/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #if defined(lint) #include <sys/systm.h> void sn1_brand_syscall32_callback(void) { } void sn1_brand_syscall_callback(void) { } #else /* !lint */ #include <sys/asm_linkage.h> #include <sys/machthread.h> #include <sys/privregs.h> #include <sn1_offsets.h> #include "assym.h" #if defined(sun4v) #define GLOBALS_SWAP(reg) \ rdpr %gl, reg ;\ wrpr reg, 1, %gl /* * The GLOBALS_RESTORE macro can only be one instruction since it's * used in a delay slot. */ #define GLOBALS_RESTORE(reg) \ wrpr reg, 0, %gl #else /* !sun4v */ #define GLOBALS_SWAP(reg) \ rdpr %pstate, reg ;\ wrpr reg, PSTATE_AG, %pstate /* * The GLOBALS_RESTORE macro can only be one instruction since it's * used in a delay slot. */ #define GLOBALS_RESTORE(reg) \ wrpr reg, %g0, %pstate #endif /* !sun4v */ /* * Input parameters: * %g1: return point * %g2: pointer to our cpu structure */ ENTRY(sn1_brand_syscall32_callback) /* * If the trapping thread has the address mask bit clear, then it's * a 64-bit process, and has no business calling 32-bit syscalls. */ rdpr %tstate, %g3 ! %tstate.am is the trapping andcc %g3, TSTATE_AM, %g3 ! threads address mask bit bne,pt %xcc, _entry nop jmp %g1 ! 64 bit process, bail out nop SET_SIZE(sn1_brand_syscall32_callback) /* * Input parameters: * %g1: return point * %g2: pointer to our cpu structure */ ENTRY(sn1_brand_syscall_callback) /* * If the trapping thread has the address mask bit set, then it's * a 32-bit process, and has no business calling 64-bit syscalls. */ rdpr %tstate, %g3 ! %tstate.am is the trapping andcc %g3, TSTATE_AM, %g3 ! threads address mask bit be,pt %xcc, _entry nop jmp %g1 ! 32 bit process, bail out nop SET_SIZE(sn1_brand_syscall_callback) ENTRY(sn1_brand_syscall_callback_common) _entry: /* * Input parameters: * %g1: return point * %g2: pointer to our cpu structure * * Note that we're free to use any %g? registers as long as * we are are executing with alternate globals. If we're * executing with user globals we need to backup any registers * that we want to use so that we can restore them when we're * done. * * Save some locals in the CPU tmp area to give us a little * room to work. */ stn %l0, [%g2 + CPU_TMP1] stn %l1, [%g2 + CPU_TMP2] #if defined(sun4v) /* * On sun4v save our input parameters (which are stored in the * alternate globals) since we'll need to switch between alternate * globals and normal globals, and on sun4v the alternate globals * are not preserved across these types of switches. */ stn %l2, [%g2 + CPU_TMP3] stn %l3, [%g2 + CPU_TMP4] mov %g1, %l2 ! save %g1 in %l2 mov %g2, %l3 ! save %g2 in %l3 #endif /* sun4v */ /* * Switch from the alternate to user globals to grab the syscall * number. */ GLOBALS_SWAP(%l0) ! switch to normal globals /* * If the system call number is >= 1024, then it is a native * syscall that doesn't need emulation. */ cmp %g1, 1024 ! is this a native syscall? bl,a _indirect_check ! probably not, continue checking mov %g1, %l1 ! delay slot - grab syscall number /* * This is a native syscall, probably from the emulation library. * Subtract 1024 from the syscall number and let it go through. */ sub %g1, 1024, %g1 ! convert magic num to real syscall ba _exit ! jump back into syscall path GLOBALS_RESTORE(%l0) ! delay slot - ! switch back to alternate globals _indirect_check: /* * If the system call number is 0 (SYS_syscall), then this might be * an indirect syscall, in which case the actual syscall number * would be stored in %o0, in which case we need to redo the * the whole >= 1024 check. */ brnz,pt %g1, _emulation_check ! is this an indirect syscall? nop ! if not, goto the emulation check /* * Indirect syscalls are only supported for 32 bit processes so * consult the tstate address mask again. */ rdpr %tstate, %l1 ! %tstate.am is the trapping andcc %l1, TSTATE_AM, %l1 ! threads address mask bit be,a,pn %xcc, _exit GLOBALS_RESTORE(%l0) ! delay slot - ! switch back to alternate globals /* * The caller is 32 bit and this an indirect system call. */ cmp %o0, 1024 ! is this a native syscall? bl,a _emulation_check ! no, goto the emulation check mov %o0, %l1 ! delay slot - grab syscall number /* * This is native indirect syscall, probably from the emulation library. * Subtract 1024 from the syscall number and let it go through. */ sub %o0, 1024, %o0 ! convert magic num to real syscall ba _exit ! jump back into syscall path GLOBALS_RESTORE(%l0) ! delay slot - ! switch back to alternate globals _emulation_check: GLOBALS_RESTORE(%l0) ! switch back to alternate globals /* * Check to see if we want to interpose on this system call. If * not, we jump back into the normal syscall path and pretend * nothing happened. %l1 contains the syscall we're invoking. */ set sn1_emulation_table, %g3 ldn [%g3], %g3 add %g3, %l1, %g3 ldub [%g3], %g3 brz %g3, _exit nop /* * Find the address of the userspace handler. * cpu->cpu_thread->t_procp->p_brand_data->spd_handler. */ #if defined(sun4v) ! restore the alternate global registers after incrementing %gl mov %l3, %g2 #endif /* sun4v */ ldn [%g2 + CPU_THREAD], %g3 ! get thread ptr ldn [%g3 + T_PROCP], %g4 ! get proc ptr ldn [%g4 + P_BRAND_DATA], %g5 ! get brand data ptr ldn [%g5 + SPD_HANDLER], %g5 ! get userland brand handler ptr brz %g5, _exit ! has it been set? nop /* * Make sure this isn't an agent lwp. We can't do syscall * interposition for system calls made by a agent lwp. See * the block comments in the top of the brand emulation library * for more information. */ ldn [%g4 + P_AGENTTP], %g4 ! get agent thread ptr cmp %g3, %g4 ! is this an agent thread? be,pn %xcc, _exit ! if so don't emulate nop /* * Now the magic happens. Grab the trap return address and then * reset it to point to the user space handler. When we execute * the 'done' instruction, we will jump into our handler instead of * the user's code. We also stick the old return address in %g5, * so we can return to the proper instruction in the user's code. * Note: we also pass back the base address of the syscall * emulation table. This is a performance hack to avoid having to * look it up on every call. */ rdpr %tnpc, %l1 ! save old tnpc wrpr %g0, %g5, %tnpc ! setup tnpc GLOBALS_SWAP(%l0) ! switch to normal globals mov %l1, %g5 ! pass tnpc to user code in %g5 GLOBALS_RESTORE(%l0) ! switch back to alternate globals /* Update the address we're going to return to */ #if defined(sun4v) set fast_trap_done_chk_intr, %l2 #else /* !sun4v */ set fast_trap_done_chk_intr, %g1 #endif /* !sun4v */ _exit: /* * Restore registers before returning. * * Note that %g2 should be loaded with the CPU struct addr and * %g1 should be loaded the address we're going to return to. */ #if defined(sun4v) ! restore the alternate global registers after incrementing %gl mov %l2, %g1 ! restore %g1 from %l2 mov %l3, %g2 ! restore %g2 from %l3 ldn [%g2 + CPU_TMP4], %l3 ! restore locals ldn [%g2 + CPU_TMP3], %l2 #endif /* sun4v */ ldn [%g2 + CPU_TMP2], %l1 ! restore locals ldn [%g2 + CPU_TMP1], %l0 jmp %g1 nop SET_SIZE(sn1_brand_syscall_callback_common) #endif /* !lint */