -ENODEV;
- goto out_mbox_free;
- }
- } else {
- struct pcc_mbox_chan *pcc_chan;
- const struct acpi_device_id *acpi_id;
- int version;
-
- acpi_id = acpi_match_device(pdev->dev.driver->acpi_match_table,
- &pdev->dev);
- if (!acpi_id) {
- rc = -EINVAL;
- goto out_mbox_free;
- }
-
- version = (int)acpi_id->driver_data;
-
- if (device_property_read_u32(&pdev->dev, "pcc-channel",
- &ctx->mbox_idx)) {
- dev_err(&pdev->dev, "no pcc-channel property\n");
- rc = -ENODEV;
- goto out_mbox_free;
- }
-
- cl->rx_callback = xgene_hwmon_pcc_rx_cb;
- pcc_chan = pcc_mbox_request_channel(cl, ctx->mbox_idx);
- if (IS_ERR(pcc_chan)) {
- dev_err(&pdev->dev,
- "PPC channel request failed\n");
- rc = -ENODEV;
- goto out_mbox_free;
- }
-
- ctx->pcc_chan = pcc_chan;
- ctx->mbox_chan = pcc_chan->mchan;
-
- if (!ctx->mbox_chan->mbox->txdone_irq) {
- dev_err(&pdev->dev, "PCC IRQ not supported\n");
- rc = -ENODEV;
- goto out;
- }
-
- /*
- * This is the shared communication region
- * for the OS and Platform to communicate over.
- */
- ctx->comm_base_addr = pcc_chan->shmem_base_addr;
- if (ctx->comm_base_addr) {
- if (version == XGENE_HWMON_V2)
- ctx->pcc_comm_addr = (void __force *)ioremap(
- ctx->comm_base_addr,
- pcc_chan->shmem_size);
- else
- ctx->pcc_comm_addr = memremap(
- ctx->comm_base_addr,
- pcc_chan->shmem_size,
- MEMREMAP_WB);
- } else {
- dev_err(&pdev->dev, "Failed to get PCC comm region\n");
- rc = -ENODEV;
- goto out;
- }
-
- if (!ctx->pcc_comm_addr) {
- dev_err(&pdev->dev,
- "Failed to ioremap PCC comm region\n");
- rc = -ENOMEM;
- goto out;
- }
-
- /*
- * pcc_chan->latency is just a Nominal value. In reality
- * the remote processor could be much slower to reply.
- * So add an arbitrary amount of wait on top of Nominal.
- */
- ctx->usecs_lat = PCC_NUM_RETRIES * pcc_chan->latency;
- }
-
- ctx->hwmon_dev = hwmon_device_register_with_groups(ctx->dev,
- "apm_xgene",
- ctx,
- xgene_hwmon_groups);
- if (IS_ERR(ctx->hwmon_dev)) {
- dev_err(&pdev->dev, "Failed to register HW monitor device\n");
- rc = PTR_ERR(ctx->hwmon_dev);
- goto out;
- }
-
- /*
- * Schedule the bottom handler if there is a pending message.
- */
- schedule_work(&ctx->workq);
-
- dev_info(&pdev->dev, "APM X-Gene SoC HW monitor driver registered\n");
-
- return 0;
-
-out:
- if (acpi_disabled)
- mbox_free_channel(ctx->mbox_chan);
- else
- pcc_mbox_free_channel(ctx->pcc_chan);
-out_mbox_free:
- kfifo_free(&ctx->async_msg_fifo);
-
- return rc;
-}
-
-static int xgene_hwmon_remove(struct platform_device *pdev)
-{
- struct xgene_hwmon_dev *ctx = platform_get_drvdata(pdev);
-
- hwmon_device_unregister(ctx->hwmon_dev);
- kfifo_free(&ctx->async_msg_fifo);
- if (acpi_disabled)
- mbox_free_channel(ctx->mbox_chan);
- else
- pcc_mbox_free_channel(ctx->pcc_chan);
-
- return 0;
-}
-
-static const struct of_device_id xgene_hwmon_of_match[] = {
- {.compatible = "apm,xgene-slimpro-hwmon"},
- {}
-};
-MODULE_DEVICE_TABLE(of, xgene_hwmon_of_match);
-
-static struct platform_driver xgene_hwmon_driver = {
- .probe = xgene_hwmon_probe,
- .remove = xgene_hwmon_remove,
- .driver = {
- .name = "xgene-slimpro-hwmon",
- .of_match_table = xgene_hwmon_of_match,
- .acpi_match_table = ACPI_PTR(xgene_hwmon_acpi_match),
- },
-};
-module_platform_driver(xgene_hwmon_driver);
-
-MODULE_DESCRIPTION("APM X-Gene SoC hardware monitor");
-MODULE_LICENSE("GPL");
--
2.35.1
D Scott Phillips <[email protected]> writes:
> Similar to the situation in commit 9049572fb145 ("hwmon: Remove amd_energy
> driver"), access to power information can be used as the basis for a side-
> channel attack. Removing unprivileged access to monitoring information
> would effectively make the driver useless, so simply remove the driver.
Well not really useless, there's still baby in this bath water.
Specifically, there's no reason to remove the temperature monitor
capabilities here. Sorry for the noise, I'll come back with something
better thought out.