diff options
Diffstat (limited to 'arch/mips/kernel/pm-cps.c')
| -rw-r--r-- | arch/mips/kernel/pm-cps.c | 716 | 
1 files changed, 716 insertions, 0 deletions
diff --git a/arch/mips/kernel/pm-cps.c b/arch/mips/kernel/pm-cps.c new file mode 100644 index 00000000000..c4c2069d3a2 --- /dev/null +++ b/arch/mips/kernel/pm-cps.c @@ -0,0 +1,716 @@ +/* + * 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(); +	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_atomic(); + +	/* 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);  | 
