coresight: catu: Add support for scatter gather tables
This patch adds the support for setting up a SG table for use by the CATU. We reuse the tmc_sg_table to represent the table/data pages, even though the table format is different. Similar to ETR SG table, CATU uses a 4KB page size for data buffers as well as page tables. All table entries are 64bit wide and have the following format: 63 12 1 0 x-----------------------------------x | Address [63-12] | SBZ | V | x-----------------------------------x Where [V] -> 0 - Pointer is invalid 1 - Pointer is Valid CATU uses only first half of the page for data page pointers. i.e, single table page will only have 256 page pointers, addressing upto 1MB of data. The second half of a table page contains only two pointers at the end of the page (i.e, pointers at index 510 and 511), which are used as links to the "Previous" and "Next" page tables respectively. The first table page has an "Invalid" previous pointer and the next pointer entry points to the second page table if there is one. Similarly the last table page has an "Invalid" next pointer to indicate the end of the table chain. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by:Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by:
Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
parent
a59e5ff9
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