[PATCH 6.6.y 0/13] arm64: errata: Speculative SSBS workaround

[PATCH 6.6.y 0/13] arm64: errata: Speculative SSBS workaround

[Mark Rutland]

Hi,

This series is a v6.6-only backport (based on v6.6.44) of the upstream
workaround for SSBS errata on Arm Ltd CPUs, as affected parts are likely
to be used with stable kernels. This does not apply to earlier stable
trees, which will receive a separate backport.

The errata mean that an MSR to the SSBS special-purpose register does not
affect subsequent speculative instructions, permitting speculative store
bypassing for a window of time.

The upstream support was original posted as:

* https://lore.kernel.org/linux-arm-kernel/20240508081400.235362-1-mark.rutland@arm.com/
  "arm64: errata: Add workaround for Arm errata 3194386 and 3312417"
  Present in v6.10

* https://lore.kernel.org/linux-arm-kernel/20240603111812.1514101-1-mark.rutland@arm.com/
  "arm64: errata: Expand speculative SSBS workaround"
  Present in v6.11-rc1

* https://lore.kernel.org/linux-arm-kernel/20240801101803.1982459-1-mark.rutland@arm.com/
  "arm64: errata: Expand speculative SSBS workaround (again)"
  Present in v6.11-rc2

This backport applies the patches which are not present in v6.6.y, and
as prerequisites backports the addition of the Neoverse-V2 MIDR values
and the restoration of the spec_bar() macro.

I have tested the backport (when applied to v6.6.44), ensuring that the
detection logic works and that the HWCAP and string in /proc/cpuinfo are
both hidden when the relevant errata are detected.

Mark.Besar Wicaksono (1):
  arm64: Add Neoverse-V2 part

Mark Rutland (12):
  arm64: barrier: Restore spec_bar() macro
  arm64: cputype: Add Cortex-X4 definitions
  arm64: cputype: Add Neoverse-V3 definitions
  arm64: errata: Add workaround for Arm errata 3194386 and 3312417
  arm64: cputype: Add Cortex-X3 definitions
  arm64: cputype: Add Cortex-A720 definitions
  arm64: cputype: Add Cortex-X925 definitions
  arm64: errata: Unify speculative SSBS errata logic
  arm64: errata: Expand speculative SSBS workaround
  arm64: cputype: Add Cortex-X1C definitions
  arm64: cputype: Add Cortex-A725 definitions
  arm64: errata: Expand speculative SSBS workaround (again)

 Documentation/arch/arm64/silicon-errata.rst | 36 +++++++++++++++++++
 arch/arm64/Kconfig                          | 38 +++++++++++++++++++++
 arch/arm64/include/asm/barrier.h            |  4 +++
 arch/arm64/include/asm/cputype.h            | 16 +++++++++
 arch/arm64/kernel/cpu_errata.c              | 31 +++++++++++++++++
 arch/arm64/kernel/cpufeature.c              | 12 +++++++
 arch/arm64/kernel/proton-pack.c             | 12 +++++++
 arch/arm64/tools/cpucaps                    |  1 +
 8 files changed, 150 insertions(+)

-- 
2.30.2

[PATCH 6.6.y 01/13] arm64: Add Neoverse-V2 part

[Mark Rutland]

From: Besar Wicaksono <bwicaksono@nvidia.com>

[ Upstream commit f4d9d9dcc70b96b5e5d7801bd5fbf8491b07b13d ]

Add the part number and MIDR for Neoverse-V2

Signed-off-by: Besar Wicaksono <bwicaksono@nvidia.com>
Reviewed-by: James Clark <james.clark@arm.com>
Link: https://lore.kernel.org/r/20240109192310.16234-2-bwicaksono@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 52f076afeb960..936389e9aecbc 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -86,6 +86,7 @@
 #define ARM_CPU_PART_CORTEX_X2		0xD48
 #define ARM_CPU_PART_NEOVERSE_N2	0xD49
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
+#define ARM_CPU_PART_NEOVERSE_V2	0xD4F
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -159,6 +160,7 @@
 #define MIDR_CORTEX_X2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X2)
 #define MIDR_NEOVERSE_N2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N2)
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
+#define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
-- 
2.30.2

[PATCH 6.6.y 02/13] arm64: barrier: Restore spec_bar() macro

[Mark Rutland]

[ Upstream commit ebfc726eae3f31bdb5fae1bbd74ef235d71046ca ]

Upcoming errata workarounds will need to use SB from C code. Restore the
spec_bar() macro so that we can use SB.

This is effectively a revert of commit:

  4f30ba1cce36d413 ("arm64: barrier: Remove spec_bar() macro")

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240508081400.235362-2-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/barrier.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index cf2987464c186..1ca947d5c9396 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -40,6 +40,10 @@
  */
 #define dgh()		asm volatile("hint #6" : : : "memory")
 
+#define spec_bar()	asm volatile(ALTERNATIVE("dsb nsh\nisb\n",		\
+						 SB_BARRIER_INSN"nop\n",	\
+						 ARM64_HAS_SB))
+
 #ifdef CONFIG_ARM64_PSEUDO_NMI
 #define pmr_sync()						\
 	do {							\
-- 
2.30.2

[PATCH 6.6.y 03/13] arm64: cputype: Add Cortex-X4 definitions

[Mark Rutland]

[ Upstream commit 02a0a04676fa7796d9cbc9eb5ca120aaa194d2dd ]

Add cputype definitions for Cortex-X4. These will be used for errata
detection in subsequent patches.

These values can be found in Table B-249 ("MIDR_EL1 bit descriptions")
in issue 0002-05 of the Cortex-X4 TRM, which can be found at:

  https://developer.arm.com/documentation/102484/0002/?lang=en

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240508081400.235362-3-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: fix conflict (dealt with upstream via a later merge) ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 936389e9aecbc..b810b1f03746c 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -87,6 +87,7 @@
 #define ARM_CPU_PART_NEOVERSE_N2	0xD49
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
 #define ARM_CPU_PART_NEOVERSE_V2	0xD4F
+#define ARM_CPU_PART_CORTEX_X4		0xD82
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -161,6 +162,7 @@
 #define MIDR_NEOVERSE_N2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N2)
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
 #define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
+#define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
-- 
2.30.2

[PATCH 6.6.y 04/13] arm64: cputype: Add Neoverse-V3 definitions

[Mark Rutland]

[ Upstream commit 0ce85db6c2141b7ffb95709d76fc55a27ff3cdc1 ]

Add cputype definitions for Neoverse-V3. These will be used for errata
detection in subsequent patches.

These values can be found in Table B-249 ("MIDR_EL1 bit descriptions")
in issue 0001-04 of the Neoverse-V3 TRM, which can be found at:

  https://developer.arm.com/documentation/107734/0001/?lang=en

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240508081400.235362-4-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index b810b1f03746c..7b32b99023a21 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -88,6 +88,7 @@
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
 #define ARM_CPU_PART_NEOVERSE_V2	0xD4F
 #define ARM_CPU_PART_CORTEX_X4		0xD82
+#define ARM_CPU_PART_NEOVERSE_V3	0xD84
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -163,6 +164,7 @@
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
 #define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
 #define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
+#define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
-- 
2.30.2

[PATCH 6.6.y 05/13] arm64: errata: Add workaround for Arm errata 3194386 and 3312417

[Mark Rutland]

[ Upstream commit 7187bb7d0b5c7dfa18ca82e9e5c75e13861b1d88 ]

Cortex-X4 and Neoverse-V3 suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time. This is described in their Software Developer Errata Notice (SDEN)
documents:

* Cortex-X4 SDEN v8.0, erratum 3194386:
  https://developer.arm.com/documentation/SDEN-2432808/0800/

* Neoverse-V3 SDEN v6.0, erratum 3312417:
  https://developer.arm.com/documentation/SDEN-2891958/0600/

To workaround these errata, it is necessary to place a speculation
barrier (SB) after MSR to the SSBS special-purpose register. This patch
adds the requisite SB after writes to SSBS within the kernel, and hides
the presence of SSBS from EL0 such that userspace software which cares
about SSBS will manipulate this via prctl(PR_GET_SPECULATION_CTRL, ...).

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240508081400.235362-5-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
[ Mark: fix conflicts, drop unneeded cpucaps.h, fold in user_feature_fixup() ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 Documentation/arch/arm64/silicon-errata.rst |  4 ++
 arch/arm64/Kconfig                          | 42 +++++++++++++++++++++
 arch/arm64/kernel/cpu_errata.c              | 19 ++++++++++
 arch/arm64/kernel/cpufeature.c              | 12 ++++++
 arch/arm64/kernel/proton-pack.c             | 12 ++++++
 arch/arm64/tools/cpucaps                    |  1 +
 6 files changed, 90 insertions(+)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index 29fd5213eeb2b..f8e49ff9ab0d4 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -133,6 +133,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2224489        | ARM64_ERRATUM_2224489       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X4       | #3194386        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N1     | #1188873,1418040| ARM64_ERRATUM_1418040       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N1     | #1349291        | N/A                         |
@@ -145,6 +147,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #2253138        | ARM64_ERRATUM_2253138       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-V3     | #3312417        | ARM64_ERRATUM_3312417       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | MMU-500         | #841119,826419  | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | MMU-600         | #1076982,1209401| N/A                         |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f9777ce2ccb2d..db5560300df84 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1068,6 +1068,48 @@ config ARM64_ERRATUM_3117295
 
 	  If unsure, say Y.
 
+config ARM64_WORKAROUND_SPECULATIVE_SSBS
+	bool
+
+config ARM64_ERRATUM_3194386
+	bool "Cortex-X4: 3194386: workaround for MSR SSBS not self-synchronizing"
+	select ARM64_WORKAROUND_SPECULATIVE_SSBS
+	default y
+	help
+	  This option adds the workaround for ARM Cortex-X4 erratum 3194386.
+
+	  On affected cores "MSR SSBS, #0" instructions may not affect
+	  subsequent speculative instructions, which may permit unexepected
+	  speculative store bypassing.
+
+	  Work around this problem by placing a speculation barrier after
+	  kernel changes to SSBS. The presence of the SSBS special-purpose
+	  register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
+	  that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
+	  SSBS.
+
+	  If unsure, say Y.
+
+config ARM64_ERRATUM_3312417
+	bool "Neoverse-V3: 3312417: workaround for MSR SSBS not self-synchronizing"
+	select ARM64_WORKAROUND_SPECULATIVE_SSBS
+	default y
+	help
+	  This option adds the workaround for ARM Neoverse-V3 erratum 3312417.
+
+	  On affected cores "MSR SSBS, #0" instructions may not affect
+	  subsequent speculative instructions, which may permit unexepected
+	  speculative store bypassing.
+
+	  Work around this problem by placing a speculation barrier after
+	  kernel changes to SSBS. The presence of the SSBS special-purpose
+	  register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
+	  that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
+	  SSBS.
+
+	  If unsure, say Y.
+
+
 config CAVIUM_ERRATUM_22375
 	bool "Cavium erratum 22375, 24313"
 	default y
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 7bba831f62c33..3e1554a58209b 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -448,6 +448,18 @@ static const struct midr_range erratum_spec_unpriv_load_list[] = {
 };
 #endif
 
+#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS
+static const struct midr_range erratum_spec_ssbs_list[] = {
+#ifdef CONFIG_ARM64_ERRATUM_3194386
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X4),
+#endif
+#ifdef CONFIG_ARM64_ERRATUM_3312417
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
+#endif
+	{}
+};
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
 	{
@@ -746,6 +758,13 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.cpu_enable = cpu_clear_bf16_from_user_emulation,
 	},
 #endif
+#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS
+	{
+		.desc = "ARM errata 3194386, 3312417",
+		.capability = ARM64_WORKAROUND_SPECULATIVE_SSBS,
+		ERRATA_MIDR_RANGE_LIST(erratum_spec_ssbs_list),
+	},
+#endif
 #ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_UNPRIV_LOAD
 	{
 		.desc = "ARM errata 2966298, 3117295",
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 444a73c2e6385..7e96604559004 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2190,6 +2190,17 @@ static void cpu_enable_mte(struct arm64_cpu_capabilities const *cap)
 }
 #endif /* CONFIG_ARM64_MTE */
 
+static void user_feature_fixup(void)
+{
+	if (cpus_have_cap(ARM64_WORKAROUND_SPECULATIVE_SSBS)) {
+		struct arm64_ftr_reg *regp;
+
+		regp = get_arm64_ftr_reg(SYS_ID_AA64PFR1_EL1);
+		if (regp)
+			regp->user_mask &= ~ID_AA64PFR1_EL1_SSBS_MASK;
+	}
+}
+
 static void elf_hwcap_fixup(void)
 {
 #ifdef CONFIG_ARM64_ERRATUM_1742098
@@ -3345,6 +3356,7 @@ void __init setup_cpu_features(void)
 	u32 cwg;
 
 	setup_system_capabilities();
+	user_feature_fixup();
 	setup_elf_hwcaps(arm64_elf_hwcaps);
 
 	if (system_supports_32bit_el0()) {
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index 05f40c4e18fda..e662c4d2856b6 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -558,6 +558,18 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void)
 
 	/* SCTLR_EL1.DSSBS was initialised to 0 during boot */
 	set_pstate_ssbs(0);
+
+	/*
+	 * SSBS is self-synchronizing and is intended to affect subsequent
+	 * speculative instructions, but some CPUs can speculate with a stale
+	 * value of SSBS.
+	 *
+	 * Mitigate this with an unconditional speculation barrier, as CPUs
+	 * could mis-speculate branches and bypass a conditional barrier.
+	 */
+	if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS))
+		spec_bar();
+
 	return SPECTRE_MITIGATED;
 }
 
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 5511bee15603a..c251ef3caae56 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -99,4 +99,5 @@ WORKAROUND_NVIDIA_CARMEL_CNP
 WORKAROUND_QCOM_FALKOR_E1003
 WORKAROUND_REPEAT_TLBI
 WORKAROUND_SPECULATIVE_AT
+WORKAROUND_SPECULATIVE_SSBS
 WORKAROUND_SPECULATIVE_UNPRIV_LOAD
-- 
2.30.2

[PATCH 6.6.y 06/13] arm64: cputype: Add Cortex-X3 definitions

[Mark Rutland]

[ Upstream commit be5a6f238700f38b534456608588723fba96c5ab ]

Add cputype definitions for Cortex-X3. These will be used for errata
detection in subsequent patches.

These values can be found in Table A-263 ("MIDR_EL1 bit descriptions")
in issue 07 of the Cortex-X3 TRM, which can be found at:

  https://developer.arm.com/documentation/101593/0102/?lang=en

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 7b32b99023a21..72fe207403c83 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -86,6 +86,7 @@
 #define ARM_CPU_PART_CORTEX_X2		0xD48
 #define ARM_CPU_PART_NEOVERSE_N2	0xD49
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
+#define ARM_CPU_PART_CORTEX_X3		0xD4E
 #define ARM_CPU_PART_NEOVERSE_V2	0xD4F
 #define ARM_CPU_PART_CORTEX_X4		0xD82
 #define ARM_CPU_PART_NEOVERSE_V3	0xD84
@@ -162,6 +163,7 @@
 #define MIDR_CORTEX_X2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X2)
 #define MIDR_NEOVERSE_N2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N2)
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
+#define MIDR_CORTEX_X3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X3)
 #define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
 #define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
 #define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
-- 
2.30.2

[PATCH 6.6.y 07/13] arm64: cputype: Add Cortex-A720 definitions

[Mark Rutland]

[ Upstream commit add332c40328cf06fe35e4b3cde8ec315c4629e5 ]

Add cputype definitions for Cortex-A720. These will be used for errata
detection in subsequent patches.

These values can be found in Table A-186 ("MIDR_EL1 bit descriptions")
in issue 0002-05 of the Cortex-A720 TRM, which can be found at:

  https://developer.arm.com/documentation/102530/0002/?lang=en

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 72fe207403c83..dcbac1ce6c25c 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -88,6 +88,7 @@
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
 #define ARM_CPU_PART_CORTEX_X3		0xD4E
 #define ARM_CPU_PART_NEOVERSE_V2	0xD4F
+#define ARM_CPU_PART_CORTEX_A720	0xD81
 #define ARM_CPU_PART_CORTEX_X4		0xD82
 #define ARM_CPU_PART_NEOVERSE_V3	0xD84
 
@@ -165,6 +166,7 @@
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
 #define MIDR_CORTEX_X3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X3)
 #define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
+#define MIDR_CORTEX_A720 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A720)
 #define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
 #define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
-- 
2.30.2

[PATCH 6.6.y 08/13] arm64: cputype: Add Cortex-X925 definitions

[Mark Rutland]

[ Upstream commit fd2ff5f0b320f418288e7a1f919f648fbc8a0dfc ]

Add cputype definitions for Cortex-X925. These will be used for errata
detection in subsequent patches.

These values can be found in Table A-285 ("MIDR_EL1 bit descriptions")
in issue 0001-05 of the Cortex-X925 TRM, which can be found at:

  https://developer.arm.com/documentation/102807/0001/?lang=en

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index dcbac1ce6c25c..1cb0704c6163f 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -91,6 +91,7 @@
 #define ARM_CPU_PART_CORTEX_A720	0xD81
 #define ARM_CPU_PART_CORTEX_X4		0xD82
 #define ARM_CPU_PART_NEOVERSE_V3	0xD84
+#define ARM_CPU_PART_CORTEX_X925	0xD85
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -169,6 +170,7 @@
 #define MIDR_CORTEX_A720 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A720)
 #define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
 #define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
+#define MIDR_CORTEX_X925 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X925)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
-- 
2.30.2

[PATCH 6.6.y 09/13] arm64: errata: Unify speculative SSBS errata logic

[Mark Rutland]

[ Upstream commit ec768766608092087dfb5c1fc45a16a6f524dee2 ]

Cortex-X4 erratum 3194386 and Neoverse-V3 erratum 3312417 are identical,
with duplicate Kconfig text and some unsightly ifdeffery. While we try
to share code behind CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS, having
separate options results in a fair amount of boilerplate code, and this
will only get worse as we expand the set of affected CPUs.

To reduce this boilerplate, unify the two behind a common Kconfig
option. This removes the duplicate text and Kconfig logic, and removes
the need for the intermediate ARM64_WORKAROUND_SPECULATIVE_SSBS option.
The set of affected CPUs is described as a list so that this can easily
be extended.

I've used ARM64_ERRATUM_3194386 (matching the Neoverse-V3 erratum ID) as
the common option, matching the way we use ARM64_ERRATUM_1319367 to
cover Cortex-A57 erratum 1319537 and Cortex-A72 erratum 1319367.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-5-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts, drop unneeded cpucaps.h ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 Documentation/arch/arm64/silicon-errata.rst |  2 +-
 arch/arm64/Kconfig                          | 29 +++------------------
 arch/arm64/kernel/cpu_errata.c              |  8 ++----
 arch/arm64/kernel/proton-pack.c             |  2 +-
 4 files changed, 8 insertions(+), 33 deletions(-)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index f8e49ff9ab0d4..e7fc5e1664265 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -147,7 +147,7 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #2253138        | ARM64_ERRATUM_2253138       |
 +----------------+-----------------+-----------------+-----------------------------+
-| ARM            | Neoverse-V3     | #3312417        | ARM64_ERRATUM_3312417       |
+| ARM            | Neoverse-V3     | #3312417        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | MMU-500         | #841119,826419  | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index db5560300df84..d9d84f716228b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1068,34 +1068,14 @@ config ARM64_ERRATUM_3117295
 
 	  If unsure, say Y.
 
-config ARM64_WORKAROUND_SPECULATIVE_SSBS
-	bool
-
 config ARM64_ERRATUM_3194386
-	bool "Cortex-X4: 3194386: workaround for MSR SSBS not self-synchronizing"
-	select ARM64_WORKAROUND_SPECULATIVE_SSBS
+	bool "Cortex-X4/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
 	default y
 	help
-	  This option adds the workaround for ARM Cortex-X4 erratum 3194386.
+	  This option adds the workaround for the following errata:
 
-	  On affected cores "MSR SSBS, #0" instructions may not affect
-	  subsequent speculative instructions, which may permit unexepected
-	  speculative store bypassing.
-
-	  Work around this problem by placing a speculation barrier after
-	  kernel changes to SSBS. The presence of the SSBS special-purpose
-	  register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
-	  that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
-	  SSBS.
-
-	  If unsure, say Y.
-
-config ARM64_ERRATUM_3312417
-	bool "Neoverse-V3: 3312417: workaround for MSR SSBS not self-synchronizing"
-	select ARM64_WORKAROUND_SPECULATIVE_SSBS
-	default y
-	help
-	  This option adds the workaround for ARM Neoverse-V3 erratum 3312417.
+	  * ARM Cortex-X4 erratum 3194386
+	  * ARM Neoverse-V3 erratum 3312417
 
 	  On affected cores "MSR SSBS, #0" instructions may not affect
 	  subsequent speculative instructions, which may permit unexepected
@@ -1109,7 +1089,6 @@ config ARM64_ERRATUM_3312417
 
 	  If unsure, say Y.
 
-
 config CAVIUM_ERRATUM_22375
 	bool "Cavium erratum 22375, 24313"
 	default y
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 3e1554a58209b..36d3f894f8637 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -448,14 +448,10 @@ static const struct midr_range erratum_spec_unpriv_load_list[] = {
 };
 #endif
 
-#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS
-static const struct midr_range erratum_spec_ssbs_list[] = {
 #ifdef CONFIG_ARM64_ERRATUM_3194386
+static const struct midr_range erratum_spec_ssbs_list[] = {
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X4),
-#endif
-#ifdef CONFIG_ARM64_ERRATUM_3312417
 	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
-#endif
 	{}
 };
 #endif
@@ -758,7 +754,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.cpu_enable = cpu_clear_bf16_from_user_emulation,
 	},
 #endif
-#ifdef CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS
+#ifdef CONFIG_ARM64_ERRATUM_3194386
 	{
 		.desc = "ARM errata 3194386, 3312417",
 		.capability = ARM64_WORKAROUND_SPECULATIVE_SSBS,
diff --git a/arch/arm64/kernel/proton-pack.c b/arch/arm64/kernel/proton-pack.c
index e662c4d2856b6..57503dc4b22fa 100644
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -567,7 +567,7 @@ static enum mitigation_state spectre_v4_enable_hw_mitigation(void)
 	 * Mitigate this with an unconditional speculation barrier, as CPUs
 	 * could mis-speculate branches and bypass a conditional barrier.
 	 */
-	if (IS_ENABLED(CONFIG_ARM64_WORKAROUND_SPECULATIVE_SSBS))
+	if (IS_ENABLED(CONFIG_ARM64_ERRATUM_3194386))
 		spec_bar();
 
 	return SPECTRE_MITIGATED;
-- 
2.30.2

[PATCH 6.6.y 10/13] arm64: errata: Expand speculative SSBS workaround

[Mark Rutland]

[ Upstream commit 75b3c43eab594bfbd8184ec8ee1a6b820950819a ]

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for Cortex-X4 and Neoverse-V3, in commit:

  7187bb7d0b5c7dfa ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")

... as per their Software Developer Errata Notice (SDEN) documents:

* Cortex-X4 SDEN v8.0, erratum 3194386:
  https://developer.arm.com/documentation/SDEN-2432808/0800/

* Neoverse-V3 SDEN v6.0, erratum 3312417:
  https://developer.arm.com/documentation/SDEN-2891958/0600/

Since then, similar errata have been published for a number of other Arm Ltd
CPUs, for which the mitigation is the same. This is described in their
respective SDEN documents:

* Cortex-A710 SDEN v19.0, errataum 3324338
  https://developer.arm.com/documentation/SDEN-1775101/1900/?lang=en

* Cortex-A720 SDEN v11.0, erratum 3456091
  https://developer.arm.com/documentation/SDEN-2439421/1100/?lang=en

* Cortex-X2 SDEN v19.0, erratum 3324338
  https://developer.arm.com/documentation/SDEN-1775100/1900/?lang=en

* Cortex-X3 SDEN v14.0, erratum 3324335
  https://developer.arm.com/documentation/SDEN-2055130/1400/?lang=en

* Cortex-X925 SDEN v8.0, erratum 3324334
  https://developer.arm.com/documentation/109108/800/?lang=en

* Neoverse-N2 SDEN v17.0, erratum 3324339
  https://developer.arm.com/documentation/SDEN-1982442/1700/?lang=en

* Neoverse-V2 SDEN v9.0, erratum 3324336
  https://developer.arm.com/documentation/SDEN-2332927/900/?lang=en

Note that due to shared design lineage, some CPUs share the same erratum
number.

Add these to the existing mitigation under CONFIG_ARM64_ERRATUM_3194386.
As listing all of the erratum IDs in the runtime description would be
unwieldy, this is reduced to:

	"SSBS not fully self-synchronizing"

... matching the description of the errata in all of the SDENs.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240603111812.1514101-6-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts in silicon-errata.rst ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 Documentation/arch/arm64/silicon-errata.rst | 14 ++++++++++++++
 arch/arm64/Kconfig                          |  9 ++++++++-
 arch/arm64/kernel/cpu_errata.c              |  9 ++++++++-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index e7fc5e1664265..0bab767f6887c 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -127,14 +127,24 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A710     | #2224489        | ARM64_ERRATUM_2224489       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A710     | #3324338        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A715     | #2645198        | ARM64_ERRATUM_2645198       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A720     | #3456091        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2119858        | ARM64_ERRATUM_2119858       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2224489        | ARM64_ERRATUM_2224489       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X2       | #3324338        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X3       | #3324335        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X4       | #3194386        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X925     | #3324334        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N1     | #1188873,1418040| ARM64_ERRATUM_1418040       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N1     | #1349291        | N/A                         |
@@ -147,6 +157,10 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #2253138        | ARM64_ERRATUM_2253138       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-N2     | #3324339        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-V2     | #3324336        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-V3     | #3312417        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | MMU-500         | #841119,826419  | N/A                         |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index d9d84f716228b..e80812a4002bb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1069,12 +1069,19 @@ config ARM64_ERRATUM_3117295
 	  If unsure, say Y.
 
 config ARM64_ERRATUM_3194386
-	bool "Cortex-X4/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
+	bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
 	default y
 	help
 	  This option adds the workaround for the following errata:
 
+	  * ARM Cortex-A710 erratam 3324338
+	  * ARM Cortex-A720 erratum 3456091
+	  * ARM Cortex-X2 erratum 3324338
+	  * ARM Cortex-X3 erratum 3324335
 	  * ARM Cortex-X4 erratum 3194386
+	  * ARM Cortex-X925 erratum 3324334
+	  * ARM Neoverse N2 erratum 3324339
+	  * ARM Neoverse V2 erratum 3324336
 	  * ARM Neoverse-V3 erratum 3312417
 
 	  On affected cores "MSR SSBS, #0" instructions may not affect
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 36d3f894f8637..bfe324854e3b5 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -450,8 +450,15 @@ static const struct midr_range erratum_spec_unpriv_load_list[] = {
 
 #ifdef CONFIG_ARM64_ERRATUM_3194386
 static const struct midr_range erratum_spec_ssbs_list[] = {
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A720),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X3),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X4),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X925),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
 	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2),
 	{}
 };
 #endif
@@ -756,7 +763,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #endif
 #ifdef CONFIG_ARM64_ERRATUM_3194386
 	{
-		.desc = "ARM errata 3194386, 3312417",
+		.desc = "SSBS not fully self-synchronizing",
 		.capability = ARM64_WORKAROUND_SPECULATIVE_SSBS,
 		ERRATA_MIDR_RANGE_LIST(erratum_spec_ssbs_list),
 	},
-- 
2.30.2

[PATCH 6.6.y 11/13] arm64: cputype: Add Cortex-X1C definitions

[Mark Rutland]

[ Upstream commit 58d245e03c324d083a0ec3b9ab8ebd46ec9848d7 ]

Add cputype definitions for Cortex-X1C. These will be used for errata
detection in subsequent patches.

These values can be found in the Cortex-X1C TRM:

  https://developer.arm.com/documentation/101968/0002/

... in section B2.107 ("MIDR_EL1, Main ID Register, EL1").

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20240801101803.1982459-2-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 1cb0704c6163f..5dc68ace305e5 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -86,6 +86,7 @@
 #define ARM_CPU_PART_CORTEX_X2		0xD48
 #define ARM_CPU_PART_NEOVERSE_N2	0xD49
 #define ARM_CPU_PART_CORTEX_A78C	0xD4B
+#define ARM_CPU_PART_CORTEX_X1C		0xD4C
 #define ARM_CPU_PART_CORTEX_X3		0xD4E
 #define ARM_CPU_PART_NEOVERSE_V2	0xD4F
 #define ARM_CPU_PART_CORTEX_A720	0xD81
@@ -165,6 +166,7 @@
 #define MIDR_CORTEX_X2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X2)
 #define MIDR_NEOVERSE_N2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_N2)
 #define MIDR_CORTEX_A78C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A78C)
+#define MIDR_CORTEX_X1C	MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X1C)
 #define MIDR_CORTEX_X3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X3)
 #define MIDR_NEOVERSE_V2 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V2)
 #define MIDR_CORTEX_A720 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A720)
-- 
2.30.2

[PATCH 6.6.y 12/13] arm64: cputype: Add Cortex-A725 definitions

[Mark Rutland]

[ Upstream commit 9ef54a384526911095db465e77acc1cb5266b32c ]

Add cputype definitions for Cortex-A725. These will be used for errata
detection in subsequent patches.

These values can be found in the Cortex-A725 TRM:

  https://developer.arm.com/documentation/107652/0001/

... in table A-247 ("MIDR_EL1 bit descriptions").

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20240801101803.1982459-3-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: trivial backport ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 arch/arm64/include/asm/cputype.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 5dc68ace305e5..5fd7caea44193 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -93,6 +93,7 @@
 #define ARM_CPU_PART_CORTEX_X4		0xD82
 #define ARM_CPU_PART_NEOVERSE_V3	0xD84
 #define ARM_CPU_PART_CORTEX_X925	0xD85
+#define ARM_CPU_PART_CORTEX_A725	0xD87
 
 #define APM_CPU_PART_XGENE		0x000
 #define APM_CPU_VAR_POTENZA		0x00
@@ -173,6 +174,7 @@
 #define MIDR_CORTEX_X4 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X4)
 #define MIDR_NEOVERSE_V3 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_NEOVERSE_V3)
 #define MIDR_CORTEX_X925 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_X925)
+#define MIDR_CORTEX_A725 MIDR_CPU_MODEL(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A725)
 #define MIDR_THUNDERX	MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX)
 #define MIDR_THUNDERX_81XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_81XX)
 #define MIDR_THUNDERX_83XX MIDR_CPU_MODEL(ARM_CPU_IMP_CAVIUM, CAVIUM_CPU_PART_THUNDERX_83XX)
-- 
2.30.2

[PATCH 6.6.y 13/13] arm64: errata: Expand speculative SSBS workaround (again)

[Mark Rutland]

[ Upstream commit b0672bbe133ebb6f7be21fce1d742d52f25bcdc7 ]

A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS
special-purpose register does not affect subsequent speculative
instructions, permitting speculative store bypassing for a window of
time.

We worked around this for a number of CPUs in commits:

* 7187bb7d0b5c7dfa ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
* 75b3c43eab594bfb ("arm64: errata: Expand speculative SSBS workaround")

Since then, similar errata have been published for a number of other Arm
Ltd CPUs, for which the same mitigation is sufficient. This is described
in their respective Software Developer Errata Notice (SDEN) documents:

* Cortex-A76 (MP052) SDEN v31.0, erratum 3324349
  https://developer.arm.com/documentation/SDEN-885749/3100/

* Cortex-A77 (MP074) SDEN v19.0, erratum 3324348
  https://developer.arm.com/documentation/SDEN-1152370/1900/

* Cortex-A78 (MP102) SDEN v21.0, erratum 3324344
  https://developer.arm.com/documentation/SDEN-1401784/2100/

* Cortex-A78C (MP138) SDEN v16.0, erratum 3324346
  https://developer.arm.com/documentation/SDEN-1707916/1600/

* Cortex-A78C (MP154) SDEN v10.0, erratum 3324347
  https://developer.arm.com/documentation/SDEN-2004089/1000/

* Cortex-A725 (MP190) SDEN v5.0, erratum 3456106
  https://developer.arm.com/documentation/SDEN-2832921/0500/

* Cortex-X1 (MP077) SDEN v21.0, erratum 3324344
  https://developer.arm.com/documentation/SDEN-1401782/2100/

* Cortex-X1C (MP136) SDEN v16.0, erratum 3324346
  https://developer.arm.com/documentation/SDEN-1707914/1600/

* Neoverse-N1 (MP050) SDEN v32.0, erratum 3324349
  https://developer.arm.com/documentation/SDEN-885747/3200/

* Neoverse-V1 (MP076) SDEN v19.0, erratum 3324341
  https://developer.arm.com/documentation/SDEN-1401781/1900/

Note that due to the manner in which Arm develops IP and tracks errata,
some CPUs share a common erratum number and some CPUs have multiple
erratum numbers for the same HW issue.

On parts without SB, it is necessary to use ISB for the workaround. The
spec_bar() macro used in the mitigation will expand to a "DSB SY; ISB"
sequence in this case, which is sufficient on all affected parts.

Enable the existing mitigation by adding the relevant MIDRs to
erratum_spec_ssbs_list. The list is sorted alphanumerically (involving
moving Neoverse-V3 after Neoverse-V2) so that this is easy to audit and
potentially extend again in future. The Kconfig text is also updated to
clarify the set of affected parts and the mitigation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20240801101803.1982459-4-mark.rutland@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
[ Mark: fix conflicts in silicon-errata.rst ]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
---
 Documentation/arch/arm64/silicon-errata.rst | 18 +++++++++++++++++
 arch/arm64/Kconfig                          | 22 +++++++++++++++------
 arch/arm64/kernel/cpu_errata.c              | 11 ++++++++++-
 3 files changed, 44 insertions(+), 7 deletions(-)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index 0bab767f6887c..357d6cb98161f 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -119,8 +119,16 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A76      | #1463225        | ARM64_ERRATUM_1463225       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A76      | #3324349        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A77      | #1508412        | ARM64_ERRATUM_1508412       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A77      | #3324348        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A78      | #3324344        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A78C     | #3324346,3324347| ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A710     | #2119858        | ARM64_ERRATUM_2119858       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A710     | #2054223        | ARM64_ERRATUM_2054223       |
@@ -133,6 +141,12 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A720     | #3456091        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A725     | #3456106        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X1       | #3324344        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-X1C      | #3324346        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2119858        | ARM64_ERRATUM_2119858       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-X2       | #2224489        | ARM64_ERRATUM_2224489       |
@@ -151,6 +165,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N1     | #1542419        | ARM64_ERRATUM_1542419       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-N1     | #3324349        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #2139208        | ARM64_ERRATUM_2139208       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #2067961        | ARM64_ERRATUM_2067961       |
@@ -159,6 +175,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #3324339        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-V1     | #3324341        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-V2     | #3324336        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-V3     | #3312417        | ARM64_ERRATUM_3194386       |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index e80812a4002bb..9e0c1ac3d13ee 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1069,18 +1069,28 @@ config ARM64_ERRATUM_3117295
 	  If unsure, say Y.
 
 config ARM64_ERRATUM_3194386
-	bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
+	bool "Cortex-*/Neoverse-*: workaround for MSR SSBS not self-synchronizing"
 	default y
 	help
 	  This option adds the workaround for the following errata:
 
+	  * ARM Cortex-A76 erratum 3324349
+	  * ARM Cortex-A77 erratum 3324348
+	  * ARM Cortex-A78 erratum 3324344
+	  * ARM Cortex-A78C erratum 3324346
+	  * ARM Cortex-A78C erratum 3324347
 	  * ARM Cortex-A710 erratam 3324338
 	  * ARM Cortex-A720 erratum 3456091
+	  * ARM Cortex-A725 erratum 3456106
+	  * ARM Cortex-X1 erratum 3324344
+	  * ARM Cortex-X1C erratum 3324346
 	  * ARM Cortex-X2 erratum 3324338
 	  * ARM Cortex-X3 erratum 3324335
 	  * ARM Cortex-X4 erratum 3194386
 	  * ARM Cortex-X925 erratum 3324334
+	  * ARM Neoverse-N1 erratum 3324349
 	  * ARM Neoverse N2 erratum 3324339
+	  * ARM Neoverse-V1 erratum 3324341
 	  * ARM Neoverse V2 erratum 3324336
 	  * ARM Neoverse-V3 erratum 3312417
 
@@ -1088,11 +1098,11 @@ config ARM64_ERRATUM_3194386
 	  subsequent speculative instructions, which may permit unexepected
 	  speculative store bypassing.
 
-	  Work around this problem by placing a speculation barrier after
-	  kernel changes to SSBS. The presence of the SSBS special-purpose
-	  register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
-	  that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
-	  SSBS.
+	  Work around this problem by placing a Speculation Barrier (SB) or
+	  Instruction Synchronization Barrier (ISB) after kernel changes to
+	  SSBS. The presence of the SSBS special-purpose register is hidden
+	  from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such that userspace
+	  will use the PR_SPEC_STORE_BYPASS prctl to change SSBS.
 
 	  If unsure, say Y.
 
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index bfe324854e3b5..57b1d6a68256b 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -450,15 +450,24 @@ static const struct midr_range erratum_spec_unpriv_load_list[] = {
 
 #ifdef CONFIG_ARM64_ERRATUM_3194386
 static const struct midr_range erratum_spec_ssbs_list[] = {
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A76),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A77),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A78),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A78C),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_A710),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_A720),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_A725),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X1),
+	MIDR_ALL_VERSIONS(MIDR_CORTEX_X1C),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X2),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X3),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X4),
 	MIDR_ALL_VERSIONS(MIDR_CORTEX_X925),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N1),
 	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2),
-	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V1),
 	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2),
+	MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3),
 	{}
 };
 #endif
-- 
2.30.2

Re: [PATCH 6.6.y 13/13] arm64: errata: Expand speculative SSBS workaround (again)

[Greg KH]

On Fri, Aug 09, 2024 at 10:57:45AM +0100, Mark Rutland wrote:
> [ Upstream commit b0672bbe133ebb6f7be21fce1d742d52f25bcdc7 ]

Now I figured it out, this is the wrong git id, and is not in any tree
anywhere.  It should be adeec61a4723fd3e39da68db4cc4d924e6d7f641.

I'll go hand-edit it now...

greg k-h

Re: [PATCH 6.6.y 13/13] arm64: errata: Expand speculative SSBS workaround (again)

[Mark Rutland]

On Mon, Aug 12, 2024 at 05:03:45PM +0200, Greg KH wrote:
> On Fri, Aug 09, 2024 at 10:57:45AM +0100, Mark Rutland wrote:
> > [ Upstream commit b0672bbe133ebb6f7be21fce1d742d52f25bcdc7 ]
> 
> Now I figured it out, this is the wrong git id, and is not in any tree
> anywhere.  It should be adeec61a4723fd3e39da68db4cc4d924e6d7f641.
> 
> I'll go hand-edit it now...

Thanks, and sorry about that.

Looking in my local tree, the incorrect commit id is a copy of
adeec61a4723fd3e39da68db4cc4d924e6d7f641 where the earlier commits had
been updated with "[ Upstream commit XXX ]" wording. Evidently I grabbed
the commit ID from the wrong branch when I was folding that in.

I'll try to make sure that doesn't happen again. Is there any public
tooling for sanity-checking this?

Mark.

Re: [PATCH 6.6.y 13/13] arm64: errata: Expand speculative SSBS workaround (again)

[Greg KH]

On Thu, Aug 15, 2024 at 03:51:41PM +0100, Mark Rutland wrote:
> On Mon, Aug 12, 2024 at 05:03:45PM +0200, Greg KH wrote:
> > On Fri, Aug 09, 2024 at 10:57:45AM +0100, Mark Rutland wrote:
> > > [ Upstream commit b0672bbe133ebb6f7be21fce1d742d52f25bcdc7 ]
> > 
> > Now I figured it out, this is the wrong git id, and is not in any tree
> > anywhere.  It should be adeec61a4723fd3e39da68db4cc4d924e6d7f641.
> > 
> > I'll go hand-edit it now...
> 
> Thanks, and sorry about that.
> 
> Looking in my local tree, the incorrect commit id is a copy of
> adeec61a4723fd3e39da68db4cc4d924e6d7f641 where the earlier commits had
> been updated with "[ Upstream commit XXX ]" wording. Evidently I grabbed
> the commit ID from the wrong branch when I was folding that in.
> 
> I'll try to make sure that doesn't happen again. Is there any public
> tooling for sanity-checking this?

Not that I know of :(