On Monday 25 November 2013 10:09 AM, Christoffer Dall wrote: > On 23 November 2013 16:07, Santosh Shilimkar <santosh.shilimkar@xxxxxx> wrote: >> Boot-CPU entry into the HYP mode is managed in boot-loader but >> the secondary CPUs directly jumps to kernel during boot. Same >> path is also used for CPU hotplug as well during suspend for >> secondary CPU. >> >> Hence patch the secondary CPU boot path for hyp mode etry. >> >> Cc: Marc Zyngier <marc.zyngier@xxxxxxx> >> Cc: Christoffer Dall <christoffer.dall@xxxxxxxxxx> >> Cc: Tony Lindgren <tony@xxxxxxxxxxx> >> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx> >> --- >> arch/arm/mach-omap2/omap-headsmp.S | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/arch/arm/mach-omap2/omap-headsmp.S b/arch/arm/mach-omap2/omap-headsmp.S >> index 75e9295..4844dd8 100644 >> --- a/arch/arm/mach-omap2/omap-headsmp.S >> +++ b/arch/arm/mach-omap2/omap-headsmp.S >> @@ -22,6 +22,7 @@ >> >> /* Physical address needed since MMU not enabled yet on secondary core */ >> #define AUX_CORE_BOOT0_PA 0x48281800 >> +#define API_HYP_ENTRY 0x102 >> >> /* >> * OMAP5 specific entry point for secondary CPU to jump from ROM >> @@ -38,6 +39,12 @@ wait: ldr r2, =AUX_CORE_BOOT0_PA @ read from AuxCoreBoot0 >> and r4, r4, #0x0f >> cmp r0, r4 >> bne wait >> +#ifdef CONFIG_KVM_ARM_HOST >> + ldr r12, =API_HYP_ENTRY >> + adr r0, hyp_boot >> + smc #0 >> +hyp_boot: >> +#endif >> b secondary_startup >> END(omap5_secondary_startup) >> /* > > hmm, this means that currently running this in a guest will fail to > bring-up SMP, right? > Nope. Because the code under 'KVM_ARM_HOST' macro. Guest build will not enable CONFIG_KVM_ARM_HOST and things should be fine then. Right ? > Couldn't you create a little wrapper-pen in U-Boot instead, which > replicates the omap boot protocol and takes care of the hyp-mode > startup there instead, keeping this completely out of the kernel? > Its not just booting but CPU hotplug also follows the same path so we need the mechanism in kernel to switch mode. In general, I think its important to consider the aspect with CPU PM. CPUs are not going to go through the boot-loaders in those paths and hence need of HYP entry in the kernel will be must. Regards, Santosh Regards, Santosh -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
