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/* * CPPC (Collaborative Processor Performance Control) methods used by CPUfreq drivers. * * (C) Copyright 2014, 2015 Linaro Ltd. * Author: Ashwin Chaugule <ashwin.chaugule@linaro.org> * * 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; version 2 * of the License. * * CPPC describes a few methods for controlling CPU performance using * information from a per CPU table called CPC. This table is described in * the ACPI v5.0+ specification. The table consists of a list of * registers which may be memory mapped or hardware registers and also may * include some static integer values. * * CPU performance is on an abstract continuous scale as against a discretized * P-state scale which is tied to CPU frequency only. In brief, the basic * operation involves: * * - OS makes a CPU performance request. (Can provide min and max bounds) * * - Platform (such as BMC) is free to optimize request within requested bounds *   depending on power/thermal budgets etc. * * - Platform conveys its decision back to OS * * The communication between OS and platform occurs through another medium * called (PCC) Platform Communication Channel. This is a generic mailbox like * mechanism which includes doorbell semantics to indicate register updates. * See drivers/mailbox/pcc.c for details on PCC. * * Finer details about the PCC and CPPC spec are available in the ACPI v5.1 and * above specifications. */ #define pr_fmt(fmt)	"ACPI CPPC: " fmt #include <linux/cpufreq.h>#include <linux/delay.h>#include <linux/ktime.h>#include <linux/rwsem.h>#include <linux/wait.h> #include <acpi/cppc_acpi.h> struct cppc_pcc_data {	struct mbox_chan *pcc_channel;	void __iomem *pcc_comm_addr;	int pcc_subspace_idx;	bool pcc_channel_acquired;	ktime_t deadline;	unsigned int pcc_mpar, pcc_mrtt, pcc_nominal; 	bool pending_pcc_write_cmd;	/* Any pending/batched PCC write cmds? */	bool platform_owns_pcc;		/* Ownership of PCC subspace */	unsigned int pcc_write_cnt;	/* Running count of PCC write commands */ 	/*	 * Lock to provide controlled access to the PCC channel.	 *	 * For performance critical usecases(currently cppc_set_perf)	 *	We need to take read_lock and check if channel belongs to OSPM	 * before reading or writing to PCC subspace	 *	We need to take write_lock before transferring the channel	 * ownership to the platform via a Doorbell	 *	This allows us to batch a number of CPPC requests if they happen	 * to originate in about the same time	 *	 * For non-performance critical usecases(init)	 *	Take write_lock for all purposes which gives exclusive access	 */	struct rw_semaphore pcc_lock; 	/* Wait queue for CPUs whose requests were batched */	wait_queue_head_t pcc_write_wait_q;}; /* Structure to represent the single PCC channel */static struct cppc_pcc_data pcc_data = {	.pcc_subspace_idx = -1,	.platform_owns_pcc = true,}; /* * The cpc_desc structure contains the ACPI register details * as described in the per CPU _CPC tables. The details * include the type of register (e.g. PCC, System IO, FFH etc.) * and destination addresses which lets us READ/WRITE CPU performance * information using the appropriate I/O methods. */static DEFINE_PER_CPU(struct cpc_desc *, cpc_desc_ptr); /* pcc mapped address + header size + offset within PCC subspace */#define GET_PCC_VADDR(offs) (pcc_data.pcc_comm_addr + 0x8 + (offs)) /* Check if a CPC regsiter is in PCC */#define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER &&		\				(cpc)->cpc_entry.reg.space_id ==	\				ACPI_ADR_SPACE_PLATFORM_COMM) /* Evalutes to True if reg is a NULL register descriptor */#define IS_NULL_REG(reg) ((reg)->space_id ==  ACPI_ADR_SPACE_SYSTEM_MEMORY && \				(reg)->address == 0 &&			\				(reg)->bit_width == 0 &&		\				(reg)->bit_offset == 0 &&		\				(reg)->access_width == 0) /* Evalutes to True if an optional cpc field is supported */#define CPC_SUPPORTED(cpc) ((cpc)->type == ACPI_TYPE_INTEGER ?		\				!!(cpc)->cpc_entry.int_value :		\				!IS_NULL_REG(&(cpc)->cpc_entry.reg))/* * Arbitrary Retries in case the remote processor is slow to respond * to PCC commands. Keeping it high enough to cover emulators where * the processors run painfully slow. */#define NUM_RETRIES 500 struct cppc_attr {	struct attribute attr;	ssize_t (*show)(struct kobject *kobj,			struct attribute *attr, char *buf);	ssize_t (*store)(struct kobject *kobj,			struct attribute *attr, const char *c, ssize_t count);}; #define define_one_cppc_ro(_name)		\static struct cppc_attr _name =			\__ATTR(_name, 0444, show_##_name, NULL) #define to_cpc_desc(a) container_of(a, struct cpc_desc, kobj) static ssize_t show_feedback_ctrs(struct kobject *kobj,		struct attribute *attr, char *buf){	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);	struct cppc_perf_fb_ctrs fb_ctrs = {0}; 	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 	return scnprintf(buf, PAGE_SIZE, "ref:%llu del:%llu\n",			fb_ctrs.reference, fb_ctrs.delivered);}define_one_cppc_ro(feedback_ctrs); static ssize_t show_reference_perf(struct kobject *kobj,		struct attribute *attr, char *buf){	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);	struct cppc_perf_fb_ctrs fb_ctrs = {0}; 	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 	return scnprintf(buf, PAGE_SIZE, "%llu\n",			fb_ctrs.reference_perf);}define_one_cppc_ro(reference_perf); static ssize_t show_wraparound_time(struct kobject *kobj,				struct attribute *attr, char *buf){	struct cpc_desc *cpc_ptr = to_cpc_desc(kobj);	struct cppc_perf_fb_ctrs fb_ctrs = {0}; 	cppc_get_perf_ctrs(cpc_ptr->cpu_id, &fb_ctrs); 	return scnprintf(buf, PAGE_SIZE, "%llu\n", fb_ctrs.ctr_wrap_time); }define_one_cppc_ro(wraparound_time); static struct attribute *cppc_attrs[] = {	&feedback_ctrs.attr,	&reference_perf.attr,	&wraparound_time.attr,	NULL}; static struct kobj_type cppc_ktype = {	.sysfs_ops = &kobj_sysfs_ops,	.default_attrs = cppc_attrs,}; static int check_pcc_chan(bool chk_err_bit){	int ret = -EIO, status = 0;	struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_data.pcc_comm_addr;	ktime_t next_deadline = ktime_add(ktime_get(), pcc_data.deadline); 	if (!pcc_data.platform_owns_pcc)		return 0; 	/* Retry in case the remote processor was too slow to catch up. */	while (!ktime_after(ktime_get(), next_deadline)) {		/*		 * Per spec, prior to boot the PCC space wil be initialized by		 * platform and should have set the command completion bit when		 * PCC can be used by OSPM		 */		status = readw_relaxed(&generic_comm_base->status);		if (status & PCC_CMD_COMPLETE_MASK) {			ret = 0;			if (chk_err_bit && (status & PCC_ERROR_MASK))				ret = -EIO;			break;		}		/*		 * Reducing the bus traffic in case this loop takes longer than		 * a few retries.		 */		udelay(3);	} 	if (likely(!ret))		pcc_data.platform_owns_pcc = false;	else		pr_err("PCC check channel failed. Status=%x\n", status); 	return ret;} /* * This function transfers the ownership of the PCC to the platform * So it must be called while holding write_lock(pcc_lock) */static int send_pcc_cmd(u16 cmd){	int ret = -EIO, i;	struct acpi_pcct_shared_memory *generic_comm_base =		(struct acpi_pcct_shared_memory *) pcc_data.pcc_comm_addr;	static ktime_t last_cmd_cmpl_time, last_mpar_reset;	static int mpar_count;	unsigned int time_delta; 	/*	 * For CMD_WRITE we know for a fact the caller should have checked	 * the channel before writing to PCC space	 */	if (cmd == CMD_READ) {		/*		 * If there are pending cpc_writes, then we stole the channel		 * before write completion, so first send a WRITE command to		 * platform		 */		if (pcc_data.pending_pcc_write_cmd)			send_pcc_cmd(CMD_WRITE); 		ret = check_pcc_chan(false);		if (ret)			goto end;	} else /* CMD_WRITE */		pcc_data.pending_pcc_write_cmd = FALSE; 	/*	 * Handle the Minimum Request Turnaround Time(MRTT)	 * "The minimum amount of time that OSPM must wait after the completion	 * of a command before issuing the next command, in microseconds"	 */	if (pcc_data.pcc_mrtt) {		time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time);		if (pcc_data.pcc_mrtt > time_delta)			udelay(pcc_data.pcc_mrtt - time_delta);	} 	/*	 * Handle the non-zero Maximum Periodic Access Rate(MPAR)	 * "The maximum number of periodic requests that the subspace channel can	 * support, reported in commands per minute. 0 indicates no limitation."	 *	 * This parameter should be ideally zero or large enough so that it can	 * handle maximum number of requests that all the cores in the system can	 * collectively generate. If it is not, we will follow the spec and just	 * not send the request to the platform after hitting the MPAR limit in	 * any 60s window	 */	if (pcc_data.pcc_mpar) {		if (mpar_count == 0) {			time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset);			if (time_delta < 60 * MSEC_PER_SEC) {				pr_debug("PCC cmd not sent due to MPAR limit");				ret = -EIO;				goto end;			}			last_mpar_reset = ktime_get();			mpar_count = pcc_data.pcc_mpar;		}		mpar_count--;	} 	/* Write to the shared comm region. */	writew_relaxed(cmd, &generic_comm_base->command); 	/* Flip CMD COMPLETE bit */	writew_relaxed(0, &generic_comm_base->status); 	pcc_data.platform_owns_pcc = true; 	/* Ring doorbell */	ret = mbox_send_message(pcc_data.pcc_channel, &cmd);	if (ret < 0) {		pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n",				cmd, ret);		goto end;	} 	/* wait for completion and check for PCC errro bit */	ret = check_pcc_chan(true); 	if (pcc_data.pcc_mrtt)		last_cmd_cmpl_time = ktime_get(); 	if (pcc_data.pcc_channel->mbox->txdone_irq)		mbox_chan_txdone(pcc_data.pcc_channel, ret);	else		mbox_client_txdone(pcc_data.pcc_channel, ret); end:	if (cmd == CMD_WRITE) {		if (unlikely(ret)) {			for_each_possible_cpu(i) {				struct cpc_desc *desc = per_cpu(cpc_desc_ptr, i);				if (!desc)					continue; 				if (desc->write_cmd_id == pcc_data.pcc_write_cnt)					desc->write_cmd_status = ret;			}		}		pcc_data.pcc_write_cnt++;		wake_up_all(&pcc_data.pcc_write_wait_q);	} 	return ret;} static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret){	if (ret < 0)		pr_debug("TX did not complete: CMD sent:%x, ret:%d\n",				*(u16 *)msg, ret);	else		pr_debug("TX completed. CMD sent:%x, ret:%d\n",				*(u16 *)msg, ret);} struct mbox_client cppc_mbox_cl = {	.tx_done = cppc_chan_tx_done,	.knows_txdone = true,}; static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle){	int result = -EFAULT;	acpi_status status = AE_OK;	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};	struct acpi_buffer format = {sizeof("NNNNN"), "NNNNN"};	struct acpi_buffer state = {0, NULL};	union acpi_object  *psd = NULL;	struct acpi_psd_package *pdomain; 	status = acpi_evaluate_object_typed(handle, "_PSD", NULL, &buffer,			ACPI_TYPE_PACKAGE);	if (ACPI_FAILURE(status))		return -ENODEV; 	psd = buffer.pointer;	if (!psd || psd->package.count != 1) {		pr_debug("Invalid _PSD data\n");		goto end;	} 	pdomain = &(cpc_ptr->domain_info); 	state.length = sizeof(struct acpi_psd_package);	state.pointer = pdomain; 	status = acpi_extract_package(&(psd->package.elements[0]),		&format, &state);	if (ACPI_FAILURE(status)) {		pr_debug("Invalid _PSD data for CPU:%d\n", cpc_ptr->cpu_id);		goto end;	} 	if (pdomain->num_entries != ACPI_PSD_REV0_ENTRIES) {		pr_debug("Unknown _PSD:num_entries for CPU:%d\n", cpc_ptr->cpu_id);		goto end;	} 	if (pdomain->revision != ACPI_PSD_REV0_REVISION) {		pr_debug("Unknown _PSD:revision for CPU: %d\n", cpc_ptr->cpu_id);		goto end;	} 	if (pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ALL &&	    pdomain->coord_type != DOMAIN_COORD_TYPE_SW_ANY &&	    pdomain->coord_type != DOMAIN_COORD_TYPE_HW_ALL) {		pr_debug("Invalid _PSD:coord_type for CPU:%d\n", cpc_ptr->cpu_id);		goto end;	} 	result = 0;end:	kfree(buffer.pointer);	return result;} /** * acpi_get_psd_map - Map the CPUs in a common freq domain. * @all_cpu_data: Ptrs to CPU specific CPPC data including PSD info. * *	Return: 0 for success or negative value for err. */int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data){	int count_target;	int retval = 0;	unsigned int i, j;	cpumask_var_t covered_cpus;	struct cppc_cpudata *pr, *match_pr;	struct acpi_psd_package *pdomain;	struct acpi_psd_package *match_pdomain;	struct cpc_desc *cpc_ptr, *match_cpc_ptr; 	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))		return -ENOMEM; 	/*	 * Now that we have _PSD data from all CPUs, lets setup P-state	 * domain info.	 */	for_each_possible_cpu(i) {		pr = all_cpu_data[i];		if (!pr)			continue; 		if (cpumask_test_cpu(i, covered_cpus))			continue; 		cpc_ptr = per_cpu(cpc_desc_ptr, i);		if (!cpc_ptr) {			retval = -EFAULT;			goto err_ret;		} 		pdomain = &(cpc_ptr->domain_info);		cpumask_set_cpu(i, pr->shared_cpu_map);		cpumask_set_cpu(i, covered_cpus);		if (pdomain->num_processors <= 1)			continue; 		/* Validate the Domain info */		count_target = pdomain->num_processors;		if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)			pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;		else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)			pr->shared_type = CPUFREQ_SHARED_TYPE_HW;		else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)			pr->shared_type = CPUFREQ_SHARED_TYPE_ANY; 		for_each_possible_cpu(j) {			if (i == j)				continue; 			match_cpc_ptr = per_cpu(cpc_desc_ptr, j);			if (!match_cpc_ptr) {				retval = -EFAULT;				goto err_ret;			} 			match_pdomain = &(match_cpc_ptr->domain_info);			if (match_pdomain->domain != pdomain->domain)				continue; 			/* Here i and j are in the same domain */			if (match_pdomain->num_processors != count_target) {				retval = -EFAULT;				goto err_ret;			} 			if (pdomain->coord_type != match_pdomain->coord_type) {				retval = -EFAULT;				goto err_ret;			} 			cpumask_set_cpu(j, covered_cpus);			cpumask_set_cpu(j, pr->shared_cpu_map);		} 		for_each_possible_cpu(j) {			if (i == j)				continue; 			match_pr = all_cpu_data[j];			if (!match_pr)				continue; 			match_cpc_ptr = per_cpu(cpc_desc_ptr, j);			if (!match_cpc_ptr) {

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