diff options
authorLinus Torvalds <>2013-10-27 10:45:00 -0700
committerLinus Torvalds <>2013-10-27 10:45:00 -0700
commita2ff82065b5b2807e699995671dc282be20ce8fd (patch)
parentaff22d3f1a8abef4d28817e0d762b3054e39cf7a (diff)
parent54e181e073fc1415e41917d725ebdbd7de956455 (diff)
Merge branch 'parisc-3.12' of git://
Pull parisc fix from Helge Deller: "This is a 2-line patch to save the CPU register which holds our task thread info pointer before calling a firmware function and then to restore it again afterwards. This is necessary because on some 64bit machines the high-order 32bits are being clobbered by the firmware call, and thus we failed to bring up secondary CPUs (and instead crashed the kernel) in some situations eg if we had more than 4GB RAM. This patch fixes a bug which has been since ever in the parisc linux kernel and which prevented some people to use a 64bit kernel" * 'parisc-3.12' of git:// parisc: Do not crash 64bit SMP kernels on machines with >= 4GB RAM
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/parisc/kernel/head.S b/arch/parisc/kernel/head.S
index 37aabd772fbb..d2d58258aea6 100644
--- a/arch/parisc/kernel/head.S
+++ b/arch/parisc/kernel/head.S
@@ -195,6 +195,8 @@ common_stext:
ldw MEM_PDC_HI(%r0),%r6
depd %r6, 31, 32, %r3 /* move to upper word */
+ mfctl %cr30,%r6 /* PCX-W2 firmware bug */
ldo PDC_PSW(%r0),%arg0 /* 21 */
ldo PDC_PSW_SET_DEFAULTS(%r0),%arg1 /* 2 */
ldo PDC_PSW_WIDE_BIT(%r0),%arg2 /* 2 */
@@ -203,6 +205,8 @@ common_stext:
copy %r0,%arg3
+ mtctl %r6,%cr30 /* restore task thread info */
/* restore rfi target address*/
ldd TI_TASK-THREAD_SZ_ALGN(%sp), %r10
tophys_r1 %r10