[PATCH][v2] KVM: PPC: add paravirt idle loop for 64-bit book E

[Alexander Graf]

On 23.01.2013, at 00:54, Stuart Yoder wrote:

> From: Stuart Yoder <stuart.yoder at freescale.com>
> 
> Signed-off-by: Stuart Yoder <stuart.yoder at freescale.com>

Ben, this one is in generic powerpc code, so I'd say it's for you :).


Alex

> ---
> 
> -v2
>   -macro'ized loop in idle_book3e.S to avoid code 
>    duplication, paravirt loop is now in idle_book3e.S
> 
> arch/powerpc/kernel/epapr_hcalls.S |    2 ++
> arch/powerpc/kernel/idle_book3e.S  |   30 ++++++++++++++++++++++++++++--
> 2 files changed, 30 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/powerpc/kernel/epapr_hcalls.S b/arch/powerpc/kernel/epapr_hcalls.S
> index 62c0dc2..9f1ebf7 100644
> --- a/arch/powerpc/kernel/epapr_hcalls.S
> +++ b/arch/powerpc/kernel/epapr_hcalls.S
> @@ -17,6 +17,7 @@
> #include <asm/asm-compat.h>
> #include <asm/asm-offsets.h>
> 
> +#ifndef CONFIG_PPC64
> /* epapr_ev_idle() was derived from e500_idle() */
> _GLOBAL(epapr_ev_idle)
> 	CURRENT_THREAD_INFO(r3, r1)
> @@ -42,6 +43,7 @@ epapr_ev_idle_start:
> 	 * _TLF_NAPPING.
> 	 */
> 	b	idle_loop
> +#endif
> 
> /* Hypercall entry point. Will be patched with device tree instructions. */
> .global epapr_hypercall_start
> diff --git a/arch/powerpc/kernel/idle_book3e.S b/arch/powerpc/kernel/idle_book3e.S
> index 4c7cb400..e1c9acd 100644
> --- a/arch/powerpc/kernel/idle_book3e.S
> +++ b/arch/powerpc/kernel/idle_book3e.S
> @@ -16,11 +16,13 @@
> #include <asm/ppc-opcode.h>
> #include <asm/processor.h>
> #include <asm/thread_info.h>
> +#include <asm/epapr_hcalls.h>
> 
> /* 64-bit version only for now */
> #ifdef CONFIG_PPC64
> 
> -_GLOBAL(book3e_idle)
> +.macro BOOK3E_IDLE name loop
> +_GLOBAL(\name)
> 	/* Save LR for later */
> 	mflr	r0
> 	std	r0,16(r1)
> @@ -67,7 +69,31 @@ _GLOBAL(book3e_idle)
> 
> 	/* We can now re-enable hard interrupts and go to sleep */
> 	wrteei	1
> -1:	PPC_WAIT(0)
> +	\loop
> +
> +.endm
> +
> +.macro BOOK3E_IDLE_LOOP
> +1:
> +	PPC_WAIT(0)
> 	b	1b
> +.endm
> +
> +.macro EPAPR_EV_IDLE_LOOP
> +idle_loop:
> +       LOAD_REG_IMMEDIATE(r11, EV_HCALL_TOKEN(EV_IDLE))
> +
> +.global epapr_ev_idle_start
> +epapr_ev_idle_start:
> +       li      r3, -1
> +       nop
> +       nop
> +       nop
> +       b       idle_loop
> +.endm
> +
> +BOOK3E_IDLE epapr_ev_idle, EPAPR_EV_IDLE_LOOP
> +
> +BOOK3E_IDLE book3e_idle BOOK3E_IDLE_LOOP
> 
> #endif /* CONFIG_PPC64 */
> -- 
> 1.7.9.7
> 
>