Hi, On 4/4/24 11:07 AM, Basavaraj Natikar wrote: > AMD MP2 STB function provides a data buffer used to log debug information > about the system execution during S2Idle suspend/resume. > > A data buffer known as the STB (Smart Trace Buffer) is a circular buffer > which is a low-level log to assist in debugging by providing insights > into any potential hangs or stalls that may occur during the S2Idle > suspend/resume processes. > > The current PMC driver retrieves STB data from MP1, but there can be > scenarios where MP1 might hang or become unresponsive, leading to the > loss of critical data present in the STB buffer. This defeats the purpose > of the STB buffer, which was originally meant to help identify system > failures. > > This feature creates stb_read_previous_boot debugfs allows users to > retrieve the STB log from MP2 specifically from the last occurrence of > the S2Idle suspend/resume. A userspace daemon can access STB log of last > S2Idle suspend/resume which can help to troubleshoot potential issues > related to hangs or stalls during the S2Idle suspend/resume sequence. > > Reviewed-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx> > Signed-off-by: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx> Thank you for your patch, I've applied this patch to my review-hans branch: https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans Note it will show up in my review-hans branch once I've pushed my local branch there, which might take a while. Once I've run some tests on this branch the patches there will be added to the platform-drivers-x86/for-next branch and eventually will be included in the pdx86 pull-request to Linus for the next merge-window. Regards, Hans > --- > Changes in v4: > - Modified Kconfig to provide clearer messages and configuration > options. > - Referenced amd_pmc instead of global variable. > - Used macros instead of constant literals. > - Added pci_clear_master to the cleanup path. > - Renamed the 'cmd' and 'response' field names of a structure to > 'field'. > - Replaced dev_err with dev_dbg wherever appropriate. > - Consolidated SZ_1K multiplication to a single location instead > of repeating it throughout the code. > > Changes in v3: > - Changed an error path for deinitialization or freeing resources. > - Modified the macro and variable to have a more specific name. > - Included header files for USEC_PER_MSEC, writeq, and writel. > - Switched the data type of the 'len' variable from 'int' to > 'unsigned int'. > - Used one variable for return values. > > Changes in v2: > - Used linux/sizes.h instead of defining KB. > - Defined timeout containing unit as per USEC_PER_MSEC. > - Modified macro of AMD_C2P_MSG and AMD_P2C_MSG. > - Changed string stb to STB in log messages. > - Defined literals using Macro. > > drivers/platform/x86/amd/pmc/Kconfig | 15 ++ > drivers/platform/x86/amd/pmc/Makefile | 1 + > drivers/platform/x86/amd/pmc/mp2_stb.c | 279 +++++++++++++++++++++++++ > drivers/platform/x86/amd/pmc/pmc.c | 4 + > drivers/platform/x86/amd/pmc/pmc.h | 15 ++ > 5 files changed, 314 insertions(+) > create mode 100644 drivers/platform/x86/amd/pmc/mp2_stb.c > > diff --git a/drivers/platform/x86/amd/pmc/Kconfig b/drivers/platform/x86/amd/pmc/Kconfig > index 883c0a95ac0c..94f9563d8be7 100644 > --- a/drivers/platform/x86/amd/pmc/Kconfig > +++ b/drivers/platform/x86/amd/pmc/Kconfig > @@ -18,3 +18,18 @@ config AMD_PMC > > If you choose to compile this driver as a module the module will be > called amd-pmc. > + > +config AMD_MP2_STB > + bool "AMD SoC MP2 STB function" > + depends on AMD_PMC > + default AMD_PMC > + help > + AMD MP2 STB function provides a data buffer used to log debug > + information about the system execution during S2Idle suspend/resume. > + A data buffer known as the STB (Smart Trace Buffer) is a circular > + buffer which is a low-level log for the SoC which is used to debug > + any hangs/stalls during S2Idle suspend/resume. > + > + Creates debugfs to get STB, a userspace daemon can access STB log of > + last S2Idle suspend/resume which can help to debug if hangs/stalls > + during S2Idle suspend/resume. > diff --git a/drivers/platform/x86/amd/pmc/Makefile b/drivers/platform/x86/amd/pmc/Makefile > index 4aaa29d351c9..f1d9ab19d24c 100644 > --- a/drivers/platform/x86/amd/pmc/Makefile > +++ b/drivers/platform/x86/amd/pmc/Makefile > @@ -6,3 +6,4 @@ > > amd-pmc-objs := pmc.o pmc-quirks.o > obj-$(CONFIG_AMD_PMC) += amd-pmc.o > +amd-pmc-$(CONFIG_AMD_MP2_STB) += mp2_stb.o > diff --git a/drivers/platform/x86/amd/pmc/mp2_stb.c b/drivers/platform/x86/amd/pmc/mp2_stb.c > new file mode 100644 > index 000000000000..dfa55327e5f1 > --- /dev/null > +++ b/drivers/platform/x86/amd/pmc/mp2_stb.c > @@ -0,0 +1,279 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * AMD MP2 STB layer > + * > + * Copyright (c) 2024, Advanced Micro Devices, Inc. > + * All Rights Reserved. > + * > + * Author: Basavaraj Natikar <Basavaraj.Natikar@xxxxxxx> > + */ > + > +#include <linux/debugfs.h> > +#include <linux/device.h> > +#include <linux/io.h> > +#include <linux/iopoll.h> > +#include <linux/pci.h> > +#include <linux/sizes.h> > +#include <linux/time.h> > + > +#include "pmc.h" > + > +#define VALID_MSG 0xA > +#define VALID_RESPONSE 2 > + > +#define AMD_C2P_MSG0 0x10500 > +#define AMD_C2P_MSG1 0x10504 > +#define AMD_P2C_MSG0 0x10680 > +#define AMD_P2C_MSG1 0x10684 > + > +#define MP2_RESP_SLEEP_US 500 > +#define MP2_RESP_TIMEOUT_US (1600 * USEC_PER_MSEC) > + > +#define MP2_STB_DATA_LEN_2KB 1 > +#define MP2_STB_DATA_LEN_16KB 4 > + > +#define MP2_MMIO_BAR 2 > + > +struct mp2_cmd_base { > + union { > + u32 ul; > + struct { > + u32 cmd_id : 4; > + u32 intr_disable : 1; > + u32 is_dma_used : 1; > + u32 rsvd : 26; > + } field; > + }; > +}; > + > +struct mp2_cmd_response { > + union { > + u32 resp; > + struct { > + u32 cmd_id : 4; > + u32 status : 4; > + u32 response : 4; > + u32 rsvd2 : 20; > + } field; > + }; > +}; > + > +struct mp2_stb_data_valid { > + union { > + u32 data_valid; > + struct { > + u32 valid : 16; > + u32 length : 16; > + } val; > + }; > +}; > + > +static int amd_mp2_wait_response(struct amd_mp2_dev *mp2, u8 cmd_id, u32 command_sts) > +{ > + struct mp2_cmd_response cmd_resp; > + > + if (!readl_poll_timeout(mp2->mmio + AMD_P2C_MSG0, cmd_resp.resp, > + (cmd_resp.field.response == 0x0 && > + cmd_resp.field.status == command_sts && > + cmd_resp.field.cmd_id == cmd_id), MP2_RESP_SLEEP_US, > + MP2_RESP_TIMEOUT_US)) > + return cmd_resp.field.status; > + > + return -ETIMEDOUT; > +} > + > +static void amd_mp2_stb_send_cmd(struct amd_mp2_dev *mp2, u8 cmd_id, bool is_dma_used) > +{ > + struct mp2_cmd_base cmd_base; > + > + cmd_base.ul = 0; > + cmd_base.field.cmd_id = cmd_id; > + cmd_base.field.intr_disable = 1; > + cmd_base.field.is_dma_used = is_dma_used; > + > + writeq(mp2->dma_addr, mp2->mmio + AMD_C2P_MSG1); > + writel(cmd_base.ul, mp2->mmio + AMD_C2P_MSG0); > +} > + > +static int amd_mp2_stb_region(struct amd_mp2_dev *mp2) > +{ > + struct device *dev = &mp2->pdev->dev; > + unsigned int len = mp2->stb_len; > + > + if (!mp2->stbdata) { > + mp2->vslbase = dmam_alloc_coherent(dev, len, &mp2->dma_addr, GFP_KERNEL); > + if (!mp2->vslbase) > + return -ENOMEM; > + > + mp2->stbdata = devm_kzalloc(dev, len, GFP_KERNEL); > + if (!mp2->stbdata) > + return -ENOMEM; > + } > + > + return 0; > +} > + > +static int amd_mp2_process_cmd(struct amd_mp2_dev *mp2, struct file *filp) > +{ > + struct device *dev = &mp2->pdev->dev; > + struct mp2_stb_data_valid stb_dv; > + int status; > + > + stb_dv.data_valid = readl(mp2->mmio + AMD_P2C_MSG1); > + > + if (stb_dv.val.valid != VALID_MSG) { > + dev_dbg(dev, "Invalid STB data\n"); > + return -EBADMSG; > + } > + > + if (stb_dv.val.length != MP2_STB_DATA_LEN_2KB && > + stb_dv.val.length != MP2_STB_DATA_LEN_16KB) { > + dev_dbg(dev, "Unsupported length\n"); > + return -EMSGSIZE; > + } > + > + mp2->stb_len = BIT(stb_dv.val.length) * SZ_1K; > + > + status = amd_mp2_stb_region(mp2); > + if (status) { > + dev_err(dev, "Failed to init STB region, status %d\n", status); > + return status; > + } > + > + amd_mp2_stb_send_cmd(mp2, VALID_MSG, true); > + status = amd_mp2_wait_response(mp2, VALID_MSG, VALID_RESPONSE); > + if (status == VALID_RESPONSE) { > + memcpy_fromio(mp2->stbdata, mp2->vslbase, mp2->stb_len); > + filp->private_data = mp2->stbdata; > + mp2->is_stb_data = true; > + } else { > + dev_err(dev, "Failed to start STB dump, status %d\n", status); > + return -EOPNOTSUPP; > + } > + > + return 0; > +} > + > +static int amd_mp2_stb_debugfs_open(struct inode *inode, struct file *filp) > +{ > + struct amd_pmc_dev *dev = filp->f_inode->i_private; > + struct amd_mp2_dev *mp2 = dev->mp2; > + > + if (mp2) { > + if (!mp2->is_stb_data) > + return amd_mp2_process_cmd(mp2, filp); > + > + filp->private_data = mp2->stbdata; > + > + return 0; > + } > + > + return -ENODEV; > +} > + > +static ssize_t amd_mp2_stb_debugfs_read(struct file *filp, char __user *buf, size_t size, > + loff_t *pos) > +{ > + struct amd_pmc_dev *dev = filp->f_inode->i_private; > + struct amd_mp2_dev *mp2 = dev->mp2; > + > + if (!mp2) > + return -ENODEV; > + > + if (!filp->private_data) > + return -EINVAL; > + > + return simple_read_from_buffer(buf, size, pos, filp->private_data, mp2->stb_len); > +} > + > +static const struct file_operations amd_mp2_stb_debugfs_fops = { > + .owner = THIS_MODULE, > + .open = amd_mp2_stb_debugfs_open, > + .read = amd_mp2_stb_debugfs_read, > +}; > + > +static void amd_mp2_dbgfs_register(struct amd_pmc_dev *dev) > +{ > + if (!dev->dbgfs_dir) > + return; > + > + debugfs_create_file("stb_read_previous_boot", 0644, dev->dbgfs_dir, dev, > + &amd_mp2_stb_debugfs_fops); > +} > + > +void amd_mp2_stb_deinit(struct amd_pmc_dev *dev) > +{ > + struct amd_mp2_dev *mp2 = dev->mp2; > + struct pci_dev *pdev; > + > + if (mp2 && mp2->pdev) { > + pdev = mp2->pdev; > + > + if (mp2->mmio) > + pci_clear_master(pdev); > + > + pci_dev_put(pdev); > + > + if (mp2->devres_gid) > + devres_release_group(&pdev->dev, mp2->devres_gid); > + > + dev->mp2 = NULL; > + } > +} > + > +void amd_mp2_stb_init(struct amd_pmc_dev *dev) > +{ > + struct amd_mp2_dev *mp2 = NULL; > + struct pci_dev *pdev; > + int rc; > + > + mp2 = devm_kzalloc(dev->dev, sizeof(*mp2), GFP_KERNEL); > + if (!mp2) > + return; > + > + pdev = pci_get_device(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_MP2_STB, NULL); > + if (!pdev) > + return; > + > + dev->mp2 = mp2; > + mp2->pdev = pdev; > + > + mp2->devres_gid = devres_open_group(&pdev->dev, NULL, GFP_KERNEL); > + if (!mp2->devres_gid) { > + dev_err(&pdev->dev, "devres_open_group failed\n"); > + goto mp2_error; > + } > + > + rc = pcim_enable_device(pdev); > + if (rc) { > + dev_err(&pdev->dev, "pcim_enable_device failed\n"); > + goto mp2_error; > + } > + > + rc = pcim_iomap_regions(pdev, BIT(MP2_MMIO_BAR), "mp2 stb"); > + if (rc) { > + dev_err(&pdev->dev, "pcim_iomap_regions failed\n"); > + goto mp2_error; > + } > + > + mp2->mmio = pcim_iomap_table(pdev)[MP2_MMIO_BAR]; > + if (!mp2->mmio) { > + dev_err(&pdev->dev, "pcim_iomap_table failed\n"); > + goto mp2_error; > + } > + > + pci_set_master(pdev); > + > + rc = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64)); > + if (rc) { > + dev_err(&pdev->dev, "failed to set DMA mask\n"); > + goto mp2_error; > + } > + > + amd_mp2_dbgfs_register(dev); > + > + return; > + > +mp2_error: > + amd_mp2_stb_deinit(dev); > +} > diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c > index 108e12fd580f..916a302e5614 100644 > --- a/drivers/platform/x86/amd/pmc/pmc.c > +++ b/drivers/platform/x86/amd/pmc/pmc.c > @@ -1106,6 +1106,8 @@ static int amd_pmc_probe(struct platform_device *pdev) > } > > amd_pmc_dbgfs_register(dev); > + if (IS_ENABLED(CONFIG_AMD_MP2_STB)) > + amd_mp2_stb_init(dev); > pm_report_max_hw_sleep(U64_MAX); > return 0; > > @@ -1122,6 +1124,8 @@ static void amd_pmc_remove(struct platform_device *pdev) > acpi_unregister_lps0_dev(&amd_pmc_s2idle_dev_ops); > amd_pmc_dbgfs_unregister(dev); > pci_dev_put(dev->rdev); > + if (IS_ENABLED(CONFIG_AMD_MP2_STB)) > + amd_mp2_stb_deinit(dev); > mutex_destroy(&dev->lock); > } > > diff --git a/drivers/platform/x86/amd/pmc/pmc.h b/drivers/platform/x86/amd/pmc/pmc.h > index 827eef65e133..9e32d3128c3a 100644 > --- a/drivers/platform/x86/amd/pmc/pmc.h > +++ b/drivers/platform/x86/amd/pmc/pmc.h > @@ -14,6 +14,17 @@ > #include <linux/types.h> > #include <linux/mutex.h> > > +struct amd_mp2_dev { > + void __iomem *mmio; > + void __iomem *vslbase; > + void *stbdata; > + void *devres_gid; > + struct pci_dev *pdev; > + dma_addr_t dma_addr; > + int stb_len; > + bool is_stb_data; > +}; > + > struct amd_pmc_dev { > void __iomem *regbase; > void __iomem *smu_virt_addr; > @@ -38,10 +49,13 @@ struct amd_pmc_dev { > struct dentry *dbgfs_dir; > struct quirk_entry *quirks; > bool disable_8042_wakeup; > + struct amd_mp2_dev *mp2; > }; > > void amd_pmc_process_restore_quirks(struct amd_pmc_dev *dev); > void amd_pmc_quirks_init(struct amd_pmc_dev *dev); > +void amd_mp2_stb_init(struct amd_pmc_dev *dev); > +void amd_mp2_stb_deinit(struct amd_pmc_dev *dev); > > /* List of supported CPU ids */ > #define AMD_CPU_ID_RV 0x15D0 > @@ -53,5 +67,6 @@ void amd_pmc_quirks_init(struct amd_pmc_dev *dev); > #define AMD_CPU_ID_PS 0x14E8 > #define AMD_CPU_ID_SP 0x14A4 > #define PCI_DEVICE_ID_AMD_1AH_M20H_ROOT 0x1507 > +#define PCI_DEVICE_ID_AMD_MP2_STB 0x172c > > #endif /* PMC_H */
