diff options
| author | Sandrine Bailleux <sandrine.bailleux@arm.com> | 2018-05-09 14:45:34 +0200 |
|---|---|---|
| committer | Sandrine Bailleux <sandrine.bailleux@arm.com> | 2018-05-15 09:59:44 +0200 |
| commit | 398489452fe50118521be845a55ce3b8773cd13d (patch) | |
| tree | 401f696b2a73a406141faf2057ad1f869e250aca /services | |
| parent | 885ca54a75e14a63c375b5d12852dc7ef2c0b568 (diff) | |
SPM: Do not trap S-EL0 access to SVE/SIMD/FP regs
This allows secure partitions to access these registers. This is
needed in some cases. For example, it has been reported that in order
to implement secure storage services, a secure partition needs to
encrypt/decrypt some authentication variables, which requires FP/SIMD
support.
Note that SPM will not do any saving/restoring of these registers on
behalf of the SP. This falls under the SP's responsibility.
Also note that if the SP gets preempted, it might not get a chance to
save/restore FP/SIMD registers first. This patch does not address this
problem. It only serves as a temporary solution to unblock development
on the secure partition side.
Change-Id: I3b8ccdebdac0219f6ac96ad66ab2be0be8374ad3
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
Diffstat (limited to 'services')
| -rw-r--r-- | services/std_svc/spm/secure_partition_setup.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/services/std_svc/spm/secure_partition_setup.c b/services/std_svc/spm/secure_partition_setup.c index 6998dae5..9b3f6222 100644 --- a/services/std_svc/spm/secure_partition_setup.c +++ b/services/std_svc/spm/secure_partition_setup.c @@ -236,12 +236,14 @@ void secure_partition_setup(void) SPM_SHIM_EXCEPTIONS_PTR); /* - * FPEN: Forbid the Secure Partition to access FP/SIMD registers. + * FPEN: Allow the Secure Partition to access FP/SIMD registers. + * Note that SPM will not do any saving/restoring of these registers on + * behalf of the SP. This falls under the SP's responsibility. * TTA: Enable access to trace registers. * ZEN (v8.2): Trap SVE instructions and access to SVE registers. */ write_ctx_reg(get_sysregs_ctx(ctx), CTX_CPACR_EL1, - CPACR_EL1_FPEN(CPACR_EL1_FP_TRAP_ALL)); + CPACR_EL1_FPEN(CPACR_EL1_FP_TRAP_NONE)); /* * Prepare information in buffer shared between EL3 and S-EL0 |