From a5d5f7daa744b34477c4a12728bde0a1694a1707 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 12 Jul 2012 23:57:35 +0100 Subject: ARM: 7465/1: Handle >4GB memory sizes in device tree and mem=size@start option The memory regions which are passed to arm_add_memory() from device tree blobs via early_init_dt_add_memory_arch() can have sizes which are larger than will fit in a 32 bit integer, so switch to using a phys_addr_t to hold them, to avoid silently dropping the top 32 bits of the size. Similarly, use phys_addr_t in early_mem() so that mem=size@start command line options specifying more than 4GB behave sensibly. Acked-by: Will Deacon Signed-off-by: Peter Maydell Signed-off-by: Russell King --- arch/arm/kernel/setup.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index e15d83bb4ea3..a81dcecc7343 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -508,7 +508,7 @@ void __init dump_machine_table(void) /* can't use cpu_relax() here as it may require MMU setup */; } -int __init arm_add_memory(phys_addr_t start, unsigned long size) +int __init arm_add_memory(phys_addr_t start, phys_addr_t size) { struct membank *bank = &meminfo.bank[meminfo.nr_banks]; @@ -538,7 +538,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size) } #endif - bank->size = size & PAGE_MASK; + bank->size = size & ~(phys_addr_t)(PAGE_SIZE - 1); /* * Check whether this memory region has non-zero size or @@ -558,7 +558,7 @@ int __init arm_add_memory(phys_addr_t start, unsigned long size) static int __init early_mem(char *p) { static int usermem __initdata = 0; - unsigned long size; + phys_addr_t size; phys_addr_t start; char *endp; -- cgit v1.2.1 From 98bd8b96b26db3399a48202318dca4aaa2515355 Mon Sep 17 00:00:00 2001 From: Shawn Guo Date: Fri, 13 Jul 2012 08:19:34 +0100 Subject: ARM: 7466/1: disable interrupt before spinning endlessly The CPU will endlessly spin at the end of machine_halt and machine_restart calls. However, this will lead to a soft lockup warning after about 20 seconds, if CONFIG_LOCKUP_DETECTOR is enabled, as system timer is still alive. Disable interrupt before going to spin endlessly, so that the lockup warning will never be seen. Cc: Reported-by: Marek Vasut Signed-off-by: Shawn Guo Signed-off-by: Russell King --- arch/arm/kernel/process.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 19c95ea65b2f..693b744fd572 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -247,6 +247,7 @@ void machine_shutdown(void) void machine_halt(void) { machine_shutdown(); + local_irq_disable(); while (1); } @@ -268,6 +269,7 @@ void machine_restart(char *cmd) /* Whoops - the platform was unable to reboot. Tell the user! */ printk("Reboot failed -- System halted\n"); + local_irq_disable(); while (1); } -- cgit v1.2.1 From 4c36595ec87115f2f876f7d4fdec8ca284a42b9c Mon Sep 17 00:00:00 2001 From: Colin Cross Date: Wed, 18 Jul 2012 19:15:25 +0100 Subject: ARM: 7468/1: ftrace: Trace function entry before updating index Commit 722b3c74695377d11d18a52f3da08114d37f3f37 modified x86 ftrace to avoid tracing all functions called from irqs when function graph was used with a filter. Port the same fix to ARM. Acked-by: Steven Rostedt Signed-off-by: Colin Cross Signed-off-by: Russell King --- arch/arm/kernel/ftrace.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/ftrace.c b/arch/arm/kernel/ftrace.c index df0bf0c8cb79..34e56647dcee 100644 --- a/arch/arm/kernel/ftrace.c +++ b/arch/arm/kernel/ftrace.c @@ -179,19 +179,20 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, old = *parent; *parent = return_hooker; - err = ftrace_push_return_trace(old, self_addr, &trace.depth, - frame_pointer); - if (err == -EBUSY) { - *parent = old; - return; - } - trace.func = self_addr; + trace.depth = current->curr_ret_stack + 1; /* Only trace if the calling function expects to */ if (!ftrace_graph_entry(&trace)) { - current->curr_ret_stack--; *parent = old; + return; + } + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer); + if (err == -EBUSY) { + *parent = old; + return; } } -- cgit v1.2.1 From c5dff4ffd327088d85035bec535b7d0c9ea03151 Mon Sep 17 00:00:00 2001 From: Javier Martinez Canillas Date: Sat, 28 Jul 2012 15:19:55 +0100 Subject: ARM: 7480/1: only call smp_send_stop() on SMP On reboot or poweroff (machine_shutdown()) a call to smp_send_stop() is made (to stop the others CPU's) when CONFIG_SMP=y. arch/arm/kernel/process.c: void machine_shutdown(void) { #ifdef CONFIG_SMP smp_send_stop(); #endif } smp_send_stop() calls the function pointer smp_cross_call(), which is set on the smp_init_cpus() function for OMAP processors. arch/arm/mach-omap2/omap-smp.c: void __init smp_init_cpus(void) { ... set_smp_cross_call(gic_raise_softirq); ... } But the ARM setup_arch() function only calls smp_init_cpus() if CONFIG_SMP=y && is_smp(). arm/kernel/setup.c: void __init setup_arch(char **cmdline_p) { ... #ifdef CONFIG_SMP if (is_smp()) smp_init_cpus(); #endif ... } Newer OMAP CPU's are SMP machines so omap2plus_defconfig sets CONFIG_SMP=y. Unfortunately on an OMAP UP machine is_smp() returns false and smp_init_cpus() is never called and the smp_cross_call() function remains NULL. If the machine is rebooted or powered off, smp_send_stop() will be called (since CONFIG_SMP=y) leading to the following error: [ 42.815551] Restarting system. [ 42.819030] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 42.827667] pgd = d7a74000 [ 42.830566] [00000000] *pgd=96ce7831, *pte=00000000, *ppte=00000000 [ 42.837249] Internal error: Oops: 80000007 [#1] SMP ARM [ 42.842773] Modules linked in: [ 42.846008] CPU: 0 Not tainted (3.5.0-rc3-next-20120622-00002-g62e87ba-dirty #44) [ 42.854278] PC is at 0x0 [ 42.856994] LR is at smp_send_stop+0x4c/0xe4 [ 42.861511] pc : [<00000000>] lr : [] psr: 60000013 [ 42.861511] sp : d6c85e70 ip : 00000000 fp : 00000000 [ 42.873626] r10: 00000000 r9 : d6c84000 r8 : 00000002 [ 42.879150] r7 : c07235a0 r6 : c06dd2d0 r5 : 000f4241 r4 : d6c85e74 [ 42.886047] r3 : 00000000 r2 : 00000000 r1 : 00000006 r0 : d6c85e74 [ 42.892944] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 42.900482] Control: 10c5387d Table: 97a74019 DAC: 00000015 [ 42.906555] Process reboot (pid: 1166, stack limit = 0xd6c842f8) [ 42.912902] Stack: (0xd6c85e70 to 0xd6c86000) [ 42.917510] 5e60: c07235a0 00000000 00000000 d6c84000 [ 42.926177] 5e80: 01234567 c00143d0 4321fedc c00511bc d6c85ebc 00000168 00000460 00000000 [ 42.934814] 5ea0: c1017950 a0000013 c1017900 d8014390 d7ec3858 c0498e48 c1017950 00000000 [ 42.943481] 5ec0: d6ddde10 d6c85f78 00000003 00000000 d6ddde10 d6c84000 00000000 00000000 [ 42.952117] 5ee0: 00000002 00000000 00000000 c0088c88 00000002 00000000 00000000 c00f4b90 [ 42.960784] 5f00: 00000000 d6c85ebc d8014390 d7e311c8 60000013 00000103 00000002 d6c84000 [ 42.969421] 5f20: c00f3274 d6e00a00 00000001 60000013 d6c84000 00000000 00000000 c00895d4 [ 42.978057] 5f40: 00000002 d8007c80 d781f000 c00f6150 d8010cc0 c00f3274 d781f000 d6c84000 [ 42.986694] 5f60: c0013020 d6e00a00 00000001 20000010 0001257c ef000000 00000000 c00895d4 [ 42.995361] 5f80: 00000002 00000001 00000003 00000000 00000001 00000003 00000000 00000058 [ 43.003997] 5fa0: c00130c8 c0012f00 00000001 00000003 fee1dead 28121969 01234567 00000002 [ 43.012634] 5fc0: 00000001 00000003 00000000 00000058 00012584 0001257c 00000001 00000000 [ 43.021270] 5fe0: 000124bc bec5cc6c 00008f9c 4a2f7c40 20000010 fee1dead 00000000 00000000 [ 43.029968] [] (smp_send_stop+0x4c/0xe4) from [] (machine_restart+0xc/0x4c) [ 43.039154] [] (machine_restart+0xc/0x4c) from [] (sys_reboot+0x144/0x1f0) [ 43.048278] [] (sys_reboot+0x144/0x1f0) from [] (ret_fast_syscall+0x0/0x3c) [ 43.057464] Code: bad PC value [ 43.060760] ---[ end trace c3988d1dd0b8f0fb ]--- Add a check so smp_cross_call() is only called when there is more than one CPU on-line. Cc: Signed-off-by: Javier Martinez Canillas Acked-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/smp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c index aea74f5bc34a..ebd8ad274d76 100644 --- a/arch/arm/kernel/smp.c +++ b/arch/arm/kernel/smp.c @@ -563,7 +563,8 @@ void smp_send_stop(void) cpumask_copy(&mask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &mask); - smp_cross_call(&mask, IPI_CPU_STOP); + if (!cpumask_empty(&mask)) + smp_cross_call(&mask, IPI_CPU_STOP); /* Wait up to one second for other CPUs to stop */ timeout = USEC_PER_SEC; -- cgit v1.2.1 From 15ac49b65024f55c4371a53214879a9c77c4fbf9 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 30 Jul 2012 19:42:10 +0100 Subject: ARM: Fix undefined instruction exception handling While trying to get a v3.5 kernel booted on the cubox, I noticed that VFP does not work correctly with VFP bounce handling. This is because of the confusion over 16-bit vs 32-bit instructions, and where PC is supposed to point to. The rule is that FP handlers are entered with regs->ARM_pc pointing at the _next_ instruction to be executed. However, if the exception is not handled, regs->ARM_pc points at the faulting instruction. This is easy for ARM mode, because we know that the next instruction and previous instructions are separated by four bytes. This is not true of Thumb2 though. Since all FP instructions are 32-bit in Thumb2, it makes things easy. We just need to select the appropriate adjustment. Do this by moving the adjustment out of do_undefinstr() into the assembly code, as only the assembly code knows whether it's dealing with a 32-bit or 16-bit instruction. Cc: Acked-by: Will Deacon Signed-off-by: Russell King --- arch/arm/kernel/entry-armv.S | 111 ++++++++++++++++++++++++++++--------------- arch/arm/kernel/traps.c | 8 ---- 2 files changed, 72 insertions(+), 47 deletions(-) (limited to 'arch/arm/kernel') diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S index 0d1851ca6eb9..0f82098c9bfe 100644 --- a/arch/arm/kernel/entry-armv.S +++ b/arch/arm/kernel/entry-armv.S @@ -244,6 +244,19 @@ svc_preempt: b 1b #endif +__und_fault: + @ Correct the PC such that it is pointing at the instruction + @ which caused the fault. If the faulting instruction was ARM + @ the PC will be pointing at the next instruction, and have to + @ subtract 4. Otherwise, it is Thumb, and the PC will be + @ pointing at the second half of the Thumb instruction. We + @ have to subtract 2. + ldr r2, [r0, #S_PC] + sub r2, r2, r1 + str r2, [r0, #S_PC] + b do_undefinstr +ENDPROC(__und_fault) + .align 5 __und_svc: #ifdef CONFIG_KPROBES @@ -261,25 +274,32 @@ __und_svc: @ @ r0 - instruction @ -#ifndef CONFIG_THUMB2_KERNEL +#ifndef CONFIG_THUMB2_KERNEL ldr r0, [r4, #-4] #else + mov r1, #2 ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2 cmp r0, #0xe800 @ 32-bit instruction if xx >= 0 - ldrhhs r9, [r4] @ bottom 16 bits - orrhs r0, r9, r0, lsl #16 + blo __und_svc_fault + ldrh r9, [r4] @ bottom 16 bits + add r4, r4, #2 + str r4, [sp, #S_PC] + orr r0, r9, r0, lsl #16 #endif - adr r9, BSYM(1f) + adr r9, BSYM(__und_svc_finish) mov r2, r4 bl call_fpe + mov r1, #4 @ PC correction to apply +__und_svc_fault: mov r0, sp @ struct pt_regs *regs - bl do_undefinstr + bl __und_fault @ @ IRQs off again before pulling preserved data off the stack @ -1: disable_irq_notrace +__und_svc_finish: + disable_irq_notrace @ @ restore SPSR and restart the instruction @@ -423,25 +443,33 @@ __und_usr: mov r2, r4 mov r3, r5 + @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the + @ faulting instruction depending on Thumb mode. + @ r3 = regs->ARM_cpsr @ - @ fall through to the emulation code, which returns using r9 if - @ it has emulated the instruction, or the more conventional lr - @ if we are to treat this as a real undefined instruction - @ - @ r0 - instruction + @ The emulation code returns using r9 if it has emulated the + @ instruction, or the more conventional lr if we are to treat + @ this as a real undefined instruction @ adr r9, BSYM(ret_from_exception) - adr lr, BSYM(__und_usr_unknown) + tst r3, #PSR_T_BIT @ Thumb mode? - itet eq @ explicit IT needed for the 1f label - subeq r4, r2, #4 @ ARM instr at LR - 4 - subne r4, r2, #2 @ Thumb instr at LR - 2 -1: ldreqt r0, [r4] + bne __und_usr_thumb + sub r4, r2, #4 @ ARM instr at LR - 4 +1: ldrt r0, [r4] #ifdef CONFIG_CPU_ENDIAN_BE8 - reveq r0, r0 @ little endian instruction + rev r0, r0 @ little endian instruction #endif - beq call_fpe + @ r0 = 32-bit ARM instruction which caused the exception + @ r2 = PC value for the following instruction (:= regs->ARM_pc) + @ r4 = PC value for the faulting instruction + @ lr = 32-bit undefined instruction function + adr lr, BSYM(__und_usr_fault_32) + b call_fpe + +__und_usr_thumb: @ Thumb instruction + sub r4, r2, #2 @ First half of thumb instr at LR - 2 #if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7 /* * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms @@ -455,7 +483,7 @@ __und_usr: ldr r5, .LCcpu_architecture ldr r5, [r5] cmp r5, #CPU_ARCH_ARMv7 - blo __und_usr_unknown + blo __und_usr_fault_16 @ 16bit undefined instruction /* * The following code won't get run unless the running CPU really is v7, so * coding round the lack of ldrht on older arches is pointless. Temporarily @@ -463,15 +491,18 @@ __und_usr: */ .arch armv6t2 #endif -2: - ARM( ldrht r5, [r4], #2 ) - THUMB( ldrht r5, [r4] ) - THUMB( add r4, r4, #2 ) +2: ldrht r5, [r4] cmp r5, #0xe800 @ 32bit instruction if xx != 0 - blo __und_usr_unknown -3: ldrht r0, [r4] + blo __und_usr_fault_16 @ 16bit undefined instruction +3: ldrht r0, [r2] add r2, r2, #2 @ r2 is PC + 2, make it PC + 4 + str r2, [sp, #S_PC] @ it's a 2x16bit instr, update orr r0, r0, r5, lsl #16 + adr lr, BSYM(__und_usr_fault_32) + @ r0 = the two 16-bit Thumb instructions which caused the exception + @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc) + @ r4 = PC value for the first 16-bit Thumb instruction + @ lr = 32bit undefined instruction function #if __LINUX_ARM_ARCH__ < 7 /* If the target arch was overridden, change it back: */ @@ -482,17 +513,13 @@ __und_usr: #endif #endif /* __LINUX_ARM_ARCH__ < 7 */ #else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */ - b __und_usr_unknown + b __und_usr_fault_16 #endif - UNWIND(.fnend ) + UNWIND(.fnend) ENDPROC(__und_usr) - @ - @ fallthrough to call_fpe - @ - /* - * The out of line fixup for the ldrt above. + * The out of line fixup for the ldrt instructions above. */ .pushsection .fixup, "ax" .align 2 @@ -524,11 +551,12 @@ ENDPROC(__und_usr) * NEON handler code. * * Emulators may wish to make use of the following registers: - * r0 = instruction opcode. - * r2 = PC+4 + * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb) + * r2 = PC value to resume execution after successful emulation * r9 = normal "successful" return address - * r10 = this threads thread_info structure. + * r10 = this threads thread_info structure * lr = unrecognised instruction return address + * IRQs disabled, FIQs enabled. */ @ @ Fall-through from Thumb-2 __und_usr @@ -659,12 +687,17 @@ ENTRY(no_fp) mov pc, lr ENDPROC(no_fp) -__und_usr_unknown: - enable_irq +__und_usr_fault_32: + mov r1, #4 + b 1f +__und_usr_fault_16: + mov r1, #2 +1: enable_irq mov r0, sp adr lr, BSYM(ret_from_exception) - b do_undefinstr -ENDPROC(__und_usr_unknown) + b __und_fault +ENDPROC(__und_usr_fault_32) +ENDPROC(__und_usr_fault_16) .align 5 __pabt_usr: diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 3647170e9a16..c7cae6b9a4d9 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -370,18 +370,10 @@ static int call_undef_hook(struct pt_regs *regs, unsigned int instr) asmlinkage void __exception do_undefinstr(struct pt_regs *regs) { - unsigned int correction = thumb_mode(regs) ? 2 : 4; unsigned int instr; siginfo_t info; void __user *pc; - /* - * According to the ARM ARM, PC is 2 or 4 bytes ahead, - * depending whether we're in Thumb mode or not. - * Correct this offset. - */ - regs->ARM_pc -= correction; - pc = (void __user *)instruction_pointer(regs); if (processor_mode(regs) == SVC_MODE) { -- cgit v1.2.1