On 18:11-20250729, Jan Kiszka wrote: > On 29.07.25 14:22, Nishanth Menon wrote: > > On 10:36-20250728, huaqian.li@xxxxxxxxxxx wrote: > >> From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > >> > >> The TI Peripheral Virtualization Unit (PVU) permits to define a limited > >> set of mappings for DMA requests on the system memory. Unlike with an > >> IOMMU, there is no fallback to a memory-backed page table, only a fixed > >> set of register-backed TLBs. Emulating an IOMMU behavior appears to be > >> the more fragile the more fragmentation of pending requests occur. > >> > >> Therefore, this driver does not expose the PVU as an IOMMU. It rather > >> introduces a simple, static interface to devices that are under > >> restricted-dma-pool constraints. They can register their pools with the > >> PVUs, enabling only those pools to work for DMA. As also MSI is issued > >> as DMA, the PVU already register the related translator region of the > >> AM654 as valid DMA target. > >> > >> This driver is the essential building block for limiting DMA from > >> untrusted devices to clearly defined memory regions in the absence of a > >> real IOMMU (SMMU). > >> > >> Co-developed-by: Diogo Ivo <diogo.ivo@xxxxxxxxxxx> > >> Signed-off-by: Diogo Ivo <diogo.ivo@xxxxxxxxxxx> > >> Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx> > >> Signed-off-by: Li Hua Qian <huaqian.li@xxxxxxxxxxx> > >> --- > >> drivers/soc/ti/Kconfig | 4 + > >> drivers/soc/ti/Makefile | 1 + > >> drivers/soc/ti/ti-pvu.c | 500 ++++++++++++++++++++++++++++++++++++++++ > >> include/linux/ti-pvu.h | 32 +++ > >> 4 files changed, 537 insertions(+) > >> create mode 100644 drivers/soc/ti/ti-pvu.c > >> create mode 100644 include/linux/ti-pvu.h > >> > >> diff --git a/drivers/soc/ti/Kconfig b/drivers/soc/ti/Kconfig > >> index 1a93001c9e36..af7173ad84de 100644 > >> --- a/drivers/soc/ti/Kconfig > >> +++ b/drivers/soc/ti/Kconfig > >> @@ -82,6 +82,10 @@ config TI_PRUSS > >> processors on various TI SoCs. It's safe to say N here if you're > >> not interested in the PRU or if you are unsure. > >> > >> +config TI_PVU > >> + bool "TI Peripheral Virtualization Unit driver" > > > > tristate please? Prefer to make this as a module. > > > > > > PCI_KEYSTONE is bool and needs this (if enabled). So this won't be a > module in practice. > Something of the form of https://lore.kernel.org/all/20250307103128.3287497-1-s-vadapalli@xxxxxx/ will need to be done then. -- Regards, Nishanth Menon Key (0xDDB5849D1736249D) / Fingerprint: F8A2 8693 54EB 8232 17A3 1A34 DDB5 849D 1736 249D https://ti.com/opensource
