Both f2fs and ext4 end up passing the ciphertext page to
wbc_account_cgroup_owner(). At the moment, the ciphertext page appears
to belong to no cgroup, so it is accounted to the root_mem_cgroup instead
of whatever cgroup the original page was in.
It's hard to say how far back this is a bug. The crypto code shared
between ext4 & f2fs was created in May 2015 with commit 0b81d0779072,
but neither filesystem did anything with memcg_data before then. memcg
writeback accounting was added to ext4 in July 2015 in commit 001e4a8775f6
and it wasn't added to f2fs until January 2018 (commit 578c647879f7).
I'm going with the ext4 commit since this is the first commit where
there was a difference in behaviour between encrypted and unencrypted
filesystems.
Fixes: 001e4a8775f6 ("ext4: implement cgroup writeback support")
Cc: stable(a)vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy(a)infradead.org>
---
fs/crypto/crypto.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c
index e78be66bbf01..a4e76f96f291 100644
--- a/fs/crypto/crypto.c
+++ b/fs/crypto/crypto.c
@@ -205,6 +205,9 @@ struct page *fscrypt_encrypt_pagecache_blocks(struct page *page,
}
SetPagePrivate(ciphertext_page);
set_page_private(ciphertext_page, (unsigned long)page);
+#ifdef CONFIG_MEMCG
+ ciphertext_page->memcg_data = page->memcg_data;
+#endif
return ciphertext_page;
}
EXPORT_SYMBOL(fscrypt_encrypt_pagecache_blocks);
--
2.35.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Change state_lock to mutex
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 1ddc7618294084fff8d673217a9479550990ee84 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Mon, 23 Jan 2023 12:59:45 +0530
Subject: bus: mhi: ep: Change state_lock to mutex
state_lock, the spinlock type is meant to protect race against concurrent
MHI state transitions. In mhi_ep_set_m0_state(), while the state_lock is
being held, the channels are resumed in mhi_ep_resume_channels() if the
previous state was M3. This causes sleeping in atomic bug, since
mhi_ep_resume_channels() use mutex internally.
Since the state_lock is supposed to be held throughout the state change,
it is not ideal to drop the lock before calling mhi_ep_resume_channels().
So to fix this issue, let's change the type of state_lock to mutex. This
would also allow holding the lock throughout all state transitions thereby
avoiding any potential race.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels")
Reported-by: Dan Carpenter <error27(a)gmail.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 8 +++++---
drivers/bus/mhi/ep/sm.c | 42 ++++++++++++++++++++++-----------------
include/linux/mhi_ep.h | 4 ++--
3 files changed, 31 insertions(+), 23 deletions(-)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index bcaaba97ef63..528c00b232bf 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1001,11 +1001,11 @@ static void mhi_ep_reset_worker(struct work_struct *work)
mhi_ep_power_down(mhi_cntrl);
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
/* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */
mhi_ep_mmio_reset(mhi_cntrl);
cur_state = mhi_cntrl->mhi_state;
- spin_unlock_bh(&mhi_cntrl->state_lock);
/*
* Only proceed further if the reset is due to SYS_ERR. The host will
@@ -1014,6 +1014,8 @@ static void mhi_ep_reset_worker(struct work_struct *work)
*/
if (cur_state == MHI_STATE_SYS_ERR)
mhi_ep_power_up(mhi_cntrl);
+
+ mutex_unlock(&mhi_cntrl->state_lock);
}
/*
@@ -1386,8 +1388,8 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
INIT_LIST_HEAD(&mhi_cntrl->st_transition_list);
INIT_LIST_HEAD(&mhi_cntrl->ch_db_list);
- spin_lock_init(&mhi_cntrl->state_lock);
spin_lock_init(&mhi_cntrl->list_lock);
+ mutex_init(&mhi_cntrl->state_lock);
mutex_init(&mhi_cntrl->event_lock);
/* Set MHI version and AMSS EE before enumeration */
diff --git a/drivers/bus/mhi/ep/sm.c b/drivers/bus/mhi/ep/sm.c
index 3655c19e23c7..fd200b2ac0bb 100644
--- a/drivers/bus/mhi/ep/sm.c
+++ b/drivers/bus/mhi/ep/sm.c
@@ -63,24 +63,23 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl)
int ret;
/* If MHI is in M3, resume suspended channels */
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
old_state = mhi_cntrl->mhi_state;
if (old_state == MHI_STATE_M3)
mhi_ep_resume_channels(mhi_cntrl);
ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
- spin_unlock_bh(&mhi_cntrl->state_lock);
-
if (ret) {
mhi_ep_handle_syserr(mhi_cntrl);
- return ret;
+ goto err_unlock;
}
/* Signal host that the device moved to M0 */
ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M0);
if (ret) {
dev_err(dev, "Failed sending M0 state change event\n");
- return ret;
+ goto err_unlock;
}
if (old_state == MHI_STATE_READY) {
@@ -88,11 +87,14 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl)
ret = mhi_ep_send_ee_event(mhi_cntrl, MHI_EE_AMSS);
if (ret) {
dev_err(dev, "Failed sending AMSS EE event\n");
- return ret;
+ goto err_unlock;
}
}
- return 0;
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
+ return ret;
}
int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
@@ -100,13 +102,12 @@ int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
struct device *dev = &mhi_cntrl->mhi_dev->dev;
int ret;
- spin_lock_bh(&mhi_cntrl->state_lock);
- ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
- spin_unlock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+ ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
if (ret) {
mhi_ep_handle_syserr(mhi_cntrl);
- return ret;
+ goto err_unlock;
}
mhi_ep_suspend_channels(mhi_cntrl);
@@ -115,10 +116,13 @@ int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M3);
if (ret) {
dev_err(dev, "Failed sending M3 state change event\n");
- return ret;
+ goto err_unlock;
}
- return 0;
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
+ return ret;
}
int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl)
@@ -127,22 +131,24 @@ int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl)
enum mhi_state mhi_state;
int ret, is_ready;
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
/* Ensure that the MHISTATUS is set to RESET by host */
mhi_state = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_MHISTATE_MASK);
is_ready = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_READY_MASK);
if (mhi_state != MHI_STATE_RESET || is_ready) {
dev_err(dev, "READY state transition failed. MHI host not in RESET state\n");
- spin_unlock_bh(&mhi_cntrl->state_lock);
- return -EIO;
+ ret = -EIO;
+ goto err_unlock;
}
ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_READY);
- spin_unlock_bh(&mhi_cntrl->state_lock);
-
if (ret)
mhi_ep_handle_syserr(mhi_cntrl);
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
return ret;
}
diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
index 478aece17046..f198a8ac7ee7 100644
--- a/include/linux/mhi_ep.h
+++ b/include/linux/mhi_ep.h
@@ -70,8 +70,8 @@ struct mhi_ep_db_info {
* @cmd_ctx_cache_phys: Physical address of the host command context cache
* @chdb: Array of channel doorbell interrupt info
* @event_lock: Lock for protecting event rings
- * @list_lock: Lock for protecting state transition and channel doorbell lists
* @state_lock: Lock for protecting state transitions
+ * @list_lock: Lock for protecting state transition and channel doorbell lists
* @st_transition_list: List of state transitions
* @ch_db_list: List of queued channel doorbells
* @wq: Dedicated workqueue for handling rings and state changes
@@ -117,8 +117,8 @@ struct mhi_ep_cntrl {
struct mhi_ep_db_info chdb[4];
struct mutex event_lock;
+ struct mutex state_lock;
spinlock_t list_lock;
- spinlock_t state_lock;
struct list_head st_transition_list;
struct list_head ch_db_list;
--
2.39.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Save channel state locally during suspend and resume
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 8a1c24bb908f9ecbc4be0fea014df67d43161551 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Wed, 28 Dec 2022 21:47:04 +0530
Subject: bus: mhi: ep: Save channel state locally during suspend and resume
During suspend and resume, the channel state needs to be saved locally.
Otherwise, the endpoint may access the channels while they were being
suspended and causing access violations.
Fix it by saving the channel state locally during suspend and resume.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com)
Link: https://lore.kernel.org/r/20221228161704.255268-7-manivannan.sadhasivam@lin…
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 2362fcc8b32c..bcaaba97ef63 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1122,6 +1122,7 @@ void mhi_ep_suspend_channels(struct mhi_ep_cntrl *mhi_cntrl)
dev_dbg(&mhi_chan->mhi_dev->dev, "Suspending channel\n");
/* Set channel state to SUSPENDED */
+ mhi_chan->state = MHI_CH_STATE_SUSPENDED;
tmp &= ~CHAN_CTX_CHSTATE_MASK;
tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_SUSPENDED);
mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);
@@ -1151,6 +1152,7 @@ void mhi_ep_resume_channels(struct mhi_ep_cntrl *mhi_cntrl)
dev_dbg(&mhi_chan->mhi_dev->dev, "Resuming channel\n");
/* Set channel state to RUNNING */
+ mhi_chan->state = MHI_CH_STATE_RUNNING;
tmp &= ~CHAN_CTX_CHSTATE_MASK;
tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);
mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);
--
2.39.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Move chan->lock to the start of processing queued ch
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From 8d6a1fea53864cd9545741f48f4ae4df804db557 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Wed, 28 Dec 2022 21:47:03 +0530
Subject: bus: mhi: ep: Move chan->lock to the start of processing queued ch
ring
There is a good chance that while the channel ring gets processed, the STOP
or RESET command for the channel might be received from the MHI host. In
those cases, the entire channel ring processing needs to be protected by
chan->lock to prevent the race where the corresponding channel ring might
be reset.
While at it, let's also add a sanity check to make sure that the ring is
started before processing it. Because, if the STOP/RESET command gets
processed while mhi_ep_ch_ring_worker() waited for chan->lock, the ring
would've been reset.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: 03c0bb8ec983 ("bus: mhi: ep: Add support for processing channel rings")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com>
Link: https://lore.kernel.org/r/20221228161704.255268-6-manivannan.sadhasivam@lin…
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 0bce6610ebf1..2362fcc8b32c 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -730,24 +730,37 @@ static void mhi_ep_ch_ring_worker(struct work_struct *work)
list_del(&itr->node);
ring = itr->ring;
+ chan = &mhi_cntrl->mhi_chan[ring->ch_id];
+ mutex_lock(&chan->lock);
+
+ /*
+ * The ring could've stopped while we waited to grab the (chan->lock), so do
+ * a sanity check before going further.
+ */
+ if (!ring->started) {
+ mutex_unlock(&chan->lock);
+ kfree(itr);
+ continue;
+ }
+
/* Update the write offset for the ring */
ret = mhi_ep_update_wr_offset(ring);
if (ret) {
dev_err(dev, "Error updating write offset for ring\n");
+ mutex_unlock(&chan->lock);
kfree(itr);
continue;
}
/* Sanity check to make sure there are elements in the ring */
if (ring->rd_offset == ring->wr_offset) {
+ mutex_unlock(&chan->lock);
kfree(itr);
continue;
}
el = &ring->ring_cache[ring->rd_offset];
- chan = &mhi_cntrl->mhi_chan[ring->ch_id];
- mutex_lock(&chan->lock);
dev_dbg(dev, "Processing the ring for channel (%u)\n", ring->ch_id);
ret = mhi_ep_process_ch_ring(ring, el);
if (ret) {
--
2.39.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Only send -ENOTCONN status if client driver is
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-next branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will also be merged in the next major kernel release
during the merge window.
If you have any questions about this process, please let me know.
From e6cebcc27519dcf1652e604c73b9fd4f416987c0 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Wed, 28 Dec 2022 21:47:01 +0530
Subject: bus: mhi: ep: Only send -ENOTCONN status if client driver is
available
For the STOP and RESET commands, only send the channel disconnect status
-ENOTCONN if client driver is available. Otherwise, it will result in
null pointer dereference.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: e827569062a8 ("bus: mhi: ep: Add support for processing command rings")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com>
Link: https://lore.kernel.org/r/20221228161704.255268-4-manivannan.sadhasivam@lin…
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 8b065a3cc848..7d68b00bdbcf 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -203,9 +203,11 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele
mhi_ep_mmio_disable_chdb(mhi_cntrl, ch_id);
/* Send channel disconnect status to client drivers */
- result.transaction_status = -ENOTCONN;
- result.bytes_xferd = 0;
- mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+ if (mhi_chan->xfer_cb) {
+ result.transaction_status = -ENOTCONN;
+ result.bytes_xferd = 0;
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+ }
/* Set channel state to STOP */
mhi_chan->state = MHI_CH_STATE_STOP;
@@ -235,9 +237,11 @@ static int mhi_ep_process_cmd_ring(struct mhi_ep_ring *ring, struct mhi_ring_ele
mhi_ep_ring_reset(mhi_cntrl, ch_ring);
/* Send channel disconnect status to client driver */
- result.transaction_status = -ENOTCONN;
- result.bytes_xferd = 0;
- mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+ if (mhi_chan->xfer_cb) {
+ result.transaction_status = -ENOTCONN;
+ result.bytes_xferd = 0;
+ mhi_chan->xfer_cb(mhi_chan->mhi_dev, &result);
+ }
/* Set channel state to DISABLED */
mhi_chan->state = MHI_CH_STATE_DISABLED;
--
2.39.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Change state_lock to mutex
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the char-misc-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
From 1ddc7618294084fff8d673217a9479550990ee84 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Mon, 23 Jan 2023 12:59:45 +0530
Subject: bus: mhi: ep: Change state_lock to mutex
state_lock, the spinlock type is meant to protect race against concurrent
MHI state transitions. In mhi_ep_set_m0_state(), while the state_lock is
being held, the channels are resumed in mhi_ep_resume_channels() if the
previous state was M3. This causes sleeping in atomic bug, since
mhi_ep_resume_channels() use mutex internally.
Since the state_lock is supposed to be held throughout the state change,
it is not ideal to drop the lock before calling mhi_ep_resume_channels().
So to fix this issue, let's change the type of state_lock to mutex. This
would also allow holding the lock throughout all state transitions thereby
avoiding any potential race.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels")
Reported-by: Dan Carpenter <error27(a)gmail.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 8 +++++---
drivers/bus/mhi/ep/sm.c | 42 ++++++++++++++++++++++-----------------
include/linux/mhi_ep.h | 4 ++--
3 files changed, 31 insertions(+), 23 deletions(-)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index bcaaba97ef63..528c00b232bf 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1001,11 +1001,11 @@ static void mhi_ep_reset_worker(struct work_struct *work)
mhi_ep_power_down(mhi_cntrl);
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
/* Reset MMIO to signal host that the MHI_RESET is completed in endpoint */
mhi_ep_mmio_reset(mhi_cntrl);
cur_state = mhi_cntrl->mhi_state;
- spin_unlock_bh(&mhi_cntrl->state_lock);
/*
* Only proceed further if the reset is due to SYS_ERR. The host will
@@ -1014,6 +1014,8 @@ static void mhi_ep_reset_worker(struct work_struct *work)
*/
if (cur_state == MHI_STATE_SYS_ERR)
mhi_ep_power_up(mhi_cntrl);
+
+ mutex_unlock(&mhi_cntrl->state_lock);
}
/*
@@ -1386,8 +1388,8 @@ int mhi_ep_register_controller(struct mhi_ep_cntrl *mhi_cntrl,
INIT_LIST_HEAD(&mhi_cntrl->st_transition_list);
INIT_LIST_HEAD(&mhi_cntrl->ch_db_list);
- spin_lock_init(&mhi_cntrl->state_lock);
spin_lock_init(&mhi_cntrl->list_lock);
+ mutex_init(&mhi_cntrl->state_lock);
mutex_init(&mhi_cntrl->event_lock);
/* Set MHI version and AMSS EE before enumeration */
diff --git a/drivers/bus/mhi/ep/sm.c b/drivers/bus/mhi/ep/sm.c
index 3655c19e23c7..fd200b2ac0bb 100644
--- a/drivers/bus/mhi/ep/sm.c
+++ b/drivers/bus/mhi/ep/sm.c
@@ -63,24 +63,23 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl)
int ret;
/* If MHI is in M3, resume suspended channels */
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
old_state = mhi_cntrl->mhi_state;
if (old_state == MHI_STATE_M3)
mhi_ep_resume_channels(mhi_cntrl);
ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M0);
- spin_unlock_bh(&mhi_cntrl->state_lock);
-
if (ret) {
mhi_ep_handle_syserr(mhi_cntrl);
- return ret;
+ goto err_unlock;
}
/* Signal host that the device moved to M0 */
ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M0);
if (ret) {
dev_err(dev, "Failed sending M0 state change event\n");
- return ret;
+ goto err_unlock;
}
if (old_state == MHI_STATE_READY) {
@@ -88,11 +87,14 @@ int mhi_ep_set_m0_state(struct mhi_ep_cntrl *mhi_cntrl)
ret = mhi_ep_send_ee_event(mhi_cntrl, MHI_EE_AMSS);
if (ret) {
dev_err(dev, "Failed sending AMSS EE event\n");
- return ret;
+ goto err_unlock;
}
}
- return 0;
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
+ return ret;
}
int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
@@ -100,13 +102,12 @@ int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
struct device *dev = &mhi_cntrl->mhi_dev->dev;
int ret;
- spin_lock_bh(&mhi_cntrl->state_lock);
- ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
- spin_unlock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+ ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_M3);
if (ret) {
mhi_ep_handle_syserr(mhi_cntrl);
- return ret;
+ goto err_unlock;
}
mhi_ep_suspend_channels(mhi_cntrl);
@@ -115,10 +116,13 @@ int mhi_ep_set_m3_state(struct mhi_ep_cntrl *mhi_cntrl)
ret = mhi_ep_send_state_change_event(mhi_cntrl, MHI_STATE_M3);
if (ret) {
dev_err(dev, "Failed sending M3 state change event\n");
- return ret;
+ goto err_unlock;
}
- return 0;
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
+ return ret;
}
int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl)
@@ -127,22 +131,24 @@ int mhi_ep_set_ready_state(struct mhi_ep_cntrl *mhi_cntrl)
enum mhi_state mhi_state;
int ret, is_ready;
- spin_lock_bh(&mhi_cntrl->state_lock);
+ mutex_lock(&mhi_cntrl->state_lock);
+
/* Ensure that the MHISTATUS is set to RESET by host */
mhi_state = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_MHISTATE_MASK);
is_ready = mhi_ep_mmio_masked_read(mhi_cntrl, EP_MHISTATUS, MHISTATUS_READY_MASK);
if (mhi_state != MHI_STATE_RESET || is_ready) {
dev_err(dev, "READY state transition failed. MHI host not in RESET state\n");
- spin_unlock_bh(&mhi_cntrl->state_lock);
- return -EIO;
+ ret = -EIO;
+ goto err_unlock;
}
ret = mhi_ep_set_mhi_state(mhi_cntrl, MHI_STATE_READY);
- spin_unlock_bh(&mhi_cntrl->state_lock);
-
if (ret)
mhi_ep_handle_syserr(mhi_cntrl);
+err_unlock:
+ mutex_unlock(&mhi_cntrl->state_lock);
+
return ret;
}
diff --git a/include/linux/mhi_ep.h b/include/linux/mhi_ep.h
index 478aece17046..f198a8ac7ee7 100644
--- a/include/linux/mhi_ep.h
+++ b/include/linux/mhi_ep.h
@@ -70,8 +70,8 @@ struct mhi_ep_db_info {
* @cmd_ctx_cache_phys: Physical address of the host command context cache
* @chdb: Array of channel doorbell interrupt info
* @event_lock: Lock for protecting event rings
- * @list_lock: Lock for protecting state transition and channel doorbell lists
* @state_lock: Lock for protecting state transitions
+ * @list_lock: Lock for protecting state transition and channel doorbell lists
* @st_transition_list: List of state transitions
* @ch_db_list: List of queued channel doorbells
* @wq: Dedicated workqueue for handling rings and state changes
@@ -117,8 +117,8 @@ struct mhi_ep_cntrl {
struct mhi_ep_db_info chdb[4];
struct mutex event_lock;
+ struct mutex state_lock;
spinlock_t list_lock;
- spinlock_t state_lock;
struct list_head st_transition_list;
struct list_head ch_db_list;
--
2.39.1
This is a note to let you know that I've just added the patch titled
bus: mhi: ep: Save channel state locally during suspend and resume
to my char-misc git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc.git
in the char-misc-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the char-misc-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
From 8a1c24bb908f9ecbc4be0fea014df67d43161551 Mon Sep 17 00:00:00 2001
From: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Date: Wed, 28 Dec 2022 21:47:04 +0530
Subject: bus: mhi: ep: Save channel state locally during suspend and resume
During suspend and resume, the channel state needs to be saved locally.
Otherwise, the endpoint may access the channels while they were being
suspended and causing access violations.
Fix it by saving the channel state locally during suspend and resume.
Cc: <stable(a)vger.kernel.org> # 5.19
Fixes: e4b7b5f0f30a ("bus: mhi: ep: Add support for suspending and resuming channels")
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
Reviewed-by: Jeffrey Hugo <quic_jhugo(a)quicinc.com)
Link: https://lore.kernel.org/r/20221228161704.255268-7-manivannan.sadhasivam@lin…
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam(a)linaro.org>
---
drivers/bus/mhi/ep/main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/bus/mhi/ep/main.c b/drivers/bus/mhi/ep/main.c
index 2362fcc8b32c..bcaaba97ef63 100644
--- a/drivers/bus/mhi/ep/main.c
+++ b/drivers/bus/mhi/ep/main.c
@@ -1122,6 +1122,7 @@ void mhi_ep_suspend_channels(struct mhi_ep_cntrl *mhi_cntrl)
dev_dbg(&mhi_chan->mhi_dev->dev, "Suspending channel\n");
/* Set channel state to SUSPENDED */
+ mhi_chan->state = MHI_CH_STATE_SUSPENDED;
tmp &= ~CHAN_CTX_CHSTATE_MASK;
tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_SUSPENDED);
mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);
@@ -1151,6 +1152,7 @@ void mhi_ep_resume_channels(struct mhi_ep_cntrl *mhi_cntrl)
dev_dbg(&mhi_chan->mhi_dev->dev, "Resuming channel\n");
/* Set channel state to RUNNING */
+ mhi_chan->state = MHI_CH_STATE_RUNNING;
tmp &= ~CHAN_CTX_CHSTATE_MASK;
tmp |= FIELD_PREP(CHAN_CTX_CHSTATE_MASK, MHI_CH_STATE_RUNNING);
mhi_cntrl->ch_ctx_cache[i].chcfg = cpu_to_le32(tmp);
--
2.39.1