From 74f5bf029ee052e3d845672728e80b7240d14f09 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 25 Feb 2013 19:01:33 +0400 Subject: xtensa: fix oprofile building as module Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/xtensa_ksyms.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/xtensa_ksyms.c b/arch/xtensa/kernel/xtensa_ksyms.c index afe058b24e6e..42c53c87c204 100644 --- a/arch/xtensa/kernel/xtensa_ksyms.c +++ b/arch/xtensa/kernel/xtensa_ksyms.c @@ -119,3 +119,8 @@ EXPORT_SYMBOL(outsl); EXPORT_SYMBOL(insb); EXPORT_SYMBOL(insw); EXPORT_SYMBOL(insl); + +extern long common_exception_return; +extern long _spill_registers; +EXPORT_SYMBOL(common_exception_return); +EXPORT_SYMBOL(_spill_registers); -- cgit v1.2.2 From d83ff0bb828854d9e7172ac5d8d007a7466934c9 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 4 Mar 2013 03:40:42 +0400 Subject: xtensa: fix ibreakenable register update Only set the register when there is at least one ibreak register, otherwise the build fails: arch/xtensa/kernel/head.S:105: Error: invalid register 'ibreakenable' for 'wsr' instruction arch/xtensa/platforms/iss/setup.c:67: Error: invalid register 'ibreakenable' for 'wsr' instruction Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/head.S | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S index df88f98737f4..4566683abc8d 100644 --- a/arch/xtensa/kernel/head.S +++ b/arch/xtensa/kernel/head.S @@ -86,7 +86,9 @@ ENTRY(_startup) /* Clear debugging registers. */ #if XCHAL_HAVE_DEBUG +#if XCHAL_NUM_IBREAK > 0 wsr a0, ibreakenable +#endif wsr a0, icount movi a1, 15 wsr a0, icountlevel -- cgit v1.2.2 From e85e335f8ff615f74e29e09cc2599f095600114b Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 3 Dec 2012 15:01:43 +0400 Subject: xtensa: add MMU v3 support MMUv3 comes out of reset with identity vaddr -> paddr mapping in the TLB way 6: Way 6 (512 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0x00000000 0x00000000 0x01 0x03 RWX Bypass 0x20000000 0x20000000 0x01 0x03 RWX Bypass 0x40000000 0x40000000 0x01 0x03 RWX Bypass 0x60000000 0x60000000 0x01 0x03 RWX Bypass 0x80000000 0x80000000 0x01 0x03 RWX Bypass 0xa0000000 0xa0000000 0x01 0x03 RWX Bypass 0xc0000000 0xc0000000 0x01 0x03 RWX Bypass 0xe0000000 0xe0000000 0x01 0x03 RWX Bypass This patch adds remapping code at the reset vector or at the kernel _start (depending on CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX) that reconfigures MMUv3 as MMUv2: Way 5 (128 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0xd0000000 0x00000000 0x01 0x07 RWX WB 0xd8000000 0x00000000 0x01 0x03 RWX Bypass Way 6 (256 MB) Vaddr Paddr ASID Attr RWX Cache ---------- ---------- ---- ---- --- ------- 0xe0000000 0xf0000000 0x01 0x07 RWX WB 0xf0000000 0xf0000000 0x01 0x03 RWX Bypass Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/Makefile | 2 ++ arch/xtensa/kernel/head.S | 37 ++++++++++++++++++++++--------- arch/xtensa/kernel/vectors.S | 3 ++- arch/xtensa/kernel/vmlinux.lds.S | 48 ++++++++++++++++++++++++++-------------- 4 files changed, 63 insertions(+), 27 deletions(-) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile index c3a59d992ac0..c433a56fbff9 100644 --- a/arch/xtensa/kernel/Makefile +++ b/arch/xtensa/kernel/Makefile @@ -12,6 +12,8 @@ obj-$(CONFIG_KGDB) += xtensa-stub.o obj-$(CONFIG_PCI) += pci.o obj-$(CONFIG_MODULES) += xtensa_ksyms.o module.o +AFLAGS_head.o += -mtext-section-literals + # In the Xtensa architecture, assembly generates literals which must always # precede the L32R instruction with a relative offset less than 256 kB. # Therefore, the .text and .literal section must be combined in parenthesis diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S index 4566683abc8d..ef12c0e6fa25 100644 --- a/arch/xtensa/kernel/head.S +++ b/arch/xtensa/kernel/head.S @@ -48,17 +48,36 @@ */ __HEAD + .begin no-absolute-literals + ENTRY(_start) - _j 2f + /* Preserve the pointer to the boot parameter list in EXCSAVE_1 */ + wsr a2, excsave1 + _j _SetupMMU + + .align 4 + .literal_position +.Lstartup: + .word _startup + .align 4 -1: .word _startup -2: l32r a0, 1b + .global _SetupMMU +_SetupMMU: + Offset = _SetupMMU - _start + +#ifdef CONFIG_INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX + initialize_mmu +#endif + .end no-absolute-literals + + l32r a0, .Lstartup jx a0 ENDPROC(_start) - .section .init.text, "ax" + __INIT + .literal_position ENTRY(_startup) @@ -67,10 +86,6 @@ ENTRY(_startup) movi a0, LOCKLEVEL wsr a0, ps - /* Preserve the pointer to the boot parameter list in EXCSAVE_1 */ - - wsr a2, excsave1 - /* Start with a fresh windowbase and windowstart. */ movi a1, 1 @@ -158,8 +173,6 @@ ENTRY(_startup) isync - initialize_mmu - /* Unpack data sections * * The linker script used to build the Linux kernel image @@ -207,6 +220,10 @@ ENTRY(_startup) ___flush_dcache_all a2 a3 #endif + memw + isync + ___invalidate_icache_all a2 a3 + isync /* Setup stack and enable window exceptions (keep irqs disabled) */ diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S index 82109b42e240..a7e1d0834c68 100644 --- a/arch/xtensa/kernel/vectors.S +++ b/arch/xtensa/kernel/vectors.S @@ -50,6 +50,7 @@ #include #include #include +#include #define WINDOW_VECTORS_SIZE 0x180 @@ -220,7 +221,7 @@ ENTRY(_DoubleExceptionVector) xsr a0, depc # get DEPC, save a0 - movi a3, XCHAL_WINDOW_VECTORS_VADDR + movi a3, WINDOW_VECTORS_VADDR _bltu a0, a3, .Lfixup addi a3, a3, WINDOW_VECTORS_SIZE _bgeu a0, a3, .Lfixup diff --git a/arch/xtensa/kernel/vmlinux.lds.S b/arch/xtensa/kernel/vmlinux.lds.S index 14695240536d..21acd11b5df2 100644 --- a/arch/xtensa/kernel/vmlinux.lds.S +++ b/arch/xtensa/kernel/vmlinux.lds.S @@ -18,6 +18,7 @@ #include #include +#include #include #include OUTPUT_ARCH(xtensa) @@ -30,7 +31,7 @@ jiffies = jiffies_64; #endif #ifndef KERNELOFFSET -#define KERNELOFFSET 0xd0001000 +#define KERNELOFFSET 0xd0003000 #endif /* Note: In the following macros, it would be nice to specify only the @@ -185,16 +186,16 @@ SECTIONS SECTION_VECTOR (_WindowVectors_text, .WindowVectors.text, - XCHAL_WINDOW_VECTORS_VADDR, 4, + WINDOW_VECTORS_VADDR, 4, .dummy) SECTION_VECTOR (_DebugInterruptVector_literal, .DebugInterruptVector.literal, - XCHAL_DEBUG_VECTOR_VADDR - 4, + DEBUG_VECTOR_VADDR - 4, SIZEOF(.WindowVectors.text), .WindowVectors.text) SECTION_VECTOR (_DebugInterruptVector_text, .DebugInterruptVector.text, - XCHAL_DEBUG_VECTOR_VADDR, + DEBUG_VECTOR_VADDR, 4, .DebugInterruptVector.literal) #undef LAST @@ -202,7 +203,7 @@ SECTIONS #if XCHAL_EXCM_LEVEL >= 2 SECTION_VECTOR (_Level2InterruptVector_text, .Level2InterruptVector.text, - XCHAL_INTLEVEL2_VECTOR_VADDR, + INTLEVEL2_VECTOR_VADDR, SIZEOF(LAST), LAST) # undef LAST # define LAST .Level2InterruptVector.text @@ -210,7 +211,7 @@ SECTIONS #if XCHAL_EXCM_LEVEL >= 3 SECTION_VECTOR (_Level3InterruptVector_text, .Level3InterruptVector.text, - XCHAL_INTLEVEL3_VECTOR_VADDR, + INTLEVEL3_VECTOR_VADDR, SIZEOF(LAST), LAST) # undef LAST # define LAST .Level3InterruptVector.text @@ -218,7 +219,7 @@ SECTIONS #if XCHAL_EXCM_LEVEL >= 4 SECTION_VECTOR (_Level4InterruptVector_text, .Level4InterruptVector.text, - XCHAL_INTLEVEL4_VECTOR_VADDR, + INTLEVEL4_VECTOR_VADDR, SIZEOF(LAST), LAST) # undef LAST # define LAST .Level4InterruptVector.text @@ -226,7 +227,7 @@ SECTIONS #if XCHAL_EXCM_LEVEL >= 5 SECTION_VECTOR (_Level5InterruptVector_text, .Level5InterruptVector.text, - XCHAL_INTLEVEL5_VECTOR_VADDR, + INTLEVEL5_VECTOR_VADDR, SIZEOF(LAST), LAST) # undef LAST # define LAST .Level5InterruptVector.text @@ -234,39 +235,39 @@ SECTIONS #if XCHAL_EXCM_LEVEL >= 6 SECTION_VECTOR (_Level6InterruptVector_text, .Level6InterruptVector.text, - XCHAL_INTLEVEL6_VECTOR_VADDR, + INTLEVEL6_VECTOR_VADDR, SIZEOF(LAST), LAST) # undef LAST # define LAST .Level6InterruptVector.text #endif SECTION_VECTOR (_KernelExceptionVector_literal, .KernelExceptionVector.literal, - XCHAL_KERNEL_VECTOR_VADDR - 4, + KERNEL_VECTOR_VADDR - 4, SIZEOF(LAST), LAST) #undef LAST SECTION_VECTOR (_KernelExceptionVector_text, .KernelExceptionVector.text, - XCHAL_KERNEL_VECTOR_VADDR, + KERNEL_VECTOR_VADDR, 4, .KernelExceptionVector.literal) SECTION_VECTOR (_UserExceptionVector_literal, .UserExceptionVector.literal, - XCHAL_USER_VECTOR_VADDR - 4, + USER_VECTOR_VADDR - 4, SIZEOF(.KernelExceptionVector.text), .KernelExceptionVector.text) SECTION_VECTOR (_UserExceptionVector_text, .UserExceptionVector.text, - XCHAL_USER_VECTOR_VADDR, + USER_VECTOR_VADDR, 4, .UserExceptionVector.literal) SECTION_VECTOR (_DoubleExceptionVector_literal, .DoubleExceptionVector.literal, - XCHAL_DOUBLEEXC_VECTOR_VADDR - 16, + DOUBLEEXC_VECTOR_VADDR - 16, SIZEOF(.UserExceptionVector.text), .UserExceptionVector.text) SECTION_VECTOR (_DoubleExceptionVector_text, .DoubleExceptionVector.text, - XCHAL_DOUBLEEXC_VECTOR_VADDR, + DOUBLEEXC_VECTOR_VADDR, 32, .DoubleExceptionVector.literal) @@ -284,11 +285,26 @@ SECTIONS . = ALIGN(0x10); .bootstrap : { *(.bootstrap.literal .bootstrap.text .bootstrap.data) } - .ResetVector.text XCHAL_RESET_VECTOR_VADDR : + .ResetVector.text RESET_VECTOR_VADDR : { *(.ResetVector.text) } + + /* + * This is a remapped copy of the Secondary Reset Vector Code. + * It keeps gdb in sync with the PC after switching + * to the temporary mapping used while setting up + * the V2 MMU mappings for Linux. + * + * Only debug information about this section is put in the kernel image. + */ + .SecondaryResetVector.remapped_text 0x46000000 (INFO): + { + *(.SecondaryResetVector.remapped_text) + } + + .xt.lit : { *(.xt.lit) } .xt.prop : { *(.xt.prop) } -- cgit v1.2.2 From b06c14e5c11a7e3fb9b4d94bb83847bf1fbbdaa3 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 31 Mar 2013 01:08:22 +0400 Subject: xtensa: provide default platform_pcibios_init implementation This fixes the following build error: arch/xtensa/kernel/built-in.o:(.init.literal+0xe8): undefined reference to `platform_pcibios_init' arch/xtensa/kernel/built-in.o: In function `setup_arch': (.init.text+0x20e): undefined reference to `platform_pcibios_init' and allows platform to omit definition of platform_pcibios_init if it's empty. Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/platform.c | 1 + 1 file changed, 1 insertion(+) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/platform.c b/arch/xtensa/kernel/platform.c index 44bf21c3769a..2bd6c351f37c 100644 --- a/arch/xtensa/kernel/platform.c +++ b/arch/xtensa/kernel/platform.c @@ -36,6 +36,7 @@ _F(void, power_off, (void), { while(1); }); _F(void, idle, (void), { __asm__ __volatile__ ("waiti 0" ::: "memory"); }); _F(void, heartbeat, (void), { }); _F(int, pcibios_fixup, (void), { return 0; }); +_F(void, pcibios_init, (void), { }); #ifdef CONFIG_XTENSA_CALIBRATE_CCOUNT _F(void, calibrate_ccount, (void), -- cgit v1.2.2 From 3e4196a5cc9cff50900f3dc8acc3d41e5963fd50 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 15 Apr 2013 09:20:48 +0400 Subject: xtensa: add stacktrace support Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/Makefile | 6 +-- arch/xtensa/kernel/stacktrace.c | 87 +++++++++++++++++++++++++++++++++++++++++ arch/xtensa/kernel/traps.c | 49 ++++++----------------- 3 files changed, 101 insertions(+), 41 deletions(-) create mode 100644 arch/xtensa/kernel/stacktrace.c (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/Makefile b/arch/xtensa/kernel/Makefile index c433a56fbff9..1e7fc87a94bb 100644 --- a/arch/xtensa/kernel/Makefile +++ b/arch/xtensa/kernel/Makefile @@ -4,9 +4,9 @@ extra-y := head.o vmlinux.lds -obj-y := align.o entry.o irq.o coprocessor.o process.o ptrace.o \ - setup.o signal.o syscall.o time.o traps.o vectors.o platform.o \ - pci-dma.o +obj-y := align.o coprocessor.o entry.o irq.o pci-dma.o platform.o process.o \ + ptrace.o setup.o signal.o stacktrace.o syscall.o time.o traps.o \ + vectors.o obj-$(CONFIG_KGDB) += xtensa-stub.o obj-$(CONFIG_PCI) += pci.o diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c new file mode 100644 index 000000000000..e3aff9575183 --- /dev/null +++ b/arch/xtensa/kernel/stacktrace.c @@ -0,0 +1,87 @@ +/* + * arch/xtensa/kernel/stacktrace.c + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2001 - 2013 Tensilica Inc. + */ +#include +#include +#include + +#include +#include + +void walk_stackframe(unsigned long *sp, + int (*fn)(struct stackframe *frame, void *data), + void *data) +{ + unsigned long a0, a1; + unsigned long sp_end; + + a1 = (unsigned long)sp; + sp_end = ALIGN(a1, THREAD_SIZE); + + spill_registers(); + + while (a1 < sp_end) { + struct stackframe frame; + + sp = (unsigned long *)a1; + + a0 = *(sp - 4); + a1 = *(sp - 3); + + if (a1 <= (unsigned long)sp) + break; + + frame.pc = MAKE_PC_FROM_RA(a0, a1); + frame.sp = a1; + + if (fn(&frame, data)) + return; + } +} + +#ifdef CONFIG_STACKTRACE + +struct stack_trace_data { + struct stack_trace *trace; + unsigned skip; +}; + +static int stack_trace_cb(struct stackframe *frame, void *data) +{ + struct stack_trace_data *trace_data = data; + struct stack_trace *trace = trace_data->trace; + + if (trace_data->skip) { + --trace_data->skip; + return 0; + } + if (!kernel_text_address(frame->pc)) + return 0; + + trace->entries[trace->nr_entries++] = frame->pc; + return trace->nr_entries >= trace->max_entries; +} + +void save_stack_trace_tsk(struct task_struct *task, struct stack_trace *trace) +{ + struct stack_trace_data trace_data = { + .trace = trace, + .skip = trace->skip, + }; + walk_stackframe(stack_pointer(task), stack_trace_cb, &trace_data); +} +EXPORT_SYMBOL_GPL(save_stack_trace_tsk); + +void save_stack_trace(struct stack_trace *trace) +{ + save_stack_trace_tsk(current, trace); +} +EXPORT_SYMBOL_GPL(save_stack_trace); + +#endif diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index 923db5c15278..cf065e165ceb 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -11,7 +11,7 @@ * * Essentially rewritten for the Xtensa architecture port. * - * Copyright (C) 2001 - 2005 Tensilica Inc. + * Copyright (C) 2001 - 2013 Tensilica Inc. * * Joe Taylor * Chris Zankel @@ -32,6 +32,7 @@ #include #include +#include #include #include #include @@ -402,53 +403,25 @@ void show_regs(struct pt_regs * regs) regs->syscall); } -static __always_inline unsigned long *stack_pointer(struct task_struct *task) +static int show_trace_cb(struct stackframe *frame, void *data) { - unsigned long *sp; - - if (!task || task == current) - __asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp)); - else - sp = (unsigned long *)task->thread.sp; - - return sp; + if (kernel_text_address(frame->pc)) { + printk(" [<%08lx>] ", frame->pc); + print_symbol("%s\n", frame->pc); + } + return 0; } void show_trace(struct task_struct *task, unsigned long *sp) { - unsigned long a0, a1, pc; - unsigned long sp_start, sp_end; - - if (sp) - a1 = (unsigned long)sp; - else - a1 = (unsigned long)stack_pointer(task); - - sp_start = a1 & ~(THREAD_SIZE-1); - sp_end = sp_start + THREAD_SIZE; + if (!sp) + sp = stack_pointer(task); printk("Call Trace:"); #ifdef CONFIG_KALLSYMS printk("\n"); #endif - spill_registers(); - - while (a1 > sp_start && a1 < sp_end) { - sp = (unsigned long*)a1; - - a0 = *(sp - 4); - a1 = *(sp - 3); - - if (a1 <= (unsigned long) sp) - break; - - pc = MAKE_PC_FROM_RA(a0, a1); - - if (kernel_text_address(pc)) { - printk(" [<%08lx>] ", pc); - print_symbol("%s\n", pc); - } - } + walk_stackframe(sp, show_trace_cb, NULL); printk("\n"); } -- cgit v1.2.2 From 3ae908c99e944a7a5c4f4b2d8c603a6bc57b728b Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 8 Apr 2013 01:29:19 +0400 Subject: xtensa: provide custom CALLER_ADDR* implementations Definition of CALLER_ADDR* through __builtin_return_address makes compiler insert calls to __xtensa_libgcc_window_spill, which in turn makes fast_syscall_spill_registers syscall that clobbers registers when called from the kernel mode, leading to invalid opcode exceptions on return to userspace. Provide definition for CALLER_ADDR0 as MAKE_PC_FROM_RA(a0, a1) and in case CONFIG_FRAME_POINTER is enabled extract CALLER_ADDR{1-3} from stack. Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/stacktrace.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/stacktrace.c b/arch/xtensa/kernel/stacktrace.c index e3aff9575183..7d2c317bd98b 100644 --- a/arch/xtensa/kernel/stacktrace.c +++ b/arch/xtensa/kernel/stacktrace.c @@ -85,3 +85,36 @@ void save_stack_trace(struct stack_trace *trace) EXPORT_SYMBOL_GPL(save_stack_trace); #endif + +#ifdef CONFIG_FRAME_POINTER + +struct return_addr_data { + unsigned long addr; + unsigned skip; +}; + +static int return_address_cb(struct stackframe *frame, void *data) +{ + struct return_addr_data *r = data; + + if (r->skip) { + --r->skip; + return 0; + } + if (!kernel_text_address(frame->pc)) + return 0; + r->addr = frame->pc; + return 1; +} + +unsigned long return_address(unsigned level) +{ + struct return_addr_data r = { + .skip = level + 1, + }; + walk_stackframe(stack_pointer(NULL), return_address_cb, &r); + return r.addr; +} +EXPORT_SYMBOL(return_address); + +#endif -- cgit v1.2.2 From c92931b200156e304350e3e9f138e6abfb1f2913 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Sun, 31 Mar 2013 06:32:42 +0400 Subject: xtensa: add irq flags trace support Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/entry.S | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 63845f950792..3729b48d798d 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -389,6 +389,22 @@ common_exception: save_xtregs_opt a1 a2 a4 a5 a6 a7 PT_XTREGS_OPT +#ifdef CONFIG_TRACE_IRQFLAGS + l32i a4, a1, PT_DEPC + /* Double exception means we came here with an exception + * while PS.EXCM was set, i.e. interrupts disabled. + */ + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + l32i a4, a1, PT_EXCCAUSE + bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f + /* We came here with an interrupt means interrupts were enabled + * and we've just disabled them. + */ + movi a4, trace_hardirqs_off + callx4 a4 +1: +#endif + /* Go to second-level dispatcher. Set up parameters to pass to the * exception handler and call the exception handler. */ @@ -407,6 +423,22 @@ common_exception: .global common_exception_return common_exception_return: +#ifdef CONFIG_TRACE_IRQFLAGS + l32i a4, a1, PT_DEPC + /* Double exception means we came here with an exception + * while PS.EXCM was set, i.e. interrupts disabled. + */ + bgeui a4, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f + l32i a4, a1, PT_EXCCAUSE + bnei a4, EXCCAUSE_LEVEL1_INTERRUPT, 1f + /* We came here with an interrupt means interrupts were enabled + * and we'll reenable them on return. + */ + movi a4, trace_hardirqs_on + callx4 a4 +1: +#endif + /* Jump if we are returning from kernel exceptions. */ 1: l32i a3, a1, PT_PS -- cgit v1.2.2 From 895666a9920f19bc256340aaf58d01da6e677a16 Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Tue, 26 Mar 2013 02:51:43 +0400 Subject: xtensa: disable IRQs while IRQ handler is running IRQ handlers are expected to run with IRQs disabled. See e.g. http://lwn.net/Articles/380931/ for a longer story. This was overlooked in the commit 2d1c645 xtensa: dispatch medium-priority interrupts Revert to old behavior and simplify interrupt entry and exit code. Interrupt handler still honours IRQ priority. do_notify_resume/schedule must be called with interrupts enabled, enable interrupts if we return from user exception. Signed-off-by: Max Filippov Signed-off-by: Chris Zankel --- arch/xtensa/kernel/entry.S | 52 ++++++++++---------------------------------- arch/xtensa/kernel/traps.c | 18 ++++++++------- arch/xtensa/kernel/vectors.S | 13 ++++++----- 3 files changed, 28 insertions(+), 55 deletions(-) (limited to 'arch/xtensa/kernel') diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S index 3729b48d798d..5082507d5631 100644 --- a/arch/xtensa/kernel/entry.S +++ b/arch/xtensa/kernel/entry.S @@ -354,16 +354,16 @@ common_exception: * so we can allow exceptions and interrupts (*) again. * Set PS(EXCM = 0, UM = 0, RING = 0, OWB = 0, WOE = 1, INTLEVEL = X) * - * (*) We only allow interrupts of higher priority than current IRQ + * (*) We only allow interrupts if they were previously enabled and + * we're not handling an IRQ */ rsr a3, ps - addi a0, a0, -4 - movi a2, 1 + addi a0, a0, -EXCCAUSE_LEVEL1_INTERRUPT + movi a2, LOCKLEVEL extui a3, a3, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH # a3 = PS.INTLEVEL - movnez a2, a3, a3 # a2 = 1: level-1, > 1: high priority - moveqz a3, a2, a0 # a3 = IRQ level iff interrupt + moveqz a3, a2, a0 # a3 = LOCKLEVEL iff interrupt movi a2, 1 << PS_WOE_BIT or a3, a3, a2 rsr a0, exccause @@ -444,6 +444,8 @@ common_exception_return: 1: l32i a3, a1, PT_PS _bbci.l a3, PS_UM_BIT, 4f + rsil a2, 0 + /* Specific to a user exception exit: * We need to check some flags for signal handling and rescheduling, * and have to restore WB and WS, extra states, and all registers @@ -684,51 +686,19 @@ common_exception_exit: l32i a0, a1, PT_DEPC l32i a3, a1, PT_AREG3 - _bltui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f - - wsr a0, depc l32i a2, a1, PT_AREG2 - l32i a0, a1, PT_AREG0 - l32i a1, a1, PT_AREG1 - rfde + _bgeui a0, VALID_DOUBLE_EXCEPTION_ADDRESS, 1f -1: /* Restore a0...a3 and return */ - rsr a0, ps - extui a2, a0, PS_INTLEVEL_SHIFT, PS_INTLEVEL_WIDTH - movi a0, 2f - slli a2, a2, 4 - add a0, a2, a0 - l32i a2, a1, PT_AREG2 - jx a0 - - .macro irq_exit_level level - .align 16 - .if XCHAL_EXCM_LEVEL >= \level - l32i a0, a1, PT_PC - wsr a0, epc\level l32i a0, a1, PT_AREG0 l32i a1, a1, PT_AREG1 - rfi \level - .endif - .endm + rfe - .align 16 -2: +1: wsr a0, depc l32i a0, a1, PT_AREG0 l32i a1, a1, PT_AREG1 - rfe - - .align 16 - /* no rfi for level-1 irq, handled by rfe above*/ - nop - - irq_exit_level 2 - irq_exit_level 3 - irq_exit_level 4 - irq_exit_level 5 - irq_exit_level 6 + rfde ENDPROC(kernel_exception) diff --git a/arch/xtensa/kernel/traps.c b/arch/xtensa/kernel/traps.c index cf065e165ceb..30e53e609104 100644 --- a/arch/xtensa/kernel/traps.c +++ b/arch/xtensa/kernel/traps.c @@ -196,7 +196,6 @@ void do_multihit(struct pt_regs *regs, unsigned long exccause) /* * IRQ handler. - * PS.INTLEVEL is the current IRQ priority level. */ extern void do_IRQ(int, struct pt_regs *); @@ -213,18 +212,21 @@ void do_interrupt(struct pt_regs *regs) XCHAL_INTLEVEL6_MASK, XCHAL_INTLEVEL7_MASK, }; - unsigned level = get_sr(ps) & PS_INTLEVEL_MASK; - - if (WARN_ON_ONCE(level >= ARRAY_SIZE(int_level_mask))) - return; for (;;) { unsigned intread = get_sr(interrupt); unsigned intenable = get_sr(intenable); - unsigned int_at_level = intread & intenable & - int_level_mask[level]; + unsigned int_at_level = intread & intenable; + unsigned level; + + for (level = LOCKLEVEL; level > 0; --level) { + if (int_at_level & int_level_mask[level]) { + int_at_level &= int_level_mask[level]; + break; + } + } - if (!int_at_level) + if (level == 0) return; /* diff --git a/arch/xtensa/kernel/vectors.S b/arch/xtensa/kernel/vectors.S index a7e1d0834c68..f9e175382aa9 100644 --- a/arch/xtensa/kernel/vectors.S +++ b/arch/xtensa/kernel/vectors.S @@ -386,9 +386,12 @@ ENDPROC(_DebugInterruptVector) .if XCHAL_EXCM_LEVEL >= \level .section .Level\level\()InterruptVector.text, "ax" ENTRY(_Level\level\()InterruptVector) - wsr a0, epc1 + wsr a0, excsave2 rsr a0, epc\level - xsr a0, epc1 + wsr a0, epc1 + movi a0, EXCCAUSE_LEVEL1_INTERRUPT + wsr a0, exccause + rsr a0, eps\level # branch to user or kernel vector j _SimulateUserKernelVectorException .endif @@ -440,10 +443,8 @@ ENDPROC(_WindowOverflow4) */ .align 4 _SimulateUserKernelVectorException: - wsr a0, excsave2 - movi a0, 4 # LEVEL1_INTERRUPT cause - wsr a0, exccause - rsr a0, ps + addi a0, a0, (1 << PS_EXCM_BIT) + wsr a0, ps bbsi.l a0, PS_UM_BIT, 1f # branch if user mode rsr a0, excsave2 # restore a0 j _KernelExceptionVector # simulate kernel vector exception -- cgit v1.2.2