On Mon, Feb 07, 2022 at 03:20:46PM +0000, Mark Brown wrote: > Allocate space for storing ZA on first access to SME and use that to save > and restore ZA state when context switching. We do this by using the vector > form of the LDR and STR ZA instructions, these do not require streaming > mode and have implementation recommendations that they avoid contention > issues in shared SMCU implementations. > > Since ZA is architecturally guaranteed to be zeroed when enabled we do not > need to explicitly zero ZA, either we will be restoring from a saved copy > or trapping on first use of SME so we know that ZA must be disabled. > > Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
