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drivers/nvme: Return an error in case of non dword-aligned data buffer

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This is a specific case for NVMe where given data buffer pointers must
be dword (4 bytes) aligned.

There is no virtual memory management between the user thread and NVMe
driver (which one could detect such wrong alignement on physical memory
and thus reallocate the memory properly, so it would be fully
transparent for the user thread), thus the need to push that check to
the user.

This has been going under the radar so far as Qemu does not seem to
follow NVMe specifications where PRP1 (in DPTR) must always be
dword-aligned. It really does not follow the rule: specifications
details that if bits 1:0 of PRP1 are set, the controller may generate
an error or treat the address as if these bits were unset. Seems like
a bug in Qemu, I did not check the code there however.

Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
This commit is contained in:
Tomasz Bursztyka 2023-09-20 10:27:42 +02:00 • committed by Carles Cufí
commit 95b8493857
2 changed files with 12 additions and 0 deletions
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10
drivers/disk/nvme/nvme_disk.c
View file

@ -34,6 +34,11 @@ static int nvme_disk_read(struct disk_info *disk,
uint32_t payload_size;
int ret = 0;
if (!NVME_IS_BUFFER_DWORD_ALIGNED(data_buf)) {
LOG_WRN("Data buffer pointer needs to be 4-bytes aligned");
return -EINVAL;
}
nvme_lock(disk->dev);
payload_size = num_sector * nvme_namespace_get_sector_size(ns);
@ -78,6 +83,11 @@ static int nvme_disk_write(struct disk_info *disk,
uint32_t payload_size;
int ret = 0;
if (!NVME_IS_BUFFER_DWORD_ALIGNED(data_buf)) {
LOG_WRN("Data buffer pointer needs to be 4-bytes aligned");
return -EINVAL;
}
nvme_lock(disk->dev);
payload_size = num_sector * nvme_namespace_get_sector_size(ns);

2
drivers/disk/nvme/nvme_helpers.h
View file

@ -514,4 +514,6 @@ enum shst_value {
(mm_reg_t)b_a + nvme_mmio_offsetof(reg) + 4); \
} while (0)
#define NVME_IS_BUFFER_DWORD_ALIGNED(_buf_addr) (!((uintptr_t)_buf_addr & 0x3))
#endif /* ZEPHYR_DRIVERS_DISK_NVME_NHME_HELPERS_H_ */