platform/x86/amd/pmc: Handle overflow cases where the num_samples range is higher

In amd_pmc_stb_debugfs_open_v2(), the stb buffer is created based on the
num_samples and the read/write pointer offset. This holds good when the
num_samples reported by PMFW is less than S2D_TELEMETRY_BYTES_MAX; where
the stb buffer gets filled from 0th position until
S2D_TELEMETRY_BYTES_MAX - 1 based on the read/write pointer offset.

But when the num_samples exceeds the S2D_TELEMETRY_BYTES_MAX, the current
code does not handle it well as it does not account for the cases where
the stb buffer has to filled up as a circular buffer.

Handle this scenario into two cases, where first memcpy will have the
samples from location:
(num_samples % S2D_TELEMETRY_BYTES_MAX) - (S2D_TELEMETRY_BYTES_MAX - 1)
and next memcpy will have the newest ones i.e.
0 - (num_samples % S2D_TELEMETRY_BYTES_MAX - 1)

Suggested-by: Hans de Goede <[email protected]>
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Sanket Goswami <[email protected]>
Signed-off-by: Shyam Sundar S K <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ij: renamed flex_arr -> stb_data_arr]
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Ilpo Järvinen <[email protected]>

0 files changed, 0 insertions, 0 deletions