[PATCH v5 3/4] iommu: rockchip: Add internal ops to handle variants
Benjamin Gaignard
benjamin.gaignard at collabora.com
Fri May 21 06:38:51 PDT 2021
Le 21/05/2021 à 14:58, Robin Murphy a écrit :
> On 2021-05-21 09:36, Benjamin Gaignard wrote:
>> Add internal ops to be able to handle incoming variant v2.
>> The goal is to keep the overall structure of the framework but
>> to allow to add the evolution of this hardware block.
>>
>> The ops are global for a SoC because iommu domains are not
>> attached to a specific devices if they are for a virtuel device like
>> drm. Use a global variable shouldn't be since SoC usually doesn't
>> embedded different versions of the iommu hardware block.
>> If that happen one day a WARN_ON will be displayed at probe time.
>
> IMO it would be a grievous error if such a "virtual device" ever gets
> near the IOMMU API, so personally I wouldn't use that as a
> justification for anything :)
>
> FWIW you should be OK to handle things on a per-instance basis, it
> just means you have to defer some of the domain setup to .attach_dev
> time, like various other drivers do. That said, there's nothing wrong
> with the global if we do expect instances to be consistent across any
> given Rockchip SoC (and my gut feeling is that we probably should).
I have tried that solution first but drm device appear to but such "virtual device" so I had to use the global.
I send a v6 to fix your others remarks.
Thanks for your advice.
Benjamin
>
>> Signed-off-by: Benjamin Gaignard <benjamin.gaignard at collabora.com>
>> ---
>> version 5:
>> - Use of_device_get_match_data()
>> - Add internal ops inside the driver
>>
>> drivers/iommu/rockchip-iommu.c | 69 ++++++++++++++++++++++++----------
>> 1 file changed, 50 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/iommu/rockchip-iommu.c
>> b/drivers/iommu/rockchip-iommu.c
>> index 7a2932772fdf..e7b9bcf174b1 100644
>> --- a/drivers/iommu/rockchip-iommu.c
>> +++ b/drivers/iommu/rockchip-iommu.c
>> @@ -19,6 +19,7 @@
>> #include <linux/iopoll.h>
>> #include <linux/list.h>
>> #include <linux/mm.h>
>> +#include <linux/module.h>
>
> This seems to be an unrelated and unnecessary change.
>
>> #include <linux/init.h>
>> #include <linux/of.h>
>> #include <linux/of_iommu.h>
>> @@ -96,6 +97,14 @@ static const char * const rk_iommu_clocks[] = {
>> "aclk", "iface",
>> };
>> +struct rk_iommu_ops {
>> + phys_addr_t (*pt_address)(u32 dte);
>> + u32 (*mk_dtentries)(dma_addr_t pt_dma);
>> + u32 (*mk_ptentries)(phys_addr_t page, int prot);
>> + phys_addr_t (*dte_addr_phys)(phys_addr_t addr);
>> + u32 pt_address_mask;
>> +};
>> +
>> struct rk_iommu {
>> struct device *dev;
>> void __iomem **bases;
>> @@ -116,6 +125,7 @@ struct rk_iommudata {
>> };
>> static struct device *dma_dev;
>> +static const struct rk_iommu_ops *rk_ops;
>> static inline void rk_table_flush(struct rk_iommu_domain *dom,
>> dma_addr_t dma,
>> unsigned int count)
>> @@ -215,11 +225,6 @@ static inline u32 rk_mk_dte(dma_addr_t pt_dma)
>> #define RK_PTE_PAGE_READABLE BIT(1)
>> #define RK_PTE_PAGE_VALID BIT(0)
>> -static inline phys_addr_t rk_pte_page_address(u32 pte)
>> -{
>> - return (phys_addr_t)pte & RK_PTE_PAGE_ADDRESS_MASK;
>> -}
>> -
>> static inline bool rk_pte_is_page_valid(u32 pte)
>> {
>> return pte & RK_PTE_PAGE_VALID;
>> @@ -451,7 +456,7 @@ static int rk_iommu_force_reset(struct rk_iommu
>> *iommu)
>> rk_iommu_write(iommu->bases[i], RK_MMU_DTE_ADDR,
>> DTE_ADDR_DUMMY);
>> dte_addr = rk_iommu_read(iommu->bases[i], RK_MMU_DTE_ADDR);
>> - if (dte_addr != (DTE_ADDR_DUMMY & RK_DTE_PT_ADDRESS_MASK)) {
>> + if (dte_addr != (DTE_ADDR_DUMMY & rk_ops->pt_address_mask)) {
>
> Nit: might it make more sense to do something like:
>
> dte_addr = rk_ops->pt_address(... DTE_ADDR_DUMMY);
> rk_iommu_write(... dte_addr)
> if (rk_iommu_read(...) != dte_addr)
>
> so that you don't need to bother defining ->pt_address_mask for just
> this one sanity-check?
>
>> dev_err(iommu->dev, "Error during raw reset.
>> MMU_DTE_ADDR is not functioning\n");
>> return -EFAULT;
>> }
>> @@ -470,6 +475,11 @@ static int rk_iommu_force_reset(struct rk_iommu
>> *iommu)
>> return 0;
>> }
>> +static inline phys_addr_t rk_dte_addr_phys(phys_addr_t addr)
>
> The argument type here should be u32, since it's a DTE, not a physical
> address...
>
>> +{
>> + return addr;
>> +}
>> +
>> static void log_iova(struct rk_iommu *iommu, int index, dma_addr_t
>> iova)
>> {
>> void __iomem *base = iommu->bases[index];
>> @@ -489,7 +499,7 @@ static void log_iova(struct rk_iommu *iommu, int
>> index, dma_addr_t iova)
>> page_offset = rk_iova_page_offset(iova);
>> mmu_dte_addr = rk_iommu_read(base, RK_MMU_DTE_ADDR);
>> - mmu_dte_addr_phys = (phys_addr_t)mmu_dte_addr;
>> + mmu_dte_addr_phys =
>> rk_ops->dte_addr_phys((phys_addr_t)mmu_dte_addr);
>
> ...and the cast here should not be here, since it *is* the conversion
> that the called function is supposed to be performing.
>
>> dte_addr_phys = mmu_dte_addr_phys + (4 * dte_index);
>> dte_addr = phys_to_virt(dte_addr_phys);
>> @@ -498,14 +508,14 @@ static void log_iova(struct rk_iommu *iommu,
>> int index, dma_addr_t iova)
>> if (!rk_dte_is_pt_valid(dte))
>> goto print_it;
>> - pte_addr_phys = rk_dte_pt_address(dte) + (pte_index * 4);
>> + pte_addr_phys = rk_ops->pt_address(dte) + (pte_index * 4);
>> pte_addr = phys_to_virt(pte_addr_phys);
>> pte = *pte_addr;
>> if (!rk_pte_is_page_valid(pte))
>> goto print_it;
>> - page_addr_phys = rk_pte_page_address(pte) + page_offset;
>> + page_addr_phys = rk_ops->pt_address(pte) + page_offset;
>> page_flags = pte & RK_PTE_PAGE_FLAGS_MASK;
>> print_it:
>> @@ -601,13 +611,13 @@ static phys_addr_t rk_iommu_iova_to_phys(struct
>> iommu_domain *domain,
>> if (!rk_dte_is_pt_valid(dte))
>> goto out;
>> - pt_phys = rk_dte_pt_address(dte);
>> + pt_phys = rk_ops->pt_address(dte);
>> page_table = (u32 *)phys_to_virt(pt_phys);
>> pte = page_table[rk_iova_pte_index(iova)];
>> if (!rk_pte_is_page_valid(pte))
>> goto out;
>> - phys = rk_pte_page_address(pte) + rk_iova_page_offset(iova);
>> + phys = rk_ops->pt_address(pte) + rk_iova_page_offset(iova);
>> out:
>> spin_unlock_irqrestore(&rk_domain->dt_lock, flags);
>> @@ -679,14 +689,14 @@ static u32 *rk_dte_get_page_table(struct
>> rk_iommu_domain *rk_domain,
>> return ERR_PTR(-ENOMEM);
>> }
>> - dte = rk_mk_dte(pt_dma);
>> + dte = rk_ops->mk_dtentries(pt_dma);
>> *dte_addr = dte;
>> rk_table_flush(rk_domain, pt_dma, NUM_PT_ENTRIES);
>> rk_table_flush(rk_domain,
>> rk_domain->dt_dma + dte_index * sizeof(u32), 1);
>> done:
>> - pt_phys = rk_dte_pt_address(dte);
>> + pt_phys = rk_ops->pt_address(dte);
>> return (u32 *)phys_to_virt(pt_phys);
>> }
>> @@ -728,7 +738,7 @@ static int rk_iommu_map_iova(struct
>> rk_iommu_domain *rk_domain, u32 *pte_addr,
>> if (rk_pte_is_page_valid(pte))
>> goto unwind;
>> - pte_addr[pte_count] = rk_mk_pte(paddr, prot);
>> + pte_addr[pte_count] = rk_ops->mk_ptentries(paddr, prot);
>> paddr += SPAGE_SIZE;
>> }
>> @@ -750,7 +760,7 @@ static int rk_iommu_map_iova(struct
>> rk_iommu_domain *rk_domain, u32 *pte_addr,
>> pte_count * SPAGE_SIZE);
>> iova += pte_count * SPAGE_SIZE;
>> - page_phys = rk_pte_page_address(pte_addr[pte_count]);
>> + page_phys = rk_ops->pt_address(pte_addr[pte_count]);
>> pr_err("iova: %pad already mapped to %pa cannot remap to phys:
>> %pa prot: %#x\n",
>> &iova, &page_phys, &paddr, prot);
>> @@ -785,7 +795,8 @@ static int rk_iommu_map(struct iommu_domain
>> *domain, unsigned long _iova,
>> dte_index = rk_domain->dt[rk_iova_dte_index(iova)];
>> pte_index = rk_iova_pte_index(iova);
>> pte_addr = &page_table[pte_index];
>> - pte_dma = rk_dte_pt_address(dte_index) + pte_index * sizeof(u32);
>> +
>> + pte_dma = rk_ops->pt_address(dte_index) + pte_index * sizeof(u32);
>> ret = rk_iommu_map_iova(rk_domain, pte_addr, pte_dma, iova,
>> paddr, size, prot);
>> @@ -821,7 +832,7 @@ static size_t rk_iommu_unmap(struct
>> iommu_domain *domain, unsigned long _iova,
>> return 0;
>> }
>> - pt_phys = rk_dte_pt_address(dte);
>> + pt_phys = rk_ops->pt_address(dte);
>> pte_addr = (u32 *)phys_to_virt(pt_phys) + rk_iova_pte_index(iova);
>> pte_dma = pt_phys + rk_iova_pte_index(iova) * sizeof(u32);
>> unmap_size = rk_iommu_unmap_iova(rk_domain, pte_addr, pte_dma,
>> size);
>> @@ -1037,7 +1048,7 @@ static void rk_iommu_domain_free(struct
>> iommu_domain *domain)
>> for (i = 0; i < NUM_DT_ENTRIES; i++) {
>> u32 dte = rk_domain->dt[i];
>> if (rk_dte_is_pt_valid(dte)) {
>> - phys_addr_t pt_phys = rk_dte_pt_address(dte);
>> + phys_addr_t pt_phys = rk_ops->pt_address(dte);
>> u32 *page_table = phys_to_virt(pt_phys);
>> dma_unmap_single(dma_dev, pt_phys,
>> SPAGE_SIZE, DMA_TO_DEVICE);
>> @@ -1138,6 +1149,15 @@ static int rk_iommu_probe(struct
>> platform_device *pdev)
>> iommu->dev = dev;
>> iommu->num_mmu = 0;
>> + if (!rk_ops)
>> + rk_ops = of_device_get_match_data(dev);
>> +
>> + /*
>> + * That should not happen unless different versions of the
>> + * hardware block are embedded the same SoC
>> + */
>> + WARN_ON(rk_ops != of_device_get_match_data(dev));
>
> Nit: calling of_device_get_match_data() twice seems rather untidy -
> how about something like:
>
> ops = of_device_get_match_data(dev);
> if (!rk_ops)
> rk_ops = ops;
> else if (WARN_ON(rk_ops != ops))
> return -EINVAL;
>
> Either way I think it would be good to treat unexpected inconsistentcy
> as an actual error, rather than second-guessing the DT and carrying on
> under the assumption the device is something other than it claimed to be.
>
>> +
>> iommu->bases = devm_kcalloc(dev, num_res, sizeof(*iommu->bases),
>> GFP_KERNEL);
>> if (!iommu->bases)
>> @@ -1277,10 +1297,21 @@ static const struct dev_pm_ops
>> rk_iommu_pm_ops = {
>> pm_runtime_force_resume)
>> };
>> +static struct rk_iommu_ops iommu_data_ops_v1 = {
>> + .pt_address = &rk_dte_pt_address,
>> + .mk_dtentries = &rk_mk_dte,
>> + .mk_ptentries = &rk_mk_pte,
>> + .dte_addr_phys = &rk_dte_addr_phys,
>> + .pt_address_mask = RK_DTE_PT_ADDRESS_MASK,
>> +};
>> +
>> static const struct of_device_id rk_iommu_dt_ids[] = {
>> - { .compatible = "rockchip,iommu" },
>> + { .compatible = "rockchip,iommu",
>> + .data = &iommu_data_ops_v1,
>> + },
>> { /* sentinel */ }
>> };
>> +MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
>
> As before, unrelated and unnecessary since this driver is still bool
> in the Kconfig. If you do want to support modular builds you'll also
> need to ensure rk_iommu_ops.owner is set, but do it all as a separate
> patch please.
>
> Thanks,
> Robin.
>
>> static struct platform_driver rk_iommu_driver = {
>> .probe = rk_iommu_probe,
>>
>
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