From 275236797916924103e133e3d7a7ea777c951273 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Wed, 29 May 2013 16:57:30 +0100 Subject: ARM: 7737/1: fix kernel decompressor compilation error with CONFIG_DEBUG_SEMIHOSTING Selecting this option produces: AS arch/arm/boot/compressed/debug.o arch/arm/boot/compressed/debug.S:4:33: fatal error: mach/debug-macro.S: No such file or directory compilation terminated. make[3]: *** [arch/arm/boot/compressed/debug.o] Error 1 The semihosting support cannot be modelled into a senduart macro as it requires memory space for argument passing. So the CONFIG_DEBUG_LL_INCLUDE may not have any sensible value and the include directive should be omitted. While at it, let's add proper semihosting output support to the decompressor. Signed-off-by: Nicolas Pitre Acked-by: Shawn Guo Signed-off-by: Russell King --- arch/arm/boot/compressed/debug.S | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'arch') diff --git a/arch/arm/boot/compressed/debug.S b/arch/arm/boot/compressed/debug.S index 6e8382d5b7a4..5392ee63338f 100644 --- a/arch/arm/boot/compressed/debug.S +++ b/arch/arm/boot/compressed/debug.S @@ -1,6 +1,8 @@ #include #include +#ifndef CONFIG_DEBUG_SEMIHOSTING + #include CONFIG_DEBUG_LL_INCLUDE ENTRY(putc) @@ -10,3 +12,29 @@ ENTRY(putc) busyuart r3, r1 mov pc, lr ENDPROC(putc) + +#else + +ENTRY(putc) + adr r1, 1f + ldmia r1, {r2, r3} + add r2, r2, r1 + ldr r1, [r2, r3] + strb r0, [r1] + mov r0, #0x03 @ SYS_WRITEC + ARM( svc #0x123456 ) + THUMB( svc #0xab ) + mov pc, lr + .align 2 +1: .word _GLOBAL_OFFSET_TABLE_ - . + .word semi_writec_buf(GOT) +ENDPROC(putc) + + .bss + .global semi_writec_buf + .type semi_writec_buf, %object +semi_writec_buf: + .space 4 + .size semi_writec_buf, 4 + +#endif -- cgit v1.2.3 From 92bdd3f5eba299b33c2f4407977d6fa2e2a6a0da Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 31 May 2013 22:49:22 +0100 Subject: ARM: 7742/1: topology: export cpu_topology The cpu_topology symbol is required by any driver using the topology interfaces, which leads to a couple of build errors: ERROR: "cpu_topology" [drivers/net/ethernet/sfc/sfc.ko] undefined! ERROR: "cpu_topology" [drivers/cpufreq/arm_big_little.ko] undefined! ERROR: "cpu_topology" [drivers/block/mtip32xx/mtip32xx.ko] undefined! The obvious solution is to export this symbol. Signed-off-by: Arnd Bergmann Acked-by: Will Deacon Cc: stable@vger.kernel.org Cc: Nicolas Pitre Cc: Vincent Guittot Signed-off-by: Russell King --- arch/arm/kernel/topology.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch') diff --git a/arch/arm/kernel/topology.c b/arch/arm/kernel/topology.c index f10316b4ecdc..c5a59546a256 100644 --- a/arch/arm/kernel/topology.c +++ b/arch/arm/kernel/topology.c @@ -13,6 +13,7 @@ #include #include +#include #include #include #include @@ -200,6 +201,7 @@ static inline void update_cpu_power(unsigned int cpuid, unsigned int mpidr) {} * cpu topology table */ struct cputopo_arm cpu_topology[NR_CPUS]; +EXPORT_SYMBOL_GPL(cpu_topology); const struct cpumask *cpu_coregroup_mask(int cpu) { -- cgit v1.2.3 From da94a829305f1c217cfdf6771cb1faca0917e3b9 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 31 May 2013 22:50:47 +0100 Subject: ARM: 7743/1: compressed/head.S: work around new binutils warning In August 2012, Matthew Gretton-Dann checked a change into binutils labelled "Error on obsolete & warn on deprecated registers", apparently as part of ARMv8 support. Apparently, this was supposed to emit the message "Warning: This coprocessor register access is deprecated in ARMv8" when using certain mcr/mrc instructions and building for ARMv8. Unfortunately, the message that is actually emitted appears to be '(null)', which is less helpful in comparison. Even more unfortunately, this is biting us on every single kernel build with a new gas, because arch/arm/boot/compressed/head.S and some other files in that directory are built with -march=all since kernel commit 80cec14a8 "[ARM] Add -march=all to assembly file build in arch/arm/boot/compressed" back in v2.6.28. This patch reverts Russell's nice solution and instead marks the head.S file to be built for armv7-a, which fortunately lets us build all instructions in that file without warnings even on the broken binutils. Without this patch, building anything results in: arch/arm/boot/compressed/head.S: Assembler messages: arch/arm/boot/compressed/head.S:565: Warning: (null) arch/arm/boot/compressed/head.S:676: Warning: (null) arch/arm/boot/compressed/head.S:698: Warning: (null) arch/arm/boot/compressed/head.S:722: Warning: (null) arch/arm/boot/compressed/head.S:726: Warning: (null) arch/arm/boot/compressed/head.S:957: Warning: (null) arch/arm/boot/compressed/head.S:996: Warning: (null) arch/arm/boot/compressed/head.S:997: Warning: (null) arch/arm/boot/compressed/head.S:1027: Warning: (null) arch/arm/boot/compressed/head.S:1035: Warning: (null) arch/arm/boot/compressed/head.S:1046: Warning: (null) arch/arm/boot/compressed/head.S:1060: Warning: (null) arch/arm/boot/compressed/head.S:1092: Warning: (null) arch/arm/boot/compressed/head.S:1094: Warning: (null) arch/arm/boot/compressed/head.S:1095: Warning: (null) arch/arm/boot/compressed/head.S:1102: Warning: (null) arch/arm/boot/compressed/head.S:1134: Warning: (null) Signed-off-by: Arnd Bergmann Cc: stable@vger.kernel.org Cc: Matthew Gretton-Dann Signed-off-by: Russell King --- arch/arm/boot/compressed/Makefile | 2 +- arch/arm/boot/compressed/head-sa1100.S | 1 + arch/arm/boot/compressed/head-shark.S | 1 + arch/arm/boot/compressed/head.S | 1 + 4 files changed, 4 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile index 3580d57ea218..79e9bdbfc491 100644 --- a/arch/arm/boot/compressed/Makefile +++ b/arch/arm/boot/compressed/Makefile @@ -124,7 +124,7 @@ KBUILD_CFLAGS = $(subst -pg, , $(ORIG_CFLAGS)) endif ccflags-y := -fpic -mno-single-pic-base -fno-builtin -I$(obj) -asflags-y := -Wa,-march=all -DZIMAGE +asflags-y := -DZIMAGE # Supply kernel BSS size to the decompressor via a linker symbol. KBSS_SZ = $(shell $(CROSS_COMPILE)size $(obj)/../../../../vmlinux | \ diff --git a/arch/arm/boot/compressed/head-sa1100.S b/arch/arm/boot/compressed/head-sa1100.S index 6179d94dd5c6..3115e313d9f6 100644 --- a/arch/arm/boot/compressed/head-sa1100.S +++ b/arch/arm/boot/compressed/head-sa1100.S @@ -11,6 +11,7 @@ #include .section ".start", "ax" + .arch armv4 __SA1100_start: diff --git a/arch/arm/boot/compressed/head-shark.S b/arch/arm/boot/compressed/head-shark.S index 089c560e07f1..92b56897ed64 100644 --- a/arch/arm/boot/compressed/head-shark.S +++ b/arch/arm/boot/compressed/head-shark.S @@ -18,6 +18,7 @@ .section ".start", "ax" + .arch armv4 b __beginning __ofw_data: .long 0 @ the number of memory blocks diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index fe4d9c3ad761..693855995407 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -11,6 +11,7 @@ #include #include + .arch armv7-a /* * Debugging stuff * -- cgit v1.2.3 From ced2a3b84965f1be8b6a142d6029faf241f109af Mon Sep 17 00:00:00 2001 From: Marc C Date: Wed, 5 Jun 2013 22:02:23 +0100 Subject: ARM: 7750/1: update legacy CPU ID in decompressor cache support jump table The previous mask values for the legacy ARM CPU IDs were conflicting with the CPU ID assignments for late-generation CPUs (like the Qualcomm MSM/QSD or Broadcom Brahma-15 processors). This change corrects the legacy ARM CPU ID value so that the jump table can fall-through to the appropriate cache maintenance / MMU functions. Signed-off-by: Marc C Signed-off-by: Russell King --- arch/arm/boot/compressed/head.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/arm/boot/compressed/head.S b/arch/arm/boot/compressed/head.S index 693855995407..032a8d987148 100644 --- a/arch/arm/boot/compressed/head.S +++ b/arch/arm/boot/compressed/head.S @@ -806,8 +806,8 @@ call_cache_fn: adr r12, proc_types .align 2 .type proc_types,#object proc_types: - .word 0x00000000 @ old ARM ID - .word 0x0000f000 + .word 0x41000000 @ old ARM ID + .word 0xff00f000 mov pc, lr THUMB( nop ) mov pc, lr -- cgit v1.2.3 From 509eb76ebf9771abc9fe51859382df2571f11447 Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 5 Jun 2013 11:20:33 +0100 Subject: ARM: 7747/1: pcpu: ensure __my_cpu_offset cannot be re-ordered across barrier() __my_cpu_offset is non-volatile, since we want its value to be cached when we access several per-cpu variables in a row with preemption disabled. This means that we rely on preempt_{en,dis}able to hazard with the operation via the barrier() macro, so that we can't end up migrating CPUs without reloading the per-cpu offset. Unfortunately, GCC doesn't treat a "memory" clobber on a non-volatile asm block as a side-effect, and will happily re-order it before other memory clobbers (including those in prempt_disable()) and cache the value. This has been observed to break the cmpxchg logic in the slub allocator, leading to livelock in kmem_cache_alloc in mainline kernels. This patch adds a dummy memory input operand to __my_cpu_offset, forcing it to be ordered with respect to the barrier() macro. Cc: Cc: Rob Herring Reviewed-by: Nicolas Pitre Signed-off-by: Will Deacon Signed-off-by: Russell King --- arch/arm/include/asm/percpu.h | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h index 968c0a14e0a3..209e6504922e 100644 --- a/arch/arm/include/asm/percpu.h +++ b/arch/arm/include/asm/percpu.h @@ -30,8 +30,15 @@ static inline void set_my_cpu_offset(unsigned long off) static inline unsigned long __my_cpu_offset(void) { unsigned long off; - /* Read TPIDRPRW */ - asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : : "memory"); + register unsigned long *sp asm ("sp"); + + /* + * Read TPIDRPRW. + * We want to allow caching the value, so avoid using volatile and + * instead use a fake stack read to hazard against barrier(). + */ + asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off) : "Q" (*sp)); + return off; } #define __my_cpu_offset __my_cpu_offset() -- cgit v1.2.3