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Message-Id: <20220926100756.539397084@linuxfoundation.org>
Date: Mon, 26 Sep 2022 12:10:47 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Nicholas Piggin <npiggin@...il.com>,
Michael Ellerman <mpe@...erman.id.au>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 013/148] powerpc/rtas: Move rtas entry assembly into its own file
From: Nicholas Piggin <npiggin@...il.com>
[ Upstream commit 838ee286ecc9a3c76e6bd8f5aaad0c8c5c66b9ca ]
This makes working on the code a bit easier.
Signed-off-by: Nicholas Piggin <npiggin@...il.com>
Signed-off-by: Michael Ellerman <mpe@...erman.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@...nel.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 */
--
2.35.1
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