/* SPDX-License-Identifier: GPL-2.0-or-later */ #include <asm/asm-offsets.h>#include <asm/bug.h>#include <asm/page.h>#include <asm/ppc_asm.h> /* * RTAS is called with MSR IR, DR, EE disabled, and LR in the return address. * * Note: r3 is an input parameter to rtas, so don't trash it... */ #ifdef CONFIG_PPC32_GLOBAL(enter_rtas)	stwu	r1,-INT_FRAME_SIZE(r1)	mflr	r0	stw	r0,INT_FRAME_SIZE+4(r1)	LOAD_REG_ADDR(r4, rtas)	lis	r6,1f@ha	/* physical return address for rtas */	addi	r6,r6,1f@l	tophys(r6,r6)	lwz	r8,RTASENTRY(r4)	lwz	r4,RTASBASE(r4)	mfmsr	r9	stw	r9,8(r1)	li	r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)	mtlr	r6	stw	r1, THREAD + RTAS_SP(r2)	mtspr	SPRN_SRR0,r8	mtspr	SPRN_SRR1,r9	rfi1:	lis	r8, 1f@h	ori	r8, r8, 1f@l	LOAD_REG_IMMEDIATE(r9,MSR_KERNEL)	mtspr	SPRN_SRR0,r8	mtspr	SPRN_SRR1,r9	rfi			/* Reactivate MMU translation */1:	lwz	r8,INT_FRAME_SIZE+4(r1)	/* get return address */	lwz	r9,8(r1)	/* original msr value */	addi	r1,r1,INT_FRAME_SIZE	li	r0,0	stw	r0, THREAD + RTAS_SP(r2)	mtlr	r8	mtmsr	r9	blr			/* return to caller */_ASM_NOKPROBE_SYMBOL(enter_rtas) #else /* CONFIG_PPC32 */#include <asm/exception-64s.h> /* * 32-bit rtas on 64-bit machines has the additional problem that RTAS may * not preserve the upper parts of registers it uses. */_GLOBAL(enter_rtas)	mflr	r0	std	r0,16(r1)	stdu	r1,-SWITCH_FRAME_SIZE(r1) /* Save SP and create stack space. */ 	/* Because RTAS is running in 32b mode, it clobbers the high order half	 * of all registers that it saves.  We therefore save those registers	 * RTAS might touch to the stack.  (r0, r3-r12 are caller saved)	 */	SAVE_GPR(2, r1)			/* Save the TOC */	SAVE_NVGPRS(r1)			/* Save the non-volatiles */ 	mfcr	r4	std	r4,_CCR(r1)	mfctr	r5	std	r5,_CTR(r1)	mfspr	r6,SPRN_XER	std	r6,_XER(r1)	mfdar	r7	std	r7,_DAR(r1)	mfdsisr	r8	std	r8,_DSISR(r1) 	/* Temporary workaround to clear CR until RTAS can be modified to	 * ignore all bits.	 */	li	r0,0	mtcr	r0 	mfmsr	r6 	/* Unfortunately, the stack pointer and the MSR are also clobbered,	 * so they are saved in the PACA which allows us to restore	 * our original state after RTAS returns.	 */	std	r1,PACAR1(r13)	std	r6,PACASAVEDMSR(r13) 	/* Setup our real return addr */	LOAD_REG_ADDR(r4,rtas_return_loc)	clrldi	r4,r4,2			/* convert to realmode address */	mtlr	r4 __enter_rtas:	LOAD_REG_ADDR(r4, rtas)	ld	r5,RTASENTRY(r4)	/* get the rtas->entry value */	ld	r4,RTASBASE(r4)		/* get the rtas->base value */ 	/*	 * RTAS runs in 32-bit big endian real mode, but leave MSR[RI] on as we	 * may hit NMI (SRESET or MCE) while in RTAS. RTAS should disable RI in	 * its critical regions (as specified in PAPR+ section 7.2.1). MSR[S]	 * is not impacted by RFI_TO_KERNEL (only urfid can unset it). So if	 * MSR[S] is set, it will remain when entering RTAS.	 * If we're in HV mode, RTAS must also run in HV mode, so extract MSR_HV	 * from the saved MSR value and insert into the value RTAS will use.	 */	extrdi	r0, r6, 1, 63 - MSR_HV_LG	LOAD_REG_IMMEDIATE(r6, MSR_ME | MSR_RI)	insrdi	r6, r0, 1, 63 - MSR_HV_LG 	li      r0,0	mtmsrd  r0,1                    /* disable RI before using SRR0/1 */		mtspr	SPRN_SRR0,r5	mtspr	SPRN_SRR1,r6	RFI_TO_KERNEL	b	.	/* prevent speculative execution */rtas_return_loc:	FIXUP_ENDIAN 	/* Set SF before anything. */	LOAD_REG_IMMEDIATE(r6, MSR_KERNEL & ~(MSR_IR|MSR_DR))	mtmsrd	r6 	/* relocation is off at this point */	GET_PACA(r13) 	bcl	20,31,$+40:	mflr	r3	ld	r3,(1f-0b)(r3)		/* get &rtas_restore_regs */ 	ld	r1,PACAR1(r13)		/* Restore our SP */	ld	r4,PACASAVEDMSR(r13)	/* Restore our MSR */ 	mtspr	SPRN_SRR0,r3	mtspr	SPRN_SRR1,r4	RFI_TO_KERNEL	b	.	/* prevent speculative execution */_ASM_NOKPROBE_SYMBOL(enter_rtas)_ASM_NOKPROBE_SYMBOL(__enter_rtas)_ASM_NOKPROBE_SYMBOL(rtas_return_loc) 	.align	31:	.8byte	rtas_restore_regs rtas_restore_regs:	/* relocation is on at this point */	REST_GPR(2, r1)			/* Restore the TOC */	REST_NVGPRS(r1)			/* Restore the non-volatiles */ 	ld	r4,_CCR(r1)	mtcr	r4	ld	r5,_CTR(r1)	mtctr	r5	ld	r6,_XER(r1)	mtspr	SPRN_XER,r6	ld	r7,_DAR(r1)	mtdar	r7	ld	r8,_DSISR(r1)	mtdsisr	r8 	addi	r1,r1,SWITCH_FRAME_SIZE	/* Unstack our frame */	ld	r0,16(r1)		/* get return address */ 	mtlr	r0	blr				/* return to caller */ #endif /* CONFIG_PPC32 */