Date: Fri, 22 Mar 2019 01:43:31 +0000 (UTC) From: Justin Hibbits <jhibbits@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r345402 - head/sys/powerpc/aim Message-ID: <201903220143.x2M1hVvr052953@repo.freebsd.org>
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Author: jhibbits Date: Fri Mar 22 01:43:31 2019 New Revision: 345402 URL: https://svnweb.freebsd.org/changeset/base/345402 Log: powerpc64: Handle the modern (2.05+) implementaiton of tlbie By happenstance gcc4 puts 'vpn' into r0 in all uses of TLBIE(), but modern gcc does not. Also, the single-argument form of tlbie zeros all unused arguments, making the modern tlbie instruction use r0 as the RS field (LPID). The vpn argument has the bottom 12 bits cleared (the input having been left-shifted by 12 bits), which just so happens, on the POWER9 and previous incarnations, to be the number of LPID bits supported. With those bits being zero, the instruction: tlbie r0, r0 will invalidate the VPN in r0, in LPAR 0 (ignoring the upper bits of r0 for the RS field). One build with gcc8 yields: tlbie r9, r0 with r0 having arbitrary contents, not equal to r9. This leads to strange crashes, behaviors, and panics, due to the requested TLB entry not actually being invalidated. As the moea64_native must work on both old and new, we explicitly zero out r0 so that it can work with only the single argument, built with base gcc and modern gcc. isa3_hashtb takes a different approach, encoding the two-argument form, soas not to explicitly clobber r0, and instead let the compiler decide. Reported by: Brandon Bergren Tested by: Brandon Bergren MFC after: 1 week Modified: head/sys/powerpc/aim/isa3_hashtb.c head/sys/powerpc/aim/moea64_native.c Modified: head/sys/powerpc/aim/isa3_hashtb.c ============================================================================== --- head/sys/powerpc/aim/isa3_hashtb.c Fri Mar 22 01:42:27 2019 (r345401) +++ head/sys/powerpc/aim/isa3_hashtb.c Fri Mar 22 01:43:31 2019 (r345402) @@ -139,7 +139,8 @@ TLBIE(uint64_t vpn) { vpn <<= ADDR_PIDX_SHFT; - __asm __volatile("tlbie %0" :: "r"(vpn) : "memory"); + __asm __volatile(".long 0x7c000264 | (%0 << 11) | (%1 << 21)" + :: "r"(vpn), "r"(0) : "memory"); __asm __volatile("eieio; tlbsync; ptesync" ::: "memory"); } Modified: head/sys/powerpc/aim/moea64_native.c ============================================================================== --- head/sys/powerpc/aim/moea64_native.c Fri Mar 22 01:42:27 2019 (r345401) +++ head/sys/powerpc/aim/moea64_native.c Fri Mar 22 01:43:31 2019 (r345402) @@ -156,7 +156,7 @@ TLBIE(uint64_t vpn) { vpn &= ~(0xffffULL << 48); #ifdef __powerpc64__ - __asm __volatile("tlbie %0" :: "r"(vpn) : "memory"); + __asm __volatile("li 0, 0; tlbie %0" :: "r"(vpn) : "0","memory"); __asm __volatile("eieio; tlbsync; ptesync" ::: "memory"); #else vpn_hi = (uint32_t)(vpn >> 32);
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