Patch "mips: DEC: honor CONFIG_MIPS_FP_SUPPORT=n" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    mips: DEC: honor CONFIG_MIPS_FP_SUPPORT=n

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mips-dec-honor-config_mips_fp_support-n.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 512c2d9d6e87c74abbeb0c8f8a641992e26634a7
Author: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Date:   Fri Mar 4 08:24:27 2022 -0800

    mips: DEC: honor CONFIG_MIPS_FP_SUPPORT=n
    
    [ Upstream commit 97bf0395c226907e1a9b908511a35192bf1e09bb ]
    
    Include the DECstation interrupt handler in opting out of
    FPU support.
    
    Fixes a linker error:
    
    mips-linux-ld: arch/mips/dec/int-handler.o: in function `fpu':
    (.text+0x148): undefined reference to `handle_fpe_int'
    
    Fixes: 183b40f992c8 ("MIPS: Allow FP support to be disabled")
    Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
    Reported-by: kernel test robot <lkp@xxxxxxxxx>
    Cc: Paul Burton <paulburton@xxxxxxxxxx>
    Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
    Cc: Maciej W. Rozycki <macro@xxxxxxxxxxx>
    Cc: linux-mips@xxxxxxxxxxxxxxx
    Acked-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
    Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/arch/mips/dec/int-handler.S b/arch/mips/dec/int-handler.S
index ea5b5a83f1e1..011d1d678840 100644
--- a/arch/mips/dec/int-handler.S
+++ b/arch/mips/dec/int-handler.S
@@ -131,7 +131,7 @@
 		 */
 		mfc0	t0,CP0_CAUSE		# get pending interrupts
 		mfc0	t1,CP0_STATUS
-#ifdef CONFIG_32BIT
+#if defined(CONFIG_32BIT) && defined(CONFIG_MIPS_FP_SUPPORT)
 		lw	t2,cpu_fpu_mask
 #endif
 		andi	t0,ST0_IM		# CAUSE.CE may be non-zero!
@@ -139,7 +139,7 @@
 
 		beqz	t0,spurious
 
-#ifdef CONFIG_32BIT
+#if defined(CONFIG_32BIT) && defined(CONFIG_MIPS_FP_SUPPORT)
 		 and	t2,t0
 		bnez	t2,fpu			# handle FPU immediately
 #endif
@@ -280,7 +280,7 @@ handle_it:
 		j	dec_irq_dispatch
 		 nop
 
-#ifdef CONFIG_32BIT
+#if defined(CONFIG_32BIT) && defined(CONFIG_MIPS_FP_SUPPORT)
 fpu:
 		lw	t0,fpu_kstat_irq
 		nop
diff --git a/arch/mips/dec/setup.c b/arch/mips/dec/setup.c
index eaad0ed4b523..99b9b29750db 100644
--- a/arch/mips/dec/setup.c
+++ b/arch/mips/dec/setup.c
@@ -746,7 +746,8 @@ void __init arch_init_irq(void)
 		dec_interrupt[DEC_IRQ_HALT] = -1;
 
 	/* Register board interrupts: FPU and cascade. */
-	if (dec_interrupt[DEC_IRQ_FPU] >= 0 && cpu_has_fpu) {
+	if (IS_ENABLED(CONFIG_MIPS_FP_SUPPORT) &&
+	    dec_interrupt[DEC_IRQ_FPU] >= 0 && cpu_has_fpu) {
 		struct irq_desc *desc_fpu;
 		int irq_fpu;