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| author | johpow01 <john.powell@arm.com> | 2020-04-22 14:05:13 -0500 |
|---|---|---|
| committer | John <john.powell@arm.com> | 2020-05-19 21:49:52 +0000 |
| commit | 6cac724d52cc8d6cac9b47f186cc47f4b3cf6bd6 (patch) | |
| tree | 1dbf1feb70c4dbc8636b87f0fdb83766f0bac6e8 /lib | |
| parent | f1a1653ce17861441383ae58a3df929cb521c9d8 (diff) | |
| download | platform_external_arm-trusted-firmware-6cac724d52cc8d6cac9b47f186cc47f4b3cf6bd6.tar.gz platform_external_arm-trusted-firmware-6cac724d52cc8d6cac9b47f186cc47f4b3cf6bd6.tar.bz2 platform_external_arm-trusted-firmware-6cac724d52cc8d6cac9b47f186cc47f4b3cf6bd6.zip | |
Enable v8.6 WFE trap delays
This patch enables the v8.6 extension to add a delay before WFE traps
are taken. A weak hook plat_arm_set_twedel_scr_el3 has been added in
plat/common/aarch64/plat_common.c that disables this feature by default
but platform-specific code can override it when needed.
The only hook provided sets the TWED fields in SCR_EL3, there are similar
fields in HCR_EL2, SCTLR_EL2, and SCTLR_EL1 to control WFE trap delays in
lower ELs but these should be configured by code running at EL2 and/or EL1
depending on the platform configuration and is outside the scope of TF-A.
Signed-off-by: John Powell <john.powell@arm.com>
Change-Id: I0a9bb814205efeab693a3d0a0623e62144abba2d
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/el3_runtime/aarch64/context_mgmt.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c index 0314a8511..64a2d7b5c 100644 --- a/lib/el3_runtime/aarch64/context_mgmt.c +++ b/lib/el3_runtime/aarch64/context_mgmt.c @@ -22,6 +22,7 @@ #include <lib/extensions/mpam.h> #include <lib/extensions/spe.h> #include <lib/extensions/sve.h> +#include <lib/extensions/twed.h> #include <lib/utils.h> @@ -229,6 +230,24 @@ void cm_setup_context(cpu_context_t *ctx, const entry_point_info_t *ep) sctlr_elx |= SCTLR_IESB_BIT; #endif + /* Enable WFE trap delay in SCR_EL3 if supported and configured */ + if (is_armv8_6_twed_present()) { + uint32_t delay = plat_arm_set_twedel_scr_el3(); + + if (delay != TWED_DISABLED) { + /* Make sure delay value fits */ + assert((delay & ~SCR_TWEDEL_MASK) == 0U); + + /* Set delay in SCR_EL3 */ + scr_el3 &= ~(SCR_TWEDEL_MASK << SCR_TWEDEL_SHIFT); + scr_el3 |= ((delay & SCR_TWEDEL_MASK) + << SCR_TWEDEL_SHIFT); + + /* Enable WFE delay */ + scr_el3 |= SCR_TWEDEn_BIT; + } + } + /* * Store the initialised SCTLR_EL1 value in the cpu_context - SCTLR_EL2 * and other EL2 registers are set up by cm_prepare_ns_entry() as they |