Re: [PATCH 6/7] iommu/ipmmu-vmsa: Extract hardware context initialization

Laurent Pinchart
2019-02-20T15:35:41Z

Hi Geert,

Thank you for the patch.

On Wed, Feb 20, 2019 at 04:05:30PM +0100, Geert Uytterhoeven wrote:
> ipmmu_domain_init_context() takes care of (1) initializing the software
> domain, and (2) initializing the hardware context for the domain.
>
> Extract the code to initialize the hardware context into a new subroutine
> ipmmu_context_init(), to prepare for later reuse.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> drivers/iommu/ipmmu-vmsa.c | 91 ++++++++++++++++++++------------------
> 1 file changed, 48 insertions(+), 43 deletions(-)
>
> diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
> index 0a21e734466eb1bd..92a766dd8b459f0c 100644
> --- a/drivers/iommu/ipmmu-vmsa.c
> +++ b/drivers/iommu/ipmmu-vmsa.c
> @@ -404,52 +404,10 @@ static void ipmmu_domain_free_context(struct ipmmu_vmsa_device *mmu,
> spin_unlock_irqrestore(&mmu->lock, flags);
> }
>
> -static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
> +static void ipmmu_context_init(struct ipmmu_vmsa_domain *domain)

ipmmu_context_init() vs. ipmmmu_domain_init_context() is confusing. You
could call this one ipmmu_domain_setup_context() maybe ?

> {
> u64 ttbr;
> u32 tmp;
> - int ret;
> -
> - /*
> - * Allocate the page table operations.
> - *
> - * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
> - * access, Long-descriptor format" that the NStable bit being set in a
> - * table descriptor will result in the NStable and NS bits of all child
> - * entries being ignored and considered as being set. The IPMMU seems
> - * not to comply with this, as it generates a secure access page fault
> - * if any of the NStable and NS bits isn't set when running in
> - * non-secure mode.
> - */
> - domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
> - domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
> - domain->cfg.ias = 32;
> - domain->cfg.oas = 40;
> - domain->cfg.tlb = &ipmmu_gather_ops;
> - domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
> - domain->io_domain.geometry.force_aperture = true;
> - /*
> - * TODO: Add support for coherent walk through CCI with DVM and remove
> - * cache handling. For now, delegate it to the io-pgtable code.
> - */
> - domain->cfg.iommu_dev = domain->mmu->root->dev;
> -
> - /*
> - * Find an unused context.
> - */
> - ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
> - if (ret < 0)
> - return ret;
> -
> - domain->context_id = ret;
> -
> - domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
> - domain);
> - if (!domain->iop) {
> - ipmmu_domain_free_context(domain->mmu->root,
> - domain->context_id);
> - return -EINVAL;
> - }
>
> /* TTBR0 */
> ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
> @@ -495,7 +453,54 @@ static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
> */
> ipmmu_ctx_write_all(domain, IMCTR,
> IMCTR_INTEN | IMCTR_FLUSH | IMCTR_MMUEN);
> +}
> +
> +static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
> +{
> + int ret;
> +
> + /*
> + * Allocate the page table operations.
> + *
> + * VMSA states in section B3.6.3 "Control of Secure or Non-secure memory
> + * access, Long-descriptor format" that the NStable bit being set in a
> + * table descriptor will result in the NStable and NS bits of all child
> + * entries being ignored and considered as being set. The IPMMU seems
> + * not to comply with this, as it generates a secure access page fault
> + * if any of the NStable and NS bits isn't set when running in
> + * non-secure mode.
> + */
> + domain->cfg.quirks = IO_PGTABLE_QUIRK_ARM_NS;
> + domain->cfg.pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K;
> + domain->cfg.ias = 32;
> + domain->cfg.oas = 40;
> + domain->cfg.tlb = &ipmmu_gather_ops;
> + domain->io_domain.geometry.aperture_end = DMA_BIT_MASK(32);
> + domain->io_domain.geometry.force_aperture = true;
> + /*
> + * TODO: Add support for coherent walk through CCI with DVM and remove
> + * cache handling. For now, delegate it to the io-pgtable code.
> + */
> + domain->cfg.iommu_dev = domain->mmu->root->dev;
> +
> + /*
> + * Find an unused context.
> + */
> + ret = ipmmu_domain_allocate_context(domain->mmu->root, domain);
> + if (ret < 0)
> + return ret;
> +
> + domain->context_id = ret;
> +
> + domain->iop = alloc_io_pgtable_ops(ARM_32_LPAE_S1, &domain->cfg,
> + domain);
> + if (!domain->iop) {
> + ipmmu_domain_free_context(domain->mmu->root,
> + domain->context_id);
> + return -EINVAL;
> + }
>
> + ipmmu_context_init(domain);
> return 0;
> }
>

--
Regards,

Laurent Pinchart