As of today we enable unaligned access unconditionally on ARCv2.
Do this under a Kconfig option to allow disable it for test, benchmarking
etc. Also while at it
- Select HAVE_EFFICIENT_UNALIGNED_ACCESS
- Although gcc defaults to unaligned access (since GNU 2018.03), add the
right toggles for enabling or disabling as appropriate
- update bootlog to prints both HW feature status (exists, enabled/disabled)
and SW status (used / not used).
- wire up the relaxed memcpy for unaligned access
Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: squashed patches, handle gcc -mno-unaligned-access quick]
if ISA_ARCV2
+config ARC_USE_UNALIGNED_MEM_ACCESS
+ bool "Enable unaligned access in HW"
+ default y
+ select HAVE_EFFICIENT_UNALIGNED_ACCESS
+ help
+ The ARC HS architecture supports unaligned memory access
+ which is disabled by default. Enable unaligned access in
+ hardware and use software to use it
+
config ARC_HAS_LL64
bool "Insn: 64bit LDD/STD"
help
ifdef CONFIG_ISA_ARCV2
+ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
+cflags-y += -munaligned-access
+else
+cflags-y += -mno-unaligned-access
+endif
+
ifndef CONFIG_ARC_HAS_LL64
cflags-y += -mno-ll64
endif
#define ECR_V_DTLB_MISS 0x05
#define ECR_V_PROTV 0x06
#define ECR_V_TRAP 0x09
+#define ECR_V_MISALIGN 0x0d
#endif
/* DTLB Miss and Protection Violation Cause Codes */
#define ARCV2_IRQ_DEF_PRIO 1
/* seed value for status register */
-#define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | STATUS_AD_MASK | \
+#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
+#define __AD_ENB STATUS_AD_MASK
+#else
+#define __AD_ENB 0
+#endif
+
+#define ISA_INIT_STATUS_BITS (STATUS_IE_MASK | __AD_ENB | \
(ARCV2_IRQ_DEF_PRIO << 1))
#ifndef __ASSEMBLY__
; gcc 7.3.1 (ARC GNU 2018.03) onwards generates unaligned access
; by default
lr r5, [status32]
+#ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
bset r5, r5, STATUS_AD_BIT
+#else
+ ; Although disabled at reset, bootloader might have enabled it
+ bclr r5, r5, STATUS_AD_BIT
+#endif
kflag r5
#endif
.endm
/* setup status32, don't enable intr yet as kernel doesn't want */
tmp = read_aux_reg(ARC_REG_STATUS32);
- tmp |= STATUS_AD_MASK | (ARCV2_IRQ_DEF_PRIO << 1);
+ tmp |= ARCV2_IRQ_DEF_PRIO << 1;
tmp &= ~STATUS_IE_MASK;
asm volatile("kflag %0 \n"::"r"(tmp));
}
{
struct cpuinfo_arc *cpu = &cpuinfo_arc700[cpu_id];
struct bcr_identity *core = &cpu->core;
- int i, n = 0, ua = 0;
+ int n = 0;
FIX_PTR(cpu);
IS_AVAIL2(cpu->extn.rtc, "RTC [UP 64-bit] ", CONFIG_ARC_TIMERS_64BIT),
IS_AVAIL2(cpu->extn.gfrc, "GFRC [SMP 64-bit] ", CONFIG_ARC_TIMERS_64BIT));
-#ifdef __ARC_UNALIGNED__
- ua = 1;
+ n += scnprintf(buf + n, len - n, "%s%s%s%s%s%s",
+ IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
+ IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
+ IS_AVAIL2(cpu->isa.unalign, "unalign ", CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS));
+
+#if defined(__ARC_UNALIGNED__) && !defined(CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS)
+ /*
+ * gcc 7.3.1 (GNU 2018.03) onwards generate unaligned access by default
+ * but -mno-unaligned-access to disable that didn't work until gcc 8.2.1
+ * (GNU 2019.03). So landing here implies the interim period, when
+ * despite Kconfig being off, gcc is generating unaligned accesses which
+ * could bomb later on. So better to disallow such broken builds
+ */
+ BUILD_BUG_ON_MSG(1, "gcc doesn't support -mno-unaligned-access");
#endif
- n += i = scnprintf(buf + n, len - n, "%s%s%s%s%s%s",
- IS_AVAIL2(cpu->isa.atomic, "atomic ", CONFIG_ARC_HAS_LLSC),
- IS_AVAIL2(cpu->isa.ldd, "ll64 ", CONFIG_ARC_HAS_LL64),
- IS_AVAIL1(cpu->isa.unalign, "unalign "), IS_USED_RUN(ua));
- if (i)
- n += scnprintf(buf + n, len - n, "\n\t\t: ");
+ n += scnprintf(buf + n, len - n, "\n\t\t: ");
if (cpu->extn_mpy.ver) {
if (cpu->extn_mpy.ver <= 0x2) { /* ARCompact */
} else if (vec == ECR_V_PROTV) {
if (cause_code == ECR_C_PROTV_INST_FETCH)
pr_cont("Execute from Non-exec Page\n");
- else if (cause_code == ECR_C_PROTV_MISALIG_DATA)
+ else if (cause_code == ECR_C_PROTV_MISALIG_DATA &&
+ IS_ENABLED(CONFIG_ISA_ARCOMPACT))
pr_cont("Misaligned r/w from 0x%08lx\n", address);
else
pr_cont("%s access not allowed on page\n",
pr_cont("Bus Error from Data Mem\n");
else
pr_cont("Bus Error, check PRM\n");
+ } else if (vec == ECR_V_MISALIGN) {
+ pr_cont("Misaligned r/w from 0x%08lx\n", address);
#endif
} else if (vec == ECR_V_TRAP) {
if (regs->ecr_param == 5)
lib-y := strchr-700.o strcpy-700.o strlen.o memcmp.o
lib-$(CONFIG_ISA_ARCOMPACT) += memcpy-700.o memset.o strcmp.o
-lib-$(CONFIG_ISA_ARCV2) += memcpy-archs.o memset-archs.o strcmp-archs.o
+lib-$(CONFIG_ISA_ARCV2) += memset-archs.o strcmp-archs.o
+
+ifdef CONFIG_ARC_USE_UNALIGNED_MEM_ACCESS
+lib-$(CONFIG_ISA_ARCV2) +=memcpy-archs-unaligned.o
+else
+lib-$(CONFIG_ISA_ARCV2) +=memcpy-archs.o
+endif