From eeedcea69e927857d32aaf089725eddd2c79dd0a Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Fri, 26 Jun 2015 08:09:29 +0100 Subject: ARM: 8395/1: l2c: Add support for the "arm,shared-override" property "CoreLink Level 2 Cache Controller L2C-310", p. 2-15, section 2.3.2 Shareable attribute" states: "The default behavior of the cache controller with respect to the shareable attribute is to transform Normal Memory Non-cacheable transactions into: - cacheable no allocate for reads - write through no write allocate for writes." Depending on the system architecture, this may cause memory corruption in the presence of bus mastering devices (e.g. OHCI). To avoid such corruption, the default behavior can be disabled by setting the Shared Override bit in the Auxiliary Control register. Currently the Shared Override bit can be set only using C code: - by calling l2x0_init() directly, which is deprecated, - by setting/clearing the bit in the machine_desc.l2c_aux_val/mask fields, but using values differing from 0/~0 is also deprecated. Hence add support for an "arm,shared-override" device tree property for the l2c device node. By specifying this property, affected systems can indicate that non-cacheable transactions must not be transformed. Then, it's up to the OS to decide. The current behavior is to set the "shared attribute override enable" bit, as there may exist kernel linear mappings and cacheable aliases for the DMA buffers, even if CMA is enabled. See also commit 1a8e41cd672f894b ("ARM: 6395/1: VExpress: Set bit 22 in the PL310 (cache controller) AuxCtlr register"): "Clearing bit 22 in the PL310 Auxiliary Control register (shared attribute override enable) has the side effect of transforming Normal Shared Non-cacheable reads into Cacheable no-allocate reads. Coherent DMA buffers in Linux always have a Cacheable alias via the kernel linear mapping and the processor can speculatively load cache lines into the PL310 controller. With bit 22 cleared, Non-cacheable reads would unexpectedly hit such cache lines leading to buffer corruption." Signed-off-by: Geert Uytterhoeven Acked-by: Catalin Marinas Signed-off-by: Russell King --- Documentation/devicetree/bindings/arm/l2cc.txt | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/devicetree/bindings') diff --git a/Documentation/devicetree/bindings/arm/l2cc.txt b/Documentation/devicetree/bindings/arm/l2cc.txt index 2251dccb141e..06c88a4d28ac 100644 --- a/Documentation/devicetree/bindings/arm/l2cc.txt +++ b/Documentation/devicetree/bindings/arm/l2cc.txt @@ -67,6 +67,12 @@ Optional properties: 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), -- cgit v1.2.3 From b6c084d7aa8bca21920cbbe13ad58572fa85ece6 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Mon, 29 Jun 2015 13:59:01 +0100 Subject: ARM: perf: extend interrupt-affinity property for PPIs On systems containing multiple, heterogeneous clusters we need a way to associate a PMU "device" with the CPU(s) on which it exists. For PMUs that signal overflow with SPIs, this relationship is determined via the "interrupt-affinity" property, which contains a list of phandles to CPU nodes for the PMU. For PMUs using PPIs, the per-cpu nature of the interrupt isn't enough to determine the set of CPUs which actually contain the device. This patch allows the interrupt-affinity property to be specified on a PMU node irrespective of the interrupt type. For PPIs, it identifies the set of CPUs signalling the PPI in question. Tested-by: Stephen Boyd # Krait PMU Signed-off-by: Will Deacon --- Documentation/devicetree/bindings/arm/pmu.txt | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'Documentation/devicetree/bindings') diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt index 3b5f5d1088c6..435251fa9ce0 100644 --- a/Documentation/devicetree/bindings/arm/pmu.txt +++ b/Documentation/devicetree/bindings/arm/pmu.txt @@ -26,13 +26,19 @@ Required properties: Optional properties: -- interrupt-affinity : Valid only when using SPIs, specifies a list of phandles - to CPU nodes corresponding directly to the affinity of +- interrupt-affinity : When using SPIs, specifies a list of phandles to CPU + nodes corresponding directly to the affinity of the SPIs listed in the interrupts property. - This property should be present when there is more than + When using a PPI, specifies a list of phandles to CPU + nodes corresponding to the set of CPUs which have + a PMU of this type signalling the PPI listed in the + interrupts property. + + This property should be present when there is more than a single SPI. + - qcom,no-pc-write : Indicates that this PMU doesn't support the 0xc and 0xd events. -- cgit v1.2.3