Re: [PATCH 06/18] iommu/fsl_pamu: remove ->domain_window_enable

[Will Deacon <will@kernel.org>]

On Tue, Mar 16, 2021 at 04:38:12PM +0100, Christoph Hellwig wrote:
> The only thing that fsl_pamu_window_enable does for the current caller
> is to fill in the prot value in the only dma_window structure, and to
> propagate a few values from the iommu_domain_geometry struture into the
> dma_window.  Remove the dma_window entirely, hardcode the prot value and
> otherwise use the iommu_domain_geometry structure instead.
> 
> Remove the now unused ->domain_window_enable iommu method.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Li Yang <leoyang.li@nxp.com>
> ---
>  drivers/iommu/fsl_pamu_domain.c     | 182 +++-------------------------
>  drivers/iommu/fsl_pamu_domain.h     |  17 ---
>  drivers/iommu/iommu.c               |  11 --
>  drivers/soc/fsl/qbman/qman_portal.c |   7 --
>  include/linux/iommu.h               |  17 ---
>  5 files changed, 14 insertions(+), 220 deletions(-)
> 
> diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
> index e6bdd38fc18409..fd2bc88b690465 100644
> --- a/drivers/iommu/fsl_pamu_domain.c
> +++ b/drivers/iommu/fsl_pamu_domain.c
> @@ -54,34 +54,18 @@ static int __init iommu_init_mempool(void)
>  	return 0;
>  }
>  
> -static phys_addr_t get_phys_addr(struct fsl_dma_domain *dma_domain, dma_addr_t iova)
> -{
> -	struct dma_window *win_ptr = &dma_domain->win_arr[0];
> -	struct iommu_domain_geometry *geom;
> -
> -	geom = &dma_domain->iommu_domain.geometry;
> -
> -	if (win_ptr->valid)
> -		return win_ptr->paddr + (iova & (win_ptr->size - 1));
> -
> -	return 0;
> -}
> -
>  /* Map the DMA window corresponding to the LIODN */
>  static int map_liodn(int liodn, struct fsl_dma_domain *dma_domain)
>  {
>  	int ret;
> -	struct dma_window *wnd = &dma_domain->win_arr[0];
> -	phys_addr_t wnd_addr = dma_domain->iommu_domain.geometry.aperture_start;
> +	struct iommu_domain_geometry *geom = &dma_domain->iommu_domain.geometry;
>  	unsigned long flags;
>  
>  	spin_lock_irqsave(&iommu_lock, flags);
> -	ret = pamu_config_ppaace(liodn, wnd_addr,
> -				 wnd->size,
> -				 ~(u32)0,
> -				 wnd->paddr >> PAMU_PAGE_SHIFT,
> -				 dma_domain->snoop_id, dma_domain->stash_id,
> -				 wnd->prot);
> +	ret = pamu_config_ppaace(liodn, geom->aperture_start,
> +				 geom->aperture_end - 1, ~(u32)0,

You're passing 'geom->aperture_end - 1' as the size here, but the old code
seemed to _add_ 1:

> -static int fsl_pamu_window_enable(struct iommu_domain *domain, u32 wnd_nr,
> -				  phys_addr_t paddr, u64 size, int prot)
> -{
> -	struct fsl_dma_domain *dma_domain = to_fsl_dma_domain(domain);
> -	struct dma_window *wnd;
> -	int pamu_prot = 0;
> -	int ret;
> -	unsigned long flags;
> -	u64 win_size;
> -
> -	if (prot & IOMMU_READ)
> -		pamu_prot |= PAACE_AP_PERMS_QUERY;
> -	if (prot & IOMMU_WRITE)
> -		pamu_prot |= PAACE_AP_PERMS_UPDATE;
> -
> -	spin_lock_irqsave(&dma_domain->domain_lock, flags);
> -	if (wnd_nr > 0) {
> -		pr_debug("Invalid window index\n");
> -		spin_unlock_irqrestore(&dma_domain->domain_lock, flags);
> -		return -EINVAL;
> -	}
> -
> -	win_size = (domain->geometry.aperture_end + 1) >> ilog2(1);

here ^^ when calculating the exclusive upper bound. In other words, I think
'1ULL << 36' used to get passed to pamu_config_ppaace(). Is that an
intentional change?

Will