--- zzzz-none-000/linux-3.10.107/Documentation/devicetree/bindings/arm/l2cc.txt 2017-06-27 09:49:32.000000000 +0000 +++ scorpion-7490-727/linux-3.10.107/Documentation/devicetree/bindings/arm/l2cc.txt 2021-02-04 17:41:59.000000000 +0000 @@ -2,20 +2,30 @@ ARM cores often have a separate level 2 cache controller. There are various implementations of the L2 cache controller with compatible programming models. +Some of the properties that are just prefixed "cache-*" are taken from section +3.7.3 of the ePAPR v1.1 specification which can be found at: +https://www.power.org/wp-content/uploads/2012/06/Power_ePAPR_APPROVED_v1.1.pdf + The ARM L2 cache representation in the device tree should be done as follows: Required properties: - compatible : should be one of: - "arm,pl310-cache" - "arm,l220-cache" - "arm,l210-cache" - "marvell,aurora-system-cache": Marvell Controller designed to be + "arm,pl310-cache" + "arm,l220-cache" + "arm,l210-cache" + "bcm,bcm11351-a2-pl310-cache": DEPRECATED by "brcm,bcm11351-a2-pl310-cache" + "brcm,bcm11351-a2-pl310-cache": For Broadcom bcm11351 chipset where an + offset needs to be added to the address before passing down to the L2 + cache controller + "marvell,aurora-system-cache": Marvell Controller designed to be compatible with the ARM one, with system cache mode (meaning maintenance operations on L1 are broadcasted to the L2 and L2 performs the same operation). - "marvell,"aurora-outer-cache: Marvell Controller designed to be - compatible with the ARM one with outer cache mode. + "marvell,aurora-outer-cache": Marvell Controller designed to be + compatible with the ARM one with outer cache mode. + "marvell,tauros3-cache": Marvell Tauros3 cache controller, compatible + with arm,pl310-cache controller. - cache-unified : Specifies the cache is a unified cache. - cache-level : Should be set to 2 for a level 2 cache. - reg : Physical base address and size of cache controller's memory mapped @@ -34,10 +44,40 @@ - arm,filter-ranges : Starting address and length of window to filter. Addresses in the filter window are directed to the M1 port. Other addresses will go to the M0 port. +- arm,io-coherent : indicates that the system is operating in an hardware + I/O coherent mode. Valid only when the arm,pl310-cache compatible + string is used. - interrupts : 1 combined interrupt. +- cache-size : specifies the size in bytes of the cache +- cache-sets : specifies the number of associativity sets of the cache +- cache-block-size : specifies the size in bytes of a cache block +- cache-line-size : specifies the size in bytes of a line in the cache, + if this is not specified, the line size is assumed to be equal to the + cache block size - cache-id-part: cache id part number to be used if it is not present on hardware - wt-override: If present then L2 is forced to Write through mode +- arm,double-linefill : Override double linefill enable setting. Enable if + non-zero, disable if zero. +- arm,double-linefill-incr : Override double linefill on INCR read. Enable + if non-zero, disable if zero. +- arm,double-linefill-wrap : Override double linefill on WRAP read. Enable + if non-zero, disable if zero. +- arm,prefetch-drop : Override prefetch drop enable setting. Enable if non-zero, + disable if zero. +- arm,prefetch-offset : Override prefetch offset value. Valid values are + 0-7, 15, 23, and 31. +- arm,shared-override : The default behavior of the pl310 cache controller with + respect to the shareable attribute is to transform "normal memory + non-cacheable transactions" into "cacheable no allocate" (for reads) or + "write through no write allocate" (for writes). + On systems where this may cause DMA buffer corruption, this property must be + specified to indicate that such transforms are precluded. +- prefetch-data : Data prefetch. Value: <0> (forcibly disable), <1> + (forcibly enable), property absent (retain settings set by firmware) +- prefetch-instr : Instruction prefetch. Value: <0> (forcibly disable), + <1> (forcibly enable), property absent (retain settings set by + firmware) Example: