On Mon, 9 Oct 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. > > 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. > > Reviewed-by: Hans de Goede <hdegoede@xxxxxxxxxx> > 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> > --- > v6->v7: > - Code simplication > > v5->v6: > - No change > > 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 | 32 ++++++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/platform/x86/amd/pmc/pmc.c b/drivers/platform/x86/amd/pmc/pmc.c > index e0b5d9de473a..af6d400193ff 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 +246,25 @@ 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; > + u32 fsize; > + > + fsize = dev->dram_size - S2D_RSVD_RAM_SPACE; > + flex_arr = kmalloc(struct_size(flex_arr, data, fsize), GFP_KERNEL); > + if (!flex_arr) > + return -ENOMEM; > + > + flex_arr->size = fsize; > + memcpy_fromio(flex_arr->data, dev->stb_virt_addr, fsize); > + filp->private_data = flex_arr; > + > + return 0; Thanks, this make much more sense than the early versions! Just one confirmation, is dev->dram_size >= S2D_RSVD_RAM_SPACE always guaranteed so that the fsize never underflows? -- i.
