Gate the use of unsupported hardware behind a new module parameter (exp_hw_support).
Signed-off-by: Matt Coster <[email protected]> --- drivers/gpu/drm/imagination/pvr_device.c | 73 +++++++++++++++++++++++++++++++- 1 file changed, 72 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/imagination/pvr_device.c b/drivers/gpu/drm/imagination/pvr_device.c index d87557812409a..f58bb66a63275 100644 --- a/drivers/gpu/drm/imagination/pvr_device.c +++ b/drivers/gpu/drm/imagination/pvr_device.c @@ -525,6 +525,77 @@ pvr_gpuid_decode_string(const struct pvr_device *pvr_dev, } EXPORT_SYMBOL_IF_KUNIT(pvr_gpuid_decode_string); +static bool pvr_exp_hw_support; +module_param_named(exp_hw_support, pvr_exp_hw_support, bool, 0600); +MODULE_PARM_DESC(exp_hw_support, "Bypass runtime checks for fully supported GPU cores. WARNING: enabling this option may result in a buggy, insecure, or otherwise unusable driver."); + +/** + * enum pvr_gpu_support_level - The level of support for a gpu_id in the current + * version of the driver. + * + * @PVR_GPU_UNKNOWN: Cores that are unknown to the driver. These may not even exist. + * @PVR_GPU_EXPERIMENTAL: Cores that have experimental support. + * @PVR_GPU_SUPPORTED: Cores that are supported and maintained. + */ +enum pvr_gpu_support_level { + PVR_GPU_UNKNOWN, + PVR_GPU_EXPERIMENTAL, + PVR_GPU_SUPPORTED, +}; + +static enum pvr_gpu_support_level +pvr_gpu_support_level(const struct pvr_gpu_id *gpu_id) +{ + switch (pvr_gpu_id_to_packed_bvnc(gpu_id)) { + case PVR_PACKED_BVNC(33, 15, 11, 3): + case PVR_PACKED_BVNC(36, 53, 104, 796): + return PVR_GPU_SUPPORTED; + + case PVR_PACKED_BVNC(36, 52, 104, 182): + return PVR_GPU_EXPERIMENTAL; + + default: + return PVR_GPU_UNKNOWN; + } +} + +static int +pvr_check_gpu_supported(struct pvr_device *pvr_dev, + const struct pvr_gpu_id *gpu_id) +{ + struct drm_device *drm_dev = from_pvr_device(pvr_dev); + + switch (pvr_gpu_support_level(gpu_id)) { + case PVR_GPU_SUPPORTED: + if (pvr_exp_hw_support) + drm_info(drm_dev, "Module parameter 'exp_hw_support' was set, but this hardware is fully supported by the current driver."); + + break; + + case PVR_GPU_EXPERIMENTAL: + if (!pvr_exp_hw_support) { + drm_err(drm_dev, "Unsupported GPU! Set 'exp_hw_support' to bypass this check."); + return -ENODEV; + } + + drm_warn(drm_dev, "Running on unsupported hardware; you may encounter bugs!"); + break; + + /* NOTE: This code path may indicate misbehaving hardware. */ + case PVR_GPU_UNKNOWN: + default: + if (!pvr_exp_hw_support) { + drm_err(drm_dev, "Unknown GPU! Set 'exp_hw_support' to bypass this check."); + return -ENODEV; + } + + drm_warn(drm_dev, "Running on unknown hardware; expect issues."); + break; + } + + return 0; +} + static char *pvr_gpuid_override; module_param_named(gpuid, pvr_gpuid_override, charp, 0400); MODULE_PARM_DESC(gpuid, "GPU ID (BVNC) to be used instead of the value read from hardware."); @@ -555,7 +626,7 @@ pvr_load_gpu_id(struct pvr_device *pvr_dev) return err; } - return 0; + return pvr_check_gpu_supported(pvr_dev, gpu_id); } /** -- 2.52.0
