opensbi.git/lib/sbi/sbi_scratch.c, branch v1.2

lib: sbi_scratch: zero out scratch memory on all harts

2021-06-11T08:29:48Z

In sbi_scratch_init() we determine the last hart. The index of the last hart cannot exceed SBI_HARTMASK_MAX_BITS - 1. We should not initialize last_hartid_having_scratch to a higher number to avoid buffer overflows when using this value before calling sbi_scratch_init(). When allocating scratch memory in sbi_scratch_alloc_offset() we zero out the allocated memory for all harts except for the last one. We should not skip the last hart. Signed-off-by: Heinrich Schuchardt Reviewed-by: Anup Patel

lib: sbi_scratch: remove owner from sbi_scratch_alloc_offset

2021-06-02T11:37:26Z

The parameter owner of function sbi_scratch_alloc_offset() is never used. The scratch memory is small. We should not use it for debug information in future. Hence eliminate the parameter. Signed-off-by: Heinrich Schuchardt Reviewed-by: Xiang W Reviewed-by: Anup Patel

lib: sbi_scratch: Introduce sbi_scratch_last_hartid() API

2020-03-28T08:02:41Z

The patch adds sbi_scratch_last_hartid() API which returns last HART id having a scratch space. We can use this new API to optimize places where we iterate over HART id from 0 to SBI_HARTMASK_MAX_BITS. Signed-off-by: Anup Patel Reviewed-by: Atish Patra

include: sbi_platform: Introduce HART index to HART id table

2020-03-19T04:00:01Z

A platform can have discontinuous and/or sparse HART ids so we cannot always assume a set of HARTs with continuous HART ids. This patch adds support for discontinuous and sparse HART ids by introducing HART index to HART id table. This table has platform hart_count entries and it maps HART index to HART id. The HART index to HART id table has only two restrictions: 1. HART index < sbi_platform hart_count 2. HART id < SBI_HARTMASK_MAX_BITS Example1: Let's say we have a platform with 2 HART ids 11 and 22, for such a a platform: hart_count = 2 hart_index2id[0] = 11 hart_index2id[1] = 22 Example2: Let's say we have a platform with 5 HARTs ids 0, 1, 2, 3, and 4 but out of these HART with id 0 is not usable so for such a platform: hart_count = 5 hart_index2id[0] = -1U hart_index2id[1] = 1 hart_index2id[2] = 2 hart_index2id[3] = 3 hart_index2id[4] = 4 OR hart_count = 4 hart_index2id[0] = 1 hart_index2id[1] = 2 hart_index2id[2] = 3 hart_index2id[3] = 4 With HART index to HART id table in place, the hart_disabled() callback is now redundant so we remove it as well. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

lib: Don't use sbi_platform_hart_count() API

2020-03-19T03:57:51Z

We don't need to use sbi_platform_hart_count() in sbi_init and sbi_scratch because checking sbi_platform_hart_disabled() or return value of sbi_hartid_to_scratch() is sufficient. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

lib: sbi_scratch: Don't set hartid_to_scratch table for disabled HART

2020-03-19T03:47:08Z

As a step towards supporting discontinuous and sparse HART ids, we don't set hartid_to_scratch table for disabled HARTs. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

lib: Handle failure of sbi_hartid_to_scratch() API

2020-03-19T03:41:12Z

The sbi_hartid_to_scratch() API can fail for non-existent HARTs so all uses of sbi_hartid_to_scratch() API should check return value. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

include: Simplify HART id to scratch macro

2020-03-19T03:34:29Z

This patch simplify HART id to scratch macro as follows: 1. Remove current "scratch" pointer argument because now we use HART id to scratch table 2. Rename sbi_hart_id_to_scratch() to sbi_hartid_to_scratch() to have macro name consistent with the name of callback in struct sbi_scratch Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

lib: sbi_scratch: Introduce HART id to scratch table

2020-03-19T03:32:23Z

Instead of calling hartid_to_scratch() callback every time when we want sbi_scratch pointer from HART id, we create a table of sbi_scratch pointers and use that to get sbi_scratch pointer. As a result of HART id to scratch table, the conversion of HART id to sbi_scratch pointer is just 2-3 instructions which was 9 instructions previously. Signed-off-by: Anup Patel Reviewed-by: Bin Meng Reviewed-by: Atish Patra

lib: sbi_scratch: use bitwise ops in sbi_scratch_alloc_offset()

2020-02-13T03:40:55Z

Instead of using loop to make "size" machine word aligned, we should use bitwise ops. Signed-off-by: Li Jinpei Signed-off-by: Anup Patel Reviewed-by: Atish Patra