[PATCH] arm64: Work around Falkor erratum 1009

Christopher Covington
2016-12-07T20:04:53Z

From: Shanker Donthineni <shankerd@codeaurora.org>

During a TLB invalidate sequence targeting the inner shareable
domain, Falkor may prematurely complete the DSB before all loads
and stores using the old translation are observed; instruction
fetches are not subject to the conditions of this erratum.

Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Christopher Covington <cov@codeaurora.org>
---
arch/arm64/Kconfig | 10 +++++++++
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/tlbflush.h | 43 +++++++++++++++++++++++++++++++++++++++
arch/arm64/kernel/cpu_errata.c | 7 +++++++
arch/arm64/kvm/hyp/tlb.c | 39 ++++++++++++++++++++++++++++++-----
5 files changed, 96 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1004a3d..125440f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -485,6 +485,16 @@ config QCOM_FALKOR_ERRATUM_E1003

If unsure, say Y.

+config QCOM_FALKOR_ERRATUM_E1009
+ bool "Falkor E1009: Prematurely complete a DSB after a TLBI"
+ default y
+ help
+ Falkor CPU may prematurely complete a DSB following a TLBI xxIS
+ invalidate maintenance operations. Repeat the TLBI operation one
+ more time to fix the issue.
+
+ If unsure, say Y.
+
endmenu

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index cb6a8c2..5357d7f 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -35,7 +35,8 @@
#define ARM64_HYP_OFFSET_LOW 14
#define ARM64_MISMATCHED_CACHE_LINE_SIZE 15
#define ARM64_WORKAROUND_QCOM_FALKOR_E1003 16
+#define ARM64_WORKAROUND_QCOM_FALKOR_E1009 17

-#define ARM64_NCAPS 17
+#define ARM64_NCAPS 18

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index deab523..03bafc5 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -23,6 +23,7 @@

#include <linux/sched.h>
#include <asm/cputype.h>
+#include <asm/alternative.h>

/*
* Raw TLBI operations.
@@ -94,6 +95,13 @@ static inline void flush_tlb_all(void)
dsb(ishst);
__tlbi(vmalle1is);
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi vmalle1is \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : :);
isb();
}

@@ -104,6 +112,13 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
dsb(ishst);
__tlbi(aside1is, asid);
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi aside1is, %0 \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (asid));
}

static inline void flush_tlb_page(struct vm_area_struct *vma,
@@ -114,6 +129,13 @@ static inline void flush_tlb_page(struct vm_area_struct *vma,
dsb(ishst);
__tlbi(vale1is, addr);
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi vale1is, %0 \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (addr));
}

/*
@@ -145,6 +167,13 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
__tlbi(vae1is, addr);
}
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi vae1is, %0 \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (end));
}

static inline void flush_tlb_range(struct vm_area_struct *vma,
@@ -169,6 +198,13 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12))
__tlbi(vaae1is, addr);
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi vaae1is, %0 \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (end));
isb();
}

@@ -183,6 +219,13 @@ static inline void __flush_tlb_pgtable(struct mm_struct *mm,

__tlbi(vae1is, addr);
dsb(ish);
+ asm volatile(ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "tlbi vae1is, %0 \n"
+ "dsb ish \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (addr));
}

#endif
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3789e2f..8013579 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -137,6 +137,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0x00, 0x00),
},
#endif
+#ifdef CONFIG_QCOM_FALKOR_ERRATUM_E1009
+ {
+ .desc = "Qualcomm Falkor erratum E1009",
+ .capability = ARM64_WORKAROUND_QCOM_FALKOR_E1009,
+ MIDR_RANGE(MIDR_QCOM_FALKOR_V1, 0x00, 0x00),
+ },
+#endif
{
}
};
diff --git a/arch/arm64/kvm/hyp/tlb.c b/arch/arm64/kvm/hyp/tlb.c
index 88e2f2b..dfd3a77 100644
--- a/arch/arm64/kvm/hyp/tlb.c
+++ b/arch/arm64/kvm/hyp/tlb.c
@@ -16,6 +16,7 @@
*/

#include <asm/kvm_hyp.h>
+#include <asm/alternative.h>

void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
{
@@ -32,7 +33,14 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
* whole of Stage-1. Weep...
*/
ipa >>= 12;
- asm volatile("tlbi ipas2e1is, %0" : : "r" (ipa));
+ asm volatile("tlbi ipas2e1is, %0 \n"
+ ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "dsb ish \n"
+ "tlbi ipas2e1is, %0 \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : "r" (ipa));

/*
* We have to ensure completion of the invalidation at Stage-2,
@@ -41,7 +49,14 @@ void __hyp_text __kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
* the Stage-1 invalidation happened first.
*/
dsb(ish);
- asm volatile("tlbi vmalle1is" : : );
+ asm volatile("tlbi vmalle1is \n"
+ ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "dsb ish \n"
+ "tlbi vmalle1is \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : );
dsb(ish);
isb();

@@ -57,7 +72,14 @@ void __hyp_text __kvm_tlb_flush_vmid(struct kvm *kvm)
write_sysreg(kvm->arch.vttbr, vttbr_el2);
isb();

- asm volatile("tlbi vmalls12e1is" : : );
+ asm volatile("tlbi vmalls12e1is \n"
+ ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "dsb ish \n"
+ "tlbi vmalls12e1is \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ : : );
dsb(ish);
isb();

@@ -82,7 +104,14 @@ void __hyp_text __kvm_tlb_flush_local_vmid(struct kvm_vcpu *vcpu)
void __hyp_text __kvm_flush_vm_context(void)
{
dsb(ishst);
- asm volatile("tlbi alle1is \n"
- "ic ialluis ": : );
+ asm volatile("tlbi alle1is \n"
+ ALTERNATIVE(
+ "nop \n"
+ "nop \n",
+ "dsb ish \n"
+ "tlbi alle1is \n",
+ ARM64_WORKAROUND_QCOM_FALKOR_E1009)
+ "ic ialluis \n"
+ : : );
dsb(ish);
}
--
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Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora
Forum, a Linux Foundation Collaborative Project.