diff options
author | dp-arm <dimitris.papastamos@arm.com> | 2017-05-23 09:32:49 +0100 |
---|---|---|
committer | Dimitris Papastamos <dimitris.papastamos@arm.com> | 2017-06-22 10:33:19 +0100 |
commit | d832aee900a92d14a08a6a2a552894188404b6a4 (patch) | |
tree | f1e12914f0bc1f687509f1b7fbbaf172a335acfd /lib/el3_runtime | |
parent | 18f2efd67d881fe0a9a535ce9e801e60d746e024 (diff) |
aarch64: Enable Statistical Profiling Extensions for lower ELs
SPE is only supported in non-secure state. Accesses to SPE specific
registers from SEL1 will trap to EL3. During a world switch, before
`TTBR` is modified the SPE profiling buffers are drained. This is to
avoid a potential invalid memory access in SEL1.
SPE is architecturally specified only for AArch64.
Change-Id: I04a96427d9f9d586c331913d815fdc726855f6b0
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
Diffstat (limited to 'lib/el3_runtime')
-rw-r--r-- | lib/el3_runtime/aarch64/context.S | 35 | ||||
-rw-r--r-- | lib/el3_runtime/aarch64/context_mgmt.c | 31 |
2 files changed, 62 insertions, 4 deletions
diff --git a/lib/el3_runtime/aarch64/context.S b/lib/el3_runtime/aarch64/context.S index afe912ab..8a6c11b7 100644 --- a/lib/el3_runtime/aarch64/context.S +++ b/lib/el3_runtime/aarch64/context.S @@ -1,5 +1,5 @@ /* - * Copyright (c) 2013-2016, ARM Limited and Contributors. All rights reserved. + * Copyright (c) 2013-2017, ARM Limited and Contributors. All rights reserved. * * SPDX-License-Identifier: BSD-3-Clause */ @@ -9,6 +9,7 @@ #include <context.h> .global el1_sysregs_context_save + .global el1_sysregs_context_save_post_ops .global el1_sysregs_context_restore #if CTX_INCLUDE_FPREGS .global fpregs_context_save @@ -111,6 +112,36 @@ endfunc el1_sysregs_context_save /* ----------------------------------------------------- * The following function strictly follows the AArch64 * PCS to use x9-x17 (temporary caller-saved registers) + * to do post operations after saving the EL1 system + * register context. + * ----------------------------------------------------- + */ +func el1_sysregs_context_save_post_ops +#if ENABLE_SPE_FOR_LOWER_ELS + /* Detect if SPE is implemented */ + mrs x9, id_aa64dfr0_el1 + ubfx x9, x9, #ID_AA64DFR0_PMS_SHIFT, #ID_AA64DFR0_PMS_LENGTH + cmp x9, #0x1 + b.ne 1f + + /* + * Before switching from normal world to secure world + * the profiling buffers need to be drained out to memory. This is + * required to avoid an invalid memory access when TTBR is switched + * for entry to SEL1. + */ + .arch armv8.2-a+profile + psb csync + dsb nsh + .arch armv8-a +1: +#endif + ret +endfunc el1_sysregs_context_save_post_ops + +/* ----------------------------------------------------- + * The following function strictly follows the AArch64 + * PCS to use x9-x17 (temporary caller-saved registers) * to restore EL1 system register context. It assumes * that 'x0' is pointing to a 'el1_sys_regs' structure * from where the register context will be restored @@ -343,7 +374,7 @@ func restore_gp_registers_callee_eret ldp x24, x25, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X24] ldp x26, x27, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X26] ldp x28, x29, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X28] - ldp x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] + ldp x30, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_LR] msr sp_el0, x17 ldp x16, x17, [sp, #CTX_GPREGS_OFFSET + CTX_GPREG_X16] eret diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c index 11ff1632..5257bf1c 100644 --- a/lib/el3_runtime/aarch64/context_mgmt.c +++ b/lib/el3_runtime/aarch64/context_mgmt.c @@ -218,7 +218,7 @@ void cm_init_my_context(const entry_point_info_t *ep) ******************************************************************************/ void cm_prepare_el3_exit(uint32_t security_state) { - uint32_t sctlr_elx, scr_el3; + uint32_t sctlr_elx, scr_el3, mdcr_el2; cpu_context_t *ctx = cm_get_context(security_state); assert(ctx); @@ -315,6 +315,13 @@ void cm_prepare_el3_exit(uint32_t security_state) * relying on hw. Some fields are architecturally * UNKNOWN on reset. * + * MDCR_EL2.TPMS (ARM v8.2): Do not trap statistical + * profiling controls to EL2. + * + * MDCR_EL2.E2PB (ARM v8.2): SPE enabled in non-secure + * state. Accesses to profiling buffer controls at + * non-secure EL1 are not trapped to EL2. + * * MDCR_EL2.TDRA: Set to zero so that Non-secure EL0 and * EL1 System register accesses to the Debug ROM * registers are not trapped to EL2. @@ -343,13 +350,32 @@ void cm_prepare_el3_exit(uint32_t security_state) * MDCR_EL2.HPMN: Set to value of PMCR_EL0.N which is the * architecturally-defined reset value. */ - write_mdcr_el2((MDCR_EL2_RESET_VAL | + mdcr_el2 = ((MDCR_EL2_RESET_VAL | ((read_pmcr_el0() & PMCR_EL0_N_BITS) >> PMCR_EL0_N_SHIFT)) & ~(MDCR_EL2_TDRA_BIT | MDCR_EL2_TDOSA_BIT | MDCR_EL2_TDA_BIT | MDCR_EL2_TDE_BIT | MDCR_EL2_HPME_BIT | MDCR_EL2_TPM_BIT | MDCR_EL2_TPMCR_BIT)); + +#if ENABLE_SPE_FOR_LOWER_ELS + uint64_t id_aa64dfr0_el1; + + /* Detect if SPE is implemented */ + id_aa64dfr0_el1 = read_id_aa64dfr0_el1() >> + ID_AA64DFR0_PMS_SHIFT; + if ((id_aa64dfr0_el1 & ID_AA64DFR0_PMS_MASK) == 1) { + /* + * Make sure traps to EL2 are not generated if + * EL2 is implemented but not used. + */ + mdcr_el2 &= ~MDCR_EL2_TPMS; + mdcr_el2 |= MDCR_EL2_E2PB(MDCR_EL2_E2PB_EL1); + } +#endif + + write_mdcr_el2(mdcr_el2); + /* * Initialise HSTR_EL2. All fields are architecturally * UNKNOWN on reset. @@ -389,6 +415,7 @@ void cm_el1_sysregs_context_save(uint32_t security_state) assert(ctx); el1_sysregs_context_save(get_sysregs_ctx(ctx)); + el1_sysregs_context_save_post_ops(); } void cm_el1_sysregs_context_restore(uint32_t security_state) |