Re: [PATCH 05/23] Add common PPC64 KVM asm helpers

[Benjamin Herrenschmidt <benh@kernel.crashing.org>]

On Tue, 2009-07-07 at 16:17 +0200, Alexander Graf wrote:

> +.macro to_phys dest_reg, source_reg
> +#if PAGE_OFFSET = 0xc000000000000000
> +	clrldi	\dest_reg, \source_reg, 2
> +#else
> +	#error Unknown PAGE_OFFSET
> +#endif

We already have tophys() for that in ppc_asm.h

BTW. We prefer using C-style #define for asm macros ... bad habit maybe
but at least it's consistent :-)

> +.endm
> +
> +.macro loadimm reg, imm
> +	lis	\reg,       \imm@highest
> +	ori	\reg, \reg, \imm@higher
> +	rldicr	\reg, \reg, 32, 31
> +	oris	\reg, \reg, \imm@h
> +	ori	\reg, \reg, \imm@l
> +.endm

We already have LOAD_REG_IMMEDIATE() in ppc_asm.h :-)

> +.macro setmagc reg
> +	ori	\reg, r13, 1		/* r3 = PACA | 1 */
> +	mtspr	SPRN_SPRG3, \reg	/* SPRG3 =PACA | 1 */
> +.endm

Fun :-) So you set the PACA low bit to indicate you are running in the
guest ? That's a pretty good way to do it I suppose.

> +#define HOST_STACK_R1	(0 * ULONG_SIZE)
> +/* We need to keep some space here that the C function */
> +/* we jump into later can clobber */
> +#define HOST_STACK_LR	(8 * ULONG_SIZE)
> +#define HOST_STACK_RUN	(9 * ULONG_SIZE)
> +#define HOST_STACK_VCPU	(10 * ULONG_SIZE)
> +#define HOST_STACK_R14	(14 * ULONG_SIZE)
> +#define HOST_STACK_R15	(15 * ULONG_SIZE)
> +#define HOST_STACK_R16	(16 * ULONG_SIZE)
> +#define HOST_STACK_R17	(17 * ULONG_SIZE)
> +#define HOST_STACK_R18	(18 * ULONG_SIZE)
> +#define HOST_STACK_R19	(19 * ULONG_SIZE)
> +#define HOST_STACK_R20	(20 * ULONG_SIZE)
> +#define HOST_STACK_R21	(21 * ULONG_SIZE)
> +#define HOST_STACK_R22	(22 * ULONG_SIZE)
> +#define HOST_STACK_R23	(23 * ULONG_SIZE)
> +#define HOST_STACK_R24	(24 * ULONG_SIZE)
> +#define HOST_STACK_R25	(25 * ULONG_SIZE)
> +#define HOST_STACK_R26	(26 * ULONG_SIZE)
> +#define HOST_STACK_R27	(27 * ULONG_SIZE)
> +#define HOST_STACK_R28	(28 * ULONG_SIZE)
> +#define HOST_STACK_R29	(29 * ULONG_SIZE)
> +#define HOST_STACK_R30	(30 * ULONG_SIZE)
> +#define HOST_STACK_R31	(31 * ULONG_SIZE)
> +#define HOST_STACK_MIN_SIZE (HOST_STACK_R31 + ULONG_SIZE)
> +#define HOST_STACK_SIZE (((HOST_STACK_MIN_SIZE + 15) / 16) * 16) /* Align. */
> +#define VCPU_GPR(n)     (VCPU_GPRS + (n * ULONG_SIZE))

Can't you define a C structure and generate offsets in asm-offsets.h
using asm-offsets.c like we do for most other stuff ?

Cheers,
Ben.

> +.macro mfpaca tmp_reg, src_reg, offset, vcpu_reg
> +	ld	\tmp_reg, (PACA_EXMC+\offset)(r13)
> +	std	\tmp_reg, VCPU_GPR(\src_reg)(\vcpu_reg)
> +.endm
> +
> +
> +.macro DO_KVM intno
> +	.if (\intno = PPC970_INTERRUPT_SYSTEM_RESET) || \
> +	    (\intno = PPC970_INTERRUPT_MACHINE_CHECK) || \
> +	    (\intno = PPC970_INTERRUPT_DATA_STORAGE) || \
> +	    (\intno = PPC970_INTERRUPT_INST_STORAGE) || \
> +	    (\intno = PPC970_INTERRUPT_DATA_SEGMENT) || \
> +	    (\intno = PPC970_INTERRUPT_INST_SEGMENT) || \
> +	    (\intno = PPC970_INTERRUPT_EXTERNAL) || \
> +	    (\intno = PPC970_INTERRUPT_ALIGNMENT) || \
> +	    (\intno = PPC970_INTERRUPT_PROGRAM) || \
> +	    (\intno = PPC970_INTERRUPT_FP_UNAVAIL) || \
> +	    (\intno = PPC970_INTERRUPT_DECREMENTER) || \
> +	    (\intno = PPC970_INTERRUPT_SYSCALL) || \
> +	    (\intno = PPC970_INTERRUPT_TRACE) || \
> +	    (\intno = PPC970_INTERRUPT_PERFMON) || \
> +	    (\intno = PPC970_INTERRUPT_ALTIVEC) || \
> +	    (\intno = PPC970_INTERRUPT_VSX)
> +
> +	b	kvmppc_trampoline_\intno
> +kvmppc_resume_\intno:
> +
> +	.endif
> +.endm
> +
> +#else
> +
> +.macro DO_KVM intno
> +.endm
> +
> +#endif /* CONFIG_KVM_970_HANDLER */
> +
> +#endif /* __ASM_KVM_970_ASM_H__ */