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| author | Nicholas Piggin <npiggin@gmail.com> | 2023-06-06 23:24:43 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-06-14 12:46:42 +1000 |
| commit | 0eb8088b5a7524f96cadfb27083f5bdd819d9d52 (patch) | |
| tree | ebd61d7db64ce6057f5bb869f4687bf50ad76930 /arch/powerpc/kernel/entry_64.S | |
| parent | d6b87c3eb6b2e0b34ba747df549e08768b019fe9 (diff) | |
| download | linux-0eb8088b5a7524f96cadfb27083f5bdd819d9d52.tar.gz | |
powerpc/64: Rearrange 64-bit _switch to prepare for 32/64 merge
More some 64-bit specifics out from the function epilogue and rearrange
this to be a bit neater, use 32-bit mem ops for CR save/restore, and
change some register numbers.
This is preparation to consolidate 32-bit and 64-bit switch code.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230606132447.315714-3-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/kernel/entry_64.S')
| -rw-r--r-- | arch/powerpc/kernel/entry_64.S | 38 |
1 files changed, 18 insertions, 20 deletions
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S index 2e02834c5824a5..7430bd020a2ae9 100644 --- a/arch/powerpc/kernel/entry_64.S +++ b/arch/powerpc/kernel/entry_64.S @@ -190,12 +190,13 @@ _GLOBAL(_switch) mflr r0 std r0,16(r1) stdu r1,-SWITCH_FRAME_SIZE(r1) + std r1,KSP(r3) /* Set old stack pointer */ /* r3-r13 are caller saved -- Cort */ SAVE_NVGPRS(r1) std r0,_NIP(r1) /* Return to switch caller */ - mfcr r23 - std r23,_CCR(r1) - std r1,KSP(r3) /* Set old stack pointer */ + mfcr r0 + stw r0,_CCR(r1) + ld r8,KSP(r4) /* Load new stack pointer */ kuap_check_amr r9, r10 @@ -232,14 +233,20 @@ _GLOBAL(_switch) DCBT_BOOK3S_STOP_ALL_STREAM_IDS(r6) #endif - addi r6,r4,-THREAD /* Convert THREAD to 'current' */ - std r6,PACACURRENT(r13) /* Set new 'current' */ + addi r3,r3,-THREAD /* old thread -> task_struct for return value */ + addi r6,r4,-THREAD /* new thread -> task_struct */ + std r6,PACACURRENT(r13) /* Set new task_struct to 'current' */ #if defined(CONFIG_STACKPROTECTOR) ld r6, TASK_CANARY(r6) std r6, PACA_CANARY(r13) #endif - - ld r8,KSP(r4) /* new stack pointer */ + /* Set the new PACAKSAVE */ + clrrdi r7, r8, THREAD_SHIFT /* base of new stack */ + /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE + because we don't need to leave the 288-byte ABI gap at the + top of the kernel stack. */ + addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE + std r7,PACAKSAVE(r13) #ifdef CONFIG_PPC_64S_HASH_MMU BEGIN_MMU_FTR_SECTION @@ -247,12 +254,6 @@ BEGIN_MMU_FTR_SECTION END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) #endif - clrrdi r7, r8, THREAD_SHIFT /* base of new stack */ - /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE - because we don't need to leave the 288-byte ABI gap at the - top of the kernel stack. */ - addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE - /* * PMU interrupts in radix may come in here. They will use r1, not * PACAKSAVE, so this stack switch will not cause a problem. They @@ -262,18 +263,15 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX) * active on the new CPU, will order those stores. */ mr r1,r8 /* start using new stack pointer */ - std r7,PACAKSAVE(r13) - ld r6,_CCR(r1) - mtcrf 0xFF,r6 + lwz r0,_CCR(r1) + mtcrf 0xFF,r0 /* r3-r13 are destroyed -- Cort */ REST_NVGPRS(r1) - /* convert old thread to its task_struct for return value */ - addi r3,r3,-THREAD - ld r7,_NIP(r1) /* Return to _switch caller in new task */ - mtlr r7 + ld r0,_NIP(r1) /* Return to _switch caller in new task */ + mtlr r0 addi r1,r1,SWITCH_FRAME_SIZE blr |