2024-06-14 14:23:11

by Zong Li

Subject: [RFC PATCH v2 04/10] iommu/riscv: add iotlb_sync_map operation support

Add iotlb_sync_map operation for flush IOTLB. Software must
flush the IOTLB after each page table.

Signed-off-by: Zong Li <[email protected]>
---
drivers/iommu/riscv/Makefile | 1 +
drivers/iommu/riscv/iommu.c | 11 +++++++++++
2 files changed, 12 insertions(+)

diff --git a/drivers/iommu/riscv/Makefile b/drivers/iommu/riscv/Makefile
index d36625a1fd08..f02ce6ebfbd0 100644
--- a/drivers/iommu/riscv/Makefile
+++ b/drivers/iommu/riscv/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only
obj-$(CONFIG_RISCV_IOMMU) += iommu.o iommu-platform.o iommu-pmu.o
obj-$(CONFIG_RISCV_IOMMU_PCI) += iommu-pci.o
+obj-$(CONFIG_SIFIVE_IOMMU) += iommu-sifive.o
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 9aeb4b20c145..df7aeb2571ae 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1115,6 +1115,16 @@ static void riscv_iommu_iotlb_sync(struct iommu_domain *iommu_domain,
riscv_iommu_iotlb_inval(domain, gather->start, gather->end);
}

+static int riscv_iommu_iotlb_sync_map(struct iommu_domain *iommu_domain,
+ unsigned long iova, size_t size)
+{
+ struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
+
+ riscv_iommu_iotlb_inval(domain, iova, iova + size - 1);
+
+ return 0;
+}
+
static inline size_t get_page_size(size_t size)
{
if (size >= IOMMU_PAGE_SIZE_512G)
@@ -1396,6 +1406,7 @@ static const struct iommu_domain_ops riscv_iommu_paging_domain_ops = {
.unmap_pages = riscv_iommu_unmap_pages,
.iova_to_phys = riscv_iommu_iova_to_phys,
.iotlb_sync = riscv_iommu_iotlb_sync,
+ .iotlb_sync_map = riscv_iommu_iotlb_sync_map,
.flush_iotlb_all = riscv_iommu_iotlb_flush_all,
};

--
2.17.1

2024-06-15 03:17:19

by Lu Baolu

Subject: Re: [RFC PATCH v2 04/10] iommu/riscv: add iotlb_sync_map operation support

On 6/14/24 10:21 PM, Zong Li wrote:
> Add iotlb_sync_map operation for flush IOTLB. Software must
> flush the IOTLB after each page table.
>
> Signed-off-by: Zong Li<[email protected]>
> ---
> drivers/iommu/riscv/Makefile | 1 +
> drivers/iommu/riscv/iommu.c | 11 +++++++++++
> 2 files changed, 12 insertions(+)
>
> diff --git a/drivers/iommu/riscv/Makefile b/drivers/iommu/riscv/Makefile
> index d36625a1fd08..f02ce6ebfbd0 100644
> --- a/drivers/iommu/riscv/Makefile
> +++ b/drivers/iommu/riscv/Makefile
> @@ -1,3 +1,4 @@
> # SPDX-License-Identifier: GPL-2.0-only
> obj-$(CONFIG_RISCV_IOMMU) += iommu.o iommu-platform.o iommu-pmu.o
> obj-$(CONFIG_RISCV_IOMMU_PCI) += iommu-pci.o
> +obj-$(CONFIG_SIFIVE_IOMMU) += iommu-sifive.o
> diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
> index 9aeb4b20c145..df7aeb2571ae 100644
> --- a/drivers/iommu/riscv/iommu.c
> +++ b/drivers/iommu/riscv/iommu.c
> @@ -1115,6 +1115,16 @@ static void riscv_iommu_iotlb_sync(struct iommu_domain *iommu_domain,
> riscv_iommu_iotlb_inval(domain, gather->start, gather->end);
> }
>
> +static int riscv_iommu_iotlb_sync_map(struct iommu_domain *iommu_domain,
> + unsigned long iova, size_t size)
> +{
> + struct riscv_iommu_domain *domain = iommu_domain_to_riscv(iommu_domain);
> +
> + riscv_iommu_iotlb_inval(domain, iova, iova + size - 1);

Does the RISC-V IOMMU architecture always cache the non-present or
erroneous translation entries? If so, can you please provide more
context in the commit message?

If not, why do you want to flush the cache when building a new
translation?

Best regards,
baolu