--- /dev/null
+/*
+ * Copyright (C) 2014 Imagination Technologies
+ * Author: Paul Burton <paul.burton@imgtec.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/init.h>
+#include <linux/percpu.h>
+#include <linux/slab.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/cacheflush.h>
+#include <asm/cacheops.h>
+#include <asm/idle.h>
+#include <asm/mips-cm.h>
+#include <asm/mips-cpc.h>
+#include <asm/mipsmtregs.h>
+#include <asm/pm.h>
+#include <asm/pm-cps.h>
+#include <asm/smp-cps.h>
+#include <asm/uasm.h>
+
+/*
+ * cps_nc_entry_fn - type of a generated non-coherent state entry function
+ * @online: the count of online coupled VPEs
+ * @nc_ready_count: pointer to a non-coherent mapping of the core ready_count
+ *
+ * The code entering & exiting non-coherent states is generated at runtime
+ * using uasm, in order to ensure that the compiler cannot insert a stray
+ * memory access at an unfortunate time and to allow the generation of optimal
+ * core-specific code particularly for cache routines. If coupled_coherence
+ * is non-zero and this is the entry function for the CPS_PM_NC_WAIT state,
+ * returns the number of VPEs that were in the wait state at the point this
+ * VPE left it. Returns garbage if coupled_coherence is zero or this is not
+ * the entry function for CPS_PM_NC_WAIT.
+ */
+typedef unsigned (*cps_nc_entry_fn)(unsigned online, u32 *nc_ready_count);
+
+/*
+ * The entry point of the generated non-coherent idle state entry/exit
+ * functions. Actually per-core rather than per-CPU.
+ */
+static DEFINE_PER_CPU_READ_MOSTLY(cps_nc_entry_fn[CPS_PM_STATE_COUNT],
+ nc_asm_enter);
+
+/* Bitmap indicating which states are supported by the system */
+DECLARE_BITMAP(state_support, CPS_PM_STATE_COUNT);
+
+/*
+ * Indicates the number of coupled VPEs ready to operate in a non-coherent
+ * state. Actually per-core rather than per-CPU.
+ */
+static DEFINE_PER_CPU_ALIGNED(u32*, ready_count);
+static DEFINE_PER_CPU_ALIGNED(void*, ready_count_alloc);
+
+/* Indicates online CPUs coupled with the current CPU */
+static DEFINE_PER_CPU_ALIGNED(cpumask_t, online_coupled);
+
+/*
+ * Used to synchronize entry to deep idle states. Actually per-core rather
+ * than per-CPU.
+ */
+static DEFINE_PER_CPU_ALIGNED(atomic_t, pm_barrier);
+
+/* Saved CPU state across the CPS_PM_POWER_GATED state */
+DEFINE_PER_CPU_ALIGNED(struct mips_static_suspend_state, cps_cpu_state);
+
+/* A somewhat arbitrary number of labels & relocs for uasm */
+static struct uasm_label labels[32] __initdata;
+static struct uasm_reloc relocs[32] __initdata;
+
+/* CPU dependant sync types */
+static unsigned stype_intervention;
+static unsigned stype_memory;
+static unsigned stype_ordering;
+
+enum mips_reg {
+ zero, at, v0, v1, a0, a1, a2, a3,
+ t0, t1, t2, t3, t4, t5, t6, t7,
+ s0, s1, s2, s3, s4, s5, s6, s7,
+ t8, t9, k0, k1, gp, sp, fp, ra,
+};
+
+bool cps_pm_support_state(enum cps_pm_state state)
+{
+ return test_bit(state, state_support);
+}
+
+static void coupled_barrier(atomic_t *a, unsigned online)
+{
+ /*
+ * This function is effectively the same as
+ * cpuidle_coupled_parallel_barrier, which can't be used here since
+ * there's no cpuidle device.
+ */
+
+ if (!coupled_coherence)
+ return;
+
+ smp_mb__before_atomic_inc();
+ atomic_inc(a);
+
+ while (atomic_read(a) < online)
+ cpu_relax();
+
+ if (atomic_inc_return(a) == online * 2) {
+ atomic_set(a, 0);
+ return;
+ }
+
+ while (atomic_read(a) > online)
+ cpu_relax();
+}
+
+int cps_pm_enter_state(enum cps_pm_state state)
+{
+ unsigned cpu = smp_processor_id();
+ unsigned core = current_cpu_data.core;
+ unsigned online, left;
+ cpumask_t *coupled_mask = this_cpu_ptr(&online_coupled);
+ u32 *core_ready_count, *nc_core_ready_count;
+ void *nc_addr;
+ cps_nc_entry_fn entry;
+ struct core_boot_config *core_cfg;
+ struct vpe_boot_config *vpe_cfg;
+
+ /* Check that there is an entry function for this state */
+ entry = per_cpu(nc_asm_enter, core)[state];
+ if (!entry)
+ return -EINVAL;
+
+ /* Calculate which coupled CPUs (VPEs) are online */
+#ifdef CONFIG_MIPS_MT
+ if (cpu_online(cpu)) {
+ cpumask_and(coupled_mask, cpu_online_mask,
+ &cpu_sibling_map[cpu]);
+ online = cpumask_weight(coupled_mask);
+ cpumask_clear_cpu(cpu, coupled_mask);
+ } else
+#endif
+ {
+ cpumask_clear(coupled_mask);
+ online = 1;
+ }
+
+ /* Setup the VPE to run mips_cps_pm_restore when started again */
+ if (config_enabled(CONFIG_CPU_PM) && state == CPS_PM_POWER_GATED) {
+ core_cfg = &mips_cps_core_bootcfg[core];
+ vpe_cfg = &core_cfg->vpe_config[current_cpu_data.vpe_id];
+ vpe_cfg->pc = (unsigned long)mips_cps_pm_restore;
+ vpe_cfg->gp = (unsigned long)current_thread_info();
+ vpe_cfg->sp = 0;
+ }
+
+ /* Indicate that this CPU might not be coherent */
+ cpumask_clear_cpu(cpu, &cpu_coherent_mask);
+ smp_mb__after_clear_bit();
+
+ /* Create a non-coherent mapping of the core ready_count */
+ core_ready_count = per_cpu(ready_count, core);
+ nc_addr = kmap_noncoherent(virt_to_page(core_ready_count),
+ (unsigned long)core_ready_count);
+ nc_addr += ((unsigned long)core_ready_count & ~PAGE_MASK);
+ nc_core_ready_count = nc_addr;
+
+ /* Ensure ready_count is zero-initialised before the assembly runs */
+ ACCESS_ONCE(*nc_core_ready_count) = 0;
+ coupled_barrier(&per_cpu(pm_barrier, core), online);
+
+ /* Run the generated entry code */
+ left = entry(online, nc_core_ready_count);
+
+ /* Remove the non-coherent mapping of ready_count */
+ kunmap_noncoherent();
+
+ /* Indicate that this CPU is definitely coherent */
+ cpumask_set_cpu(cpu, &cpu_coherent_mask);
+
+ /*
+ * If this VPE is the first to leave the non-coherent wait state then
+ * it needs to wake up any coupled VPEs still running their wait
+ * instruction so that they return to cpuidle, which can then complete
+ * coordination between the coupled VPEs & provide the governor with
+ * a chance to reflect on the length of time the VPEs were in the
+ * idle state.
+ */
+ if (coupled_coherence && (state == CPS_PM_NC_WAIT) && (left == online))
+ arch_send_call_function_ipi_mask(coupled_mask);
+
+ return 0;
+}
+
+static void __init cps_gen_cache_routine(u32 **pp, struct uasm_label **pl,
+ struct uasm_reloc **pr,
+ const struct cache_desc *cache,
+ unsigned op, int lbl)
+{
+ unsigned cache_size = cache->ways << cache->waybit;
+ unsigned i;
+ const unsigned unroll_lines = 32;
+
+ /* If the cache isn't present this function has it easy */
+ if (cache->flags & MIPS_CACHE_NOT_PRESENT)
+ return;
+
+ /* Load base address */
+ UASM_i_LA(pp, t0, (long)CKSEG0);
+
+ /* Calculate end address */
+ if (cache_size < 0x8000)
+ uasm_i_addiu(pp, t1, t0, cache_size);
+ else
+ UASM_i_LA(pp, t1, (long)(CKSEG0 + cache_size));
+
+ /* Start of cache op loop */
+ uasm_build_label(pl, *pp, lbl);
+
+ /* Generate the cache ops */
+ for (i = 0; i < unroll_lines; i++)
+ uasm_i_cache(pp, op, i * cache->linesz, t0);
+
+ /* Update the base address */
+ uasm_i_addiu(pp, t0, t0, unroll_lines * cache->linesz);
+
+ /* Loop if we haven't reached the end address yet */
+ uasm_il_bne(pp, pr, t0, t1, lbl);
+ uasm_i_nop(pp);
+}
+
+static int __init cps_gen_flush_fsb(u32 **pp, struct uasm_label **pl,
+ struct uasm_reloc **pr,
+ const struct cpuinfo_mips *cpu_info,
+ int lbl)
+{
+ unsigned i, fsb_size = 8;
+ unsigned num_loads = (fsb_size * 3) / 2;
+ unsigned line_stride = 2;
+ unsigned line_size = cpu_info->dcache.linesz;
+ unsigned perf_counter, perf_event;
+ unsigned revision = cpu_info->processor_id & PRID_REV_MASK;
+
+ /*
+ * Determine whether this CPU requires an FSB flush, and if so which
+ * performance counter/event reflect stalls due to a full FSB.
+ */
+ switch (__get_cpu_type(cpu_info->cputype)) {
+ case CPU_INTERAPTIV:
+ perf_counter = 1;
+ perf_event = 51;
+ break;
+
+ case CPU_PROAPTIV:
+ /* Newer proAptiv cores don't require this workaround */
+ if (revision >= PRID_REV_ENCODE_332(1, 1, 0))
+ return 0;
+
+ /* On older ones it's unavailable */
+ return -1;
+
+ /* CPUs which do not require the workaround */
+ case CPU_P5600:
+ return 0;
+
+ default:
+ WARN_ONCE(1, "pm-cps: FSB flush unsupported for this CPU\n");
+ return -1;
+ }
+
+ /*
+ * Ensure that the fill/store buffer (FSB) is not holding the results
+ * of a prefetch, since if it is then the CPC sequencer may become
+ * stuck in the D3 (ClrBus) state whilst entering a low power state.
+ */
+
+ /* Preserve perf counter setup */
+ uasm_i_mfc0(pp, t2, 25, (perf_counter * 2) + 0); /* PerfCtlN */
+ uasm_i_mfc0(pp, t3, 25, (perf_counter * 2) + 1); /* PerfCntN */
+
+ /* Setup perf counter to count FSB full pipeline stalls */
+ uasm_i_addiu(pp, t0, zero, (perf_event << 5) | 0xf);
+ uasm_i_mtc0(pp, t0, 25, (perf_counter * 2) + 0); /* PerfCtlN */
+ uasm_i_ehb(pp);
+ uasm_i_mtc0(pp, zero, 25, (perf_counter * 2) + 1); /* PerfCntN */
+ uasm_i_ehb(pp);
+
+ /* Base address for loads */
+ UASM_i_LA(pp, t0, (long)CKSEG0);
+
+ /* Start of clear loop */
+ uasm_build_label(pl, *pp, lbl);
+
+ /* Perform some loads to fill the FSB */
+ for (i = 0; i < num_loads; i++)
+ uasm_i_lw(pp, zero, i * line_size * line_stride, t0);
+
+ /*
+ * Invalidate the new D-cache entries so that the cache will need
+ * refilling (via the FSB) if the loop is executed again.
+ */
+ for (i = 0; i < num_loads; i++) {
+ uasm_i_cache(pp, Hit_Invalidate_D,
+ i * line_size * line_stride, t0);
+ uasm_i_cache(pp, Hit_Writeback_Inv_SD,
+ i * line_size * line_stride, t0);
+ }
+
+ /* Completion barrier */
+ uasm_i_sync(pp, stype_memory);
+ uasm_i_ehb(pp);
+
+ /* Check whether the pipeline stalled due to the FSB being full */
+ uasm_i_mfc0(pp, t1, 25, (perf_counter * 2) + 1); /* PerfCntN */
+
+ /* Loop if it didn't */
+ uasm_il_beqz(pp, pr, t1, lbl);
+ uasm_i_nop(pp);
+
+ /* Restore perf counter 1. The count may well now be wrong... */
+ uasm_i_mtc0(pp, t2, 25, (perf_counter * 2) + 0); /* PerfCtlN */
+ uasm_i_ehb(pp);
+ uasm_i_mtc0(pp, t3, 25, (perf_counter * 2) + 1); /* PerfCntN */
+ uasm_i_ehb(pp);
+
+ return 0;
+}
+
+static void __init cps_gen_set_top_bit(u32 **pp, struct uasm_label **pl,
+ struct uasm_reloc **pr,
+ unsigned r_addr, int lbl)
+{
+ uasm_i_lui(pp, t0, uasm_rel_hi(0x80000000));
+ uasm_build_label(pl, *pp, lbl);
+ uasm_i_ll(pp, t1, 0, r_addr);
+ uasm_i_or(pp, t1, t1, t0);
+ uasm_i_sc(pp, t1, 0, r_addr);
+ uasm_il_beqz(pp, pr, t1, lbl);
+ uasm_i_nop(pp);
+}
+
+static void * __init cps_gen_entry_code(unsigned cpu, enum cps_pm_state state)
+{
+ struct uasm_label *l = labels;
+ struct uasm_reloc *r = relocs;
+ u32 *buf, *p;
+ const unsigned r_online = a0;
+ const unsigned r_nc_count = a1;
+ const unsigned r_pcohctl = t7;
+ const unsigned max_instrs = 256;
+ unsigned cpc_cmd;
+ int err;
+ enum {
+ lbl_incready = 1,
+ lbl_poll_cont,
+ lbl_secondary_hang,
+ lbl_disable_coherence,
+ lbl_flush_fsb,
+ lbl_invicache,
+ lbl_flushdcache,
+ lbl_hang,
+ lbl_set_cont,
+ lbl_secondary_cont,
+ lbl_decready,
+ };
+
+ /* Allocate a buffer to hold the generated code */
+ p = buf = kcalloc(max_instrs, sizeof(u32), GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ /* Clear labels & relocs ready for (re)use */
+ memset(labels, 0, sizeof(labels));
+ memset(relocs, 0, sizeof(relocs));
+
+ if (config_enabled(CONFIG_CPU_PM) && state == CPS_PM_POWER_GATED) {
+ /*
+ * Save CPU state. Note the non-standard calling convention
+ * with the return address placed in v0 to avoid clobbering
+ * the ra register before it is saved.
+ */
+ UASM_i_LA(&p, t0, (long)mips_cps_pm_save);
+ uasm_i_jalr(&p, v0, t0);
+ uasm_i_nop(&p);
+ }
+
+ /*
+ * Load addresses of required CM & CPC registers. This is done early
+ * because they're needed in both the enable & disable coherence steps
+ * but in the coupled case the enable step will only run on one VPE.
+ */
+ UASM_i_LA(&p, r_pcohctl, (long)addr_gcr_cl_coherence());
+
+ if (coupled_coherence) {
+ /* Increment ready_count */
+ uasm_i_sync(&p, stype_ordering);
+ uasm_build_label(&l, p, lbl_incready);
+ uasm_i_ll(&p, t1, 0, r_nc_count);
+ uasm_i_addiu(&p, t2, t1, 1);
+ uasm_i_sc(&p, t2, 0, r_nc_count);
+ uasm_il_beqz(&p, &r, t2, lbl_incready);
+ uasm_i_addiu(&p, t1, t1, 1);
+
+ /* Ordering barrier */
+ uasm_i_sync(&p, stype_ordering);
+
+ /*
+ * If this is the last VPE to become ready for non-coherence
+ * then it should branch below.
+ */
+ uasm_il_beq(&p, &r, t1, r_online, lbl_disable_coherence);
+ uasm_i_nop(&p);
+
+ if (state < CPS_PM_POWER_GATED) {
+ /*
+ * Otherwise this is not the last VPE to become ready
+ * for non-coherence. It needs to wait until coherence
+ * has been disabled before proceeding, which it will do
+ * by polling for the top bit of ready_count being set.
+ */
+ uasm_i_addiu(&p, t1, zero, -1);
+ uasm_build_label(&l, p, lbl_poll_cont);
+ uasm_i_lw(&p, t0, 0, r_nc_count);
+ uasm_il_bltz(&p, &r, t0, lbl_secondary_cont);
+ uasm_i_ehb(&p);
+ uasm_i_yield(&p, zero, t1);
+ uasm_il_b(&p, &r, lbl_poll_cont);
+ uasm_i_nop(&p);
+ } else {
+ /*
+ * The core will lose power & this VPE will not continue
+ * so it can simply halt here.
+ */
+ uasm_i_addiu(&p, t0, zero, TCHALT_H);
+ uasm_i_mtc0(&p, t0, 2, 4);
+ uasm_build_label(&l, p, lbl_secondary_hang);
+ uasm_il_b(&p, &r, lbl_secondary_hang);
+ uasm_i_nop(&p);
+ }
+ }
+
+ /*
+ * This is the point of no return - this VPE will now proceed to
+ * disable coherence. At this point we *must* be sure that no other
+ * VPE within the core will interfere with the L1 dcache.
+ */
+ uasm_build_label(&l, p, lbl_disable_coherence);
+
+ /* Invalidate the L1 icache */
+ cps_gen_cache_routine(&p, &l, &r, &cpu_data[cpu].icache,
+ Index_Invalidate_I, lbl_invicache);
+
+ /* Writeback & invalidate the L1 dcache */
+ cps_gen_cache_routine(&p, &l, &r, &cpu_data[cpu].dcache,
+ Index_Writeback_Inv_D, lbl_flushdcache);
+
+ /* Completion barrier */
+ uasm_i_sync(&p, stype_memory);
+ uasm_i_ehb(&p);
+
+ /*
+ * Disable all but self interventions. The load from COHCTL is defined
+ * by the interAptiv & proAptiv SUMs as ensuring that the operation
+ * resulting from the preceeding store is complete.
+ */
+ uasm_i_addiu(&p, t0, zero, 1 << cpu_data[cpu].core);
+ uasm_i_sw(&p, t0, 0, r_pcohctl);
+ uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+ /* Sync to ensure previous interventions are complete */
+ uasm_i_sync(&p, stype_intervention);
+ uasm_i_ehb(&p);
+
+ /* Disable coherence */
+ uasm_i_sw(&p, zero, 0, r_pcohctl);
+ uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+ if (state >= CPS_PM_CLOCK_GATED) {
+ err = cps_gen_flush_fsb(&p, &l, &r, &cpu_data[cpu],
+ lbl_flush_fsb);
+ if (err)
+ goto out_err;
+
+ /* Determine the CPC command to issue */
+ switch (state) {
+ case CPS_PM_CLOCK_GATED:
+ cpc_cmd = CPC_Cx_CMD_CLOCKOFF;
+ break;
+ case CPS_PM_POWER_GATED:
+ cpc_cmd = CPC_Cx_CMD_PWRDOWN;
+ break;
+ default:
+ BUG();
+ goto out_err;
+ }
+
+ /* Issue the CPC command */
+ UASM_i_LA(&p, t0, (long)addr_cpc_cl_cmd());
+ uasm_i_addiu(&p, t1, zero, cpc_cmd);
+ uasm_i_sw(&p, t1, 0, t0);
+
+ if (state == CPS_PM_POWER_GATED) {
+ /* If anything goes wrong just hang */
+ uasm_build_label(&l, p, lbl_hang);
+ uasm_il_b(&p, &r, lbl_hang);
+ uasm_i_nop(&p);
+
+ /*
+ * There's no point generating more code, the core is
+ * powered down & if powered back up will run from the
+ * reset vector not from here.
+ */
+ goto gen_done;
+ }
+
+ /* Completion barrier */
+ uasm_i_sync(&p, stype_memory);
+ uasm_i_ehb(&p);
+ }
+
+ if (state == CPS_PM_NC_WAIT) {
+ /*
+ * At this point it is safe for all VPEs to proceed with
+ * execution. This VPE will set the top bit of ready_count
+ * to indicate to the other VPEs that they may continue.
+ */
+ if (coupled_coherence)
+ cps_gen_set_top_bit(&p, &l, &r, r_nc_count,
+ lbl_set_cont);
+
+ /*
+ * VPEs which did not disable coherence will continue
+ * executing, after coherence has been disabled, from this
+ * point.
+ */
+ uasm_build_label(&l, p, lbl_secondary_cont);
+
+ /* Now perform our wait */
+ uasm_i_wait(&p, 0);
+ }
+
+ /*
+ * Re-enable coherence. Note that for CPS_PM_NC_WAIT all coupled VPEs
+ * will run this. The first will actually re-enable coherence & the
+ * rest will just be performing a rather unusual nop.
+ */
+ uasm_i_addiu(&p, t0, zero, CM_GCR_Cx_COHERENCE_COHDOMAINEN_MSK);
+ uasm_i_sw(&p, t0, 0, r_pcohctl);
+ uasm_i_lw(&p, t0, 0, r_pcohctl);
+
+ /* Completion barrier */
+ uasm_i_sync(&p, stype_memory);
+ uasm_i_ehb(&p);
+
+ if (coupled_coherence && (state == CPS_PM_NC_WAIT)) {
+ /* Decrement ready_count */
+ uasm_build_label(&l, p, lbl_decready);
+ uasm_i_sync(&p, stype_ordering);
+ uasm_i_ll(&p, t1, 0, r_nc_count);
+ uasm_i_addiu(&p, t2, t1, -1);
+ uasm_i_sc(&p, t2, 0, r_nc_count);
+ uasm_il_beqz(&p, &r, t2, lbl_decready);
+ uasm_i_andi(&p, v0, t1, (1 << fls(smp_num_siblings)) - 1);
+
+ /* Ordering barrier */
+ uasm_i_sync(&p, stype_ordering);
+ }
+
+ if (coupled_coherence && (state == CPS_PM_CLOCK_GATED)) {
+ /*
+ * At this point it is safe for all VPEs to proceed with
+ * execution. This VPE will set the top bit of ready_count
+ * to indicate to the other VPEs that they may continue.
+ */
+ cps_gen_set_top_bit(&p, &l, &r, r_nc_count, lbl_set_cont);
+
+ /*
+ * This core will be reliant upon another core sending a
+ * power-up command to the CPC in order to resume operation.
+ * Thus an arbitrary VPE can't trigger the core leaving the
+ * idle state and the one that disables coherence might as well
+ * be the one to re-enable it. The rest will continue from here
+ * after that has been done.
+ */
+ uasm_build_label(&l, p, lbl_secondary_cont);
+
+ /* Ordering barrier */
+ uasm_i_sync(&p, stype_ordering);
+ }
+
+ /* The core is coherent, time to return to C code */
+ uasm_i_jr(&p, ra);
+ uasm_i_nop(&p);
+
+gen_done:
+ /* Ensure the code didn't exceed the resources allocated for it */
+ BUG_ON((p - buf) > max_instrs);
+ BUG_ON((l - labels) > ARRAY_SIZE(labels));
+ BUG_ON((r - relocs) > ARRAY_SIZE(relocs));
+
+ /* Patch branch offsets */
+ uasm_resolve_relocs(relocs, labels);
+
+ /* Flush the icache */
+ local_flush_icache_range((unsigned long)buf, (unsigned long)p);
+
+ return buf;
+out_err:
+ kfree(buf);
+ return NULL;
+}
+
+static int __init cps_gen_core_entries(unsigned cpu)
+{
+ enum cps_pm_state state;
+ unsigned core = cpu_data[cpu].core;
+ unsigned dlinesz = cpu_data[cpu].dcache.linesz;
+ void *entry_fn, *core_rc;
+
+ for (state = CPS_PM_NC_WAIT; state < CPS_PM_STATE_COUNT; state++) {
+ if (per_cpu(nc_asm_enter, core)[state])
+ continue;
+ if (!test_bit(state, state_support))
+ continue;
+
+ entry_fn = cps_gen_entry_code(cpu, state);
+ if (!entry_fn) {
+ pr_err("Failed to generate core %u state %u entry\n",
+ core, state);
+ clear_bit(state, state_support);
+ }
+
+ per_cpu(nc_asm_enter, core)[state] = entry_fn;
+ }
+
+ if (!per_cpu(ready_count, core)) {
+ core_rc = kmalloc(dlinesz * 2, GFP_KERNEL);
+ if (!core_rc) {
+ pr_err("Failed allocate core %u ready_count\n", core);
+ return -ENOMEM;
+ }
+ per_cpu(ready_count_alloc, core) = core_rc;
+
+ /* Ensure ready_count is aligned to a cacheline boundary */
+ core_rc += dlinesz - 1;
+ core_rc = (void *)((unsigned long)core_rc & ~(dlinesz - 1));
+ per_cpu(ready_count, core) = core_rc;
+ }
+
+ return 0;
+}
+
+static int __init cps_pm_init(void)
+{
+ unsigned cpu;
+ int err;
+
+ /* Detect appropriate sync types for the system */
+ switch (current_cpu_data.cputype) {
+ case CPU_INTERAPTIV:
+ case CPU_PROAPTIV:
+ case CPU_M5150:
+ case CPU_P5600:
+ stype_intervention = 0x2;
+ stype_memory = 0x3;
+ stype_ordering = 0x10;
+ break;
+
+ default:
+ pr_warn("Power management is using heavyweight sync 0\n");
+ }
+
+ /* A CM is required for all non-coherent states */
+ if (!mips_cm_present()) {
+ pr_warn("pm-cps: no CM, non-coherent states unavailable\n");
+ goto out;
+ }
+
+ /*
+ * If interrupts were enabled whilst running a wait instruction on a
+ * non-coherent core then the VPE may end up processing interrupts
+ * whilst non-coherent. That would be bad.
+ */
+ if (cpu_wait == r4k_wait_irqoff)
+ set_bit(CPS_PM_NC_WAIT, state_support);
+ else
+ pr_warn("pm-cps: non-coherent wait unavailable\n");
+
+ /* Detect whether a CPC is present */
+ if (mips_cpc_present()) {
+ /* Detect whether clock gating is implemented */
+ if (read_cpc_cl_stat_conf() & CPC_Cx_STAT_CONF_CLKGAT_IMPL_MSK)
+ set_bit(CPS_PM_CLOCK_GATED, state_support);
+ else
+ pr_warn("pm-cps: CPC does not support clock gating\n");
+
+ /* Power gating is available with CPS SMP & any CPC */
+ if (mips_cps_smp_in_use())
+ set_bit(CPS_PM_POWER_GATED, state_support);
+ else
+ pr_warn("pm-cps: CPS SMP not in use, power gating unavailable\n");
+ } else {
+ pr_warn("pm-cps: no CPC, clock & power gating unavailable\n");
+ }
+
+ for_each_present_cpu(cpu) {
+ err = cps_gen_core_entries(cpu);
+ if (err)
+ return err;
+ }
+out:
+ return 0;
+}
+arch_initcall(cps_pm_init);
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