Date: Sun, 1 Dec 2013 19:45:04 +0000 (UTC) From: Nathan Whitehorn <nwhitehorn@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r258808 - head/sys/powerpc/ofw Message-ID: <201312011945.rB1Jj492079019@svn.freebsd.org>
next in thread | raw e-mail | index | archive | help
Author: nwhitehorn Date: Sun Dec 1 19:45:04 2013 New Revision: 258808 URL: http://svnweb.freebsd.org/changeset/base/258808 Log: No actual hardware supported by FreeBSD requires this SPRG save/restore paranoia, so kill it. In particular, changes to SPRG0 are dangerous, since that is where the PCPU pointer is kept. Modified: head/sys/powerpc/ofw/ofw_machdep.c Modified: head/sys/powerpc/ofw/ofw_machdep.c ============================================================================== --- head/sys/powerpc/ofw/ofw_machdep.c Sun Dec 1 19:43:15 2013 (r258807) +++ head/sys/powerpc/ofw/ofw_machdep.c Sun Dec 1 19:45:04 2013 (r258808) @@ -91,52 +91,6 @@ ofw_restore_trap_vec(char *restore_trap_ __syncicache(EXC_RSVD, EXC_LAST - EXC_RSVD); } -/* - * Saved SPRG0-3 from OpenFirmware. Will be restored prior to the callback. - */ -register_t ofw_sprg0_save; - -static __inline void -ofw_sprg_prepare(void) -{ - if (ofw_real_mode) - return; - - /* - * Assume that interrupt are disabled at this point, or - * SPRG1-3 could be trashed - */ - __asm __volatile("mfsprg0 %0\n\t" - "mtsprg0 %1\n\t" - "mtsprg1 %2\n\t" - "mtsprg2 %3\n\t" - "mtsprg3 %4\n\t" - : "=&r"(ofw_sprg0_save) - : "r"(ofmsr[1]), - "r"(ofmsr[2]), - "r"(ofmsr[3]), - "r"(ofmsr[4])); -} - -static __inline void -ofw_sprg_restore(void) -{ -#if 0 - if (ofw_real_mode) - return; -#endif - - /* - * Note that SPRG1-3 contents are irrelevant. They are scratch - * registers used in the early portion of trap handling when - * interrupts are disabled. - * - * PCPU data cannot be used until this routine is called ! - */ - __asm __volatile("mtsprg0 %0" :: "r"(ofw_sprg0_save)); -} -#endif - static int parse_ofw_memory(phandle_t node, const char *prop, struct mem_region *output) { @@ -332,13 +286,10 @@ openfirmware_core(void *args) /* * Turn off exceptions - we really don't want to end up - * anywhere unexpected with PCPU set to something strange - * or the stack pointer wrong. + * anywhere in the kernel while in OF state. */ oldmsr = intr_disable(); - ofw_sprg_prepare(); - /* Save trap vectors */ ofw_save_trap_vec(save_trap_of); @@ -360,8 +311,6 @@ openfirmware_core(void *args) /* Restore trap vecotrs */ ofw_restore_trap_vec(save_trap_of); - ofw_sprg_restore(); - intr_restore(oldmsr); return (result);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201312011945.rB1Jj492079019>