Leave out gp initialization from kernel entry on mips64

On OpenBSD/mips64, the kernel is compiled with -mno-abicalls. This
disables gp-relative addressing and essentially makes gp a spare
register in the kernel. Hence it is unnecessary to initialize gp when
entering the kernel. The _gp symbol is not needed either.

Suggested by miod@

diff --git a/sys/arch/loongson/conf/ld.script b/sys/arch/loongson/conf/ld.script
index c8680b0..d529e3d 100644 (file)
--- a/sys/arch/loongson/conf/ld.script
+++ b/sys/arch/loongson/conf/ld.script
@@ -7,7 +7,6 @@ SECTIONS
        .text :         { *(.text .text.* .gnu.linkonce.t.*) }
        PROVIDE (etext = .);
        .rodata :       { *(.rodata .rodata.* .gnu.linkonce.r.*) }
-       _gp = ALIGN(16) + 0x7ff0;
        .data :         { *(.data .data.* .gnu.linkonce.d.*) }
        .openbsd.randomdata :
        {

diff --git a/sys/arch/loongson/loongson/locore.S b/sys/arch/loongson/loongson/locore.S
index 481235e..fe50aa5 100644 (file)
--- a/sys/arch/loongson/loongson/locore.S
+++ b/sys/arch/loongson/loongson/locore.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: locore.S,v 1.8 2017/06/08 11:44:00 visa Exp $ */
+/*     $OpenBSD: locore.S,v 1.9 2021/02/11 14:44:13 visa Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -53,7 +53,6 @@ locore_start:
         * Initialize stack and call machine startup.
         */
        LA      t0, start - FRAMESZ(CF_SZ)
-       LA      gp, _gp
        PTR_S   ra, CF_RA_OFFS(t0)              # save pmon return address
        PTR_S   sp, 0(t0)                       # and stack
        move    sp, t0
@@ -111,7 +110,7 @@ LEAF(hw_cpu_spinup_trampoline, 0)
        LA      t0, cpu_spinup_sp
        ld      sp, 0(t0)
        jal     hw_cpu_hatch
-        LA     gp, _gp
+       nop
 END(hw_cpu_spinup_trampoline)
 
 LEAF(hw_getcurcpu, 0)

diff --git a/sys/arch/mips64/mips64/exception.S b/sys/arch/mips64/mips64/exception.S
index 5d67f09..e406718 100644 (file)
--- a/sys/arch/mips64/mips64/exception.S
+++ b/sys/arch/mips64/mips64/exception.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: exception.S,v 1.40 2019/05/06 12:54:51 visa Exp $ */
+/*     $OpenBSD: exception.S,v 1.41 2021/02/11 14:44:13 visa Exp $ */
 
 /*
  * Copyright (c) 2002-2003 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -205,7 +205,6 @@ NNON_LEAF(k_intr, FRAMESZ(KERN_EXC_FRAME_SIZE), ra)
 #endif
        .set    at
        move    sp, k0                  # Already on kernel stack
-       LA      gp, _gp
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        MTC0    t0, COP_0_STATUS_REG
        MTC0_SR_IE_HAZARD
@@ -242,7 +241,6 @@ NNON_LEAF(u_intr, FRAMESZ(CF_SZ), ra)
        SAVE_REG(v1, IC, k0, 0)
 #endif
        PTR_ADDU sp, k0, USPACE-FRAMESZ(CF_SZ)
-       LA      gp, _gp
        .set    at
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        MTC0    t0, COP_0_STATUS_REG
@@ -328,7 +326,6 @@ NNON_LEAF(k_general, FRAMESZ(KERN_EXC_FRAME_SIZE), ra)
 #endif
        .set    at
        move    sp, k0                  # Already on kernel stack
-       LA      gp, _gp
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        MTC0    t0, COP_0_STATUS_REG
        MTC0_SR_IE_HAZARD
@@ -370,7 +367,6 @@ NNON_LEAF(u_general, FRAMESZ(CF_SZ), ra)
 #endif
        SAVE_CPU_SREG(k0, 0)
        PTR_ADDU sp, k0, USPACE-FRAMESZ(CF_SZ)
-       LA      gp, _gp
        .set    at
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        MTC0    t0, COP_0_STATUS_REG

diff --git a/sys/arch/mips64/mips64/exception_tfp.S b/sys/arch/mips64/mips64/exception_tfp.S
index e1ca77e..6fdf368 100644 (file)
--- a/sys/arch/mips64/mips64/exception_tfp.S
+++ b/sys/arch/mips64/mips64/exception_tfp.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: exception_tfp.S,v 1.7 2018/05/09 15:03:04 visa Exp $  */
+/*     $OpenBSD: exception_tfp.S,v 1.8 2021/02/11 14:44:13 visa Exp $  */
 
 /*
  * Copyright (c) 2012 Miodrag Vallat.
@@ -288,7 +288,6 @@ u_intr:
        SAVE_CPU(k0, 0)
        SAVE_CPU_SREG(k0, 0)
        PTR_ADDU sp, k0, USPACE-FRAMESZ(CF_SZ)
-       LA      gp, _gp
        .set    at
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        DMTC0   t0, COP_0_STATUS_REG
@@ -400,7 +399,6 @@ k_intr:
 #endif
        .set    at
        move    sp, k0                  # Already on kernel stack
-       LA      gp, _gp
        and     t0, a1, ~(SR_COP_1_BIT | SR_EXL | SR_INT_ENAB | SR_KSU_MASK)
        DMTC0   t0, COP_0_STATUS_REG
        MTC0_SR_IE_HAZARD

diff --git a/sys/arch/octeon/conf/ld.script b/sys/arch/octeon/conf/ld.script
index 9fe8c66..c5613cc 100644 (file)
--- a/sys/arch/octeon/conf/ld.script
+++ b/sys/arch/octeon/conf/ld.script
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ld.script,v 1.6 2021/02/06 09:31:47 visa Exp $        */
+/*     $OpenBSD: ld.script,v 1.7 2021/02/11 14:44:13 visa Exp $        */
 
 OUTPUT_FORMAT("elf64-tradbigmips")
 OUTPUT_ARCH(mips)
@@ -40,7 +40,6 @@ SECTIONS
        . = ALIGN(8);
        PROVIDE (__kernel_randomdata_end = .);
 
-       _gp = ALIGN(16) + 0x7ff0;
        .data :
        {
                *(.data .data.* .gnu.linkonce.d.*)

diff --git a/sys/arch/octeon/octeon/locore.S b/sys/arch/octeon/octeon/locore.S
index 609d476..ff2c794 100644 (file)
--- a/sys/arch/octeon/octeon/locore.S
+++ b/sys/arch/octeon/octeon/locore.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: locore.S,v 1.21 2020/07/11 15:18:08 visa Exp $ */
+/*     $OpenBSD: locore.S,v 1.22 2021/02/11 14:44:14 visa Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -72,8 +72,6 @@ locore_start:
 
        mtc0    zero, COP_0_CAUSE_REG   # Clear soft interrupts
 
-       LA      gp, _gp
-
        /* Let the init core continue. The others have to wait. */
        bne     a2, zero, 2f
        nop

diff --git a/sys/arch/sgi/conf/ld.script b/sys/arch/sgi/conf/ld.script
index ac05ba0..99134c0 100644 (file)
--- a/sys/arch/sgi/conf/ld.script
+++ b/sys/arch/sgi/conf/ld.script
@@ -7,7 +7,6 @@ SECTIONS
        .text :         { *(.text .text.* .gnu.linkonce.t.*) }
        PROVIDE (etext = .);
        .rodata :       { *(.rodata .rodata.* .gnu.linkonce.r.*) }
-       _gp = ALIGN(16) + 0x7ff0;
        .data :         { *(.data .data.* .gnu.linkonce.d.*) }
        .openbsd.randomdata :
        {

diff --git a/sys/arch/sgi/sgi/ip30_nmi.S b/sys/arch/sgi/sgi/ip30_nmi.S
index 1402c98..f13c50f 100644 (file)
--- a/sys/arch/sgi/sgi/ip30_nmi.S
+++ b/sys/arch/sgi/sgi/ip30_nmi.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: ip30_nmi.S,v 1.6 2012/10/03 11:18:23 miod Exp $       */
+/*     $OpenBSD: ip30_nmi.S,v 1.7 2021/02/11 14:44:14 visa Exp $       */
 
 /*
  * Copyright (c) 2010 Miodrag Vallat.
@@ -71,7 +71,6 @@ ip30_nmi:
        .set    at
 
        PTR_ADDU sp, k0, 0x2000
-       LA      gp, _gp
        
        /*
         * Interrupts should be disabled. Just in case they aren't,

diff --git a/sys/arch/sgi/sgi/locore.S b/sys/arch/sgi/sgi/locore.S
index 10703ad..39e076b 100644 (file)
--- a/sys/arch/sgi/sgi/locore.S
+++ b/sys/arch/sgi/sgi/locore.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: locore.S,v 1.19 2019/06/30 07:37:47 visa Exp $ */
+/*     $OpenBSD: locore.S,v 1.20 2021/02/11 14:44:14 visa Exp $ */
 
 /*
  * Copyright (c) 2001-2004 Opsycon AB  (www.opsycon.se / www.opsycon.com)
@@ -55,7 +55,6 @@ locore_start:
         * Initialize stack and call machine startup.
         */
        LA      sp, start - FRAMESZ(CF_SZ)
-       LA      gp, _gp
        jal     mips_init                       # mips_init(argc, argv, envp)
        PTR_S   zero, CF_RA_OFFS(sp)            # Zero out old ra for debugger
 
@@ -73,7 +72,6 @@ LEAF(hw_cpu_spinup_trampoline, 0)
        ori     v0, SR_KX | SR_UX
        MTC0    v0, COP_0_STATUS_REG            # disable all interrupts
        MTC0    zero, COP_0_CAUSE_REG           # Clear soft interrupts
-       LA      gp, _gp
        jal     hw_cpu_hatch
         NOP
 END(hw_cpu_spinup_trampoline)
@@ -122,7 +120,6 @@ LEAF(ip27_cpu_spinup_trampoline, 0)
        and     v0, v1
        MTC0    v0, COP_0_STATUS_REG            # Disable all interrupts.
        MTC0    zero, COP_0_CAUSE_REG           # Clear soft interrupts.
-       LA      gp, _gp
 
        /* Wait the turn of this CPU. */
        LA      v1, ip27_spinup_turn