diff options
Diffstat (limited to 'drivers/arm/gic/v3/arm_gicv3_common.c')
-rw-r--r-- | drivers/arm/gic/v3/arm_gicv3_common.c | 115 |
1 files changed, 115 insertions, 0 deletions
diff --git a/drivers/arm/gic/v3/arm_gicv3_common.c b/drivers/arm/gic/v3/arm_gicv3_common.c new file mode 100644 index 0000000..4489892 --- /dev/null +++ b/drivers/arm/gic/v3/arm_gicv3_common.c @@ -0,0 +1,115 @@ +/* + * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +/* + * Driver for implementation defined features that are identical in ARM GICv3 +* implementations (GIC-500 and GIC-600 for now). This driver only overrides +* APIs that are different to those generic ones in GICv3 driver. + */ + +#include <assert.h> + +#include <arch_helpers.h> +#include <drivers/arm/arm_gicv3_common.h> +#include <drivers/arm/gicv3.h> + +#include "gicv3_private.h" + +/* + * Flush the internal GIC cache of the LPIs pending tables to memory before + * saving the state of the Redistributor. This is required before powering off + * the GIC when the pending status must be preserved. + * `rdist_proc_num` is the processor number corresponding to the Redistributor of the + * current CPU. + */ +void arm_gicv3_distif_pre_save(unsigned int rdist_proc_num) +{ + uintptr_t gicr_base = 0; + + assert(gicv3_driver_data); + assert(gicv3_driver_data->rdistif_base_addrs); + + /* + * The GICR_WAKER.Sleep bit should be set only when both + * GICR_WAKER.ChildrenAsleep and GICR_WAKER.ProcessorSleep are set on + * all the Redistributors. + */ + for (unsigned int i = 0; i < gicv3_driver_data->rdistif_num; i++) { + gicr_base = gicv3_driver_data->rdistif_base_addrs[i]; + assert(gicr_base); + assert(gicr_read_waker(gicr_base) & WAKER_CA_BIT); + assert(gicr_read_waker(gicr_base) & WAKER_PS_BIT); + } + + gicr_base = gicv3_driver_data->rdistif_base_addrs[rdist_proc_num]; + /* + * According to the TRM, there is only one instance of the + * GICR_WAKER.Sleep and GICR_WAKER.Quiescent bits that can be accessed + * through any of the Redistributor. + */ + + /* + * Set GICR_WAKER.Sleep + * After this point, the system must be configured so that the + * wake_request signals for the right cores are asserted when a wakeup + * interrupt is detected. The GIC will not be able to do that anymore + * when the GICR_WAKER.Sleep bit is set to 1. + */ + gicr_write_waker(gicr_base, gicr_read_waker(gicr_base) | WAKER_SL_BIT); + + /* Wait until the GICR_WAKER.Quiescent bit is set */ + while (!(gicr_read_waker(gicr_base) & WAKER_QSC_BIT)) + ; +} + +/* + * Allow the LPIs pending state to be read back from the tables in memory after + * having restored the state of the GIC Redistributor. + */ +void arm_gicv3_distif_post_restore(unsigned int rdist_proc_num) +{ + uintptr_t gicr_base; + + assert(gicv3_driver_data); + assert(gicv3_driver_data->rdistif_base_addrs); + + /* + * According to the TRM, there is only one instance of the + * GICR_WAKER.Sleep and GICR_WAKER.Quiescent bits that can be accessed + * through any of the Redistributor. + */ + gicr_base = gicv3_driver_data->rdistif_base_addrs[rdist_proc_num]; + assert(gicr_base); + + /* + * If the GIC had power removed, the GICR_WAKER state will be reset. + * Since the GICR_WAKER.Sleep and GICR_WAKER.Quiescent bits are cleared, + * we can exit early. This also prevents the following assert from + * erroneously triggering. + */ + if (!(gicr_read_waker(gicr_base) & WAKER_SL_BIT)) + return; + + /* + * Writes to GICR_WAKER.Sleep bit are ignored if GICR_WAKER.Quiescent + * bit is not set. We should be alright on power on path, therefore + * coming out of sleep and Quiescent should be set, but we assert in + * case. + */ + assert(gicr_read_waker(gicr_base) & WAKER_QSC_BIT); + + /* Clear GICR_WAKER.Sleep */ + gicr_write_waker(gicr_base, gicr_read_waker(gicr_base) & ~WAKER_SL_BIT); + + /* + * We don't know if the effects of setting GICR_WAKER.Sleep bit is + * instantaneous, so we wait until the interface is not Quiescent + * anymore. + */ + while (gicr_read_waker(gicr_base) & WAKER_QSC_BIT) + ; +} + |