[PATCH AUTOSEL 6.14 178/642] hwmon: (dell-smm) Increment the number of fans

[PATCH AUTOSEL 6.14 178/642] hwmon: (dell-smm) Increment the number of fans

[Sasha Levin]

From: Kurt Borja <kuurtb@gmail.com>

[ Upstream commit dbcfcb239b3b452ef8782842c36fb17dd1b9092f ]

Some Alienware laptops that support the SMM interface, may have up to 4
fans.

Tested on an Alienware x15 r1.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
Link: https://lore.kernel.org/r/20250304055249.51940-2-kuurtb@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/hwmon/dell-smm-hwmon.rst | 14 +++++++-------
 drivers/hwmon/dell-smm-hwmon.c         |  5 ++++-
 2 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/Documentation/hwmon/dell-smm-hwmon.rst b/Documentation/hwmon/dell-smm-hwmon.rst
index 74905675d71f9..5a4edb6565cf9 100644
--- a/Documentation/hwmon/dell-smm-hwmon.rst
+++ b/Documentation/hwmon/dell-smm-hwmon.rst
@@ -32,12 +32,12 @@ Temperature sensors and fans can be queried and set via the standard
 =============================== ======= =======================================
 Name				Perm	Description
 =============================== ======= =======================================
-fan[1-3]_input                  RO      Fan speed in RPM.
-fan[1-3]_label                  RO      Fan label.
-fan[1-3]_min                    RO      Minimal Fan speed in RPM
-fan[1-3]_max                    RO      Maximal Fan speed in RPM
-fan[1-3]_target                 RO      Expected Fan speed in RPM
-pwm[1-3]                        RW      Control the fan PWM duty-cycle.
+fan[1-4]_input                  RO      Fan speed in RPM.
+fan[1-4]_label                  RO      Fan label.
+fan[1-4]_min                    RO      Minimal Fan speed in RPM
+fan[1-4]_max                    RO      Maximal Fan speed in RPM
+fan[1-4]_target                 RO      Expected Fan speed in RPM
+pwm[1-4]                        RW      Control the fan PWM duty-cycle.
 pwm1_enable                     WO      Enable or disable automatic BIOS fan
                                         control (not supported on all laptops,
                                         see below for details).
@@ -93,7 +93,7 @@ Again, when you find new codes, we'd be happy to have your patches!
 ---------------------------
 
 The driver also exports the fans as thermal cooling devices with
-``type`` set to ``dell-smm-fan[1-3]``. This allows for easy fan control
+``type`` set to ``dell-smm-fan[1-4]``. This allows for easy fan control
 using one of the thermal governors.
 
 Module parameters
diff --git a/drivers/hwmon/dell-smm-hwmon.c b/drivers/hwmon/dell-smm-hwmon.c
index cd00adaad1b41..79e5606e6d2f8 100644
--- a/drivers/hwmon/dell-smm-hwmon.c
+++ b/drivers/hwmon/dell-smm-hwmon.c
@@ -73,7 +73,7 @@
 #define DELL_SMM_LEGACY_EXECUTE	0x1
 
 #define DELL_SMM_NO_TEMP	10
-#define DELL_SMM_NO_FANS	3
+#define DELL_SMM_NO_FANS	4
 
 struct smm_regs {
 	unsigned int eax;
@@ -1074,11 +1074,14 @@ static const struct hwmon_channel_info * const dell_smm_info[] = {
 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
 			   HWMON_F_TARGET,
 			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
+			   HWMON_F_TARGET,
+			   HWMON_F_INPUT | HWMON_F_LABEL | HWMON_F_MIN | HWMON_F_MAX |
 			   HWMON_F_TARGET
 			   ),
 	HWMON_CHANNEL_INFO(pwm,
 			   HWMON_PWM_INPUT | HWMON_PWM_ENABLE,
 			   HWMON_PWM_INPUT,
+			   HWMON_PWM_INPUT,
 			   HWMON_PWM_INPUT
 			   ),
 	NULL
-- 
2.39.5

[PATCH AUTOSEL 6.14 283/642] x86/bugs: Make spectre user default depend on MITIGATION_SPECTRE_V2

[Sasha Levin]

From: Breno Leitao <leitao@debian.org>

[ Upstream commit 98fdaeb296f51ef08e727a7cc72e5b5c864c4f4d ]

Change the default value of spectre v2 in user mode to respect the
CONFIG_MITIGATION_SPECTRE_V2 config option.

Currently, user mode spectre v2 is set to auto
(SPECTRE_V2_USER_CMD_AUTO) by default, even if
CONFIG_MITIGATION_SPECTRE_V2 is disabled.

Set the spectre_v2 value to auto (SPECTRE_V2_USER_CMD_AUTO) if the
Spectre v2 config (CONFIG_MITIGATION_SPECTRE_V2) is enabled, otherwise
set the value to none (SPECTRE_V2_USER_CMD_NONE).

Important to say the command line argument "spectre_v2_user" overwrites
the default value in both cases.

When CONFIG_MITIGATION_SPECTRE_V2 is not set, users have the flexibility
to opt-in for specific mitigations independently. In this scenario,
setting spectre_v2= will not enable spectre_v2_user=, and command line
options spectre_v2_user and spectre_v2 are independent when
CONFIG_MITIGATION_SPECTRE_V2=n.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David Kaplan <David.Kaplan@amd.com>
Link: https://lore.kernel.org/r/20241031-x86_bugs_last_v2-v2-2-b7ff1dab840e@debian.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/admin-guide/kernel-parameters.txt |  2 ++
 arch/x86/kernel/cpu/bugs.c                      | 10 +++++++---
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 56be1fc99bdd4..fef456a990f45 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -6584,6 +6584,8 @@
 
 			Selecting 'on' will also enable the mitigation
 			against user space to user space task attacks.
+			Selecting specific mitigation does not force enable
+			user mitigations.
 
 			Selecting 'off' will disable both the kernel and
 			the user space protections.
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 9152285aaaf96..4f9898836da13 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -1293,9 +1293,13 @@ static __ro_after_init enum spectre_v2_mitigation_cmd spectre_v2_cmd;
 static enum spectre_v2_user_cmd __init
 spectre_v2_parse_user_cmdline(void)
 {
+	enum spectre_v2_user_cmd mode;
 	char arg[20];
 	int ret, i;
 
+	mode = IS_ENABLED(CONFIG_MITIGATION_SPECTRE_V2) ?
+		SPECTRE_V2_USER_CMD_AUTO : SPECTRE_V2_USER_CMD_NONE;
+
 	switch (spectre_v2_cmd) {
 	case SPECTRE_V2_CMD_NONE:
 		return SPECTRE_V2_USER_CMD_NONE;
@@ -1308,7 +1312,7 @@ spectre_v2_parse_user_cmdline(void)
 	ret = cmdline_find_option(boot_command_line, "spectre_v2_user",
 				  arg, sizeof(arg));
 	if (ret < 0)
-		return SPECTRE_V2_USER_CMD_AUTO;
+		return mode;
 
 	for (i = 0; i < ARRAY_SIZE(v2_user_options); i++) {
 		if (match_option(arg, ret, v2_user_options[i].option)) {
@@ -1318,8 +1322,8 @@ spectre_v2_parse_user_cmdline(void)
 		}
 	}
 
-	pr_err("Unknown user space protection option (%s). Switching to AUTO select\n", arg);
-	return SPECTRE_V2_USER_CMD_AUTO;
+	pr_err("Unknown user space protection option (%s). Switching to default\n", arg);
+	return mode;
 }
 
 static inline bool spectre_v2_in_ibrs_mode(enum spectre_v2_mitigation mode)
-- 
2.39.5

[PATCH AUTOSEL 6.14 313/642] tcp: be less liberal in TSEcr received while in SYN_RECV state

[Sasha Levin]

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 3ba075278c11cdb19e2dbb80362042f1b0c08f74 ]

Yong-Hao Zou mentioned that linux was not strict as other OS in 3WHS,
for flows using TCP TS option (RFC 7323)

As hinted by an old comment in tcp_check_req(),
we can check the TSEcr value in the incoming packet corresponds
to one of the SYNACK TSval values we have sent.

In this patch, I record the oldest and most recent values
that SYNACK packets have used.

Send a challenge ACK if we receive a TSEcr outside
of this range, and increase a new SNMP counter.

nstat -az | grep TSEcrRejected
TcpExtTSEcrRejected            0                  0.0

Due to TCP fastopen implementation, do not apply yet these checks
for fastopen flows.

v2: No longer use req->num_timeout, but treq->snt_tsval_first
    to detect when first SYNACK is prepared. This means
    we make sure to not send an initial zero TSval.
    Make sure MPTCP and TCP selftests are passing.
    Change MIB name to TcpExtTSEcrRejected

v1: https://lore.kernel.org/netdev/CADVnQykD8i4ArpSZaPKaoNxLJ2if2ts9m4As+=Jvdkrgx1qMHw@mail.gmail.com/T/

Reported-by: Yong-Hao Zou <yonghaoz1994@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250225171048.3105061-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../networking/net_cachelines/snmp.rst        |  1 +
 include/linux/tcp.h                           |  2 ++
 include/uapi/linux/snmp.h                     |  1 +
 net/ipv4/proc.c                               |  1 +
 net/ipv4/syncookies.c                         |  1 +
 net/ipv4/tcp_input.c                          |  1 +
 net/ipv4/tcp_minisocks.c                      | 26 +++++++++++--------
 net/ipv4/tcp_output.c                         |  6 +++++
 8 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/Documentation/networking/net_cachelines/snmp.rst b/Documentation/networking/net_cachelines/snmp.rst
index 90ca2d92547d4..bc96efc92cf5b 100644
--- a/Documentation/networking/net_cachelines/snmp.rst
+++ b/Documentation/networking/net_cachelines/snmp.rst
@@ -36,6 +36,7 @@ unsigned_long  LINUX_MIB_TIMEWAITRECYCLED
 unsigned_long  LINUX_MIB_TIMEWAITKILLED
 unsigned_long  LINUX_MIB_PAWSACTIVEREJECTED
 unsigned_long  LINUX_MIB_PAWSESTABREJECTED
+unsigned_long  LINUX_MIB_TSECR_REJECTED
 unsigned_long  LINUX_MIB_DELAYEDACKLOST
 unsigned_long  LINUX_MIB_LISTENOVERFLOWS
 unsigned_long  LINUX_MIB_LISTENDROPS
diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index f88daaa76d836..159b2c59eb627 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -160,6 +160,8 @@ struct tcp_request_sock {
 	u32				rcv_isn;
 	u32				snt_isn;
 	u32				ts_off;
+	u32				snt_tsval_first;
+	u32				snt_tsval_last;
 	u32				last_oow_ack_time; /* last SYNACK */
 	u32				rcv_nxt; /* the ack # by SYNACK. For
 						  * FastOpen it's the seq#
diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h
index 848c7784e684c..eb9fb776fdc3e 100644
--- a/include/uapi/linux/snmp.h
+++ b/include/uapi/linux/snmp.h
@@ -186,6 +186,7 @@ enum
 	LINUX_MIB_TIMEWAITKILLED,		/* TimeWaitKilled */
 	LINUX_MIB_PAWSACTIVEREJECTED,		/* PAWSActiveRejected */
 	LINUX_MIB_PAWSESTABREJECTED,		/* PAWSEstabRejected */
+	LINUX_MIB_TSECRREJECTED,		/* TSEcrRejected */
 	LINUX_MIB_PAWS_OLD_ACK,			/* PAWSOldAck */
 	LINUX_MIB_DELAYEDACKS,			/* DelayedACKs */
 	LINUX_MIB_DELAYEDACKLOCKED,		/* DelayedACKLocked */
diff --git a/net/ipv4/proc.c b/net/ipv4/proc.c
index affd21a0f5728..10cbeb76c2745 100644
--- a/net/ipv4/proc.c
+++ b/net/ipv4/proc.c
@@ -189,6 +189,7 @@ static const struct snmp_mib snmp4_net_list[] = {
 	SNMP_MIB_ITEM("TWKilled", LINUX_MIB_TIMEWAITKILLED),
 	SNMP_MIB_ITEM("PAWSActive", LINUX_MIB_PAWSACTIVEREJECTED),
 	SNMP_MIB_ITEM("PAWSEstab", LINUX_MIB_PAWSESTABREJECTED),
+	SNMP_MIB_ITEM("TSEcrRejected", LINUX_MIB_TSECRREJECTED),
 	SNMP_MIB_ITEM("PAWSOldAck", LINUX_MIB_PAWS_OLD_ACK),
 	SNMP_MIB_ITEM("DelayedACKs", LINUX_MIB_DELAYEDACKS),
 	SNMP_MIB_ITEM("DelayedACKLocked", LINUX_MIB_DELAYEDACKLOCKED),
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 1948d15f1f281..25976fa7768c9 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -279,6 +279,7 @@ static int cookie_tcp_reqsk_init(struct sock *sk, struct sk_buff *skb,
 		ireq->smc_ok = 0;
 
 	treq->snt_synack = 0;
+	treq->snt_tsval_first = 0;
 	treq->tfo_listener = false;
 	treq->txhash = net_tx_rndhash();
 	treq->rcv_isn = ntohl(th->seq) - 1;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 23cf8f4a37214..1b09b4d76c296 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -7089,6 +7089,7 @@ static void tcp_openreq_init(struct request_sock *req,
 	tcp_rsk(req)->rcv_isn = TCP_SKB_CB(skb)->seq;
 	tcp_rsk(req)->rcv_nxt = TCP_SKB_CB(skb)->seq + 1;
 	tcp_rsk(req)->snt_synack = 0;
+	tcp_rsk(req)->snt_tsval_first = 0;
 	tcp_rsk(req)->last_oow_ack_time = 0;
 	req->mss = rx_opt->mss_clamp;
 	req->ts_recent = rx_opt->saw_tstamp ? rx_opt->rcv_tsval : 0;
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
index dfdb7a4608a85..0d4ff5f2352f8 100644
--- a/net/ipv4/tcp_minisocks.c
+++ b/net/ipv4/tcp_minisocks.c
@@ -665,6 +665,7 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 	struct sock *child;
 	const struct tcphdr *th = tcp_hdr(skb);
 	__be32 flg = tcp_flag_word(th) & (TCP_FLAG_RST|TCP_FLAG_SYN|TCP_FLAG_ACK);
+	bool tsecr_reject = false;
 	bool paws_reject = false;
 	bool own_req;
 
@@ -674,8 +675,13 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 
 		if (tmp_opt.saw_tstamp) {
 			tmp_opt.ts_recent = READ_ONCE(req->ts_recent);
-			if (tmp_opt.rcv_tsecr)
+			if (tmp_opt.rcv_tsecr) {
+				if (inet_rsk(req)->tstamp_ok && !fastopen)
+					tsecr_reject = !between(tmp_opt.rcv_tsecr,
+							tcp_rsk(req)->snt_tsval_first,
+							READ_ONCE(tcp_rsk(req)->snt_tsval_last));
 				tmp_opt.rcv_tsecr -= tcp_rsk(req)->ts_off;
+			}
 			/* We do not store true stamp, but it is not required,
 			 * it can be estimated (approximately)
 			 * from another data.
@@ -790,18 +796,14 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 	     tcp_rsk(req)->snt_isn + 1))
 		return sk;
 
-	/* Also, it would be not so bad idea to check rcv_tsecr, which
-	 * is essentially ACK extension and too early or too late values
-	 * should cause reset in unsynchronized states.
-	 */
-
 	/* RFC793: "first check sequence number". */
 
-	if (paws_reject || !tcp_in_window(TCP_SKB_CB(skb)->seq,
-					  TCP_SKB_CB(skb)->end_seq,
-					  tcp_rsk(req)->rcv_nxt,
-					  tcp_rsk(req)->rcv_nxt +
-					  tcp_synack_window(req))) {
+	if (paws_reject || tsecr_reject ||
+	    !tcp_in_window(TCP_SKB_CB(skb)->seq,
+			   TCP_SKB_CB(skb)->end_seq,
+			   tcp_rsk(req)->rcv_nxt,
+			   tcp_rsk(req)->rcv_nxt +
+			   tcp_synack_window(req))) {
 		/* Out of window: send ACK and drop. */
 		if (!(flg & TCP_FLAG_RST) &&
 		    !tcp_oow_rate_limited(sock_net(sk), skb,
@@ -810,6 +812,8 @@ struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
 			req->rsk_ops->send_ack(sk, skb, req);
 		if (paws_reject)
 			NET_INC_STATS(sock_net(sk), LINUX_MIB_PAWSESTABREJECTED);
+		else if (tsecr_reject)
+			NET_INC_STATS(sock_net(sk), LINUX_MIB_TSECRREJECTED);
 		return NULL;
 	}
 
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index bc95d2a5924fd..6031d7f7f5198 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -941,6 +941,12 @@ static unsigned int tcp_synack_options(const struct sock *sk,
 		opts->options |= OPTION_TS;
 		opts->tsval = tcp_skb_timestamp_ts(tcp_rsk(req)->req_usec_ts, skb) +
 			      tcp_rsk(req)->ts_off;
+		if (!tcp_rsk(req)->snt_tsval_first) {
+			if (!opts->tsval)
+				opts->tsval = ~0U;
+			tcp_rsk(req)->snt_tsval_first = opts->tsval;
+		}
+		WRITE_ONCE(tcp_rsk(req)->snt_tsval_last, opts->tsval);
 		opts->tsecr = READ_ONCE(req->ts_recent);
 		remaining -= TCPOLEN_TSTAMP_ALIGNED;
 	}
-- 
2.39.5

[PATCH AUTOSEL 6.14 317/642] x86/bugs: KVM: Add support for SRSO_MSR_FIX

[Sasha Levin]

From: Borislav Petkov <bp@alien8.de>

[ Upstream commit 8442df2b49ed9bcd67833ad4f091d15ac91efd00 ]

Add support for

  CPUID Fn8000_0021_EAX[31] (SRSO_MSR_FIX). If this bit is 1, it
  indicates that software may use MSR BP_CFG[BpSpecReduce] to mitigate
  SRSO.

Enable BpSpecReduce to mitigate SRSO across guest/host boundaries.

Switch back to enabling the bit when virtualization is enabled and to
clear the bit when virtualization is disabled because using a MSR slot
would clear the bit when the guest is exited and any training the guest
has done, would potentially influence the host kernel when execution
enters the kernel and hasn't VMRUN the guest yet.

More detail on the public thread in Link below.

Co-developed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20241202120416.6054-1-bp@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/admin-guide/hw-vuln/srso.rst | 13 ++++++++++++
 arch/x86/include/asm/cpufeatures.h         |  4 ++++
 arch/x86/include/asm/msr-index.h           |  1 +
 arch/x86/kernel/cpu/bugs.c                 | 24 ++++++++++++++++++----
 arch/x86/kvm/svm/svm.c                     |  6 ++++++
 arch/x86/lib/msr.c                         |  2 ++
 6 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/Documentation/admin-guide/hw-vuln/srso.rst b/Documentation/admin-guide/hw-vuln/srso.rst
index 2ad1c05b8c883..66af95251a3d1 100644
--- a/Documentation/admin-guide/hw-vuln/srso.rst
+++ b/Documentation/admin-guide/hw-vuln/srso.rst
@@ -104,7 +104,20 @@ The possible values in this file are:
 
    (spec_rstack_overflow=ibpb-vmexit)
 
+ * 'Mitigation: Reduced Speculation':
 
+   This mitigation gets automatically enabled when the above one "IBPB on
+   VMEXIT" has been selected and the CPU supports the BpSpecReduce bit.
+
+   It gets automatically enabled on machines which have the
+   SRSO_USER_KERNEL_NO=1 CPUID bit. In that case, the code logic is to switch
+   to the above =ibpb-vmexit mitigation because the user/kernel boundary is
+   not affected anymore and thus "safe RET" is not needed.
+
+   After enabling the IBPB on VMEXIT mitigation option, the BpSpecReduce bit
+   is detected (functionality present on all such machines) and that
+   practically overrides IBPB on VMEXIT as it has a lot less performance
+   impact and takes care of the guest->host attack vector too.
 
 In order to exploit vulnerability, an attacker needs to:
 
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 508c0dad116bc..43653f2704c93 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -468,6 +468,10 @@
 #define X86_FEATURE_IBPB_BRTYPE		(20*32+28) /* MSR_PRED_CMD[IBPB] flushes all branch type predictions */
 #define X86_FEATURE_SRSO_NO		(20*32+29) /* CPU is not affected by SRSO */
 #define X86_FEATURE_SRSO_USER_KERNEL_NO	(20*32+30) /* CPU is not affected by SRSO across user/kernel boundaries */
+#define X86_FEATURE_SRSO_BP_SPEC_REDUCE	(20*32+31) /*
+						    * BP_CFG[BpSpecReduce] can be used to mitigate SRSO for VMs.
+						    * (SRSO_MSR_FIX in the official doc).
+						    */
 
 /*
  * Extended auxiliary flags: Linux defined - for features scattered in various
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 72765b2fe0d87..d35519b337ba2 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -721,6 +721,7 @@
 
 /* Zen4 */
 #define MSR_ZEN4_BP_CFG                 0xc001102e
+#define MSR_ZEN4_BP_CFG_BP_SPEC_REDUCE_BIT 4
 #define MSR_ZEN4_BP_CFG_SHARED_BTB_FIX_BIT 5
 
 /* Fam 19h MSRs */
diff --git a/arch/x86/kernel/cpu/bugs.c b/arch/x86/kernel/cpu/bugs.c
index 4f9898836da13..fee115316dd3e 100644
--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -2526,6 +2526,7 @@ enum srso_mitigation {
 	SRSO_MITIGATION_SAFE_RET,
 	SRSO_MITIGATION_IBPB,
 	SRSO_MITIGATION_IBPB_ON_VMEXIT,
+	SRSO_MITIGATION_BP_SPEC_REDUCE,
 };
 
 enum srso_mitigation_cmd {
@@ -2543,7 +2544,8 @@ static const char * const srso_strings[] = {
 	[SRSO_MITIGATION_MICROCODE]		= "Vulnerable: Microcode, no safe RET",
 	[SRSO_MITIGATION_SAFE_RET]		= "Mitigation: Safe RET",
 	[SRSO_MITIGATION_IBPB]			= "Mitigation: IBPB",
-	[SRSO_MITIGATION_IBPB_ON_VMEXIT]	= "Mitigation: IBPB on VMEXIT only"
+	[SRSO_MITIGATION_IBPB_ON_VMEXIT]	= "Mitigation: IBPB on VMEXIT only",
+	[SRSO_MITIGATION_BP_SPEC_REDUCE]	= "Mitigation: Reduced Speculation"
 };
 
 static enum srso_mitigation srso_mitigation __ro_after_init = SRSO_MITIGATION_NONE;
@@ -2582,7 +2584,7 @@ static void __init srso_select_mitigation(void)
 	    srso_cmd == SRSO_CMD_OFF) {
 		if (boot_cpu_has(X86_FEATURE_SBPB))
 			x86_pred_cmd = PRED_CMD_SBPB;
-		return;
+		goto out;
 	}
 
 	if (has_microcode) {
@@ -2594,7 +2596,7 @@ static void __init srso_select_mitigation(void)
 		 */
 		if (boot_cpu_data.x86 < 0x19 && !cpu_smt_possible()) {
 			setup_force_cpu_cap(X86_FEATURE_SRSO_NO);
-			return;
+			goto out;
 		}
 
 		if (retbleed_mitigation == RETBLEED_MITIGATION_IBPB) {
@@ -2674,6 +2676,12 @@ static void __init srso_select_mitigation(void)
 
 ibpb_on_vmexit:
 	case SRSO_CMD_IBPB_ON_VMEXIT:
+		if (boot_cpu_has(X86_FEATURE_SRSO_BP_SPEC_REDUCE)) {
+			pr_notice("Reducing speculation to address VM/HV SRSO attack vector.\n");
+			srso_mitigation = SRSO_MITIGATION_BP_SPEC_REDUCE;
+			break;
+		}
+
 		if (IS_ENABLED(CONFIG_MITIGATION_IBPB_ENTRY)) {
 			if (has_microcode) {
 				setup_force_cpu_cap(X86_FEATURE_IBPB_ON_VMEXIT);
@@ -2695,7 +2703,15 @@ static void __init srso_select_mitigation(void)
 	}
 
 out:
-	pr_info("%s\n", srso_strings[srso_mitigation]);
+	/*
+	 * Clear the feature flag if this mitigation is not selected as that
+	 * feature flag controls the BpSpecReduce MSR bit toggling in KVM.
+	 */
+	if (srso_mitigation != SRSO_MITIGATION_BP_SPEC_REDUCE)
+		setup_clear_cpu_cap(X86_FEATURE_SRSO_BP_SPEC_REDUCE);
+
+	if (srso_mitigation != SRSO_MITIGATION_NONE)
+		pr_info("%s\n", srso_strings[srso_mitigation]);
 }
 
 #undef pr_fmt
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index e67de787fc714..0660b85883de4 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -607,6 +607,9 @@ static void svm_disable_virtualization_cpu(void)
 	kvm_cpu_svm_disable();
 
 	amd_pmu_disable_virt();
+
+	if (cpu_feature_enabled(X86_FEATURE_SRSO_BP_SPEC_REDUCE))
+		msr_clear_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_BP_SPEC_REDUCE_BIT);
 }
 
 static int svm_enable_virtualization_cpu(void)
@@ -684,6 +687,9 @@ static int svm_enable_virtualization_cpu(void)
 		rdmsr(MSR_TSC_AUX, sev_es_host_save_area(sd)->tsc_aux, msr_hi);
 	}
 
+	if (cpu_feature_enabled(X86_FEATURE_SRSO_BP_SPEC_REDUCE))
+		msr_set_bit(MSR_ZEN4_BP_CFG, MSR_ZEN4_BP_CFG_BP_SPEC_REDUCE_BIT);
+
 	return 0;
 }
 
diff --git a/arch/x86/lib/msr.c b/arch/x86/lib/msr.c
index 4bf4fad5b148e..5a18ecc04a6c3 100644
--- a/arch/x86/lib/msr.c
+++ b/arch/x86/lib/msr.c
@@ -103,6 +103,7 @@ int msr_set_bit(u32 msr, u8 bit)
 {
 	return __flip_bit(msr, bit, true);
 }
+EXPORT_SYMBOL_GPL(msr_set_bit);
 
 /**
  * msr_clear_bit - Clear @bit in a MSR @msr.
@@ -118,6 +119,7 @@ int msr_clear_bit(u32 msr, u8 bit)
 {
 	return __flip_bit(msr, bit, false);
 }
+EXPORT_SYMBOL_GPL(msr_clear_bit);
 
 #ifdef CONFIG_TRACEPOINTS
 void do_trace_write_msr(unsigned int msr, u64 val, int failed)
-- 
2.39.5

Re: [PATCH AUTOSEL 6.14 317/642] x86/bugs: KVM: Add support for SRSO_MSR_FIX

[Sean Christopherson]

On Mon, May 05, 2025, Sasha Levin wrote:
> From: Borislav Petkov <bp@alien8.de>
> 
> [ Upstream commit 8442df2b49ed9bcd67833ad4f091d15ac91efd00 ]
> 
> Add support for
> 
>   CPUID Fn8000_0021_EAX[31] (SRSO_MSR_FIX). If this bit is 1, it
>   indicates that software may use MSR BP_CFG[BpSpecReduce] to mitigate
>   SRSO.
> 
> Enable BpSpecReduce to mitigate SRSO across guest/host boundaries.
> 
> Switch back to enabling the bit when virtualization is enabled and to
> clear the bit when virtualization is disabled because using a MSR slot
> would clear the bit when the guest is exited and any training the guest
> has done, would potentially influence the host kernel when execution
> enters the kernel and hasn't VMRUN the guest yet.
> 
> More detail on the public thread in Link below.
> 
> Co-developed-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Sean Christopherson <seanjc@google.com>
> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
> Link: https://lore.kernel.org/r/20241202120416.6054-1-bp@kernel.org
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---

Can we please hold off on this until the fix lands[1]?  This version introduces
a very measurable performance regression[2] for non-KVM use cases.

[1] https://lore.kernel.org/all/20250502223456.887618-1-seanjc@google.com
[2] https://www.phoronix.com/review/linux-615-amd-regression

Re: [PATCH AUTOSEL 6.14 317/642] x86/bugs: KVM: Add support for SRSO_MSR_FIX

[Sasha Levin]

On Mon, May 05, 2025 at 03:37:17PM -0700, Sean Christopherson wrote:
>On Mon, May 05, 2025, Sasha Levin wrote:
>> From: Borislav Petkov <bp@alien8.de>
>>
>> [ Upstream commit 8442df2b49ed9bcd67833ad4f091d15ac91efd00 ]
>>
>> Add support for
>>
>>   CPUID Fn8000_0021_EAX[31] (SRSO_MSR_FIX). If this bit is 1, it
>>   indicates that software may use MSR BP_CFG[BpSpecReduce] to mitigate
>>   SRSO.
>>
>> Enable BpSpecReduce to mitigate SRSO across guest/host boundaries.
>>
>> Switch back to enabling the bit when virtualization is enabled and to
>> clear the bit when virtualization is disabled because using a MSR slot
>> would clear the bit when the guest is exited and any training the guest
>> has done, would potentially influence the host kernel when execution
>> enters the kernel and hasn't VMRUN the guest yet.
>>
>> More detail on the public thread in Link below.
>>
>> Co-developed-by: Sean Christopherson <seanjc@google.com>
>> Signed-off-by: Sean Christopherson <seanjc@google.com>
>> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
>> Link: https://lore.kernel.org/r/20241202120416.6054-1-bp@kernel.org
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>
>Can we please hold off on this until the fix lands[1]?  This version introduces
>a very measurable performance regression[2] for non-KVM use cases.

Sure, I'll drop it. Thanks!

-- 
Thanks,
Sasha

[PATCH AUTOSEL 6.14 359/642] pps: generators: replace copy of pps-gen info struct with const pointer

[Sasha Levin]

From: Subramanian Mohan <subramanian.mohan@intel.com>

[ Upstream commit ac9c5170a18162d45c6edd1f0fa2d2b2504bc2cb ]

Some PPS generator drivers may need to retrieve a pointer to their
internal data while executing the PPS generator enable() method.

During the driver registration the pps_gen_device pointer is returned
from the framework, and for that reason, there is difficulty in
getting generator driver data back in the enable function. We won't be
able to use container_of macro as it results in static assert, and we
might end up in using static pointer.

To solve the issue and to get back the generator driver data back, we
should not copy the struct pps_gen_source_info within the struct
pps_gen_device during the registration stage, but simply save the
pointer of the driver one. In this manner, driver may get a pointer
to their internal data as shown below:

struct pps_gen_foo_data_s {
        ...
	struct pps_gen_source_info gen_info;
	struct pps_gen_device *pps_gen;
	...
};

static int __init pps_gen_foo_init(void)
{
        struct pps_gen_foo_data_s *foo;
	...
        foo->pps_gen = pps_gen_register_source(&foo->gen_info);
	...
}

Then, in the enable() method, we can retrieve the pointer to the main
struct by using the code below:

static int pps_gen_foo_enable(struct pps_gen_device *pps_gen, bool enable)
{
        struct pps_gen_foo_data_s *foo = container_of(pps_gen->info,
						struct pps_gen_foo_data_s, gen_info);
        ...
}

Signed-off-by: Rodolfo Giometti <giometti@enneenne.com>
Tested-by: Subramanian Mohan <subramanian.mohan@intel.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Subramanian Mohan <subramanian.mohan@intel.com>
Link: https://lore.kernel.org/r/20250219040618.70962-2-subramanian.mohan@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/driver-api/pps.rst       |  3 +--
 drivers/pps/generators/pps_gen-dummy.c |  2 +-
 drivers/pps/generators/pps_gen.c       | 14 +++++++-------
 drivers/pps/generators/sysfs.c         |  6 +++---
 include/linux/pps_gen_kernel.h         |  4 ++--
 5 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/Documentation/driver-api/pps.rst b/Documentation/driver-api/pps.rst
index 71ad04c82d6cf..04f1b88778fc5 100644
--- a/Documentation/driver-api/pps.rst
+++ b/Documentation/driver-api/pps.rst
@@ -206,8 +206,7 @@ To do so the class pps-gen has been added. PPS generators can be
 registered in the kernel by defining a struct pps_gen_source_info as
 follows::
 
-    static struct pps_gen_source_info pps_gen_dummy_info = {
-            .name                   = "dummy",
+    static const struct pps_gen_source_info pps_gen_dummy_info = {
             .use_system_clock       = true,
             .get_time               = pps_gen_dummy_get_time,
             .enable                 = pps_gen_dummy_enable,
diff --git a/drivers/pps/generators/pps_gen-dummy.c b/drivers/pps/generators/pps_gen-dummy.c
index b284c200cbe50..55de4aecf35ed 100644
--- a/drivers/pps/generators/pps_gen-dummy.c
+++ b/drivers/pps/generators/pps_gen-dummy.c
@@ -61,7 +61,7 @@ static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enable)
  * The PPS info struct
  */
 
-static struct pps_gen_source_info pps_gen_dummy_info = {
+static const struct pps_gen_source_info pps_gen_dummy_info = {
 	.use_system_clock	= true,
 	.get_time		= pps_gen_dummy_get_time,
 	.enable			= pps_gen_dummy_enable,
diff --git a/drivers/pps/generators/pps_gen.c b/drivers/pps/generators/pps_gen.c
index ca592f1736f46..5b8bb454913cd 100644
--- a/drivers/pps/generators/pps_gen.c
+++ b/drivers/pps/generators/pps_gen.c
@@ -66,7 +66,7 @@ static long pps_gen_cdev_ioctl(struct file *file,
 		if (ret)
 			return -EFAULT;
 
-		ret = pps_gen->info.enable(pps_gen, status);
+		ret = pps_gen->info->enable(pps_gen, status);
 		if (ret)
 			return ret;
 		pps_gen->enabled = status;
@@ -76,7 +76,7 @@ static long pps_gen_cdev_ioctl(struct file *file,
 	case PPS_GEN_USESYSTEMCLOCK:
 		dev_dbg(pps_gen->dev, "PPS_GEN_USESYSTEMCLOCK\n");
 
-		ret = put_user(pps_gen->info.use_system_clock, uiuarg);
+		ret = put_user(pps_gen->info->use_system_clock, uiuarg);
 		if (ret)
 			return -EFAULT;
 
@@ -175,7 +175,7 @@ static int pps_gen_register_cdev(struct pps_gen_device *pps_gen)
 	devt = MKDEV(MAJOR(pps_gen_devt), pps_gen->id);
 
 	cdev_init(&pps_gen->cdev, &pps_gen_cdev_fops);
-	pps_gen->cdev.owner = pps_gen->info.owner;
+	pps_gen->cdev.owner = pps_gen->info->owner;
 
 	err = cdev_add(&pps_gen->cdev, devt, 1);
 	if (err) {
@@ -183,8 +183,8 @@ static int pps_gen_register_cdev(struct pps_gen_device *pps_gen)
 				MAJOR(pps_gen_devt), pps_gen->id);
 		goto free_ida;
 	}
-	pps_gen->dev = device_create(pps_gen_class, pps_gen->info.parent, devt,
-					pps_gen, "pps-gen%d", pps_gen->id);
+	pps_gen->dev = device_create(pps_gen_class, pps_gen->info->parent, devt,
+				     pps_gen, "pps-gen%d", pps_gen->id);
 	if (IS_ERR(pps_gen->dev)) {
 		err = PTR_ERR(pps_gen->dev);
 		goto del_cdev;
@@ -225,7 +225,7 @@ static void pps_gen_unregister_cdev(struct pps_gen_device *pps_gen)
  * Return: the PPS generator device in case of success, and ERR_PTR(errno)
  *	 otherwise.
  */
-struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info)
+struct pps_gen_device *pps_gen_register_source(const struct pps_gen_source_info *info)
 {
 	struct pps_gen_device *pps_gen;
 	int err;
@@ -235,7 +235,7 @@ struct pps_gen_device *pps_gen_register_source(struct pps_gen_source_info *info)
 		err = -ENOMEM;
 		goto pps_gen_register_source_exit;
 	}
-	pps_gen->info = *info;
+	pps_gen->info = info;
 	pps_gen->enabled = false;
 
 	init_waitqueue_head(&pps_gen->queue);
diff --git a/drivers/pps/generators/sysfs.c b/drivers/pps/generators/sysfs.c
index faf8b1c6d2026..6d6bc0006feae 100644
--- a/drivers/pps/generators/sysfs.c
+++ b/drivers/pps/generators/sysfs.c
@@ -19,7 +19,7 @@ static ssize_t system_show(struct device *dev, struct device_attribute *attr,
 {
 	struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
 
-	return sysfs_emit(buf, "%d\n", pps_gen->info.use_system_clock);
+	return sysfs_emit(buf, "%d\n", pps_gen->info->use_system_clock);
 }
 static DEVICE_ATTR_RO(system);
 
@@ -30,7 +30,7 @@ static ssize_t time_show(struct device *dev, struct device_attribute *attr,
 	struct timespec64 time;
 	int ret;
 
-	ret = pps_gen->info.get_time(pps_gen, &time);
+	ret = pps_gen->info->get_time(pps_gen, &time);
 	if (ret)
 		return ret;
 
@@ -49,7 +49,7 @@ static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
 	if (ret)
 		return ret;
 
-	ret = pps_gen->info.enable(pps_gen, status);
+	ret = pps_gen->info->enable(pps_gen, status);
 	if (ret)
 		return ret;
 	pps_gen->enabled = status;
diff --git a/include/linux/pps_gen_kernel.h b/include/linux/pps_gen_kernel.h
index 022ea0ac44402..6214c8aa2e020 100644
--- a/include/linux/pps_gen_kernel.h
+++ b/include/linux/pps_gen_kernel.h
@@ -43,7 +43,7 @@ struct pps_gen_source_info {
 
 /* The main struct */
 struct pps_gen_device {
-	struct pps_gen_source_info info;	/* PSS generator info */
+	const struct pps_gen_source_info *info;	/* PSS generator info */
 	bool enabled;				/* PSS generator status */
 
 	unsigned int event;
@@ -70,7 +70,7 @@ extern const struct attribute_group *pps_gen_groups[];
  */
 
 extern struct pps_gen_device *pps_gen_register_source(
-				struct pps_gen_source_info *info);
+				const struct pps_gen_source_info *info);
 extern void pps_gen_unregister_source(struct pps_gen_device *pps_gen);
 extern void pps_gen_event(struct pps_gen_device *pps_gen,
 				unsigned int event, void *data);
-- 
2.39.5

[PATCH AUTOSEL 6.14 390/642] serial: mctrl_gpio: split disable_ms into sync and no_sync APIs

[Sasha Levin]

From: Alexis Lothoré <alexis.lothore@bootlin.com>

[ Upstream commit 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685 ]

The following splat has been observed on a SAMA5D27 platform using
atmel_serial:

BUG: sleeping function called from invalid context at kernel/irq/manage.c:738
in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 0
hardirqs last  enabled at (0): [<00000000>] 0x0
hardirqs last disabled at (0): [<c01588f0>] copy_process+0x1c4c/0x7bec
softirqs last  enabled at (0): [<c0158944>] copy_process+0x1ca0/0x7bec
softirqs last disabled at (0): [<00000000>] 0x0
CPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74
Hardware name: Atmel SAMA5
Workqueue: hci0 hci_power_on [bluetooth]
Call trace:
  unwind_backtrace from show_stack+0x18/0x1c
  show_stack from dump_stack_lvl+0x44/0x70
  dump_stack_lvl from __might_resched+0x38c/0x598
  __might_resched from disable_irq+0x1c/0x48
  disable_irq from mctrl_gpio_disable_ms+0x74/0xc0
  mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4
  atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8
  atmel_set_termios from uart_change_line_settings+0x15c/0x994
  uart_change_line_settings from uart_set_termios+0x2b0/0x668
  uart_set_termios from tty_set_termios+0x600/0x8ec
  tty_set_termios from ttyport_set_flow_control+0x188/0x1e0
  ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc]
  wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth]
  hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth]
  hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth]
  hci_power_on [bluetooth] from process_one_work+0x998/0x1a38
  process_one_work from worker_thread+0x6e0/0xfb4
  worker_thread from kthread+0x3d4/0x484
  kthread from ret_from_fork+0x14/0x28

This warning is emitted when trying to toggle, at the highest level,
some flow control (with serdev_device_set_flow_control) in a device
driver. At the lowest level, the atmel_serial driver is using
serial_mctrl_gpio lib to enable/disable the corresponding IRQs
accordingly.  The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to
disable_irq (called in mctrl_gpio_disable_ms) being possibly called in
some atomic context (some tty drivers perform modem lines configuration
in regions protected by port lock).

Split mctrl_gpio_disable_ms into two differents APIs, a non-blocking one
and a blocking one. Replace mctrl_gpio_disable_ms calls with the
relevant version depending on whether the call is protected by some port
lock.

Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>
Acked-by: Richard Genoud <richard.genoud@bootlin.com>
Link: https://lore.kernel.org/r/20250217-atomic_sleep_mctrl_serial_gpio-v3-1-59324b313eef@bootlin.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 Documentation/driver-api/serial/driver.rst |  2 +-
 drivers/tty/serial/8250/8250_port.c        |  2 +-
 drivers/tty/serial/atmel_serial.c          |  2 +-
 drivers/tty/serial/imx.c                   |  2 +-
 drivers/tty/serial/serial_mctrl_gpio.c     | 34 +++++++++++++++++-----
 drivers/tty/serial/serial_mctrl_gpio.h     | 17 +++++++++--
 drivers/tty/serial/sh-sci.c                |  2 +-
 drivers/tty/serial/stm32-usart.c           |  2 +-
 8 files changed, 47 insertions(+), 16 deletions(-)

diff --git a/Documentation/driver-api/serial/driver.rst b/Documentation/driver-api/serial/driver.rst
index 84b43061c11be..60434f2b02863 100644
--- a/Documentation/driver-api/serial/driver.rst
+++ b/Documentation/driver-api/serial/driver.rst
@@ -103,4 +103,4 @@ Some helpers are provided in order to set/get modem control lines via GPIO.
 .. kernel-doc:: drivers/tty/serial/serial_mctrl_gpio.c
    :identifiers: mctrl_gpio_init mctrl_gpio_free mctrl_gpio_to_gpiod
            mctrl_gpio_set mctrl_gpio_get mctrl_gpio_enable_ms
-           mctrl_gpio_disable_ms
+           mctrl_gpio_disable_ms_sync mctrl_gpio_disable_ms_no_sync
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 442967a6cd52d..886e40f680d45 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1680,7 +1680,7 @@ static void serial8250_disable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
-	mctrl_gpio_disable_ms(up->gpios);
+	mctrl_gpio_disable_ms_no_sync(up->gpios);
 
 	up->ier &= ~UART_IER_MSI;
 	serial_port_out(port, UART_IER, up->ier);
diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index f44f9d20a9744..8918fbd4bddd5 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -700,7 +700,7 @@ static void atmel_disable_ms(struct uart_port *port)
 
 	atmel_port->ms_irq_enabled = false;
 
-	mctrl_gpio_disable_ms(atmel_port->gpios);
+	mctrl_gpio_disable_ms_no_sync(atmel_port->gpios);
 
 	if (!mctrl_gpio_to_gpiod(atmel_port->gpios, UART_GPIO_CTS))
 		idr |= ATMEL_US_CTSIC;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 9c59ec128bb4f..cfeb3f8cf45ea 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1608,7 +1608,7 @@ static void imx_uart_shutdown(struct uart_port *port)
 		imx_uart_dma_exit(sport);
 	}
 
-	mctrl_gpio_disable_ms(sport->gpios);
+	mctrl_gpio_disable_ms_sync(sport->gpios);
 
 	uart_port_lock_irqsave(&sport->port, &flags);
 	ucr2 = imx_uart_readl(sport, UCR2);
diff --git a/drivers/tty/serial/serial_mctrl_gpio.c b/drivers/tty/serial/serial_mctrl_gpio.c
index 8855688a5b6c0..ca55bcc0b6111 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.c
+++ b/drivers/tty/serial/serial_mctrl_gpio.c
@@ -322,11 +322,7 @@ void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 }
 EXPORT_SYMBOL_GPL(mctrl_gpio_enable_ms);
 
-/**
- * mctrl_gpio_disable_ms - disable irqs and handling of changes to the ms lines
- * @gpios: gpios to disable
- */
-void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+static void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios, bool sync)
 {
 	enum mctrl_gpio_idx i;
 
@@ -342,10 +338,34 @@ void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
 		if (!gpios->irq[i])
 			continue;
 
-		disable_irq(gpios->irq[i]);
+		if (sync)
+			disable_irq(gpios->irq[i]);
+		else
+			disable_irq_nosync(gpios->irq[i]);
 	}
 }
-EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms);
+
+/**
+ * mctrl_gpio_disable_ms_sync - disable irqs and handling of changes to the ms
+ * lines, and wait for any pending IRQ to be processed
+ * @gpios: gpios to disable
+ */
+void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios)
+{
+	mctrl_gpio_disable_ms(gpios, true);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_sync);
+
+/**
+ * mctrl_gpio_disable_ms_no_sync - disable irqs and handling of changes to the
+ * ms lines, and return immediately
+ * @gpios: gpios to disable
+ */
+void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios)
+{
+	mctrl_gpio_disable_ms(gpios, false);
+}
+EXPORT_SYMBOL_GPL(mctrl_gpio_disable_ms_no_sync);
 
 void mctrl_gpio_enable_irq_wake(struct mctrl_gpios *gpios)
 {
diff --git a/drivers/tty/serial/serial_mctrl_gpio.h b/drivers/tty/serial/serial_mctrl_gpio.h
index fc76910fb105a..79e97838ebe56 100644
--- a/drivers/tty/serial/serial_mctrl_gpio.h
+++ b/drivers/tty/serial/serial_mctrl_gpio.h
@@ -87,9 +87,16 @@ void mctrl_gpio_free(struct device *dev, struct mctrl_gpios *gpios);
 void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios);
 
 /*
- * Disable gpio interrupts to report status line changes.
+ * Disable gpio interrupts to report status line changes, and block until
+ * any corresponding IRQ is processed
  */
-void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios);
+void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios);
+
+/*
+ * Disable gpio interrupts to report status line changes, and return
+ * immediately
+ */
+void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios);
 
 /*
  * Enable gpio wakeup interrupts to enable wake up source.
@@ -148,7 +155,11 @@ static inline void mctrl_gpio_enable_ms(struct mctrl_gpios *gpios)
 {
 }
 
-static inline void mctrl_gpio_disable_ms(struct mctrl_gpios *gpios)
+static inline void mctrl_gpio_disable_ms_sync(struct mctrl_gpios *gpios)
+{
+}
+
+static inline void mctrl_gpio_disable_ms_no_sync(struct mctrl_gpios *gpios)
 {
 }
 
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index b1ea48f38248e..41f987632bce8 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -2298,7 +2298,7 @@ static void sci_shutdown(struct uart_port *port)
 	dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
 
 	s->autorts = false;
-	mctrl_gpio_disable_ms(to_sci_port(port)->gpios);
+	mctrl_gpio_disable_ms_sync(to_sci_port(port)->gpios);
 
 	uart_port_lock_irqsave(port, &flags);
 	sci_stop_rx(port);
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c
index 0854ad8c90cd2..ad06b760cfca7 100644
--- a/drivers/tty/serial/stm32-usart.c
+++ b/drivers/tty/serial/stm32-usart.c
@@ -944,7 +944,7 @@ static void stm32_usart_enable_ms(struct uart_port *port)
 
 static void stm32_usart_disable_ms(struct uart_port *port)
 {
-	mctrl_gpio_disable_ms(to_stm32_port(port)->gpios);
+	mctrl_gpio_disable_ms_sync(to_stm32_port(port)->gpios);
 }
 
 /* Transmit stop */
-- 
2.39.5