git: bad9fa56620e - main - [PowerPC] Fix AP bringup on 32-bit AIM SMP

[Brandon Bergren]

The branch main has been updated by bdragon:

URL: https://cgit.FreeBSD.org/src/commit/?id=bad9fa56620eb82395c5ab66d300e91a0222dde2

commit bad9fa56620eb82395c5ab66d300e91a0222dde2
Author:     Brandon Bergren <bdragon at FreeBSD.org>
AuthorDate: 2021-03-06 21:26:16 +0000
Commit:     Brandon Bergren <bdragon at FreeBSD.org>
CommitDate: 2021-03-06 21:46:28 +0000

    [PowerPC] Fix AP bringup on 32-bit AIM SMP
    
    In r361544, the pmap drivers were converted to ifuncs. When doing so,
    this changed the call type of pmap functions to be called via the
    secure-plt stubs.
    
    These stubs depend on the TOC base being loaded to r30 to run properly.
    
    On SMP AIM (i.e. a dual processor G4 or running 32-bit on G5), since the
    APs were being started up from the reset vector instead of going
    through __start, they had never had r30 initialized properly, so when the
    cpu_reset code in trap_subr32.S attempted to branch to
    pmap_cpu_bootstrap(), it was loading the target from the wrong location.
    
    Ensure r30 is set up directly in the cpu_reset trap code, so we can make
    PLT calls as normal.
    
    Fixes boot on my SMP G4.
    
    Reviewed by:    jhibbits
    MFC after:      3 days
    Sponsored by:   Tag1 Consulting, Inc.
---
 sys/powerpc/aim/trap_subr32.S | 1 +
 1 file changed, 1 insertion(+)

diff --git a/sys/powerpc/aim/trap_subr32.S b/sys/powerpc/aim/trap_subr32.S
index 710a222fd84c..9664dcc92d2d 100644
--- a/sys/powerpc/aim/trap_subr32.S
+++ b/sys/powerpc/aim/trap_subr32.S
@@ -316,6 +316,7 @@ cpu_reset:
 1:
 	mflr	%r1
 	addi	%r1,%r1,(124-16)@l
+	lwz	%r30,TRAP_TOCBASE(0)
 
 	bl	CNAME(cpudep_ap_early_bootstrap)
 	lis	%r3,1 at l