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From: Michael Ellerman <mpe@ellerman.id.au>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH 6/9] powerpc/32s: Remove TAUException wart in traps.c
Date: Fri, 24 Jul 2020 23:17:25 +1000	[thread overview]
Message-ID: <20200724131728.1643966-6-mpe@ellerman.id.au> (raw)
In-Reply-To: <20200724131728.1643966-1-mpe@ellerman.id.au>

All 32 and 64-bit builds that don't have CONFIG_TAU_INT enabled (all
of them), get a definition of TAUException() in traps.c.

On 64-bit it's completely useless, and just wastes ~120 bytes of text.
On 32-bit it allows the kernel to link because head_32.S calls it
unconditionally.

Instead follow the example of altivec_assist_exception(), and if
CONFIG_TAU_INT is not enabled just point it at unknown_exception using
the preprocessor.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

Can we just remove TAU_INT entirely? It's in zero defconfigs and
doesn't sound like something anyone really wants to enable:

  However, on some cpus it appears that the TAU interrupt hardware
  is buggy and can cause a situation which would lead unexplained hard
  lockups.

  Unless you are extending the TAU driver, or enjoy kernel/hardware
  debugging, leave this option off.
---
 arch/powerpc/kernel/head_32.S | 4 ++++
 arch/powerpc/kernel/traps.c   | 8 --------
 2 files changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 705c042309d8..dcfb7dceb6d6 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -671,6 +671,10 @@ END_MMU_FTR_SECTION_IFSET(MMU_FTR_NEED_DTLB_SW_LRU)
 
 #ifndef CONFIG_ALTIVEC
 #define altivec_assist_exception	unknown_exception
+#endif
+
+#ifndef CONFIG_TAU_INT
+#define TAUException	unknown_exception
 #endif
 
 	EXCEPTION(0x1300, Trap_13, instruction_breakpoint_exception, EXC_XFER_STD)
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 97413a385720..d1ebe152f210 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -2060,14 +2060,6 @@ void DebugException(struct pt_regs *regs, unsigned long debug_status)
 NOKPROBE_SYMBOL(DebugException);
 #endif /* CONFIG_PPC_ADV_DEBUG_REGS */
 
-#if !defined(CONFIG_TAU_INT)
-void TAUException(struct pt_regs *regs)
-{
-	printk("TAU trap at PC: %lx, MSR: %lx, vector=%lx    %s\n",
-	       regs->nip, regs->msr, regs->trap, print_tainted());
-}
-#endif /* CONFIG_INT_TAU */
-
 #ifdef CONFIG_ALTIVEC
 void altivec_assist_exception(struct pt_regs *regs)
 {
-- 
2.25.1


  parent reply	other threads:[~2020-07-24 13:58 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-24 13:17 [PATCH 1/9] powerpc/configs: Drop old symbols from ppc6xx_defconfig Michael Ellerman
2020-07-24 13:17 ` [PATCH 2/9] powerpc/configs: Remove dead symbols Michael Ellerman
2020-07-24 13:17 ` [PATCH 3/9] powerpc/52xx: Fix comment about CONFIG_BDI* Michael Ellerman
2020-07-24 13:17 ` [PATCH 4/9] powerpc/64e: Drop dead BOOK3E_MMU_TLB_STATS code Michael Ellerman
2020-07-24 13:17 ` [PATCH 5/9] powerpc/32s: Fix CONFIG_BOOK3S_601 uses Michael Ellerman
2020-07-24 18:42   ` Christophe Leroy
2020-07-24 13:17 ` Michael Ellerman [this message]
2020-07-24 13:17 ` [PATCH 7/9] powerpc/boot: Fix CONFIG_PPC_MPC52XX references Michael Ellerman
2020-07-24 13:17 ` [PATCH 8/9] powerpc/kvm: Use correct CONFIG symbol in comment Michael Ellerman
2020-07-24 13:17 ` [PATCH 9/9] powerpc: Drop old comment about CONFIG_POWER Michael Ellerman
2020-07-30 12:50 ` [PATCH 1/9] powerpc/configs: Drop old symbols from ppc6xx_defconfig Michael Ellerman

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