Hi Heinrich,
On Wed, 13 Dec 2023 at 07:23, Heinrich Schuchardt xypron.glpk@gmx.de wrote:
On 13.12.23 09:57, Masahisa Kojima wrote:
Current code uses struct efi_disk_obj to keep information about block devices and partitions. As the efi handle already has a field with the udevice, we should eliminate struct efi_disk_obj and use an pointer to struct efi_object for the handle.
efi_link_dev() call is moved inside of efi_disk_add_dev() function to simplify the cleanup process in case of error.
I agree that using struct efi_disk_obj as a container for protocols of a block IO device is a bit messy.
But we should keep looking up the handle easy. Currently we use
diskobj = container_of(this, struct efi_disk_obj, ops);
Instead we could append a private field with the handle to the EFI_BLOCK_IO_PROTOCOL structure.
Signed-off-by: Masahisa Kojima masahisa.kojima@linaro.org
lib/efi_loader/efi_disk.c | 209 +++++++++++++++++++++----------------- 1 file changed, 116 insertions(+), 93 deletions(-)
diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c index f0d76113b0..cfb7ace551 100644 --- a/lib/efi_loader/efi_disk.c +++ b/lib/efi_loader/efi_disk.c @@ -27,27 +27,24 @@ struct efi_system_partition efi_system_partition = { const efi_guid_t efi_block_io_guid = EFI_BLOCK_IO_PROTOCOL_GUID; const efi_guid_t efi_system_partition_guid = PARTITION_SYSTEM_GUID;
-/**
- struct efi_disk_obj - EFI disk object
- @header: EFI object header
- @ops: EFI disk I/O protocol interface
- @dev_index: device index of block device
- @media: block I/O media information
- @dp: device path to the block device
- @part: partition
- @volume: simple file system protocol of the partition
- @dev: associated DM device
- */
-struct efi_disk_obj {
struct efi_object header;struct efi_block_io ops;int dev_index;struct efi_block_io_media media;struct efi_device_path *dp;unsigned int part;struct efi_simple_file_system_protocol *volume;-}; +static efi_handle_t efi_blkio_find_obj(struct efi_block_io *blkio) +{
efi_handle_t handle;list_for_each_entry(handle, &efi_obj_list, link) {efi_status_t ret;struct efi_handler *handler;ret = efi_search_protocol(handle, &efi_block_io_guid, &handler);if (ret != EFI_SUCCESS)continue;if (blkio == handler->protocol_interface)return handle;}Depending on the number of handles and pointers this will take a considerable time. A private field for the handle appended to struct efi_block_io would allow a fast lookup.
EDK II does the same. See the definition of RAM_DISK_PRIVATE_FROM_BLKIO which uses macro BASE_CR() to find the private fields.
That seems pretty ugly to me, but if it really is that slow, I suppose it is OK.
Can we attach efi_block_io to the driver model BLK device?
Regards, Simon