[RFC PATCH v1 1/3] arm64: tlb: add TTL field to __TLBI_ADDR

From: Zhenyu Ye
Date: Tue Mar 10 2020 - 22:56:38 EST


ARMv8.4-TTL provides the TTL field in tlbi instruction to indicate
the level of translation table walk holding the leaf entry for the
address that is being invalidated.

This patch add support for TTL feature and set the default value 0
where __TLBI_ADDR is called.

Signed-off-by: Zhenyu Ye <yezhenyu2@xxxxxxxxxx>
---
arch/arm64/include/asm/cpucaps.h | 3 ++-
arch/arm64/include/asm/sysreg.h | 4 ++++
arch/arm64/include/asm/tlbflush.h | 33 ++++++++++++++++++++++---------
arch/arm64/kernel/cpufeature.c | 10 ++++++++++
arch/arm64/kernel/sys_compat.c | 2 +-
5 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index 865e0253fc1e..60f3b090ea9a 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -58,7 +58,8 @@
#define ARM64_WORKAROUND_SPECULATIVE_AT_NVHE 48
#define ARM64_HAS_E0PD 49
#define ARM64_HAS_RNG 50
+#define ARM64_HAS_TLBI_TTL 51

-#define ARM64_NCAPS 51
+#define ARM64_NCAPS 52

#endif /* __ASM_CPUCAPS_H */
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index b91570ff9db1..7caa3c9facfe 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -685,6 +685,7 @@

/* id_aa64mmfr2 */
#define ID_AA64MMFR2_E0PD_SHIFT 60
+#define ID_AA64MMFR2_TTL_SHIFT 48
#define ID_AA64MMFR2_FWB_SHIFT 40
#define ID_AA64MMFR2_AT_SHIFT 32
#define ID_AA64MMFR2_LVA_SHIFT 16
@@ -693,6 +694,9 @@
#define ID_AA64MMFR2_UAO_SHIFT 4
#define ID_AA64MMFR2_CNP_SHIFT 0

+#define ID_AA64MMFR2_TTL_NI 0x0
+#define ID_AA64MMFR2_TTL_SUPPORTED 0x1
+
/* id_aa64dfr0 */
#define ID_AA64DFR0_PMSVER_SHIFT 32
#define ID_AA64DFR0_CTX_CMPS_SHIFT 28
diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index bc3949064725..10b12710b7cc 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -50,15 +50,30 @@
__tlbi(op, (arg) | USER_ASID_FLAG); \
} while (0)

-/* This macro creates a properly formatted VA operand for the TLBI */
-#define __TLBI_VADDR(addr, asid) \
+/* This macro creates a properly formatted VA operand for the TLBI.
+ * The TTL field is introduced since ARMv8.4. ARMv8.4-TTL provides the TTL
+ * field to indicate the level of translation table walk holding the leaf entry
+ * for the address that is being invalidated.
+ */
+#define __TLBI_VADDR(addr, asid, ttl) \
({ \
unsigned long __ta = (addr) >> 12; \
__ta &= GENMASK_ULL(43, 0); \
+ if (cpus_have_const_cap(ARM64_HAS_TLBI_TTL)) \
+ __ta |= (unsigned long)(ttl) << 44; \
__ta |= (unsigned long)(asid) << 48; \
__ta; \
})

+/*
+ * __TLB_TG defines translation granule of the system, which is defined by
+ * PAGE_SHIFT. Used by TTL.
+ * - 4KB : 1
+ * - 16KB : 2
+ * - 64KB : 3
+ */
+#define __TLB_TG ((PAGE_SHIFT - 12) / 2 + 1)
+
/*
* TLB Invalidation
* ================
@@ -146,7 +161,7 @@ static inline void flush_tlb_all(void)

static inline void flush_tlb_mm(struct mm_struct *mm)
{
- unsigned long asid = __TLBI_VADDR(0, ASID(mm));
+ unsigned long asid = __TLBI_VADDR(0, ASID(mm), 0);

dsb(ishst);
__tlbi(aside1is, asid);
@@ -157,7 +172,7 @@ static inline void flush_tlb_mm(struct mm_struct *mm)
static inline void flush_tlb_page_nosync(struct vm_area_struct *vma,
unsigned long uaddr)
{
- unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm));
+ unsigned long addr = __TLBI_VADDR(uaddr, ASID(vma->vm_mm), 0);

dsb(ishst);
__tlbi(vale1is, addr);
@@ -195,8 +210,8 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
/* Convert the stride into units of 4k */
stride >>= 12;

- start = __TLBI_VADDR(start, asid);
- end = __TLBI_VADDR(end, asid);
+ start = __TLBI_VADDR(start, asid, 0);
+ end = __TLBI_VADDR(end, asid, 0);

dsb(ishst);
for (addr = start; addr < end; addr += stride) {
@@ -230,8 +245,8 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
return;
}

- start = __TLBI_VADDR(start, 0);
- end = __TLBI_VADDR(end, 0);
+ start = __TLBI_VADDR(start, 0, 0);
+ end = __TLBI_VADDR(end, 0, 0);

dsb(ishst);
for (addr = start; addr < end; addr += 1 << (PAGE_SHIFT - 12))
@@ -246,7 +261,7 @@ static inline void flush_tlb_kernel_range(unsigned long start, unsigned long end
*/
static inline void __flush_tlb_kernel_pgtable(unsigned long kaddr)
{
- unsigned long addr = __TLBI_VADDR(kaddr, 0);
+ unsigned long addr = __TLBI_VADDR(kaddr, 0, 0);

dsb(ishst);
__tlbi(vaae1is, addr);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0b6715625cf6..9a84c59e1482 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1672,6 +1672,16 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.min_field_value = 1,
},
#endif
+ {
+ .desc = "TTL field in TLBI operation",
+ .capability = ARM64_HAS_TLBI_TTL,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .matches = has_cpuid_feature,
+ .sys_reg = SYS_ID_AA64MMFR2_EL1,
+ .field_pos = ID_AA64MMFR2_TTL_SHIFT,
+ .sign = FTR_UNSIGNED,
+ .min_field_value = ID_AA64MMFR2_TTL_SUPPORTED,
+ },
{},
};

diff --git a/arch/arm64/kernel/sys_compat.c b/arch/arm64/kernel/sys_compat.c
index 3c18c2454089..5d1570354d29 100644
--- a/arch/arm64/kernel/sys_compat.c
+++ b/arch/arm64/kernel/sys_compat.c
@@ -37,7 +37,7 @@ __do_compat_cache_op(unsigned long start, unsigned long end)
* The workaround requires an inner-shareable tlbi.
* We pick the reserved-ASID to minimise the impact.
*/
- __tlbi(aside1is, __TLBI_VADDR(0, 0));
+ __tlbi(aside1is, __TLBI_VADDR(0, 0, 0));
dsb(ish);
}

--
2.19.1