[PATCH v17 08/20] drm/msm: Add support to create a local pagetable

Rob Clark
2020-09-05T20:06:09Z

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 enabled.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
drivers/gpu/drm/msm/Kconfig | 1 +
drivers/gpu/drm/msm/msm_gpummu.c | 2 +-
drivers/gpu/drm/msm/msm_iommu.c | 199 ++++++++++++++++++++++++++++++-
drivers/gpu/drm/msm/msm_mmu.h | 16 ++-
4 files changed, 215 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/Kconfig b/drivers/gpu/drm/msm/Kconfig
index 6deaa7d01654..5102a58830b9 100644
--- a/drivers/gpu/drm/msm/Kconfig
+++ b/drivers/gpu/drm/msm/Kconfig
@@ -8,6 +8,7 @@ config DRM_MSM
depends on MMU
depends on INTERCONNECT || !INTERCONNECT
depends on QCOM_OCMEM || QCOM_OCMEM=n
+ select IOMMU_IO_PGTABLE
select QCOM_MDT_LOADER if ARCH_QCOM
select REGULATOR
select DRM_KMS_HELPER
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..697cc0a059d6 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -4,15 +4,210 @@
* Author: Rob Clark <robdclark@gmail.com>
*/

+#include <linux/adreno-smmu-priv.h>
+#include <linux/io-pgtable.h>
#include "msm_drv.h"
#include "msm_mmu.h"

struct msm_iommu {
struct msm_mmu base;
struct iommu_domain *domain;
+ atomic_t pagetables;
};
+
#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;
+}
+
+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, GFP_KERNEL)) {
+ 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);
+ struct msm_iommu *iommu = to_msm_iommu(pagetable->parent);
+ struct adreno_smmu_priv *adreno_smmu =
+ dev_get_drvdata(pagetable->parent->dev);
+
+ /*
+ * If this is the last attached pagetable for the parent,
+ * disable TTBR0 in the arm-smmu driver
+ */
+ if (atomic_dec_return(&iommu->pagetables) == 0)
+ adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, NULL);
+
+ free_io_pgtable_ops(pagetable->pgtbl_ops);
+ kfree(pagetable);
+}
+
+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,
+};
+
+static void msm_iommu_tlb_flush_all(void *cookie)
+{
+}
+
+static void msm_iommu_tlb_flush_walk(unsigned long iova, size_t size,
+ size_t granule, void *cookie)
+{
+}
+
+static void msm_iommu_tlb_add_page(struct iommu_iotlb_gather *gather,
+ unsigned long iova, size_t granule, void *cookie)
+{
+}
+
+static const struct iommu_flush_ops null_tlb_ops = {
+ .tlb_flush_all = msm_iommu_tlb_flush_all,
+ .tlb_flush_walk = msm_iommu_tlb_flush_walk,
+ .tlb_flush_leaf = msm_iommu_tlb_flush_walk,
+ .tlb_add_page = msm_iommu_tlb_add_page,
+};
+
+struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
+{
+ struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(parent->dev);
+ struct msm_iommu *iommu = to_msm_iommu(parent);
+ struct msm_iommu_pagetable *pagetable;
+ const struct io_pgtable_cfg *ttbr1_cfg = NULL;
+ struct io_pgtable_cfg ttbr0_cfg;
+ int ret;
+
+ /* Get the pagetable configuration from the domain */
+ if (adreno_smmu->cookie)
+ ttbr1_cfg = adreno_smmu->get_ttbr1_cfg(adreno_smmu->cookie);
+ if (!ttbr1_cfg)
+ return ERR_PTR(-ENODEV);
+
+ 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);
+
+ /* Clone the TTBR1 cfg as starting point for TTBR0 cfg: */
+ ttbr0_cfg = *ttbr1_cfg;
+
+ /* The incoming cfg will have the TTBR1 quirk enabled */
+ ttbr0_cfg.quirks &= ~IO_PGTABLE_QUIRK_ARM_TTBR1;
+ ttbr0_cfg.tlb = &null_tlb_ops;
+
+ pagetable->pgtbl_ops = alloc_io_pgtable_ops(ARM_64_LPAE_S1,
+ &ttbr0_cfg, iommu->domain);
+
+ if (!pagetable->pgtbl_ops) {
+ kfree(pagetable);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /*
+ * If this is the first pagetable that we've allocated, send it back to
+ * the arm-smmu driver as a trigger to set up TTBR0
+ */
+ if (atomic_inc_return(&iommu->pagetables) == 1) {
+ ret = adreno_smmu->set_ttbr0_cfg(adreno_smmu->cookie, &ttbr0_cfg);
+ if (ret) {
+ free_io_pgtable_ops(pagetable->pgtbl_ops);
+ kfree(pagetable);
+ return ERR_PTR(ret);
+ }
+ }
+
+ /* Needed later for TLB flush */
+ pagetable->parent = parent;
+ pagetable->ttbr = ttbr0_cfg.arm_lpae_s1_cfg.ttbr;
+
+ /*
+ * TODO we would like each set of page tables to have a unique ASID
+ * to optimize TLB invalidation. But iommu_flush_tlb_all() will
+ * end up flushing the ASID used for TTBR1 pagetables, which is not
+ * what we want. So for now just use the same ASID as TTBR1.
+ */
+ pagetable->asid = 0;
+
+ return &pagetable->base;
+}
+
static int msm_fault_handler(struct iommu_domain *domain, struct device *dev,
unsigned long iova, int flags, void *arg)
{
@@ -85,9 +280,11 @@ 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);

+ atomic_set(&iommu->pagetables, 0);
+
ret = iommu_attach_device(iommu->domain, dev);
if (ret) {
kfree(iommu);
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__ */
--
2.26.2