On Wed, 19 Jun 2024 at 15:36, Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:
On 19.06.24 14:23, Ilias Apalodimas wrote:
On Sun, 16 Jun 2024 at 20:31, Heinrich Schuchardt heinrich.schuchardt@canonical.com wrote:
If we have multiple weak implementations of functions, the linker might choose any of these. ARM and RISC-V already provide a weak implementation of flush_dcache_all().
Signed-off-by: Heinrich Schuchardt heinrich.schuchardt@canonical.com
cmd/cache.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/cmd/cache.c b/cmd/cache.c index 0254ff17f9b..16fa0f7c652 100644 --- a/cmd/cache.c +++ b/cmd/cache.c @@ -52,11 +52,14 @@ static int do_icache(struct cmd_tbl *cmdtp, int flag, int argc, return 0; }
+/* ARM and RISC-V define a weak flush_dcache_all() themselves. */ +#if !defined(CONFIG_ARM) && !defined(CONFIG_RISCV) void __weak flush_dcache_all(void) { puts("No arch specific flush_dcache_all available!\n"); /* please define arch specific flush_dcache_all */ }
Aren't we supposed to add a single __weak function so the linker can replace it? IOW why is the declaration for Arm/riscv a weak one?
Some sub-architectures override the architecture specific weak implementation, e.g.
arch/riscv/cpu/andes/cache.c:44: void flush_dcache_all(void)
arch/arm/cpu/arm926ejs/cache.c:17: void flush_dcache_all(void)
Ok, this does fix a problem, but afaict this is a band-aid and the cache management is a mess overall -- e.g invalidate_icache_all() will suffer from the same issue if a sub-architecture decides to define its own in the future.
Would it be less bad to define static inline __weak flush_dcache_all(void) { } static inline __weak flush_icache_all(void) { } in include/cpu_func.h instead of a random cmd file? We can only define those if !CONFIG_ARM && !!CONFIG_RISCV and add a comment on why. It's kind of putting lipstick on a pig, but at least we'll have them gathered in a single header file and know what we have to fix.
Cheers /Ilias
Best regards
Heinrich
Thanks /Ilias
+#endif
static int do_dcache(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[]) -- 2.43.0