From: Klaus Jensen k.jensen@samsung.com

stable inclusion from stable-v5.10.188 commit f5d8738fbe33e71959b5a69221ecf515032d3fc7 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7PZZC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=l...

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[ Upstream commit b5f96cb719d8ba220b565ddd3ba4ac0d8bcfb130 ]

When using shadow doorbells, the event index and the doorbell values are written to host memory. Prior to this patch, the values written would erroneously be written in host endianness. This causes trouble on big-endian platforms. Fix this by adding missing endian conversions.

This issue was noticed by Guenter while testing various big-endian platforms under QEMU[1]. A similar fix required for hw/nvme in QEMU is up for review as well[2].

[1]: https://lore.kernel.org/qemu-devel/20221209110022.GA3396194@roeck-us.net/ [2]: https://lore.kernel.org/qemu-devel/20221212114409.34972-4-its@irrelevant.dk/

Fixes: f9f38e33389c ("nvme: improve performance for virtual NVMe devices") Reported-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Klaus Jensen k.jensen@samsung.com Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yong Hu yong.hu@windriver.com --- drivers/nvme/host/pci.c | 25 +++++++++++++------------ 1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 72fe56857cb0..510ce0c145c7 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -139,9 +139,9 @@ struct nvme_dev { mempool_t *iod_mempool;

/* shadow doorbell buffer support: */ - u32 *dbbuf_dbs; + __le32 *dbbuf_dbs; dma_addr_t dbbuf_dbs_dma_addr; - u32 *dbbuf_eis; + __le32 *dbbuf_eis; dma_addr_t dbbuf_eis_dma_addr;

/* host memory buffer support: */ @@ -209,10 +209,10 @@ struct nvme_queue { #define NVMEQ_SQ_CMB 1 #define NVMEQ_DELETE_ERROR 2 #define NVMEQ_POLLED 3 - u32 *dbbuf_sq_db; - u32 *dbbuf_cq_db; - u32 *dbbuf_sq_ei; - u32 *dbbuf_cq_ei; + __le32 *dbbuf_sq_db; + __le32 *dbbuf_cq_db; + __le32 *dbbuf_sq_ei; + __le32 *dbbuf_cq_ei; struct completion delete_done; };

@@ -334,11 +334,11 @@ static inline int nvme_dbbuf_need_event(u16 event_idx, u16 new_idx, u16 old) }

/* Update dbbuf and return true if an MMIO is required */ -static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db, - volatile u32 *dbbuf_ei) +static bool nvme_dbbuf_update_and_check_event(u16 value, __le32 *dbbuf_db, + volatile __le32 *dbbuf_ei) { if (dbbuf_db) { - u16 old_value; + u16 old_value, event_idx;

/* * Ensure that the queue is written before updating @@ -346,8 +346,8 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db, */ wmb();

- old_value = *dbbuf_db; - *dbbuf_db = value; + old_value = le32_to_cpu(*dbbuf_db); + *dbbuf_db = cpu_to_le32(value);

/* * Ensure that the doorbell is updated before reading the event @@ -357,7 +357,8 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, u32 *dbbuf_db, */ mb();

- if (!nvme_dbbuf_need_event(*dbbuf_ei, value, old_value)) + event_idx = le32_to_cpu(*dbbuf_ei); + if (!nvme_dbbuf_need_event(event_idx, value, old_value)) return false; }