Date: Tue, 11 Mar 2014 03:19:44 +0000 (UTC) From: Ian Lepore <ian@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r262995 - head/sys/arm/arm Message-ID: <201403110319.s2B3JiY6023250@svn.freebsd.org>
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Author: ian Date: Tue Mar 11 03:19:43 2014 New Revision: 262995 URL: http://svnweb.freebsd.org/changeset/base/262995 Log: Now that the PUSHFRAME and PULLFRAME macros are used only in the swi entry/exit code, they don't need to be macros. Now they're just inline code, and rewritten to use shorter instruction sequences. Modified: head/sys/arm/arm/exception.S Modified: head/sys/arm/arm/exception.S ============================================================================== --- head/sys/arm/arm/exception.S Tue Mar 11 01:45:46 2014 (r262994) +++ head/sys/arm/arm/exception.S Tue Mar 11 03:19:43 2014 (r262995) @@ -57,75 +57,6 @@ __FBSDID("$FreeBSD$"); .align 0 /* - * ASM macros for pushing and pulling trapframes from the stack - * - * These macros are used to handle the irqframe and trapframe structures - * defined above. - */ - -/* - * PUSHFRAME - macro to push a trap frame on the stack in the current mode - * Since the current mode is used, the SVC lr field is not defined. - * - * NOTE: r13 and r14 are stored separately as a work around for the - * SA110 rev 2 STM^ bug - */ -#ifdef ARM_TP_ADDRESS -#define PUSHFRAME \ - sub sp, sp, #4; /* Align the stack */ \ - str lr, [sp, #-4]!; /* Push the return address */ \ - sub sp, sp, #(4*17); /* Adjust the stack pointer */ \ - stmia sp, {r0-r12}; /* Push the user mode registers */ \ - add r0, sp, #(4*13); /* Adjust the stack pointer */ \ - stmia r0, {r13-r14}^; /* Push the user mode registers */ \ - mov r0, r0; /* NOP for previous instruction */ \ - mrs r0, spsr; /* Put the SPSR on the stack */ \ - str r0, [sp, #-4]!; \ - ldr r0, =ARM_RAS_START; \ - mov r1, #0; \ - str r1, [r0]; \ - mov r1, #0xffffffff; \ - str r1, [r0, #4]; -#else -#define PUSHFRAME \ - sub sp, sp, #4; /* Align the stack */ \ - str lr, [sp, #-4]!; /* Push the return address */ \ - sub sp, sp, #(4*17); /* Adjust the stack pointer */ \ - stmia sp, {r0-r12}; /* Push the user mode registers */ \ - add r0, sp, #(4*13); /* Adjust the stack pointer */ \ - stmia r0, {r13-r14}^; /* Push the user mode registers */ \ - mov r0, r0; /* NOP for previous instruction */ \ - mrs r0, spsr; /* Put the SPSR on the stack */ \ - str r0, [sp, #-4]!; -#endif - -/* - * PULLFRAME - macro to pull a trap frame from the stack in the current mode - * Since the current mode is used, the SVC lr field is ignored. - */ - -#ifdef ARM_TP_ADDRESS -#define PULLFRAME \ - ldr r0, [sp], #0x0004; /* Get the SPSR from stack */ \ - msr spsr_fsxc, r0; \ - ldmia sp, {r0-r14}^; /* Restore registers (usr mode) */ \ - mov r0, r0; /* NOP for previous instruction */ \ - add sp, sp, #(4*17); /* Adjust the stack pointer */ \ - ldr lr, [sp], #0x0004; /* Pull the return address */ \ - add sp, sp, #4 /* Align the stack */ -#else -#define PULLFRAME \ - ldr r0, [sp], #0x0004; /* Get the SPSR from stack */ \ - msr spsr_fsxc, r0; \ - clrex; \ - ldmia sp, {r0-r14}^; /* Restore registers (usr mode) */ \ - mov r0, r0; /* NOP for previous instruction */ \ - add sp, sp, #(4*17); /* Adjust the stack pointer */ \ - ldr lr, [sp], #0x0004; /* Pull the return address */ \ - add sp, sp, #4 /* Align the stack */ -#endif - -/* * PUSHFRAMEINSVC - macro to push a trap frame on the stack in SVC32 mode * This should only be used if the processor is not currently in SVC32 * mode. The processor mode is switched to SVC mode and the trap frame is @@ -263,8 +194,15 @@ __FBSDID("$FreeBSD$"); b 1b ;\ 2: - - +/* + * If ARM_TP_ADDRESS is defined we're on armv4 or v5 and there is no clrex + * instruction, or need for one, so just #define it away. + */ +#ifdef ARM_TP_ADDRESS +#define CLREX +#else +#define CLREX clrex +#endif /* * reset_entry: @@ -281,17 +219,27 @@ Lreset_panicmsg: END(reset_entry) /* - * swi_entry - * - * Handler for the Software Interrupt exception. + * Entry point for Software Interrupt (SWI). + * + * The swi instruction switches to svc32 mode, so we're already on the + * right stack. We build a trapframe and invoke swi_handler(). */ ASENTRY_NP(swi_entry) - STOP_UNWINDING /* Don't unwind into user mode. */ - - PUSHFRAME - - mov r0, sp /* Pass the frame to any function */ - bl _C_LABEL(swi_handler) /* It's a SWI ! */ + sub sp, sp, #4 /* Align the stack (tf_pad). */ + str lr, [sp, #-4]! /* Push the return address (tf_pc). */ + sub sp, sp, #(4*17) /* Point sp to tf_r0, store the user */ + stmia sp, {r0-r14}^ /* registers. Store SPSR in tf_spsr. */ + mrs r0, spsr /* Now sp points to struct trapframe */ + str r0, [sp, #-4]! /* we've constructed on svc32 stack. */ +#ifdef ARM_RAS_START + ldr r0, =ARM_RAS_START /* If we're using RAS-based atomicity */ + mov r1, #0 /* we should never have a SWI in the */ + str r1, [r0] /* midst of a RAS sequence, but */ + mov r1, #0xffffffff /* be safe and reset the RAS vars. */ + str r1, [r0, #4] +#endif + mov r0, sp /* Pass the trapframe we just built */ + bl _C_LABEL(swi_handler) /* on the stack to the swi handler. */ /* * The fork_trampoline() code in swtch.S aranges for the MI fork_exit() @@ -301,11 +249,17 @@ ASENTRY_NP(swi_entry) */ ASENTRY_NP(swi_exit) - DO_AST /* Deliver signals. */ + DO_AST /* Do scheduling and signal delivery. */ - PULLFRAME - movs pc, lr /* Exit */ + CLREX /* Should never happen but be safe */ + ldr r0, [sp], #4 /* and don't exit with open monitor. */ + msr spsr_fsxc, r0 /* Restore SPSR. */ + ldmia sp, {r0-r14}^ /* Restore user mode registers. */ + ldr lr, [sp, #8] /* Restore the return address. */ + add sp, sp, #12 /* Deallocate the rest of trapframe. */ + movs pc, lr /* Return to user mode. */ + STOP_UNWINDING /* Don't unwind into user mode. */ END(swi_exit) END(swi_entry)
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