From: Nicholas Piggin npiggin@gmail.com
[ Upstream commit 838ee286ecc9a3c76e6bd8f5aaad0c8c5c66b9ca ]
This makes working on the code a bit easier.
Signed-off-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20220308135047.478297-2-npiggin@gmail.com Stable-dep-of: 91926d8b7e71 ("powerpc/rtas: Fix RTAS MSR[HV] handling for Cell") Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kernel/Makefile | 2 +- arch/powerpc/kernel/entry_32.S | 49 -------- arch/powerpc/kernel/entry_64.S | 150 ----------------------- arch/powerpc/kernel/rtas_entry.S | 198 +++++++++++++++++++++++++++++++ 4 files changed, 199 insertions(+), 200 deletions(-) create mode 100644 arch/powerpc/kernel/rtas_entry.S
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ed91d5b9ffc6..df1692020693 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -69,7 +69,7 @@ obj-$(CONFIG_PPC_BOOK3S_IDLE) += idle_book3s.o procfs-y := proc_powerpc.o obj-$(CONFIG_PROC_FS) += $(procfs-y) rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI) := rtas_pci.o -obj-$(CONFIG_PPC_RTAS) += rtas.o rtas-rtc.o $(rtaspci-y-y) +obj-$(CONFIG_PPC_RTAS) += rtas_entry.o rtas.o rtas-rtc.o $(rtaspci-y-y) obj-$(CONFIG_PPC_RTAS_DAEMON) += rtasd.o obj-$(CONFIG_RTAS_FLASH) += rtas_flash.o obj-$(CONFIG_RTAS_PROC) += rtas-proc.o diff --git a/arch/powerpc/kernel/entry_32.S b/arch/powerpc/kernel/entry_32.S index c62dd9815965..77b6b0e4b752 100644 --- a/arch/powerpc/kernel/entry_32.S +++ b/arch/powerpc/kernel/entry_32.S @@ -526,52 +526,3 @@ ret_from_mcheck_exc: _ASM_NOKPROBE_SYMBOL(ret_from_mcheck_exc) #endif /* CONFIG_BOOKE */ #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ - -/* - * PROM code for specific machines follows. Put it - * here so it's easy to add arch-specific sections later. - * -- Cort - */ -#ifdef CONFIG_PPC_RTAS -/* - * On CHRP, the Run-Time Abstraction Services (RTAS) have to be - * called with the MMU off. - */ -_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) - LOAD_REG_IMMEDIATE(r0,MSR_KERNEL) - mtmsr r0 /* disable interrupts so SRR0/1 don't get trashed */ - li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR) - mtlr r6 - stw r1, THREAD + RTAS_SP(r2) - mtspr SPRN_SRR0,r8 - mtspr SPRN_SRR1,r9 - rfi -1: - 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) -#endif /* CONFIG_PPC_RTAS */ diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 07a1448146e2..d1ec22fe59f6 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -264,156 +264,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) addi r1,r1,SWITCH_FRAME_SIZE blr
-#ifdef CONFIG_PPC_RTAS -/* - * On CHRP, the Run-Time Abstraction Services (RTAS) have to be - * called with the MMU off. - * - * In addition, we need to be in 32b mode, at least for now. - * - * Note: r3 is an input parameter to rtas, so don't trash it... - */ -_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-r13 are caller saved) - */ - SAVE_GPR(2, r1) /* Save the TOC */ - SAVE_GPR(13, r1) /* Save paca */ - 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 - -#ifdef CONFIG_BUG - /* There is no way it is acceptable to get here with interrupts enabled, - * check it with the asm equivalent of WARN_ON - */ - lbz r0,PACAIRQSOFTMASK(r13) -1: tdeqi r0,IRQS_ENABLED - EMIT_WARN_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING -#endif - - /* Hard-disable interrupts */ - mfmsr r6 - rldicl r7,r6,48,1 - rotldi r7,r7,16 - mtmsrd r7,1 - - /* 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. - */ - LOAD_REG_IMMEDIATE(r6, MSR_ME | MSR_RI) - - 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 - - /* - * Clear RI and set SF before anything. - */ - mfmsr r6 - li r0,MSR_RI - andc r6,r6,r0 - sldi r0,r0,(MSR_SF_LG - MSR_RI_LG) - or r6,r6,r0 - sync - mtmsrd r6 - - /* relocation is off at this point */ - GET_PACA(r4) - clrldi r4,r4,2 /* convert to realmode address */ - - bcl 20,31,$+4 -0: mflr r3 - ld r3,(1f-0b)(r3) /* get &rtas_restore_regs */ - - ld r1,PACAR1(r4) /* Restore our SP */ - ld r4,PACASAVEDMSR(r4) /* 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(rtas_return_loc) - - .align 3 -1: .8byte rtas_restore_regs - -rtas_restore_regs: - /* relocation is on at this point */ - REST_GPR(2, r1) /* Restore the TOC */ - REST_GPR(13, r1) /* Restore paca */ - REST_NVGPRS(r1) /* Restore the non-volatiles */ - - GET_PACA(r13) - - 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_PPC_RTAS */ - _GLOBAL(enter_prom) mflr r0 std r0,16(r1) diff --git a/arch/powerpc/kernel/rtas_entry.S b/arch/powerpc/kernel/rtas_entry.S new file mode 100644 index 000000000000..9ae1ca3c6fca --- /dev/null +++ b/arch/powerpc/kernel/rtas_entry.S @@ -0,0 +1,198 @@ +/* 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) + LOAD_REG_IMMEDIATE(r0,MSR_KERNEL) + mtmsr r0 /* disable interrupts so SRR0/1 don't get trashed */ + li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR) + mtlr r6 + stw r1, THREAD + RTAS_SP(r2) + mtspr SPRN_SRR0,r8 + mtspr SPRN_SRR1,r9 + rfi +1: + 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-r13 are caller saved) + */ + SAVE_GPR(2, r1) /* Save the TOC */ + SAVE_GPR(13, r1) /* Save paca */ + 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 + +#ifdef CONFIG_BUG + /* There is no way it is acceptable to get here with interrupts enabled, + * check it with the asm equivalent of WARN_ON + */ + lbz r0,PACAIRQSOFTMASK(r13) +1: tdeqi r0,IRQS_ENABLED + EMIT_WARN_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING +#endif + + /* Hard-disable interrupts */ + mfmsr r6 + rldicl r7,r6,48,1 + rotldi r7,r7,16 + mtmsrd r7,1 + + /* 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. + */ + LOAD_REG_IMMEDIATE(r6, MSR_ME | MSR_RI) + + 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 + + /* + * Clear RI and set SF before anything. + */ + mfmsr r6 + li r0,MSR_RI + andc r6,r6,r0 + sldi r0,r0,(MSR_SF_LG - MSR_RI_LG) + or r6,r6,r0 + sync + mtmsrd r6 + + /* relocation is off at this point */ + GET_PACA(r4) + clrldi r4,r4,2 /* convert to realmode address */ + + bcl 20,31,$+4 +0: mflr r3 + ld r3,(1f-0b)(r3) /* get &rtas_restore_regs */ + + ld r1,PACAR1(r4) /* Restore our SP */ + ld r4,PACASAVEDMSR(r4) /* 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(rtas_return_loc) + + .align 3 +1: .8byte rtas_restore_regs + +rtas_restore_regs: + /* relocation is on at this point */ + REST_GPR(2, r1) /* Restore the TOC */ + REST_GPR(13, r1) /* Restore paca */ + REST_NVGPRS(r1) /* Restore the non-volatiles */ + + GET_PACA(r13) + + 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 */