Not sure if this has been merged yet, but if not, try to add it as a
pull request on the github repo, then it'll get more visibility.
-- Robin
On 2020-05-26 16:17, Pankaj Bansal wrote:
> Hi Michael et. al
>
> Gentle ping.
>
> Regards,
> Pankaj Bansal
>
>> -----Original Message-----
>> From: Pankaj Bansal (OSS)
>> Sent: Tuesday, May 12, 2020 6:29 PM
>> To: Michael Brown <mc...@ipxe.org>
>> Cc: ipxe-devel@lists.ipxe.org
>> Subject: [PATCH] [efi] implement api to convert pci address to host address
>>
>> From: Pankaj Bansal <pankaj.ban...@nxp.com>
>>
>> The PCI device address may not be same as host address (CPU view address)
>> To read/write directly to PCI device's BARs (without using
>> EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.Mem.Read() and
>> EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.Mem.Write()) we need to convert PCI
>> device address to host address.
>>
>> The UEFI specifications 2.7 provide a method to translate the PCI device
>> address to host address and vice versa.
>>
>> device address = host address + translation offset
>>
>> EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL.Configuration() method can provide us
>> with
>> the translation offset and host address range.
>>
>> Using this we can convert the PCI device address to host address.
>>
>> Signed-off-by: Pankaj Bansal <pankaj.ban...@nxp.com>
>> ---
>> src/include/ipxe/pci_io.h | 10 ++++
>> src/interface/efi/efi_pci.c | 60 ++++++++++++++++++++
>> 2 files changed, 70 insertions(+)
>>
>> diff --git a/src/include/ipxe/pci_io.h b/src/include/ipxe/pci_io.h
>> index 10e69763..5806390d 100644
>> --- a/src/include/ipxe/pci_io.h
>> +++ b/src/include/ipxe/pci_io.h
>> @@ -122,4 +122,14 @@ int pci_write_config_word ( struct pci_device *pci,
>> unsigned int where,
>> int pci_write_config_dword ( struct pci_device *pci, unsigned int where,
>> uint32_t value );
>>
>> +/**
>> + * retrieve Host Address corresponding to pci bus address
>> + *
>> + * @v pci PCI device
>> + * @v bus_addr PCI Bus address
>> + * @v len Length of region
>> + * @ret io_addr Host address
>> + */
>> +uint64_t pci_ioremap ( struct pci_device *pci, uint64_t bus_addr, size_t
>> len );
>> +
>> #endif /* _IPXE_PCI_IO_H */
>> diff --git a/src/interface/efi/efi_pci.c b/src/interface/efi/efi_pci.c
>> index c1f451c9..b688210e 100644
>> --- a/src/interface/efi/efi_pci.c
>> +++ b/src/interface/efi/efi_pci.c
>> @@ -215,6 +215,66 @@ int efipci_write ( struct pci_device *pci, unsigned long
>> location,
>> return rc;
>> }
>>
>> +/**
>> + * retrieve Host Address corresponding to pci bus address
>> + *
>> + * @v pci PCI device
>> + * @v bus_addr PCI Bus address
>> + * @v len Length of region
>> + * @ret io_addr Host address
>> + */
>> +static uint64_t efi_pci_ioremap ( struct pci_device *pci, uint64_t bus_addr,
>> + size_t len ) {
>> + EFI_BOOT_SERVICES *bs = efi_systab->BootServices;
>> + EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL *root;
>> + EFI_ACPI_ADDRESS_SPACE_DESCRIPTOR *config;
>> + EFI_HANDLE handle;
>> + EFI_STATUS efirc;
>> + uint64_t bus_addr_start;
>> + int rc;
>> +
>> + /* Identify root bridge */
>> + if ( ( rc = efipci_root ( pci, &handle, &root ) ) != 0 )
>> + goto err_root;
>> +
>> + /* Retrieves the current resource settings of this PCI root bridge */
>> + efirc = root->Configuration ( root, (void **) &config);
>> + if (efirc != 0) {
>> + rc = -EEFI ( efirc );
>> + DBGC ( pci, "EFIPCI " PCI_FMT "Retrieval of current resource "
>> + "settings of PCI root bridge failed: %s\n",
>> + PCI_ARGS ( pci ), strerror ( rc ) );
>> + goto err_configuration;
>> + }
>> +
>> + /* According to UEFI 2.7,
>> + * EFI_PCI_ROOT_BRIDGE_IO_PROTOCOL::Configuration()
>> + * returns host address instead of device address,
>> + * while AddrTranslationOffset is not zero, and
>> + * device address = host address + AddrTranslationOffset, so
>> + * we convert host address to device address for range compare.
>> + */
>> + while ( config->Desc == ACPI_ADDRESS_SPACE_DESCRIPTOR ) {
>> + bus_addr_start = config->AddrRangeMin +
>> + config->AddrTranslationOffset;
>> + if ( ( config->ResType == ACPI_ADDRESS_SPACE_TYPE_MEM )
>> &&
>> + ( bus_addr_start <= bus_addr ) &&
>> + ( bus_addr_start + config->AddrLen >= bus_addr + len ) ) {
>> + return ( bus_addr - config->AddrTranslationOffset );
>> + }
>> + config++;
>> + }
>> +
>> + return bus_addr;
>> +
>> +err_configuration:
>> + bs->CloseProtocol ( handle, &efi_pci_root_bridge_io_protocol_guid,
>> + efi_image_handle, handle );
>> +err_root:
>> + return rc;
>> +}
>> +
>> +PROVIDE_PCIAPI (efi, pci_ioremap, efi_pci_ioremap);
>> PROVIDE_PCIAPI_INLINE ( efi, pci_num_bus );
>> PROVIDE_PCIAPI_INLINE ( efi, pci_read_config_byte );
>> PROVIDE_PCIAPI_INLINE ( efi, pci_read_config_word );
>> --
>> 2.17.1
>
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