The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x c91e140c82eb58724c435f623702e51cc7896646 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025082105-fit-porridge-a9dc@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c91e140c82eb58724c435f623702e51cc7896646 Mon Sep 17 00:00:00 2001 From: Ranjan Kumar ranjan.kumar@broadcom.com Date: Sat, 28 Jun 2025 01:15:38 +0530 Subject: [PATCH] scsi: mpi3mr: Serialize admin queue BAR writes on 32-bit systems

On 32-bit systems, 64-bit BAR writes to admin queue registers are performed as two 32-bit writes. Without locking, this can cause partial writes when accessed concurrently.

Updated per-queue spinlocks is used to serialize these writes and prevent race conditions.

Fixes: 824a156633df ("scsi: mpi3mr: Base driver code") Cc: stable@vger.kernel.org Signed-off-by: Ranjan Kumar ranjan.kumar@broadcom.com Link: https://lore.kernel.org/r/20250627194539.48851-4-ranjan.kumar@broadcom.com Signed-off-by: Martin K. Petersen martin.petersen@oracle.com

diff --git a/drivers/scsi/mpi3mr/mpi3mr.h b/drivers/scsi/mpi3mr/mpi3mr.h index bf272dd69d23..f2201108ea91 100644 --- a/drivers/scsi/mpi3mr/mpi3mr.h +++ b/drivers/scsi/mpi3mr/mpi3mr.h @@ -1137,6 +1137,8 @@ struct scmd_priv { * @logdata_buf: Circular buffer to store log data entries * @logdata_buf_idx: Index of entry in buffer to store * @logdata_entry_sz: log data entry size + * @adm_req_q_bar_writeq_lock: Admin request queue lock + * @adm_reply_q_bar_writeq_lock: Admin reply queue lock * @pend_large_data_sz: Counter to track pending large data * @io_throttle_data_length: I/O size to track in 512b blocks * @io_throttle_high: I/O size to start throttle in 512b blocks @@ -1339,6 +1341,8 @@ struct mpi3mr_ioc { u8 *logdata_buf; u16 logdata_buf_idx; u16 logdata_entry_sz; + spinlock_t adm_req_q_bar_writeq_lock; + spinlock_t adm_reply_q_bar_writeq_lock;

atomic_t pend_large_data_sz; u32 io_throttle_data_length; diff --git a/drivers/scsi/mpi3mr/mpi3mr_fw.c b/drivers/scsi/mpi3mr/mpi3mr_fw.c index 8976582946a2..0152d31d430a 100644 --- a/drivers/scsi/mpi3mr/mpi3mr_fw.c +++ b/drivers/scsi/mpi3mr/mpi3mr_fw.c @@ -23,17 +23,22 @@ module_param(poll_queues, int, 0444); MODULE_PARM_DESC(poll_queues, "Number of queues for io_uring poll mode. (Range 1 - 126)");

#if defined(writeq) && defined(CONFIG_64BIT) -static inline void mpi3mr_writeq(__u64 b, void __iomem *addr) +static inline void mpi3mr_writeq(__u64 b, void __iomem *addr, + spinlock_t *write_queue_lock) { writeq(b, addr); } #else -static inline void mpi3mr_writeq(__u64 b, void __iomem *addr) +static inline void mpi3mr_writeq(__u64 b, void __iomem *addr, + spinlock_t *write_queue_lock) { __u64 data_out = b; + unsigned long flags;

+ spin_lock_irqsave(write_queue_lock, flags); writel((u32)(data_out), addr); writel((u32)(data_out >> 32), (addr + 4)); + spin_unlock_irqrestore(write_queue_lock, flags); } #endif

@@ -2954,9 +2959,11 @@ static int mpi3mr_setup_admin_qpair(struct mpi3mr_ioc *mrioc) (mrioc->num_admin_req); writel(num_admin_entries, &mrioc->sysif_regs->admin_queue_num_entries); mpi3mr_writeq(mrioc->admin_req_dma, - &mrioc->sysif_regs->admin_request_queue_address); + &mrioc->sysif_regs->admin_request_queue_address, + &mrioc->adm_req_q_bar_writeq_lock); mpi3mr_writeq(mrioc->admin_reply_dma, - &mrioc->sysif_regs->admin_reply_queue_address); + &mrioc->sysif_regs->admin_reply_queue_address, + &mrioc->adm_reply_q_bar_writeq_lock); writel(mrioc->admin_req_pi, &mrioc->sysif_regs->admin_request_queue_pi); writel(mrioc->admin_reply_ci, &mrioc->sysif_regs->admin_reply_queue_ci); return retval; diff --git a/drivers/scsi/mpi3mr/mpi3mr_os.c b/drivers/scsi/mpi3mr/mpi3mr_os.c index ce444efd859e..0d1c9bbb13b5 100644 --- a/drivers/scsi/mpi3mr/mpi3mr_os.c +++ b/drivers/scsi/mpi3mr/mpi3mr_os.c @@ -5365,6 +5365,8 @@ mpi3mr_probe(struct pci_dev *pdev, const struct pci_device_id *id) spin_lock_init(&mrioc->tgtdev_lock); spin_lock_init(&mrioc->watchdog_lock); spin_lock_init(&mrioc->chain_buf_lock); + spin_lock_init(&mrioc->adm_req_q_bar_writeq_lock); + spin_lock_init(&mrioc->adm_reply_q_bar_writeq_lock); spin_lock_init(&mrioc->sas_node_lock); spin_lock_init(&mrioc->trigger_lock);