Re: [PATCH v2 4/6] drm/msm: Add support to create a local pagetable
From: Robin Murphy
Date: Tue Jul 07 2020 - 07:36:48 EST
On 2020-06-26 21:04, Jordan Crouse wrote:
Add support to create a io-pgtable for use by targets that support
per-instance pagetables. In order to support per-instance pagetables the
GPU SMMU device needs to have the qcom,adreno-smmu compatible string and
split pagetables and auxiliary domains need to be supported and enabled.
Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_gpummu.c | 2 +-
drivers/gpu/drm/msm/msm_iommu.c | 180 ++++++++++++++++++++++++++++++-
drivers/gpu/drm/msm/msm_mmu.h | 16 ++-
3 files changed, 195 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpummu.c b/drivers/gpu/drm/msm/msm_gpummu.c
index 310a31b05faa..aab121f4beb7 100644
--- a/drivers/gpu/drm/msm/msm_gpummu.c
+++ b/drivers/gpu/drm/msm/msm_gpummu.c
@@ -102,7 +102,7 @@ struct msm_mmu *msm_gpummu_new(struct device *dev, struct msm_gpu *gpu)
}
gpummu->gpu = gpu;
- msm_mmu_init(&gpummu->base, dev, &funcs);
+ msm_mmu_init(&gpummu->base, dev, &funcs, MSM_MMU_GPUMMU);
return &gpummu->base;
}
diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index 1b6635504069..f455c597f76d 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -4,15 +4,192 @@
* Author: Rob Clark <robdclark@xxxxxxxxx>
*/
+#include <linux/io-pgtable.h>
#include "msm_drv.h"
#include "msm_mmu.h"
struct msm_iommu {
struct msm_mmu base;
struct iommu_domain *domain;
+ struct iommu_domain *aux_domain;
};
+
#define to_msm_iommu(x) container_of(x, struct msm_iommu, base)
+struct msm_iommu_pagetable {
+ struct msm_mmu base;
+ struct msm_mmu *parent;
+ struct io_pgtable_ops *pgtbl_ops;
+ phys_addr_t ttbr;
+ u32 asid;
+};
+
+static struct msm_iommu_pagetable *to_pagetable(struct msm_mmu *mmu)
+{
+ return container_of(mmu, struct msm_iommu_pagetable, base);
+}
+
+static int msm_iommu_pagetable_unmap(struct msm_mmu *mmu, u64 iova,
+ size_t size)
+{
+ struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
+ struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
+ size_t unmapped = 0;
+
+ /* Unmap the block one page at a time */
+ while (size) {
+ unmapped += ops->unmap(ops, iova, 4096, NULL);
+ iova += 4096;
+ size -= 4096;
+ }
+
+ iommu_flush_tlb_all(to_msm_iommu(pagetable->parent)->domain);
+
+ return (unmapped == size) ? 0 : -EINVAL;
+}
Remember in patch #1 when you said "Then 'domain' can be used like any
other iommu domain to map and unmap iova addresses in the pagetable."?
This appears to be very much not that :/
Robin.
+
+static int msm_iommu_pagetable_map(struct msm_mmu *mmu, u64 iova,
+ struct sg_table *sgt, size_t len, int prot)
+{
+ struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
+ struct io_pgtable_ops *ops = pagetable->pgtbl_ops;
+ struct scatterlist *sg;
+ size_t mapped = 0;
+ u64 addr = iova;
+ unsigned int i;
+
+ for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+ size_t size = sg->length;
+ phys_addr_t phys = sg_phys(sg);
+
+ /* Map the block one page at a time */
+ while (size) {
+ if (ops->map(ops, addr, phys, 4096, prot)) {
+ msm_iommu_pagetable_unmap(mmu, iova, mapped);
+ return -EINVAL;
+ }
+
+ phys += 4096;
+ addr += 4096;
+ size -= 4096;
+ mapped += 4096;
+ }
+ }
+
+ return 0;
+}
+
+static void msm_iommu_pagetable_destroy(struct msm_mmu *mmu)
+{
+ struct msm_iommu_pagetable *pagetable = to_pagetable(mmu);
+
+ free_io_pgtable_ops(pagetable->pgtbl_ops);
+ kfree(pagetable);
+}
+
+/*
+ * Given a parent device, create and return an aux domain. This will enable the
+ * TTBR0 region
+ */
+static struct iommu_domain *msm_iommu_get_aux_domain(struct msm_mmu *parent)
+{
+ struct msm_iommu *iommu = to_msm_iommu(parent);
+ struct iommu_domain *domain;
+ int ret;
+
+ if (iommu->aux_domain)
+ return iommu->aux_domain;
+
+ if (!iommu_dev_has_feature(parent->dev, IOMMU_DEV_FEAT_AUX))
+ return ERR_PTR(-ENODEV);
+
+ domain = iommu_domain_alloc(&platform_bus_type);
+ if (!domain)
+ return ERR_PTR(-ENODEV);
+
+ ret = iommu_aux_attach_device(domain, parent->dev);
+ if (ret) {
+ iommu_domain_free(domain);
+ return ERR_PTR(ret);
+ }
+
+ iommu->aux_domain = domain;
+ return domain;
+}
+
+int msm_iommu_pagetable_params(struct msm_mmu *mmu,
+ phys_addr_t *ttbr, int *asid)
+{
+ struct msm_iommu_pagetable *pagetable;
+
+ if (mmu->type != MSM_MMU_IOMMU_PAGETABLE)
+ return -EINVAL;
+
+ pagetable = to_pagetable(mmu);
+
+ if (ttbr)
+ *ttbr = pagetable->ttbr;
+
+ if (asid)
+ *asid = pagetable->asid;
+
+ return 0;
+}
+
+static const struct msm_mmu_funcs pagetable_funcs = {
+ .map = msm_iommu_pagetable_map,
+ .unmap = msm_iommu_pagetable_unmap,
+ .destroy = msm_iommu_pagetable_destroy,
+};
+
+struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
+{
+ static int next_asid = 16;
+ struct msm_iommu_pagetable *pagetable;
+ struct iommu_domain *aux_domain;
+ struct io_pgtable_cfg cfg;
+ int ret;
+
+ /* Make sure that the parent has a aux domain attached */
+ aux_domain = msm_iommu_get_aux_domain(parent);
+ if (IS_ERR(aux_domain))
+ return ERR_CAST(aux_domain);
+
+ /* Get the pagetable configuration from the aux domain */
+ ret = iommu_domain_get_attr(aux_domain, DOMAIN_ATTR_PGTABLE_CFG, &cfg);
+ if (ret)
+ return ERR_PTR(ret);
+
+ pagetable = kzalloc(sizeof(*pagetable), GFP_KERNEL);
+ if (!pagetable)
+ return ERR_PTR(-ENOMEM);
+
+ msm_mmu_init(&pagetable->base, parent->dev, &pagetable_funcs,
+ MSM_MMU_IOMMU_PAGETABLE);
+
+ cfg.tlb = NULL;
+
+ pagetable->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1,
+ &cfg, aux_domain);
+
+ if (!pagetable->pgtbl_ops) {
+ kfree(pagetable);
+ return ERR_PTR(-ENOMEM);
+ }
+
+
+ /* Needed later for TLB flush */
+ pagetable->parent = parent;
+ pagetable->ttbr = cfg.arm_lpae_s1_cfg.ttbr;
+
+ pagetable->asid = next_asid;
+ next_asid = (next_asid + 1) % 255;
+ if (next_asid < 16)
+ next_asid = 16;
+
+ return &pagetable->base;
+}
+
static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
unsigned long iova, int flags, void *arg)
{
@@ -40,6 +217,7 @@ static int msm_iommu_map(struct msm_mmu *mmu, uint64_t iova,
if (iova & BIT_ULL(48))
iova |= GENMASK_ULL(63, 49);
+
ret = iommu_map_sg(iommu->domain, iova, sgt->sgl, sgt->nents, prot);
WARN_ON(!ret);
@@ -85,7 +263,7 @@ struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain)
return ERR_PTR(-ENOMEM);
iommu->domain = domain;
- msm_mmu_init(&iommu->base, dev, &funcs);
+ msm_mmu_init(&iommu->base, dev, &funcs, MSM_MMU_IOMMU);
iommu_set_fault_handler(domain, msm_fault_handler, iommu);
ret = iommu_attach_device(iommu->domain, dev);
diff --git a/drivers/gpu/drm/msm/msm_mmu.h b/drivers/gpu/drm/msm/msm_mmu.h
index 3a534ee59bf6..61ade89d9e48 100644
--- a/drivers/gpu/drm/msm/msm_mmu.h
+++ b/drivers/gpu/drm/msm/msm_mmu.h
@@ -17,18 +17,26 @@ struct msm_mmu_funcs {
void (*destroy)(struct msm_mmu *mmu);
};
+enum msm_mmu_type {
+ MSM_MMU_GPUMMU,
+ MSM_MMU_IOMMU,
+ MSM_MMU_IOMMU_PAGETABLE,
+};
+
struct msm_mmu {
const struct msm_mmu_funcs *funcs;
struct device *dev;
int (*handler)(void *arg, unsigned long iova, int flags);
void *arg;
+ enum msm_mmu_type type;
};
static inline void msm_mmu_init(struct msm_mmu *mmu, struct device *dev,
- const struct msm_mmu_funcs *funcs)
+ const struct msm_mmu_funcs *funcs, enum msm_mmu_type type)
{
mmu->dev = dev;
mmu->funcs = funcs;
+ mmu->type = type;
}
struct msm_mmu *msm_iommu_new(struct device *dev, struct iommu_domain *domain);
@@ -41,7 +49,13 @@ static inline void msm_mmu_set_fault_handler(struct msm_mmu *mmu, void *arg,
mmu->handler = handler;
}
+struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent);
+
void msm_gpummu_params(struct msm_mmu *mmu, dma_addr_t *pt_base,
dma_addr_t *tran_error);
+
+int msm_iommu_pagetable_params(struct msm_mmu *mmu, phys_addr_t *ttbr,
+ int *asid);
+
#endif /* __MSM_MMU_H__ */