There have been instances when the default size (1M) of the STB is not sufficient to get the complete traces of the failure. In such scenarios we can use a module_param to enable full trace that shall contain more debugging data. This is not a regular case and hence not enabling this capability by default. With this change, there will be two cases on how the driver fetches the stb data: 1) A special case (proposed now) - which is required only for certain platforms. Here, a new module param will be supplied to the driver that will have a special PMFW supporting enhanced dram sizes for getting the stb data. Without the special PMFW support, just setting the module param will not help to get the enhanced stb data. To adapt to this change, we will have a new amd_pmc_stb_handle_efr() to handle enhanced firmware reporting mechanism. Note that, since num_samples based r/w pointer offset calculation is not required for enhanced firmware reporting we will have this mailbox command sent only in case of regular STB cases. 2) Current code branch which fetches the stb data based on the parameters like the num_samples, fsize and the r/w pointer. Co-developed-by: Harsh Jain <Harsh.Jain@xxxxxxx> Signed-off-by: Harsh Jain <Harsh.Jain@xxxxxxx> Signed-off-by: Sanket Goswami <Sanket.Goswami@xxxxxxx> Signed-off-by: Shyam Sundar S K <Shyam-sundar.S-k@xxxxxxx> --- v4->v5: - create a new function amd_pmc_stb_handle_efr() to handle enhanced firmware reporting mechanism - based on review-ilpo branch v3->v4: - Update code branches and commit-msg as per Ilpo's remark. v2->v3: - no change v1->v2: - rebase to 'review-hans' branch - drop 2/4 of v1 (https://patchwork.kernel.org/project/platform-driver-x86/list/?series=775324&state=%2A&archive=both) drivers/platform/x86/amd/pmc/pmc.c | 45 ++++++++++++++++++++++++++++-- 1 file changed, 43 insertions(+), 2 deletions(-) diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c index 071d92b7fbde..1424c03c1f03 100644 --- a/drivers/platform/x86/amd/pmc/pmc.c +++ b/drivers/platform/x86/amd/pmc/pmc.c @@ -53,6 +53,7 @@ /* STB Spill to DRAM Parameters */ #define S2D_TELEMETRY_BYTES_MAX 0x100000 +#define S2D_RSVD_RAM_SPACE 0x100000 #define S2D_TELEMETRY_DRAMBYTES_MAX 0x1000000 /* STB Spill to DRAM Message Definition */ @@ -165,6 +166,10 @@ static bool disable_workarounds; module_param(disable_workarounds, bool, 0644); MODULE_PARM_DESC(disable_workarounds, "Disable workarounds for platform bugs"); +static bool dump_custom_stb; +module_param(dump_custom_stb, bool, 0644); +MODULE_PARM_DESC(dump_custom_stb, "Enable to dump full STB buffer"); + static struct amd_pmc_dev pmc; static int amd_pmc_send_cmd(struct amd_pmc_dev *dev, u32 arg, u32 *data, u8 msg, bool ret); static int amd_pmc_read_stb(struct amd_pmc_dev *dev, u32 *buf); @@ -241,6 +246,26 @@ static const struct file_operations amd_pmc_stb_debugfs_fops = { .release = amd_pmc_stb_debugfs_release, }; +/* Enhanced STB Firmware Reporting Mechanism */ +static int amd_pmc_stb_handle_efr(struct file *filp) +{ + struct amd_pmc_dev *dev = filp->f_inode->i_private; + struct amd_pmc_stb_v2_data *flex_arr; + + dev->fsize = dev->dram_size - S2D_RSVD_RAM_SPACE; + dev->stb_rdptr_offset = 0; + + flex_arr = kzalloc(struct_size(flex_arr, data, dev->fsize), GFP_KERNEL); + if (!flex_arr) + return -ENOMEM; + + memcpy_fromio(flex_arr->data, dev->stb_virt_addr + dev->stb_rdptr_offset, dev->fsize); + flex_arr->size = dev->fsize; + filp->private_data = flex_arr->data; + + return 0; +} + static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) { struct amd_pmc_dev *dev = filp->f_inode->i_private; @@ -260,6 +285,16 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) if (ret) dev_warn_once(dev->dev, "S2D force flush not supported\n"); + /* + * We have a custom stb size and the PMFW is supposed to give + * the enhanced dram size. Note that we land here only for the + * platforms that support enhanced dram size reporting. + */ + if (dump_custom_stb) { + ret = amd_pmc_stb_handle_efr(filp); + return ret; + } + /* Get the num_samples to calculate the last push location */ ret = amd_pmc_send_cmd(dev, S2D_NUM_SAMPLES, &dev->num_samples, dev->s2d_msg_id, true); /* Clear msg_port for other SMU operation */ @@ -269,7 +304,11 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) return ret; } - /* Start capturing data from the last push location */ + /* + * Start capturing data from the last push location. + * This is for general cases, where the stb limits + * are meant for standard usage. + */ if (dev->num_samples > S2D_TELEMETRY_BYTES_MAX) { /* First read oldest data starting 1 behind last write till end of ringbuffer */ dev->stb_rdptr_offset = dev->num_samples % S2D_TELEMETRY_BYTES_MAX; @@ -303,11 +342,13 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) static ssize_t amd_pmc_stb_debugfs_read_v2(struct file *filp, char __user *buf, size_t size, loff_t *pos) { + struct amd_pmc_dev *dev = filp->f_inode->i_private; + if (!filp->private_data) return -EINVAL; return simple_read_from_buffer(buf, size, pos, filp->private_data, - S2D_TELEMETRY_BYTES_MAX); + dev->fsize); } static int amd_pmc_stb_debugfs_release_v2(struct inode *inode, struct file *filp) -- 2.25.1
