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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/mips/kernel/mips-cpc.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/mips/kernel/mips-cpc.c')
-rw-r--r-- | arch/mips/kernel/mips-cpc.c | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/mips/kernel/mips-cpc.c b/arch/mips/kernel/mips-cpc.c new file mode 100644 index 000000000..3e386f7e1 --- /dev/null +++ b/arch/mips/kernel/mips-cpc.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright (C) 2013 Imagination Technologies + * Author: Paul Burton <paul.burton@mips.com> + */ + +#include <linux/bitfield.h> +#include <linux/errno.h> +#include <linux/percpu.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/spinlock.h> + +#include <asm/mips-cps.h> + +void __iomem *mips_cpc_base; + +static DEFINE_PER_CPU_ALIGNED(spinlock_t, cpc_core_lock); + +static DEFINE_PER_CPU_ALIGNED(unsigned long, cpc_core_lock_flags); + +phys_addr_t __weak mips_cpc_default_phys_base(void) +{ + struct device_node *cpc_node; + struct resource res; + int err; + + cpc_node = of_find_compatible_node(of_root, NULL, "mti,mips-cpc"); + if (cpc_node) { + err = of_address_to_resource(cpc_node, 0, &res); + of_node_put(cpc_node); + if (!err) + return res.start; + } + + return 0; +} + +/** + * mips_cpc_phys_base - retrieve the physical base address of the CPC + * + * This function returns the physical base address of the Cluster Power + * Controller memory mapped registers, or 0 if no Cluster Power Controller + * is present. + */ +static phys_addr_t mips_cpc_phys_base(void) +{ + unsigned long cpc_base; + + if (!mips_cm_present()) + return 0; + + if (!(read_gcr_cpc_status() & CM_GCR_CPC_STATUS_EX)) + return 0; + + /* If the CPC is already enabled, leave it so */ + cpc_base = read_gcr_cpc_base(); + if (cpc_base & CM_GCR_CPC_BASE_CPCEN) + return cpc_base & CM_GCR_CPC_BASE_CPCBASE; + + /* Otherwise, use the default address */ + cpc_base = mips_cpc_default_phys_base(); + if (!cpc_base) + return cpc_base; + + /* Enable the CPC, mapped at the default address */ + write_gcr_cpc_base(cpc_base | CM_GCR_CPC_BASE_CPCEN); + return cpc_base; +} + +int mips_cpc_probe(void) +{ + phys_addr_t addr; + unsigned int cpu; + + for_each_possible_cpu(cpu) + spin_lock_init(&per_cpu(cpc_core_lock, cpu)); + + addr = mips_cpc_phys_base(); + if (!addr) + return -ENODEV; + + mips_cpc_base = ioremap(addr, 0x8000); + if (!mips_cpc_base) + return -ENXIO; + + return 0; +} + +void mips_cpc_lock_other(unsigned int core) +{ + unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + + preempt_disable(); + curr_core = cpu_core(¤t_cpu_data); + spin_lock_irqsave(&per_cpu(cpc_core_lock, curr_core), + per_cpu(cpc_core_lock_flags, curr_core)); + write_cpc_cl_other(FIELD_PREP(CPC_Cx_OTHER_CORENUM, core)); + + /* + * Ensure the core-other region reflects the appropriate core & + * VP before any accesses to it occur. + */ + mb(); +} + +void mips_cpc_unlock_other(void) +{ + unsigned int curr_core; + + if (mips_cm_revision() >= CM_REV_CM3) + /* Systems with CM >= 3 lock the CPC via mips_cm_lock_other */ + return; + + curr_core = cpu_core(¤t_cpu_data); + spin_unlock_irqrestore(&per_cpu(cpc_core_lock, curr_core), + per_cpu(cpc_core_lock_flags, curr_core)); + preempt_enable(); +} |