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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:13:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 09:13:47 +0000 |
commit | 102b0d2daa97dae68d3eed54d8fe37a9cc38a892 (patch) | |
tree | bcf648efac40ca6139842707f0eba5a4496a6dd2 /plat/arm/board/arm_fpga/fpga_pm.c | |
parent | Initial commit. (diff) | |
download | arm-trusted-firmware-upstream.tar.xz arm-trusted-firmware-upstream.zip |
Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'plat/arm/board/arm_fpga/fpga_pm.c')
-rw-r--r-- | plat/arm/board/arm_fpga/fpga_pm.c | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/plat/arm/board/arm_fpga/fpga_pm.c b/plat/arm/board/arm_fpga/fpga_pm.c new file mode 100644 index 0000000..a306a23 --- /dev/null +++ b/plat/arm/board/arm_fpga/fpga_pm.c @@ -0,0 +1,103 @@ +/* + * Copyright (c) 2020, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <assert.h> + +#include <lib/psci/psci.h> +#include <plat/arm/common/plat_arm.h> +#include <plat/common/platform.h> + +#include "fpga_private.h" +#include <platform_def.h> + +/* + * This is a basic PSCI implementation that allows secondary CPUs to be + * released from their initial state and continue to the warm boot entrypoint. + * + * The secondary CPUs are placed in a holding pen and released by calls + * to fpga_pwr_domain_on(mpidr), which updates the hold entry for the CPU + * specified by the mpidr argument - the (polling) target CPU will then branch + * to the BL31 warm boot sequence at the entrypoint address. + * + * Additionally, the secondary CPUs are kept in a low-power wfe() state + * (placed there at the end of each poll) and woken when necessary through + * calls to sev() in fpga_pwr_domain_on(mpidr), once the hold state for the + * relevant CPU has been updated. + * + * Hotplug is currently implemented using a wfi-loop, which removes the + * dependencies on any power controllers or other mechanism that is specific + * to the running system as specified by the FPGA image. + */ + +uint64_t hold_base[PLATFORM_CORE_COUNT]; +uintptr_t fpga_sec_entrypoint; + +/* + * Calls to the CPU specified by the mpidr will set its hold entry to a value + * indicating that it should stop polling and branch off to the warm entrypoint. + */ +static int fpga_pwr_domain_on(u_register_t mpidr) +{ + int pos = plat_core_pos_by_mpidr(mpidr); + unsigned long current_mpidr = read_mpidr_el1(); + + if (pos < 0) { + panic(); + } + + if (mpidr == current_mpidr) { + return PSCI_E_ALREADY_ON; + } + hold_base[pos] = PLAT_FPGA_HOLD_STATE_GO; + flush_dcache_range((uintptr_t)&hold_base[pos], sizeof(uint64_t)); + sev(); /* Wake any CPUs from wfe */ + + return PSCI_E_SUCCESS; +} + +void fpga_pwr_domain_on_finish(const psci_power_state_t *target_state) +{ + fpga_pwr_gic_on_finish(); +} + +static void fpga_pwr_domain_off(const psci_power_state_t *target_state) +{ + fpga_pwr_gic_off(); + + while (1) { + wfi(); + } +} + +static void fpga_cpu_standby(plat_local_state_t cpu_state) +{ + /* + * Enter standby state + * dsb is good practice before using wfi to enter low power states + */ + u_register_t scr = read_scr_el3(); + write_scr_el3(scr|SCR_IRQ_BIT); + dsb(); + wfi(); + write_scr_el3(scr); +} + +plat_psci_ops_t plat_fpga_psci_pm_ops = { + .pwr_domain_on = fpga_pwr_domain_on, + .pwr_domain_on_finish = fpga_pwr_domain_on_finish, + .pwr_domain_off = fpga_pwr_domain_off, + .cpu_standby = fpga_cpu_standby +}; + +int plat_setup_psci_ops(uintptr_t sec_entrypoint, + const plat_psci_ops_t **psci_ops) +{ + fpga_sec_entrypoint = sec_entrypoint; + flush_dcache_range((uint64_t)&fpga_sec_entrypoint, + sizeof(fpga_sec_entrypoint)); + *psci_ops = &plat_fpga_psci_pm_ops; + return 0; +} |