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commit e8b50608f666cf5c314a9df3dc4b85789a6aeaa5
parent e5a8a1163211e2ab6f71c3545b26d55dc99ff1d3
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Sat,  9 Feb 2019 12:41:14 -0800

Merge tag 'mips_fixes_5.0_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Pull MIPS fixes from Paul Burton:
 "A batch of MIPS fixes for 5.0, nothing too scary.

   - A workaround for a Loongson 3 CPU bug is the biggest change, but
     still fairly straightforward. It adds extra memory barriers (sync
     instructions) around atomics to avoid a CPU bug that can break
     atomicity.

   - Loongson64 also sees a fix for powering off some systems which
     would incorrectly reboot rather than waiting for the power down
     sequence to complete.

   - We have DT fixes for the Ingenic JZ4740 SoC & the JZ4780-based Ci20
     board, and a DT warning fix for the Nexsys4/MIPSfpga board.

   - The Cavium Octeon platform sees a further fix to the behaviour of
     the pcie_disable command line argument that was introduced in v3.3.

   - The VDSO, introduced in v4.4, sees build fixes for configurations
     of GCC that were built using the --with-fp-32= flag to specify a
     default 32-bit floating point ABI.

   - get_frame_info() sees a fix for configurations with
     CONFIG_KALLSYMS=n, for which it previously always returned an
     error.

   - If the MIPS Coherence Manager (CM) reports an error then we'll now
     clear that error correctly so that the GCR_ERROR_CAUSE register
     will be updated with information about any future errors"

* tag 'mips_fixes_5.0_3' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  MIPS: Remove function size check in get_frame_info()
  MIPS: Use lower case for addresses in nexys4ddr.dts
  MIPS: Loongson: Introduce and use loongson_llsc_mb()
  MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds
  MIPS: VDSO: Use same -m%-float cflag as the kernel proper
  MIPS: OCTEON: don't set octeon_dma_bar_type if PCI is disabled
  DTS: CI20: Fix bugs in ci20's device tree.
  MIPS: DTS: jz4740: Correct interrupt number of DMA core

Diffstat:
March/mips/Kconfig | 15+++++++++++++++
March/mips/boot/dts/ingenic/ci20.dts | 8++++----
March/mips/boot/dts/ingenic/jz4740.dtsi | 2+-
March/mips/boot/dts/xilfpga/nexys4ddr.dts | 8++++----
March/mips/include/asm/atomic.h | 6++++++
March/mips/include/asm/barrier.h | 36++++++++++++++++++++++++++++++++++++
March/mips/include/asm/bitops.h | 5+++++
March/mips/include/asm/futex.h | 3+++
March/mips/include/asm/pgtable.h | 2++
March/mips/kernel/mips-cm.c | 2+-
March/mips/kernel/process.c | 7+++----
March/mips/loongson64/Platform | 23+++++++++++++++++++++++
March/mips/loongson64/common/reset.c | 7++++++-
March/mips/mm/tlbex.c | 10++++++++++
March/mips/pci/pci-octeon.c | 10+++++-----
March/mips/vdso/Makefile | 5+++--
16 files changed, 127 insertions(+), 22 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig @@ -1403,6 +1403,21 @@ config LOONGSON3_ENHANCEMENT please say 'N' here. If you want a high-performance kernel to run on new Loongson 3 machines only, please say 'Y' here. +config CPU_LOONGSON3_WORKAROUNDS + bool "Old Loongson 3 LLSC Workarounds" + default y if SMP + depends on CPU_LOONGSON3 + help + Loongson 3 processors have the llsc issues which require workarounds. + Without workarounds the system may hang unexpectedly. + + Newer Loongson 3 will fix these issues and no workarounds are needed. + The workarounds have no significant side effect on them but may + decrease the performance of the system so this option should be + disabled unless the kernel is intended to be run on old systems. + + If unsure, please say Y. + config CPU_LOONGSON2E bool "Loongson 2E" depends on SYS_HAS_CPU_LOONGSON2E diff --git a/arch/mips/boot/dts/ingenic/ci20.dts b/arch/mips/boot/dts/ingenic/ci20.dts @@ -76,7 +76,7 @@ status = "okay"; pinctrl-names = "default"; - pinctrl-0 = <&pins_uart2>; + pinctrl-0 = <&pins_uart3>; }; &uart4 { @@ -196,9 +196,9 @@ bias-disable; }; - pins_uart2: uart2 { - function = "uart2"; - groups = "uart2-data", "uart2-hwflow"; + pins_uart3: uart3 { + function = "uart3"; + groups = "uart3-data", "uart3-hwflow"; bias-disable; }; diff --git a/arch/mips/boot/dts/ingenic/jz4740.dtsi b/arch/mips/boot/dts/ingenic/jz4740.dtsi @@ -161,7 +161,7 @@ #dma-cells = <2>; interrupt-parent = <&intc>; - interrupts = <29>; + interrupts = <20>; clocks = <&cgu JZ4740_CLK_DMA>; diff --git a/arch/mips/boot/dts/xilfpga/nexys4ddr.dts b/arch/mips/boot/dts/xilfpga/nexys4ddr.dts @@ -90,11 +90,11 @@ interrupts = <0>; }; - axi_i2c: i2c@10A00000 { + axi_i2c: i2c@10a00000 { compatible = "xlnx,xps-iic-2.00.a"; interrupt-parent = <&axi_intc>; interrupts = <4>; - reg = < 0x10A00000 0x10000 >; + reg = < 0x10a00000 0x10000 >; clocks = <&ext>; xlnx,clk-freq = <0x5f5e100>; xlnx,family = "Artix7"; @@ -106,9 +106,9 @@ #address-cells = <1>; #size-cells = <0>; - ad7420@4B { + ad7420@4b { compatible = "adi,adt7420"; - reg = <0x4B>; + reg = <0x4b>; }; } ; }; diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h @@ -58,6 +58,7 @@ static __inline__ void atomic_##op(int i, atomic_t * v) \ if (kernel_uses_llsc) { \ int temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ @@ -85,6 +86,7 @@ static __inline__ int atomic_##op##_return_relaxed(int i, atomic_t * v) \ if (kernel_uses_llsc) { \ int temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ @@ -118,6 +120,7 @@ static __inline__ int atomic_fetch_##op##_relaxed(int i, atomic_t * v) \ if (kernel_uses_llsc) { \ int temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ @@ -256,6 +259,7 @@ static __inline__ void atomic64_##op(long i, atomic64_t * v) \ if (kernel_uses_llsc) { \ long temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ @@ -283,6 +287,7 @@ static __inline__ long atomic64_##op##_return_relaxed(long i, atomic64_t * v) \ if (kernel_uses_llsc) { \ long temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ @@ -316,6 +321,7 @@ static __inline__ long atomic64_fetch_##op##_relaxed(long i, atomic64_t * v) \ if (kernel_uses_llsc) { \ long temp; \ \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set "MIPS_ISA_LEVEL" \n" \ diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h @@ -222,6 +222,42 @@ #define __smp_mb__before_atomic() __smp_mb__before_llsc() #define __smp_mb__after_atomic() smp_llsc_mb() +/* + * Some Loongson 3 CPUs have a bug wherein execution of a memory access (load, + * store or pref) in between an ll & sc can cause the sc instruction to + * erroneously succeed, breaking atomicity. Whilst it's unusual to write code + * containing such sequences, this bug bites harder than we might otherwise + * expect due to reordering & speculation: + * + * 1) A memory access appearing prior to the ll in program order may actually + * be executed after the ll - this is the reordering case. + * + * In order to avoid this we need to place a memory barrier (ie. a sync + * instruction) prior to every ll instruction, in between it & any earlier + * memory access instructions. Many of these cases are already covered by + * smp_mb__before_llsc() but for the remaining cases, typically ones in + * which multiple CPUs may operate on a memory location but ordering is not + * usually guaranteed, we use loongson_llsc_mb() below. + * + * This reordering case is fixed by 3A R2 CPUs, ie. 3A2000 models and later. + * + * 2) If a conditional branch exists between an ll & sc with a target outside + * of the ll-sc loop, for example an exit upon value mismatch in cmpxchg() + * or similar, then misprediction of the branch may allow speculative + * execution of memory accesses from outside of the ll-sc loop. + * + * In order to avoid this we need a memory barrier (ie. a sync instruction) + * at each affected branch target, for which we also use loongson_llsc_mb() + * defined below. + * + * This case affects all current Loongson 3 CPUs. + */ +#ifdef CONFIG_CPU_LOONGSON3_WORKAROUNDS /* Loongson-3's LLSC workaround */ +#define loongson_llsc_mb() __asm__ __volatile__(__WEAK_LLSC_MB : : :"memory") +#else +#define loongson_llsc_mb() do { } while (0) +#endif + #include <asm-generic/barrier.h> #endif /* __ASM_BARRIER_H */ diff --git a/arch/mips/include/asm/bitops.h b/arch/mips/include/asm/bitops.h @@ -69,6 +69,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr) : "ir" (1UL << bit), GCC_OFF_SMALL_ASM() (*m)); #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) } else if (kernel_uses_llsc && __builtin_constant_p(bit)) { + loongson_llsc_mb(); do { __asm__ __volatile__( " " __LL "%0, %1 # set_bit \n" @@ -79,6 +80,7 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr) } while (unlikely(!temp)); #endif /* CONFIG_CPU_MIPSR2 || CONFIG_CPU_MIPSR6 */ } else if (kernel_uses_llsc) { + loongson_llsc_mb(); do { __asm__ __volatile__( " .set push \n" @@ -123,6 +125,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr) : "ir" (~(1UL << bit))); #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) } else if (kernel_uses_llsc && __builtin_constant_p(bit)) { + loongson_llsc_mb(); do { __asm__ __volatile__( " " __LL "%0, %1 # clear_bit \n" @@ -133,6 +136,7 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr) } while (unlikely(!temp)); #endif /* CONFIG_CPU_MIPSR2 || CONFIG_CPU_MIPSR6 */ } else if (kernel_uses_llsc) { + loongson_llsc_mb(); do { __asm__ __volatile__( " .set push \n" @@ -193,6 +197,7 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr) unsigned long *m = ((unsigned long *) addr) + (nr >> SZLONG_LOG); unsigned long temp; + loongson_llsc_mb(); do { __asm__ __volatile__( " .set push \n" diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h @@ -50,6 +50,7 @@ "i" (-EFAULT) \ : "memory"); \ } else if (cpu_has_llsc) { \ + loongson_llsc_mb(); \ __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ @@ -163,6 +164,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, "i" (-EFAULT) : "memory"); } else if (cpu_has_llsc) { + loongson_llsc_mb(); __asm__ __volatile__( "# futex_atomic_cmpxchg_inatomic \n" " .set push \n" @@ -192,6 +194,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, : GCC_OFF_SMALL_ASM() (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT) : "memory"); + loongson_llsc_mb(); } else return -ENOSYS; diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h @@ -228,6 +228,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) : [global] "r" (page_global)); } else if (kernel_uses_llsc) { + loongson_llsc_mb(); __asm__ __volatile__ ( " .set push \n" " .set "MIPS_ISA_ARCH_LEVEL" \n" @@ -242,6 +243,7 @@ static inline void set_pte(pte_t *ptep, pte_t pteval) " .set pop \n" : [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp) : [global] "r" (page_global)); + loongson_llsc_mb(); } #else /* !CONFIG_SMP */ if (pte_none(*buddy)) diff --git a/arch/mips/kernel/mips-cm.c b/arch/mips/kernel/mips-cm.c @@ -457,5 +457,5 @@ void mips_cm_error_report(void) } /* reprime cause register */ - write_gcr_error_cause(0); + write_gcr_error_cause(cm_error); } diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c @@ -371,7 +371,7 @@ static inline int is_sp_move_ins(union mips_instruction *ip, int *frame_size) static int get_frame_info(struct mips_frame_info *info) { bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS); - union mips_instruction insn, *ip, *ip_end; + union mips_instruction insn, *ip; const unsigned int max_insns = 128; unsigned int last_insn_size = 0; unsigned int i; @@ -384,10 +384,9 @@ static int get_frame_info(struct mips_frame_info *info) if (!ip) goto err; - ip_end = (void *)ip + info->func_size; - - for (i = 0; i < max_insns && ip < ip_end; i++) { + for (i = 0; i < max_insns; i++) { ip = (void *)ip + last_insn_size; + if (is_mmips && mm_insn_16bit(ip->halfword[0])) { insn.word = ip->halfword[0] << 16; last_insn_size = 2; diff --git a/arch/mips/loongson64/Platform b/arch/mips/loongson64/Platform @@ -23,6 +23,29 @@ ifdef CONFIG_CPU_LOONGSON2F_WORKAROUNDS endif cflags-$(CONFIG_CPU_LOONGSON3) += -Wa,--trap + +# +# Some versions of binutils, not currently mainline as of 2019/02/04, support +# an -mfix-loongson3-llsc flag which emits a sync prior to each ll instruction +# to work around a CPU bug (see loongson_llsc_mb() in asm/barrier.h for a +# description). +# +# We disable this in order to prevent the assembler meddling with the +# instruction that labels refer to, ie. if we label an ll instruction: +# +# 1: ll v0, 0(a0) +# +# ...then with the assembler fix applied the label may actually point at a sync +# instruction inserted by the assembler, and if we were using the label in an +# exception table the table would no longer contain the address of the ll +# instruction. +# +# Avoid this by explicitly disabling that assembler behaviour. If upstream +# binutils does not merge support for the flag then we can revisit & remove +# this later - for now it ensures vendor toolchains don't cause problems. +# +cflags-$(CONFIG_CPU_LOONGSON3) += $(call as-option,-Wa$(comma)-mno-fix-loongson3-llsc,) + # # binutils from v2.25 on and gcc starting from v4.9.0 treat -march=loongson3a # as MIPS64 R2; older versions as just R1. This leaves the possibility open diff --git a/arch/mips/loongson64/common/reset.c b/arch/mips/loongson64/common/reset.c @@ -59,7 +59,12 @@ static void loongson_poweroff(void) { #ifndef CONFIG_LEFI_FIRMWARE_INTERFACE mach_prepare_shutdown(); - unreachable(); + + /* + * It needs a wait loop here, but mips/kernel/reset.c already calls + * a generic delay loop, machine_hang(), so simply return. + */ + return; #else void (*fw_poweroff)(void) = (void *)loongson_sysconf.poweroff_addr; diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c @@ -932,6 +932,8 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, * to mimic that here by taking a load/istream page * fault. */ + if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) + uasm_i_sync(p, 0); UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0); uasm_i_jr(p, ptr); @@ -1646,6 +1648,8 @@ static void iPTE_LW(u32 **p, unsigned int pte, unsigned int ptr) { #ifdef CONFIG_SMP + if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) + uasm_i_sync(p, 0); # ifdef CONFIG_PHYS_ADDR_T_64BIT if (cpu_has_64bits) uasm_i_lld(p, pte, 0, ptr); @@ -2259,6 +2263,8 @@ static void build_r4000_tlb_load_handler(void) #endif uasm_l_nopage_tlbl(&l, p); + if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) + uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_0 & 1) { @@ -2313,6 +2319,8 @@ static void build_r4000_tlb_store_handler(void) #endif uasm_l_nopage_tlbs(&l, p); + if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) + uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_1 & 1) { @@ -2368,6 +2376,8 @@ static void build_r4000_tlb_modify_handler(void) #endif uasm_l_nopage_tlbm(&l, p); + if (IS_ENABLED(CONFIG_CPU_LOONGSON3_WORKAROUNDS)) + uasm_i_sync(&p, 0); build_restore_work_registers(&p); #ifdef CONFIG_CPU_MICROMIPS if ((unsigned long)tlb_do_page_fault_1 & 1) { diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c @@ -568,6 +568,11 @@ static int __init octeon_pci_setup(void) if (octeon_has_feature(OCTEON_FEATURE_PCIE)) return 0; + if (!octeon_is_pci_host()) { + pr_notice("Not in host mode, PCI Controller not initialized\n"); + return 0; + } + /* Point pcibios_map_irq() to the PCI version of it */ octeon_pcibios_map_irq = octeon_pci_pcibios_map_irq; @@ -579,11 +584,6 @@ static int __init octeon_pci_setup(void) else octeon_dma_bar_type = OCTEON_DMA_BAR_TYPE_BIG; - if (!octeon_is_pci_host()) { - pr_notice("Not in host mode, PCI Controller not initialized\n"); - return 0; - } - /* PCI I/O and PCI MEM values */ set_io_port_base(OCTEON_PCI_IOSPACE_BASE); ioport_resource.start = 0; diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile @@ -8,6 +8,7 @@ ccflags-vdso := \ $(filter -E%,$(KBUILD_CFLAGS)) \ $(filter -mmicromips,$(KBUILD_CFLAGS)) \ $(filter -march=%,$(KBUILD_CFLAGS)) \ + $(filter -m%-float,$(KBUILD_CFLAGS)) \ -D__VDSO__ ifdef CONFIG_CC_IS_CLANG @@ -129,7 +130,7 @@ $(obj)/%-o32.o: $(src)/%.c FORCE $(call cmd,force_checksrc) $(call if_changed_rule,cc_o_c) -$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := -mabi=32 +$(obj)/vdso-o32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=32 $(obj)/vdso-o32.lds: $(src)/vdso.lds.S FORCE $(call if_changed_dep,cpp_lds_S) @@ -169,7 +170,7 @@ $(obj)/%-n32.o: $(src)/%.c FORCE $(call cmd,force_checksrc) $(call if_changed_rule,cc_o_c) -$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := -mabi=n32 +$(obj)/vdso-n32.lds: KBUILD_CPPFLAGS := $(ccflags-vdso) -mabi=n32 $(obj)/vdso-n32.lds: $(src)/vdso.lds.S FORCE $(call if_changed_dep,cpp_lds_S)