From be2bd024de2e67ecbb787998fb85457d81b2c836 Mon Sep 17 00:00:00 2001 From: Leandro Lupori Date: Mon, 10 Dec 2018 14:54:28 +0000 Subject: [PATCH] ppc64: handle exception 0x1500 (soft patch) This change adds a hypervisor trap handler for exception 0x1500 (soft patch), normalizing all VSX registers and returning. This avoids a kernel panic due to unknown exception. Change made with the collaboration of leonardo.bianconi_eldorado.org.br, that found out that this is a hypervisor exception and not a supervisor one, and fixed this in the code. Reviewed by: jhibbits, sbruno Differential Revision: https://reviews.freebsd.org/D17806 --- sys/powerpc/aim/aim_machdep.c | 1 + sys/powerpc/include/trap.h | 3 ++ sys/powerpc/powerpc/db_trace.c | 1 + sys/powerpc/powerpc/trap.c | 56 ++++++++++++++++++++++++++++++++++ 4 files changed, 61 insertions(+) diff --git a/sys/powerpc/aim/aim_machdep.c b/sys/powerpc/aim/aim_machdep.c index 977296a2209a..e47728259140 100644 --- a/sys/powerpc/aim/aim_machdep.c +++ b/sys/powerpc/aim/aim_machdep.c @@ -366,6 +366,7 @@ aim_cpu_init(vm_offset_t toc) bcopy(&hypertrapcode, (void *)(EXC_HEA + trap_offset), trapsize); bcopy(&hypertrapcode, (void *)(EXC_HMI + trap_offset), trapsize); bcopy(&hypertrapcode, (void *)(EXC_HVI + trap_offset), trapsize); + bcopy(&hypertrapcode, (void *)(EXC_SOFT_PATCH + trap_offset), trapsize); #endif bcopy(&rstcode, (void *)(EXC_RST + trap_offset), (size_t)&rstcodeend - diff --git a/sys/powerpc/include/trap.h b/sys/powerpc/include/trap.h index 27ab7b89d3ed..aea6ba582606 100644 --- a/sys/powerpc/include/trap.h +++ b/sys/powerpc/include/trap.h @@ -103,6 +103,9 @@ #define EXC_SPFPD 0x2f30 /* SPE Floating-point Data */ #define EXC_SPFPR 0x2f40 /* SPE Floating-point Round */ +/* POWER8 */ +#define EXC_SOFT_PATCH 0x1500 /* POWER8 Soft Patch Exception */ + #define EXC_LAST 0x2f00 /* Last possible exception vector */ #define EXC_AST 0x3000 /* Fake AST vector */ diff --git a/sys/powerpc/powerpc/db_trace.c b/sys/powerpc/powerpc/db_trace.c index a3ee988d4386..e5d29361fedb 100644 --- a/sys/powerpc/powerpc/db_trace.c +++ b/sys/powerpc/powerpc/db_trace.c @@ -255,6 +255,7 @@ db_backtrace(struct thread *td, db_addr_t fp, int count) case EXC_DECR: trapstr = "DECR"; break; case EXC_PERF: trapstr = "PERF"; break; case EXC_VSX: trapstr = "VSX"; break; + case EXC_SOFT_PATCH: trapstr = "SOFT_PATCH"; break; default: trapstr = NULL; break; } if (trapstr != NULL) { diff --git a/sys/powerpc/powerpc/trap.c b/sys/powerpc/powerpc/trap.c index 815ea21d4213..04decf3387ac 100644 --- a/sys/powerpc/powerpc/trap.c +++ b/sys/powerpc/powerpc/trap.c @@ -95,6 +95,7 @@ static void syscall(struct trapframe *frame); void handle_kernel_slb_spill(int, register_t, register_t); static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr); extern int n_slbs; +static void normalize_inputs(void); #endif extern vm_offset_t __startkernel; @@ -147,6 +148,7 @@ static struct powerpc_exception powerpc_exceptions[] = { { EXC_VECAST_G4, "altivec assist" }, { EXC_THRM, "thermal management" }, { EXC_RUNMODETRC, "run mode/trace" }, + { EXC_SOFT_PATCH, "soft patch exception" }, { EXC_LAST, NULL } }; @@ -382,6 +384,17 @@ trap(struct trapframe *frame) ucode = BUS_OBJERR; break; +#if defined(__powerpc64__) && defined(AIM) + case EXC_SOFT_PATCH: + /* + * Point to the instruction that generated the exception to execute it again, + * and normalize the register values. + */ + frame->srr0 -= 4; + normalize_inputs(); + break; +#endif + default: trap_fatal(frame); } @@ -909,6 +922,49 @@ fix_unaligned(struct thread *td, struct trapframe *frame) return (-1); } +#if defined(__powerpc64__) && defined(AIM) +#define MSKNSHL(x, m, n) "(((" #x ") & " #m ") << " #n ")" +#define MSKNSHR(x, m, n) "(((" #x ") & " #m ") >> " #n ")" + +/* xvcpsgndp instruction, built in opcode format. + * This can be changed to use mnemonic after a toolchain update. + */ +#define XVCPSGNDP(xt, xa, xb) \ + __asm __volatile(".long (" \ + MSKNSHL(60, 0x3f, 26) " | " \ + MSKNSHL(xt, 0x1f, 21) " | " \ + MSKNSHL(xa, 0x1f, 16) " | " \ + MSKNSHL(xb, 0x1f, 11) " | " \ + MSKNSHL(240, 0xff, 3) " | " \ + MSKNSHR(xa, 0x20, 3) " | " \ + MSKNSHR(xa, 0x20, 4) " | " \ + MSKNSHR(xa, 0x20, 5) ")") + +/* Macros to normalize 1 or 10 VSX registers */ +#define NORM(x) XVCPSGNDP(x, x, x) +#define NORM10(x) \ + NORM(x ## 0); NORM(x ## 1); NORM(x ## 2); NORM(x ## 3); NORM(x ## 4); \ + NORM(x ## 5); NORM(x ## 6); NORM(x ## 7); NORM(x ## 8); NORM(x ## 9) + +static void +normalize_inputs(void) +{ + unsigned long msr; + + /* enable VSX */ + msr = mfmsr(); + mtmsr(msr | PSL_VSX); + + NORM(0); NORM(1); NORM(2); NORM(3); NORM(4); + NORM(5); NORM(6); NORM(7); NORM(8); NORM(9); + NORM10(1); NORM10(2); NORM10(3); NORM10(4); NORM10(5); + NORM(60); NORM(61); NORM(62); NORM(63); + + /* restore MSR */ + mtmsr(msr); +} +#endif + #ifdef KDB int db_trap_glue(struct trapframe *frame)