MPAMCFG_CPBM, MPAM Cache Portion Bitmap Partition Configuration Register

The MPAMCFG_CPBM characteristics are:

Purpose

The MPAMCFG_CPBM register is a read-write register that configures the cache portions that a PARTID is allowed to allocate. After setting MPAMCFG_PART_SEL with a PARTID, software (usually a hypervisor) writes to the MPAMCFG_CPBM register to configure which cache portions the PARTID is allowed to allocate.

MPAMCFG_CPBM_s controls cache portions for the Secure PARTID selected by the Secure instance of MPAMCFG_PART_SEL. MPAMCFG_CPBM_ns controls the cache portions for the Non-secure PARTID selected by the Non-secure instance of MPAMCFG_PART_SEL.

Configuration

The power domain of MPAMCFG_CPBM is IMPLEMENTATION DEFINED.

This register is present only when MPAMF_IDR.HAS_CPOR == 1. Otherwise, direct accesses to MPAMCFG_CPBM are RES0.

Attributes

MPAMCFG_CPBM is a 32768-bit register.

Field descriptions

The MPAMCFG_CPBM bit assignments are:

CPBM<n>, bit [n], for n = 0 to 32767

Each bit, CPBM<n>, grants permission to the PARTID to allocate cache lines within cache portion n.

The number of bits in the cache portion partitioning bit map of this component is given in MPAMF_CPOR_IDR.CPBM_WD. CPBM_WD contains a value from 1 to 2¹⁵, inclusive. Values of CPBM_WD greater than 32 require a group of 32-bit registers to access the CPBM, up to 1024 registers.

Bits CPBM<n>, where n is greater than CPBM_WD, are not required to be implemented.

Accessing the MPAMCFG_CPBM

This register is within the MPAM feature page memory frames. In a system that supports Secure and Non-secure memory maps, there must be both Secure and Non-secure MPAM feature pages.

MPAMCFG_CPBM_s must be accessible from the Secure MPAM feature page. MPAMCFG_CPBM_ns must be accessible from the Non-secure MPAM feature page.

MPAMCFG_CPBM_s and MPAMCFG_CPBM_ns must be separate registers. The Secure instance (MPAMCFG_CPBM_s) accesses the cache portion bitmaps used for Secure PARTIDs, and the Non-secure instance (MPAMCFG_CPBM_ns) accesses the cache portion bitmaps used for Non-secure PARTIDs.

MPAMCFG_CPBM can be accessed through the memory-mapped interfaces:

Accesses on this interface are RW.

Accesses on this interface are RW.