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| author |   Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
|---|---|---|
| committer | Angelos Mouzakitis <a.mouzakitis@virtualopensystems.com> | 2023-10-10 14:33:42 +0000 |
| commit | af1a266670d040d2f4083ff309d732d648afba2a (patch) | |
| tree | 2fc46203448ddcc6f81546d379abfaeb323575e9 /roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst | |
| parent | e02cda008591317b1625707ff8e115a4841aa889 (diff) | |
Change-Id: Iaf8d18082d3991dec7c0ebbea540f092188eb4ec
Diffstat (limited to 'roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst')
| -rw-r--r-- | roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst b/roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst new file mode 100644 index 000000000..87395d1ee --- /dev/null +++ b/roms/skiboot/doc/opal-api/opal-pci-map-pe-dma-window-real-45.rst @@ -0,0 +1,55 @@ +.. _OPAL_PCI_MAP_PE_DMA_WINDOW_REAL: + +OPAL_PCI_MAP_PE_DMA_WINDOW_REAL +=============================== + +.. code-block:: c + + #define OPAL_PCI_MAP_PE_DMA_WINDOW_REAL 45 + + int64_t opal_pci_map_pe_dma_window_real(uint64_t phb_id, + uint64_t pe_number, + uint16_t window_id, + uint64_t pci_start_addr, + uint64_t pci_mem_size); + + +**WARNING:** following documentation is from old sources, and is possibly +not representative of OPALv3 as implemented by skiboot. This should be +used as a starting point for full documentation. + +The host calls this function to initialize the specified DMA window for +untranslated DMA addresses. This allows a PE to DMA directly to system memory +without TCE translation. The DMA window PCI memory address is equal to the +system memory real address. The PHB passes PCI address bits 04:63 directly to +system real address bits 04:63 when PCI address bits 04:39 are within the +region specified by mem_addr t0 mem_addr + window_size. + +The addresses must be 16MB aligned and a multiple of 16MB in size. + +``phb_id`` + is the value from the PHB node ibm,opal-phbid property. + +``dma_window_number`` + specifies the DMA window + +For ibm,opal-ioda PHBs the dma_window_number is an index from 0 to the PHB +total number of windows minus 1. For ibm,opal-ioda2 PHBs the DMA window_number +is an index from 0 to n-1, where n is the number of windows per window set, +within the window set associated with the specified PE number. + +``pe_number`` + is the index of the PE that is authorized to DMA to this window + address space in PCI memory, + +``mem_addr`` + is the starting 64-bit system real address mapped directly to the + starting address in PCI memory. Addresses below 4GB are zero in bits above + bit 32. This value must be aligned on a 16MB boundary; OPAL returns + OPAL_PARAMETER for any value that is not a multiple of 16MB. + +``window_size`` + is the size, in bytes, of the address range defined by this + window. This value must be a multiple of 16MB; OPAL returns :ref:`OPAL_PARAMETER` + for any value that is not a multiple of 16MB. A value of '0' indicates to + disable this DMA window. |