From 8a1bef4193e81c8afae4d2f107f1c09c8ce89470 Mon Sep 17 00:00:00 2001 From: Vincenzo Frascino Date: Wed, 16 Oct 2019 14:40:24 +0100 Subject: mips: vdso: Fix __arch_get_hw_counter() On some MIPS variants (e.g. MIPS r1), vDSO clock_mode is set to VDSO_CLOCK_NONE. When VDSO_CLOCK_NONE is set the expected kernel behavior is to fallback on syscalls. To do that the generic vDSO library expects UULONG_MAX as return value of __arch_get_hw_counter(). Fix __arch_get_hw_counter() on MIPS defining a __VDSO_USE_SYSCALL case that addressed the described scenario. Reported-by: Maxime Bizon Signed-off-by: Vincenzo Frascino Tested-by: Maxime Bizon Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org --- arch/mips/include/asm/vdso/gettimeofday.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h index e78462e8ca2e..b08825531e9f 100644 --- a/arch/mips/include/asm/vdso/gettimeofday.h +++ b/arch/mips/include/asm/vdso/gettimeofday.h @@ -24,6 +24,8 @@ #define VDSO_HAS_CLOCK_GETRES 1 +#define __VDSO_USE_SYSCALL ULLONG_MAX + #ifdef CONFIG_MIPS_CLOCK_VSYSCALL static __always_inline long gettimeofday_fallback( @@ -205,7 +207,7 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode) break; #endif default: - cycle_now = 0; + cycle_now = __VDSO_USE_SYSCALL; break; } -- cgit v1.2.3 From e4f5cb1a9b27c0f94ef4f5a0178a3fde2d3d0e9e Mon Sep 17 00:00:00 2001 From: Jonas Gorski Date: Tue, 22 Oct 2019 21:11:00 +0200 Subject: MIPS: bmips: mark exception vectors as char arrays The vectors span more than one byte, so mark them as arrays. Fixes the following build error when building when using GCC 8.3: In file included from ./include/linux/string.h:19, from ./include/linux/bitmap.h:9, from ./include/linux/cpumask.h:12, from ./arch/mips/include/asm/processor.h:15, from ./arch/mips/include/asm/thread_info.h:16, from ./include/linux/thread_info.h:38, from ./include/asm-generic/preempt.h:5, from ./arch/mips/include/generated/asm/preempt.h:1, from ./include/linux/preempt.h:81, from ./include/linux/spinlock.h:51, from ./include/linux/mmzone.h:8, from ./include/linux/bootmem.h:8, from arch/mips/bcm63xx/prom.c:10: arch/mips/bcm63xx/prom.c: In function 'prom_init': ./arch/mips/include/asm/string.h:162:11: error: '__builtin_memcpy' forming offset [2, 32] is out of the bounds [0, 1] of object 'bmips_smp_movevec' with type 'char' [-Werror=array-bounds] __ret = __builtin_memcpy((dst), (src), __len); \ ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ arch/mips/bcm63xx/prom.c:97:3: note: in expansion of macro 'memcpy' memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20); ^~~~~~ In file included from arch/mips/bcm63xx/prom.c:14: ./arch/mips/include/asm/bmips.h:80:13: note: 'bmips_smp_movevec' declared here extern char bmips_smp_movevec; Fixes: 18a1eef92dcd ("MIPS: BMIPS: Introduce bmips.h") Signed-off-by: Jonas Gorski Reviewed-by: Florian Fainelli Signed-off-by: Paul Burton Cc: linux-mips@vger.kernel.org Cc: Ralf Baechle Cc: James Hogan --- arch/mips/bcm63xx/prom.c | 2 +- arch/mips/include/asm/bmips.h | 10 +++++----- arch/mips/kernel/smp-bmips.c | 8 ++++---- 3 files changed, 10 insertions(+), 10 deletions(-) (limited to 'arch') diff --git a/arch/mips/bcm63xx/prom.c b/arch/mips/bcm63xx/prom.c index 77a836e661c9..df69eaa453a1 100644 --- a/arch/mips/bcm63xx/prom.c +++ b/arch/mips/bcm63xx/prom.c @@ -84,7 +84,7 @@ void __init prom_init(void) * Here we will start up CPU1 in the background and ask it to * reconfigure itself then go back to sleep. */ - memcpy((void *)0xa0000200, &bmips_smp_movevec, 0x20); + memcpy((void *)0xa0000200, bmips_smp_movevec, 0x20); __sync(); set_c0_cause(C_SW0); cpumask_set_cpu(1, &bmips_booted_mask); diff --git a/arch/mips/include/asm/bmips.h b/arch/mips/include/asm/bmips.h index bf6a8afd7ad2..581a6a3c66e4 100644 --- a/arch/mips/include/asm/bmips.h +++ b/arch/mips/include/asm/bmips.h @@ -75,11 +75,11 @@ static inline int register_bmips_smp_ops(void) #endif } -extern char bmips_reset_nmi_vec; -extern char bmips_reset_nmi_vec_end; -extern char bmips_smp_movevec; -extern char bmips_smp_int_vec; -extern char bmips_smp_int_vec_end; +extern char bmips_reset_nmi_vec[]; +extern char bmips_reset_nmi_vec_end[]; +extern char bmips_smp_movevec[]; +extern char bmips_smp_int_vec[]; +extern char bmips_smp_int_vec_end[]; extern int bmips_smp_enabled; extern int bmips_cpu_offset; diff --git a/arch/mips/kernel/smp-bmips.c b/arch/mips/kernel/smp-bmips.c index 76fae9b79f13..712c15de6ab9 100644 --- a/arch/mips/kernel/smp-bmips.c +++ b/arch/mips/kernel/smp-bmips.c @@ -464,10 +464,10 @@ static void bmips_wr_vec(unsigned long dst, char *start, char *end) static inline void bmips_nmi_handler_setup(void) { - bmips_wr_vec(BMIPS_NMI_RESET_VEC, &bmips_reset_nmi_vec, - &bmips_reset_nmi_vec_end); - bmips_wr_vec(BMIPS_WARM_RESTART_VEC, &bmips_smp_int_vec, - &bmips_smp_int_vec_end); + bmips_wr_vec(BMIPS_NMI_RESET_VEC, bmips_reset_nmi_vec, + bmips_reset_nmi_vec_end); + bmips_wr_vec(BMIPS_WARM_RESTART_VEC, bmips_smp_int_vec, + bmips_smp_int_vec_end); } struct reset_vec_info { -- cgit v1.2.3 From b42aa3fd5957e4daf4b69129e5ce752a2a53e7d6 Mon Sep 17 00:00:00 2001 From: Paul Burton Date: Fri, 18 Oct 2019 15:38:48 -0700 Subject: MIPS: tlbex: Fix build_restore_pagemask KScratch restore build_restore_pagemask() will restore the value of register $1/$at when its restore_scratch argument is non-zero, and aims to do so by filling a branch delay slot. Commit 0b24cae4d535 ("MIPS: Add missing EHB in mtc0 -> mfc0 sequence.") added an EHB instruction (Execution Hazard Barrier) prior to restoring $1 from a KScratch register, in order to resolve a hazard that can result in stale values of the KScratch register being observed. In particular, P-class CPUs from MIPS with out of order execution pipelines such as the P5600 & P6600 are affected. Unfortunately this EHB instruction was inserted in the branch delay slot causing the MFC0 instruction which performs the restoration to no longer execute along with the branch. The result is that the $1 register isn't actually restored, ie. the TLB refill exception handler clobbers it - which is exactly the problem the EHB is meant to avoid for the P-class CPUs. Similarly build_get_pgd_vmalloc() will restore the value of $1/$at when its mode argument equals refill_scratch, and suffers from the same problem. Fix this by in both cases moving the EHB earlier in the emitted code. There's no reason it needs to immediately precede the MFC0 - it simply needs to be between the MTC0 & MFC0. This bug only affects Cavium Octeon systems which use build_fast_tlb_refill_handler(). Signed-off-by: Paul Burton Fixes: 0b24cae4d535 ("MIPS: Add missing EHB in mtc0 -> mfc0 sequence.") Cc: Dmitry Korotin Cc: stable@vger.kernel.org # v3.15+ Cc: linux-mips@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- arch/mips/mm/tlbex.c | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) (limited to 'arch') diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c index e01cb33bfa1a..41bb91f05688 100644 --- a/arch/mips/mm/tlbex.c +++ b/arch/mips/mm/tlbex.c @@ -653,6 +653,13 @@ static void build_restore_pagemask(u32 **p, struct uasm_reloc **r, int restore_scratch) { if (restore_scratch) { + /* + * Ensure the MFC0 below observes the value written to the + * KScratch register by the prior MTC0. + */ + if (scratch_reg >= 0) + uasm_i_ehb(p); + /* Reset default page size */ if (PM_DEFAULT_MASK >> 16) { uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16); @@ -667,12 +674,10 @@ static void build_restore_pagemask(u32 **p, struct uasm_reloc **r, uasm_i_mtc0(p, 0, C0_PAGEMASK); uasm_il_b(p, r, lid); } - if (scratch_reg >= 0) { - uasm_i_ehb(p); + if (scratch_reg >= 0) UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg); - } else { + else UASM_i_LW(p, 1, scratchpad_offset(0), 0); - } } else { /* Reset default page size */ if (PM_DEFAULT_MASK >> 16) { @@ -921,6 +926,10 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, } if (mode != not_refill && check_for_high_segbits) { uasm_l_large_segbits_fault(l, *p); + + if (mode == refill_scratch && scratch_reg >= 0) + uasm_i_ehb(p); + /* * We get here if we are an xsseg address, or if we are * an xuseg address above (PGDIR_SHIFT+PGDIR_BITS) boundary. @@ -939,12 +948,10 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r, uasm_i_jr(p, ptr); if (mode == refill_scratch) { - if (scratch_reg >= 0) { - uasm_i_ehb(p); + if (scratch_reg >= 0) UASM_i_MFC0(p, 1, c0_kscratch(), scratch_reg); - } else { + else UASM_i_LW(p, 1, scratchpad_offset(0), 0); - } } else { uasm_i_nop(p); } -- cgit v1.2.3