> From: Alistair Popple <apopple@xxxxxxxxxx>
> Sent: Thursday, February 25, 2021 11:19 PM
> To: linux-mm@xxxxxxxxx; nouveau@xxxxxxxxxxxxxxxxxxxxx;
> bskeggs@xxxxxxxxxx; akpm@xxxxxxxxxxxxxxxxxxxx
> Cc: linux-doc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; dri-
> devel@xxxxxxxxxxxxxxxxxxxxx; John Hubbard <jhubbard@xxxxxxxxxx>; Ralph
> Campbell <rcampbell@xxxxxxxxxx>; jglisse@xxxxxxxxxx; Jason Gunthorpe
> <jgg@xxxxxxxxxx>; hch@xxxxxxxxxxxxx; daniel@xxxxxxxx; Alistair Popple
> <apopple@xxxxxxxxxx>
> Subject: [PATCH v3 6/8] mm: Selftests for exclusive device memory
>
> Adds some selftests for exclusive device memory.
>
> Signed-off-by: Alistair Popple <apopple@xxxxxxxxxx>
One minor nit below, but you can add
Tested-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
Reviewed-by: Ralph Campbell <rcampbell@xxxxxxxxxx>
> +static int dmirror_exclusive(struct dmirror *dmirror,
> + struct hmm_dmirror_cmd *cmd)
> +{
> + unsigned long start, end, addr;
> + unsigned long size = cmd->npages << PAGE_SHIFT;
> + struct mm_struct *mm = dmirror->notifier.mm;
> + struct page *pages[64];
> + struct dmirror_bounce bounce;
> + unsigned long next;
> + int ret;
> +
> + start = cmd->addr;
> + end = start + size;
> + if (end < start)
> + return -EINVAL;
> +
> + /* Since the mm is for the mirrored process, get a reference first. */
> + if (!mmget_not_zero(mm))
> + return -EINVAL;
> +
> + mmap_read_lock(mm);
> + for (addr = start; addr < end; addr = next) {
> + int i, mapped;
> +
> + if (end < addr + (64 << PAGE_SHIFT))
> + next = end;
> + else
> + next = addr + (64 << PAGE_SHIFT);
I suggest using ARRAY_SIZE(pages) instead of '64' to make the meaning clear.
