On Tue, 29 Aug 2023, Shyam Sundar S K wrote: > 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. > > 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> > --- > 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 | 34 +++++++++++++++++++----------- > drivers/platform/x86/amd/pmc/pmc.h | 1 + > 2 files changed, 23 insertions(+), 12 deletions(-) > > diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c > index 443bb78ea5f4..0e61ae74f1a9 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_TELEMETRY_FSIZE_MAX 0x200000 > #define S2D_TELEMETRY_DRAMBYTES_MAX 0x1000000 > > /* STB Spill to DRAM Message Definition */ > @@ -160,6 +161,10 @@ 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); > @@ -239,7 +244,7 @@ static const struct file_operations amd_pmc_stb_debugfs_fops = { > static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) > { > struct amd_pmc_dev *dev = filp->f_inode->i_private; > - u32 *buf, fsize, num_samples, val, stb_rdptr_offset = 0; > + u32 *buf, num_samples, val, stb_rdptr_offset = 0; > int ret; > > /* Write dummy postcode while reading the STB buffer */ > @@ -247,10 +252,6 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) > if (ret) > dev_err(dev->dev, "error writing to STB: %d\n", ret); > > - buf = kzalloc(S2D_TELEMETRY_BYTES_MAX, GFP_KERNEL); > - if (!buf) > - return -ENOMEM; > - > /* Spill to DRAM num_samples uses separate SMU message port */ > dev->msg_port = 1; > > @@ -264,20 +265,27 @@ static int amd_pmc_stb_debugfs_open_v2(struct inode *inode, struct file *filp) > dev->msg_port = 0; > if (ret) { > dev_err(dev->dev, "error: S2D_NUM_SAMPLES not supported : %d\n", ret); > - kfree(buf); > return ret; > } > > /* Start capturing data from the last push location */ > - if (num_samples > S2D_TELEMETRY_BYTES_MAX) { > - fsize = S2D_TELEMETRY_BYTES_MAX; > - stb_rdptr_offset = num_samples - fsize; > + if (dump_custom_stb && > + (dev->dram_size - S2D_TELEMETRY_BYTES_MAX <= S2D_TELEMETRY_FSIZE_MAX)) { > + dev->fsize = dev->dram_size - S2D_TELEMETRY_BYTES_MAX; > + stb_rdptr_offset = 0; > + } else if (num_samples > S2D_TELEMETRY_BYTES_MAX) { I find the logic here somewhat suspicious in the first if check (I fail to follow the reasoning here despite spending considerable amount of time staring at it). Lets assume dump_custom_stb is set. If dev->dram_size is large, the first if condition will be false because LHS of <= is large. Thus, we go to the second branch and dump exactly as many samples as before this patch. ...And that is opposite of what this patch claims to do? > + dev->fsize = S2D_TELEMETRY_BYTES_MAX; Please remove also the extra space here since you're touching this line. -- i. > + stb_rdptr_offset = num_samples - dev->fsize; > } else { > - fsize = num_samples; > + dev->fsize = num_samples; > stb_rdptr_offset = 0; > } > > - memcpy_fromio(buf, dev->stb_virt_addr + stb_rdptr_offset, fsize); > + buf = kzalloc(dev->fsize, GFP_KERNEL); > + if (!buf) > + return -ENOMEM; > + > + memcpy_fromio(buf, dev->stb_virt_addr + stb_rdptr_offset, dev->fsize); > filp->private_data = buf; > > return 0; > @@ -286,11 +294,13 @@ 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) > diff --git a/drivers/platform/x86/amd/pmc/pmc.h b/drivers/platform/x86/amd/pmc/pmc.h > index c27bd6a5642f..f73d265430b8 100644 > --- a/drivers/platform/x86/amd/pmc/pmc.h > +++ b/drivers/platform/x86/amd/pmc/pmc.h > @@ -26,6 +26,7 @@ struct amd_pmc_dev { > u32 dram_size; > u32 num_ips; > u32 s2d_msg_id; > + u32 fsize; > /* SMU version information */ > u8 smu_program; > u8 major; >
