Messages in this thread | | | Subject | Re: [PATCH] irqchip/gicv3: Fix GICR_WAKE & GICD_IGROUPR accesses from non-secure | From | Shanker Donthineni <> | Date | Mon, 6 Feb 2017 06:59:40 -0600 |
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Hi Marc,
On 02/06/2017 03:33 AM, Marc Zyngier wrote: > Hi Shanker, > > On 06/02/17 02:17, Shanker Donthineni wrote: >> On systems where it supports two security states, both the register >> GICR_WAKE and GICD_IGROUPR accesses are RAZ/WI from non-secure. >> The function gic_enable_redist() to wake/sleep redistributor is not >> harmful at all, but it is confusing looking at the code. The current >> code checks the single security state based on bit GICD_CTLR.DS which >> is absolutely incorrect. The disable security bit GICD_CTLR.DS is RAZ >> to non-secure. > I'm afraid we don't have the same definition of GICD_CTLR.DS. In my copy > of the architecture spec, it says: > > "When this field is set to 1, all accesses to GICD_CTLR access the > single Security state view, and all bits are accessible". > ^^^^^^^^^^^^^^^^^^^^^^^ Yes, but GICD_CTLR.DS is reversed bit not defined when accessing from non-secure. Please look at GICD_CTLR definition 'When access is Non-secure, in a system that supports two Security states'
> This would tend to support my interpretation that once DS has been set > from the secure side, it becomes visible to all type of accesses. > >> The GICD_TYPE.SecurityExtn indicates whether the GIC >> implementation supports two security states or only one security >> state. > Yes, and that's orthogonal to having set DS or not. > > So clearly, we have a difference of interpretation. What part of the > spec is supporting yours? I've verified three releases of GIC specs, all of them have the same definition of GICD_CTLR.
1) First release of GICv3 and GICv4 issue A 2) First release of GICv3 and GICv4 issue B 3) First release of GICv3 and GICv4 issue C
Section '8.9.4 GICD_CTLR, Distributor Control Register' has the three definitions. 1) When access is Secure, in a system that supports two Security states DS bit: When this field is set to 1, all accesses to GICD_CTLR access the single Security state view, and all bits are accessible.
2) When access is Non-secure, in a system that supports two Security states DS bit: Reserved. 3) When in a system that supports only a single Security state DS bit: Disable Security. This field is RAO/WI.
-- Shanker Donthineni Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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