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commit 2cc63b39003913fdf564cde5c646ac8f174e3ac7
parent 8456e98e18f35f4d4376e8ff3110a3342f81ce9b
Author: Linus Torvalds <torvalds@linux-foundation.org>
Date:   Fri, 22 Feb 2019 16:31:26 -0800

Merge tag 'arc-5.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
 "Fixes for ARC for 5.0, bunch of those are stable fodder anyways so
  sooner the better.

   - Fix memcpy to prevent prefetchw beyond end of buffer [Eugeniy]

   - Enable unaligned access early to prevent exceptions given newer gcc
     code gen [Eugeniy]

   - Tighten up uboot arg checking to prevent false negatives and also
     allow both jtag and bootloading to coexist w/o config option as
     needed by kernelCi folks [Eugeniy]

   - Set slab alignment to 8 for ARC to avoid the atomic64_t unalign
     [Alexey]

   - Disable regfile auto save on interrupts on HSDK platform due to a
     silicon issue [Vineet]

   - Avoid HS38x boot printing crash by not reading HS48x only reg
     [Vineet]"

* tag 'arc-5.0-final' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: don't assume core 0x54 has dual issue
  ARC: define ARCH_SLAB_MINALIGN = 8
  ARC: enable uboot support unconditionally
  ARC: U-boot: check arguments paranoidly
  ARCv2: support manual regfile save on interrupts
  ARC: uacces: remove lp_start, lp_end from clobber list
  ARC: fix actionpoints configuration detection
  ARCv2: lib: memcpy: fix doing prefetchw outside of buffer
  ARCv2: Enable unaligned access in early ASM code

Diffstat:
March/arc/Kconfig | 20++++++++------------
March/arc/configs/nps_defconfig | 1-
March/arc/configs/vdk_hs38_defconfig | 1-
March/arc/configs/vdk_hs38_smp_defconfig | 2--
March/arc/include/asm/arcregs.h | 8++++++++
March/arc/include/asm/cache.h | 11+++++++++++
March/arc/include/asm/entry-arcv2.h | 54++++++++++++++++++++++++++++++++++++++++++++++++++++++
March/arc/include/asm/uaccess.h | 8++++----
March/arc/kernel/entry-arcv2.S | 4+++-
March/arc/kernel/head.S | 16++++++++++++----
March/arc/kernel/intc-arcv2.c | 2++
March/arc/kernel/setup.c | 119++++++++++++++++++++++++++++++++++++++++++++++++++++++++-----------------------
March/arc/lib/memcpy-archs.S | 14--------------
March/arc/plat-hsdk/Kconfig | 1+
14 files changed, 188 insertions(+), 73 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig @@ -191,7 +191,6 @@ config NR_CPUS config ARC_SMP_HALT_ON_RESET bool "Enable Halt-on-reset boot mode" - default y if ARC_UBOOT_SUPPORT help In SMP configuration cores can be configured as Halt-on-reset or they could all start at same time. For Halt-on-reset, non @@ -407,6 +406,14 @@ config ARC_HAS_ACCL_REGS (also referred to as r58:r59). These can also be used by gcc as GPR so kernel needs to save/restore per process +config ARC_IRQ_NO_AUTOSAVE + bool "Disable hardware autosave regfile on interrupts" + default n + help + On HS cores, taken interrupt auto saves the regfile on stack. + This is programmable and can be optionally disabled in which case + software INTERRUPT_PROLOGUE/EPILGUE do the needed work + endif # ISA_ARCV2 endmenu # "ARC CPU Configuration" @@ -515,17 +522,6 @@ config ARC_DBG_TLB_PARANOIA endif -config ARC_UBOOT_SUPPORT - bool "Support uboot arg Handling" - help - ARC Linux by default checks for uboot provided args as pointers to - external cmdline or DTB. This however breaks in absence of uboot, - when booting from Metaware debugger directly, as the registers are - not zeroed out on reset by mdb and/or ARCv2 based cores. The bogus - registers look like uboot args to kernel which then chokes. - So only enable the uboot arg checking/processing if users are sure - of uboot being in play. - config ARC_BUILTIN_DTB_NAME string "Built in DTB" help diff --git a/arch/arc/configs/nps_defconfig b/arch/arc/configs/nps_defconfig @@ -31,7 +31,6 @@ CONFIG_ARC_CACHE_LINE_SHIFT=5 # CONFIG_ARC_HAS_LLSC is not set CONFIG_ARC_KVADDR_SIZE=402 CONFIG_ARC_EMUL_UNALIGNED=y -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_PREEMPT=y CONFIG_NET=y CONFIG_UNIX=y diff --git a/arch/arc/configs/vdk_hs38_defconfig b/arch/arc/configs/vdk_hs38_defconfig @@ -13,7 +13,6 @@ CONFIG_PARTITION_ADVANCED=y CONFIG_ARC_PLAT_AXS10X=y CONFIG_AXS103=y CONFIG_ISA_ARCV2=y -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_ARC_BUILTIN_DTB_NAME="vdk_hs38" CONFIG_PREEMPT=y CONFIG_NET=y diff --git a/arch/arc/configs/vdk_hs38_smp_defconfig b/arch/arc/configs/vdk_hs38_smp_defconfig @@ -15,8 +15,6 @@ CONFIG_AXS103=y CONFIG_ISA_ARCV2=y CONFIG_SMP=y # CONFIG_ARC_TIMERS_64BIT is not set -# CONFIG_ARC_SMP_HALT_ON_RESET is not set -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_ARC_BUILTIN_DTB_NAME="vdk_hs38_smp" CONFIG_PREEMPT=y CONFIG_NET=y diff --git a/arch/arc/include/asm/arcregs.h b/arch/arc/include/asm/arcregs.h @@ -151,6 +151,14 @@ struct bcr_isa_arcv2 { #endif }; +struct bcr_uarch_build_arcv2 { +#ifdef CONFIG_CPU_BIG_ENDIAN + unsigned int pad:8, prod:8, maj:8, min:8; +#else + unsigned int min:8, maj:8, prod:8, pad:8; +#endif +}; + struct bcr_mpy { #ifdef CONFIG_CPU_BIG_ENDIAN unsigned int pad:8, x1616:8, dsp:4, cycles:2, type:2, ver:8; diff --git a/arch/arc/include/asm/cache.h b/arch/arc/include/asm/cache.h @@ -52,6 +52,17 @@ #define cache_line_size() SMP_CACHE_BYTES #define ARCH_DMA_MINALIGN SMP_CACHE_BYTES +/* + * Make sure slab-allocated buffers are 64-bit aligned when atomic64_t uses + * ARCv2 64-bit atomics (LLOCKD/SCONDD). This guarantess runtime 64-bit + * alignment for any atomic64_t embedded in buffer. + * Default ARCH_SLAB_MINALIGN is __alignof__(long long) which has a relaxed + * value of 4 (and not 8) in ARC ABI. + */ +#if defined(CONFIG_ARC_HAS_LL64) && defined(CONFIG_ARC_HAS_LLSC) +#define ARCH_SLAB_MINALIGN 8 +#endif + extern void arc_cache_init(void); extern char *arc_cache_mumbojumbo(int cpu_id, char *buf, int len); extern void read_decode_cache_bcr(void); diff --git a/arch/arc/include/asm/entry-arcv2.h b/arch/arc/include/asm/entry-arcv2.h @@ -17,6 +17,33 @@ ; ; Now manually save: r12, sp, fp, gp, r25 +#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE +.ifnc \called_from, exception + st.as r9, [sp, -10] ; save r9 in it's final stack slot + sub sp, sp, 12 ; skip JLI, LDI, EI + + PUSH lp_count + PUSHAX lp_start + PUSHAX lp_end + PUSH blink + + PUSH r11 + PUSH r10 + + sub sp, sp, 4 ; skip r9 + + PUSH r8 + PUSH r7 + PUSH r6 + PUSH r5 + PUSH r4 + PUSH r3 + PUSH r2 + PUSH r1 + PUSH r0 +.endif +#endif + #ifdef CONFIG_ARC_HAS_ACCL_REGS PUSH r59 PUSH r58 @@ -86,6 +113,33 @@ POP r59 #endif +#ifdef CONFIG_ARC_IRQ_NO_AUTOSAVE +.ifnc \called_from, exception + POP r0 + POP r1 + POP r2 + POP r3 + POP r4 + POP r5 + POP r6 + POP r7 + POP r8 + POP r9 + POP r10 + POP r11 + + POP blink + POPAX lp_end + POPAX lp_start + + POP r9 + mov lp_count, r9 + + add sp, sp, 12 ; skip JLI, LDI, EI + ld.as r9, [sp, -10] ; reload r9 which got clobbered +.endif +#endif + .endm /*------------------------------------------------------------------------*/ diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h @@ -207,7 +207,7 @@ raw_copy_from_user(void *to, const void __user *from, unsigned long n) */ "=&r" (tmp), "+r" (to), "+r" (from) : - : "lp_count", "lp_start", "lp_end", "memory"); + : "lp_count", "memory"); return n; } @@ -433,7 +433,7 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n) */ "=&r" (tmp), "+r" (to), "+r" (from) : - : "lp_count", "lp_start", "lp_end", "memory"); + : "lp_count", "memory"); return n; } @@ -653,7 +653,7 @@ static inline unsigned long __arc_clear_user(void __user *to, unsigned long n) " .previous \n" : "+r"(d_char), "+r"(res) : "i"(0) - : "lp_count", "lp_start", "lp_end", "memory"); + : "lp_count", "memory"); return res; } @@ -686,7 +686,7 @@ __arc_strncpy_from_user(char *dst, const char __user *src, long count) " .previous \n" : "+r"(res), "+r"(dst), "+r"(src), "=r"(val) : "g"(-EFAULT), "r"(count) - : "lp_count", "lp_start", "lp_end", "memory"); + : "lp_count", "memory"); return res; } diff --git a/arch/arc/kernel/entry-arcv2.S b/arch/arc/kernel/entry-arcv2.S @@ -209,7 +209,9 @@ restore_regs: ;####### Return from Intr ####### debug_marker_l1: - bbit1.nt r0, STATUS_DE_BIT, .Lintr_ret_to_delay_slot + ; bbit1.nt r0, STATUS_DE_BIT, .Lintr_ret_to_delay_slot + btst r0, STATUS_DE_BIT ; Z flag set if bit clear + bnz .Lintr_ret_to_delay_slot ; branch if STATUS_DE_BIT set .Lisr_ret_fast_path: ; Handle special case #1: (Entry via Exception, Return via IRQ) diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S @@ -17,6 +17,7 @@ #include <asm/entry.h> #include <asm/arcregs.h> #include <asm/cache.h> +#include <asm/irqflags.h> .macro CPU_EARLY_SETUP @@ -47,6 +48,15 @@ sr r5, [ARC_REG_DC_CTRL] 1: + +#ifdef CONFIG_ISA_ARCV2 + ; Unaligned access is disabled at reset, so re-enable early as + ; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access + ; by default + lr r5, [status32] + bset r5, r5, STATUS_AD_BIT + kflag r5 +#endif .endm .section .init.text, "ax",@progbits @@ -90,15 +100,13 @@ ENTRY(stext) st.ab 0, [r5, 4] 1: -#ifdef CONFIG_ARC_UBOOT_SUPPORT ; Uboot - kernel ABI ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2 - ; r1 = magic number (board identity, unused as of now + ; r1 = magic number (always zero as of now) ; r2 = pointer to uboot provided cmdline or external DTB in mem - ; These are handled later in setup_arch() + ; These are handled later in handle_uboot_args() st r0, [@uboot_tag] st r2, [@uboot_arg] -#endif ; setup "current" tsk and optionally cache it in dedicated r25 mov r9, @init_task diff --git a/arch/arc/kernel/intc-arcv2.c b/arch/arc/kernel/intc-arcv2.c @@ -49,11 +49,13 @@ void arc_init_IRQ(void) *(unsigned int *)&ictrl = 0; +#ifndef CONFIG_ARC_IRQ_NO_AUTOSAVE ictrl.save_nr_gpr_pairs = 6; /* r0 to r11 (r12 saved manually) */ ictrl.save_blink = 1; ictrl.save_lp_regs = 1; /* LP_COUNT, LP_START, LP_END */ ictrl.save_u_to_u = 0; /* user ctxt saved on kernel stack */ ictrl.save_idx_regs = 1; /* JLI, LDI, EI */ +#endif WRITE_AUX(AUX_IRQ_CTRL, ictrl); diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c @@ -199,20 +199,36 @@ static void read_arc_build_cfg_regs(void) cpu->bpu.ret_stk = 4 << bpu.rse; if (cpu->core.family >= 0x54) { - unsigned int exec_ctrl; - READ_BCR(AUX_EXEC_CTRL, exec_ctrl); - cpu->extn.dual_enb = !(exec_ctrl & 1); + struct bcr_uarch_build_arcv2 uarch; - /* dual issue always present for this core */ - cpu->extn.dual = 1; + /* + * The first 0x54 core (uarch maj:min 0:1 or 0:2) was + * dual issue only (HS4x). But next uarch rev (1:0) + * allows it be configured for single issue (HS3x) + * Ensure we fiddle with dual issue only on HS4x + */ + READ_BCR(ARC_REG_MICRO_ARCH_BCR, uarch); + + if (uarch.prod == 4) { + unsigned int exec_ctrl; + + /* dual issue hardware always present */ + cpu->extn.dual = 1; + + READ_BCR(AUX_EXEC_CTRL, exec_ctrl); + + /* dual issue hardware enabled ? */ + cpu->extn.dual_enb = !(exec_ctrl & 1); + + } } } READ_BCR(ARC_REG_AP_BCR, ap); if (ap.ver) { cpu->extn.ap_num = 2 << ap.num; - cpu->extn.ap_full = !!ap.min; + cpu->extn.ap_full = !ap.min; } READ_BCR(ARC_REG_SMART_BCR, bcr); @@ -462,43 +478,78 @@ void setup_processor(void) arc_chk_core_config(); } -static inline int is_kernel(unsigned long addr) +static inline bool uboot_arg_invalid(unsigned long addr) { - if (addr >= (unsigned long)_stext && addr <= (unsigned long)_end) - return 1; - return 0; + /* + * Check that it is a untranslated address (although MMU is not enabled + * yet, it being a high address ensures this is not by fluke) + */ + if (addr < PAGE_OFFSET) + return true; + + /* Check that address doesn't clobber resident kernel image */ + return addr >= (unsigned long)_stext && addr <= (unsigned long)_end; } -void __init setup_arch(char **cmdline_p) +#define IGNORE_ARGS "Ignore U-boot args: " + +/* uboot_tag values for U-boot - kernel ABI revision 0; see head.S */ +#define UBOOT_TAG_NONE 0 +#define UBOOT_TAG_CMDLINE 1 +#define UBOOT_TAG_DTB 2 + +void __init handle_uboot_args(void) { -#ifdef CONFIG_ARC_UBOOT_SUPPORT - /* make sure that uboot passed pointer to cmdline/dtb is valid */ - if (uboot_tag && is_kernel((unsigned long)uboot_arg)) - panic("Invalid uboot arg\n"); - - /* See if u-boot passed an external Device Tree blob */ - machine_desc = setup_machine_fdt(uboot_arg); /* uboot_tag == 2 */ - if (!machine_desc) -#endif - { - /* No, so try the embedded one */ + bool use_embedded_dtb = true; + bool append_cmdline = false; + + /* check that we know this tag */ + if (uboot_tag != UBOOT_TAG_NONE && + uboot_tag != UBOOT_TAG_CMDLINE && + uboot_tag != UBOOT_TAG_DTB) { + pr_warn(IGNORE_ARGS "invalid uboot tag: '%08x'\n", uboot_tag); + goto ignore_uboot_args; + } + + if (uboot_tag != UBOOT_TAG_NONE && + uboot_arg_invalid((unsigned long)uboot_arg)) { + pr_warn(IGNORE_ARGS "invalid uboot arg: '%px'\n", uboot_arg); + goto ignore_uboot_args; + } + + /* see if U-boot passed an external Device Tree blob */ + if (uboot_tag == UBOOT_TAG_DTB) { + machine_desc = setup_machine_fdt((void *)uboot_arg); + + /* external Device Tree blob is invalid - use embedded one */ + use_embedded_dtb = !machine_desc; + } + + if (uboot_tag == UBOOT_TAG_CMDLINE) + append_cmdline = true; + +ignore_uboot_args: + + if (use_embedded_dtb) { machine_desc = setup_machine_fdt(__dtb_start); if (!machine_desc) panic("Embedded DT invalid\n"); + } - /* - * If we are here, it is established that @uboot_arg didn't - * point to DT blob. Instead if u-boot says it is cmdline, - * append to embedded DT cmdline. - * setup_machine_fdt() would have populated @boot_command_line - */ - if (uboot_tag == 1) { - /* Ensure a whitespace between the 2 cmdlines */ - strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); - strlcat(boot_command_line, uboot_arg, - COMMAND_LINE_SIZE); - } + /* + * NOTE: @boot_command_line is populated by setup_machine_fdt() so this + * append processing can only happen after. + */ + if (append_cmdline) { + /* Ensure a whitespace between the 2 cmdlines */ + strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); + strlcat(boot_command_line, uboot_arg, COMMAND_LINE_SIZE); } +} + +void __init setup_arch(char **cmdline_p) +{ + handle_uboot_args(); /* Save unparsed command line copy for /proc/cmdline */ *cmdline_p = boot_command_line; diff --git a/arch/arc/lib/memcpy-archs.S b/arch/arc/lib/memcpy-archs.S @@ -25,15 +25,11 @@ #endif #ifdef CONFIG_ARC_HAS_LL64 -# define PREFETCH_READ(RX) prefetch [RX, 56] -# define PREFETCH_WRITE(RX) prefetchw [RX, 64] # define LOADX(DST,RX) ldd.ab DST, [RX, 8] # define STOREX(SRC,RX) std.ab SRC, [RX, 8] # define ZOLSHFT 5 # define ZOLAND 0x1F #else -# define PREFETCH_READ(RX) prefetch [RX, 28] -# define PREFETCH_WRITE(RX) prefetchw [RX, 32] # define LOADX(DST,RX) ld.ab DST, [RX, 4] # define STOREX(SRC,RX) st.ab SRC, [RX, 4] # define ZOLSHFT 4 @@ -41,8 +37,6 @@ #endif ENTRY_CFI(memcpy) - prefetch [r1] ; Prefetch the read location - prefetchw [r0] ; Prefetch the write location mov.f 0, r2 ;;; if size is zero jz.d [blink] @@ -72,8 +66,6 @@ ENTRY_CFI(memcpy) lpnz @.Lcopy32_64bytes ;; LOOP START LOADX (r6, r1) - PREFETCH_READ (r1) - PREFETCH_WRITE (r3) LOADX (r8, r1) LOADX (r10, r1) LOADX (r4, r1) @@ -117,9 +109,7 @@ ENTRY_CFI(memcpy) lpnz @.Lcopy8bytes_1 ;; LOOP START ld.ab r6, [r1, 4] - prefetch [r1, 28] ;Prefetch the next read location ld.ab r8, [r1,4] - prefetchw [r3, 32] ;Prefetch the next write location SHIFT_1 (r7, r6, 24) or r7, r7, r5 @@ -162,9 +152,7 @@ ENTRY_CFI(memcpy) lpnz @.Lcopy8bytes_2 ;; LOOP START ld.ab r6, [r1, 4] - prefetch [r1, 28] ;Prefetch the next read location ld.ab r8, [r1,4] - prefetchw [r3, 32] ;Prefetch the next write location SHIFT_1 (r7, r6, 16) or r7, r7, r5 @@ -204,9 +192,7 @@ ENTRY_CFI(memcpy) lpnz @.Lcopy8bytes_3 ;; LOOP START ld.ab r6, [r1, 4] - prefetch [r1, 28] ;Prefetch the next read location ld.ab r8, [r1,4] - prefetchw [r3, 32] ;Prefetch the next write location SHIFT_1 (r7, r6, 8) or r7, r7, r5 diff --git a/arch/arc/plat-hsdk/Kconfig b/arch/arc/plat-hsdk/Kconfig @@ -9,6 +9,7 @@ menuconfig ARC_SOC_HSDK bool "ARC HS Development Kit SOC" depends on ISA_ARCV2 select ARC_HAS_ACCL_REGS + select ARC_IRQ_NO_AUTOSAVE select CLK_HSDK select RESET_HSDK select HAVE_PCI