From: Shyam Sundar S K Shyam-sundar.S-k@amd.com
[ Upstream commit 95e1b60f8dc8f225b14619e9aca9bdd7d99167db ]
The protocol to submit a job request to SMU is to wait for AMD_PMC_REGISTER_RESPONSE to return 1,meaning SMU is ready to take requests. PMC driver has to make sure that the response code is always AMD_PMC_RESULT_OK before making any command submissions.
When we submit a message to SMU, we have to wait until it processes the request. Adding a read_poll_timeout() check as this was missing in the existing code.
Also, add a mutex to protect amd_pmc_send_cmd() calls to SMU.
Fixes: 156ec4731cb2 ("platform/x86: amd-pmc: Add AMD platform support for S2Idle") Signed-off-by: Shyam Sundar S K Shyam-sundar.S-k@amd.com Acked-by: Raul E Rangel rrangel@chromium.org Reviewed-by: Hans de Goede hdegoede@redhat.com Link: https://lore.kernel.org/r/20210629084803.248498-2-Shyam-sundar.S-k@amd.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/amd-pmc.c | 38 ++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/amd-pmc.c b/drivers/platform/x86/amd-pmc.c index b9da58ee9b1e..1b5f149932c1 100644 --- a/drivers/platform/x86/amd-pmc.c +++ b/drivers/platform/x86/amd-pmc.c @@ -68,6 +68,7 @@ struct amd_pmc_dev { u32 base_addr; u32 cpu_id; struct device *dev; + struct mutex lock; /* generic mutex lock */ #if IS_ENABLED(CONFIG_DEBUG_FS) struct dentry *dbgfs_dir; #endif /* CONFIG_DEBUG_FS */ @@ -138,9 +139,10 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set) u8 msg; u32 val;
+ mutex_lock(&dev->lock); /* Wait until we get a valid response */ rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMC_REGISTER_RESPONSE, - val, val > 0, PMC_MSG_DELAY_MIN_US, + val, val != 0, PMC_MSG_DELAY_MIN_US, PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX); if (rc) { dev_err(dev->dev, "failed to talk to SMU\n"); @@ -156,7 +158,37 @@ static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, bool set) /* Write message ID to message ID register */ msg = (dev->cpu_id == AMD_CPU_ID_RN) ? MSG_OS_HINT_RN : MSG_OS_HINT_PCO; amd_pmc_reg_write(dev, AMD_PMC_REGISTER_MESSAGE, msg); - return 0; + /* Wait until we get a valid response */ + rc = readx_poll_timeout(ioread32, dev->regbase + AMD_PMC_REGISTER_RESPONSE, + val, val != 0, PMC_MSG_DELAY_MIN_US, + PMC_MSG_DELAY_MIN_US * RESPONSE_REGISTER_LOOP_MAX); + if (rc) { + dev_err(dev->dev, "SMU response timed out\n"); + goto out_unlock; + } + + switch (val) { + case AMD_PMC_RESULT_OK: + break; + case AMD_PMC_RESULT_CMD_REJECT_BUSY: + dev_err(dev->dev, "SMU not ready. err: 0x%x\n", val); + rc = -EBUSY; + goto out_unlock; + case AMD_PMC_RESULT_CMD_UNKNOWN: + dev_err(dev->dev, "SMU cmd unknown. err: 0x%x\n", val); + rc = -EINVAL; + goto out_unlock; + case AMD_PMC_RESULT_CMD_REJECT_PREREQ: + case AMD_PMC_RESULT_FAILED: + default: + dev_err(dev->dev, "SMU cmd failed. err: 0x%x\n", val); + rc = -EIO; + goto out_unlock; + } + +out_unlock: + mutex_unlock(&dev->lock); + return rc; }
static int __maybe_unused amd_pmc_suspend(struct device *dev) @@ -259,6 +291,7 @@ static int amd_pmc_probe(struct platform_device *pdev)
amd_pmc_dump_registers(dev);
+ mutex_init(&dev->lock); platform_set_drvdata(pdev, dev); amd_pmc_dbgfs_register(dev); return 0; @@ -269,6 +302,7 @@ static int amd_pmc_remove(struct platform_device *pdev) struct amd_pmc_dev *dev = platform_get_drvdata(pdev);
amd_pmc_dbgfs_unregister(dev); + mutex_destroy(&dev->lock); return 0; }