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* ARM: add SMP support for non-secure switchAndre Przywara2013-10-03-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the non-secure switch is only done for the boot processor. To enable full SMP support, we have to switch all secondary cores into non-secure state also. So we add an entry point for secondary CPUs coming out of low-power state and make sure we put them into WFI again after having switched to non-secure state. For this we acknowledge and EOI the wake-up IPI, then go into WFI. Once being kicked out of it later, we sanity check that the start address has actually been changed (since another attempt to switch to non-secure would block the core) and jump to the new address. The actual CPU kick is done by sending an inter-processor interrupt via the GIC to all CPU interfaces except the requesting processor. The secondary cores will then setup their respective GIC CPU interface. While this approach is pretty universal across several ARMv7 boards, we make this function weak in case someone needs to tweak this for a specific board. The way of setting the secondary's start address is board specific, but mostly different only in the actual SMP pen address, so we also provide a weak default implementation and just depend on the proper address to be set in the config file. Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
* ARM: add assembly routine to switch to non-secure stateAndre Przywara2013-10-03-0/+17
While actually switching to non-secure state is one thing, another part of this process is to make sure that we still have full access to the interrupt controller (GIC). The GIC is fully aware of secure vs. non-secure state, some registers are banked, others may be configured to be accessible from secure state only. To be as generic as possible, we get the GIC memory mapped address based on the PERIPHBASE value in the CBAR register. Since this register is not architecturally defined, we check the MIDR before to be from an A15 or A7. For CPUs not having the CBAR or boards with wrong information herein we allow providing the base address as a configuration variable. Now that we know the GIC address, we: a) allow private interrupts to be delivered to the core (GICD_IGROUPR0 = 0xFFFFFFFF) b) enable the CPU interface (GICC_CTLR[0] = 1) c) set the priority filter to allow non-secure interrupts (GICC_PMR = 0xFF) Also we allow access to all coprocessor interfaces from non-secure state by writing the appropriate bits in the NSACR register. The generic timer base frequency register is only accessible from secure state, so we have to program it now. Actually this should be done from primary firmware before, but some boards seems to omit this, so if needed we do this here with a board specific value. The Versatile Express board does not need this, so we remove the frequency from the configuration file here. After having switched to non-secure state, we also enable the non-secure GIC CPU interface, since this register is banked. Since we need to call this routine also directly from the smp_pen later (where we don't have any stack), we can only use caller saved registers r0-r3 and r12 to not mess with the compiler. Signed-off-by: Andre Przywara <andre.przywara@linaro.org>