Re: [PATCH] iommu/sun50i: Allow page sizes between 4K and 1M

Jernej Škrabec
2023-09-11T19:29:58Z

On Monday, September 11, 2023 9:06:12 PM CEST Robin Murphy wrote:
> On 2023-09-11 20:02, Jernej Skrabec wrote:
> > While peripheral supports only 4K page sizes, we can easily emulate
> > support for bigger page sizes, up to 1M. This is done by making multiple
> > entries in map function or clearing multiple entries in unmap.
>
> No, it's done by converting over to the {map,unmap}_pages ops. There's
> no need to resurrect this horrible bodge.

Missed those, thanks! In any case, logic to implement those isn't that
different than here.

Best regards,
Jernej

>
> Thanks,
> Robin.
>
> > Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
> > ---
> >
> > drivers/iommu/sun50i-iommu.c | 49 +++++++++++++++++++++++-------------
> > 1 file changed, 31 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c
> > index 74c5cb93e900..93077575d60f 100644
> > --- a/drivers/iommu/sun50i-iommu.c
> > +++ b/drivers/iommu/sun50i-iommu.c
> > @@ -95,6 +95,10 @@
> >
> > #define SPAGE_SIZE 4096
> >
> > +#define SUN50I_IOMMU_PGSIZES (SZ_4K | SZ_8K | SZ_16K | SZ_32K |
\
> > + SZ_64K | SZ_128K |
SZ_256K | \
> > + SZ_512K | SZ_1M)
> > +
> >
> > struct sun50i_iommu {
> >
> > struct iommu_device iommu;
> >
> > @@ -593,10 +597,12 @@ static int sun50i_iommu_map(struct iommu_domain
> > *domain, unsigned long iova,>
> > {
> >
> > struct sun50i_iommu_domain *sun50i_domain =
to_sun50i_domain(domain);
> > struct sun50i_iommu *iommu = sun50i_domain->iommu;
> >
> > - u32 pte_index;
> > + u32 pte_index, pages, i;
> >
> > u32 *page_table, *pte_addr;
> > int ret = 0;
> >
> > + pages = size / SPAGE_SIZE;
> > +
> >
> > page_table = sun50i_dte_get_page_table(sun50i_domain, iova, gfp);
> > if (IS_ERR(page_table)) {
> >
> > ret = PTR_ERR(page_table);
> >
> > @@ -604,18 +610,22 @@ static int sun50i_iommu_map(struct iommu_domain
> > *domain, unsigned long iova,>
> > }
> >
> > pte_index = sun50i_iova_get_pte_index(iova);
> >
> > - pte_addr = &page_table[pte_index];
> > - if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
> > - phys_addr_t page_phys =
sun50i_pte_get_page_address(*pte_addr);
> > - dev_err(iommu->dev,
> > - "iova %pad already mapped to %pa cannot
remap to %pa prot: %#x\n",
> > - &iova, &page_phys, &paddr, prot);
> > - ret = -EBUSY;
> > - goto out;
> > + for (i = 0; i < pages; i++) {
> > + pte_addr = &page_table[pte_index + i];
> > + if (unlikely(sun50i_pte_is_page_valid(*pte_addr))) {
> > + phys_addr_t page_phys =
sun50i_pte_get_page_address(*pte_addr);
> > +
> > + dev_err(iommu->dev,
> > + "iova %pad already mapped to %pa
cannot remap to %pa prot: %#x\n",
> > + &iova, &page_phys, &paddr, prot);
> > + ret = -EBUSY;
> > + goto out;
> > + }
> > + *pte_addr = sun50i_mk_pte(paddr, prot);
> > + paddr += SPAGE_SIZE;
> >
> > }
> >
> > - *pte_addr = sun50i_mk_pte(paddr, prot);
> > - sun50i_table_flush(sun50i_domain, pte_addr, 1);
> > + sun50i_table_flush(sun50i_domain, &page_table[pte_index], pages);
> >
> > out:
> > return ret;
> >
> > @@ -626,8 +636,10 @@ static size_t sun50i_iommu_unmap(struct iommu_domain
> > *domain, unsigned long iova>
> > {
> >
> > struct sun50i_iommu_domain *sun50i_domain =
to_sun50i_domain(domain);
> > phys_addr_t pt_phys;
> >
> > + u32 dte, pages, i;
> >
> > u32 *pte_addr;
> >
> > - u32 dte;
> > +
> > + pages = size / SPAGE_SIZE;
> >
> > dte = sun50i_domain->dt[sun50i_iova_get_dte_index(iova)];
> > if (!sun50i_dte_is_pt_valid(dte))
> >
> > @@ -636,13 +648,14 @@ static size_t sun50i_iommu_unmap(struct iommu_domain
> > *domain, unsigned long iova>
> > pt_phys = sun50i_dte_get_pt_address(dte);
> > pte_addr = (u32 *)phys_to_virt(pt_phys) +
> > sun50i_iova_get_pte_index(iova);
> >
> > - if (!sun50i_pte_is_page_valid(*pte_addr))
> > - return 0;
> > + for (i = 0; i < pages; i++)
> > + if (!sun50i_pte_is_page_valid(pte_addr[i]))
> > + return 0;
> >
> > - memset(pte_addr, 0, sizeof(*pte_addr));
> > - sun50i_table_flush(sun50i_domain, pte_addr, 1);
> > + memset(pte_addr, 0, sizeof(*pte_addr) * pages);
> > + sun50i_table_flush(sun50i_domain, pte_addr, pages);
> >
> > - return SZ_4K;
> > + return size;
> >
> > }
> >
> > static phys_addr_t sun50i_iommu_iova_to_phys(struct iommu_domain
> > *domain,
> >
> > @@ -827,7 +840,7 @@ static int sun50i_iommu_of_xlate(struct device *dev,
> >
> > }
> >
> > static const struct iommu_ops sun50i_iommu_ops = {
> >
> > - .pgsize_bitmap = SZ_4K,
> > + .pgsize_bitmap = SUN50I_IOMMU_PGSIZES,
> >
> > .device_group = sun50i_iommu_device_group,
> > .domain_alloc = sun50i_iommu_domain_alloc,
> > .of_xlate = sun50i_iommu_of_xlate,