PCIe Control

Functions

PCIe Control

Functions
amdsmi_status_t	amdsmi_set_gpu_pci_bandwidth (amdsmi_processor_handle processor_handle, uint64_t bw_bitmask)
	Control the set of allowed PCIe bandwidths that can be used. It is not supported on virtual machine guest.

Detailed Description

These functions provide some control over PCIe.

Function Documentation

◆ amdsmi_set_gpu_pci_bandwidth()

amdsmi_status_t amdsmi_set_gpu_pci_bandwidth	(	amdsmi_processor_handle	processor_handle,
		uint64_t	bw_bitmask
	)

Control the set of allowed PCIe bandwidths that can be used. It is not supported on virtual machine guest.

Platform:

gpu_bm_linux

Given a processor handle processor_handle and a 64 bit bitmask bw_bitmask, this function will limit the set of allowable bandwidths. If a bit in bw_bitmask has a value of 1, then the frequency (as ordered in an amdsmi_frequencies_t returned by :: amdsmi_get_clk_freq()) corresponding to that bit index will be allowed.

This function will change the performance level to AMDSMI_DEV_PERF_LEVEL_MANUAL in order to modify the set of allowable band_widths. Caller will need to set to AMDSMI_DEV_PERF_LEVEL_AUTO in order to get back to default state.

All bits with indices greater than or equal to the value of the amdsmi_frequencies_t::num_supported field of amdsmi_pcie_bandwidth_t will be ignored.

Note

This function requires root access

Parameters

[in]	processor_handle	a processor handle
[in]	bw_bitmask	A bitmask indicating the indices of the bandwidths that are to be enabled (1) and disabled (0). Only the lowest amdsmi_frequencies_t::num_supported (of amdsmi_pcie_bandwidth_t) bits of this mask are relevant.

Returns

amdsmi_status_t | AMDSMI_STATUS_SUCCESS on success, non-zero on fail