--- /dev/null
+/*
+ * 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 <acpi/cppc_acpi.h>
+/*
+ * Lock to provide mutually exclusive access to the PCC
+ * channel. e.g. When the remote updates the shared region
+ * with new data, the reader needs to be protected from
+ * other CPUs activity on the same channel.
+ */
+static DEFINE_SPINLOCK(pcc_lock);
+
+/*
+ * 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);
+
+/* This layer handles all the PCC specifics for CPPC. */
+static struct mbox_chan *pcc_channel;
+static void __iomem *pcc_comm_addr;
+static u64 comm_base_addr;
+static int pcc_subspace_idx = -1;
+static u16 pcc_cmd_delay;
+static bool pcc_channel_acquired;
+
+/*
+ * Arbitrary Retries in case the remote processor is slow to respond
+ * to PCC commands.
+ */
+#define NUM_RETRIES 500
+
+static int send_pcc_cmd(u16 cmd)
+{
+ int retries, result = -EIO;
+ struct acpi_pcct_hw_reduced *pcct_ss = pcc_channel->con_priv;
+ struct acpi_pcct_shared_memory *generic_comm_base =
+ (struct acpi_pcct_shared_memory *) pcc_comm_addr;
+ u32 cmd_latency = pcct_ss->latency;
+
+ /* Min time OS should wait before sending next command. */
+ udelay(pcc_cmd_delay);
+
+ /* Write to the shared comm region. */
+ writew(cmd, &generic_comm_base->command);
+
+ /* Flip CMD COMPLETE bit */
+ writew(0, &generic_comm_base->status);
+
+ /* Ring doorbell */
+ result = mbox_send_message(pcc_channel, &cmd);
+ if (result < 0) {
+ pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n",
+ cmd, result);
+ return result;
+ }
+
+ /* Wait for a nominal time to let platform process command. */
+ udelay(cmd_latency);
+
+ /* Retry in case the remote processor was too slow to catch up. */
+ for (retries = NUM_RETRIES; retries > 0; retries--) {
+ if (readw_relaxed(&generic_comm_base->status) & PCC_CMD_COMPLETE) {
+ result = 0;
+ break;
+ }
+ }
+
+ mbox_client_txdone(pcc_channel, result);
+ return result;
+}
+
+static void cppc_chan_tx_done(struct mbox_client *cl, void *msg, int ret)
+{
+ if (ret)
+ 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 cpudata **all_cpu_data)
+{
+ int count_target;
+ int retval = 0;
+ unsigned int i, j;
+ cpumask_var_t covered_cpus;
+ struct 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)
+ continue;
+
+ 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)
+ continue;
+
+ 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)
+ continue;
+
+ match_pdomain = &(match_cpc_ptr->domain_info);
+ if (match_pdomain->domain != pdomain->domain)
+ continue;
+
+ match_pr->shared_type = pr->shared_type;
+ cpumask_copy(match_pr->shared_cpu_map,
+ pr->shared_cpu_map);
+ }
+ }
+
+err_ret:
+ for_each_possible_cpu(i) {
+ pr = all_cpu_data[i];
+ if (!pr)
+ continue;
+
+ /* Assume no coordination on any error parsing domain info */
+ if (retval) {
+ cpumask_clear(pr->shared_cpu_map);
+ cpumask_set_cpu(i, pr->shared_cpu_map);
+ pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;
+ }
+ }
+
+ free_cpumask_var(covered_cpus);
+ return retval;
+}
+EXPORT_SYMBOL_GPL(acpi_get_psd_map);
+
+static int register_pcc_channel(int pcc_subspace_idx)
+{
+ struct acpi_pcct_subspace *cppc_ss;
+ unsigned int len;
+
+ if (pcc_subspace_idx >= 0) {
+ pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl,
+ pcc_subspace_idx);
+
+ if (IS_ERR(pcc_channel)) {
+ pr_err("Failed to find PCC communication channel\n");
+ return -ENODEV;
+ }
+
+ /*
+ * The PCC mailbox controller driver should
+ * have parsed the PCCT (global table of all
+ * PCC channels) and stored pointers to the
+ * subspace communication region in con_priv.
+ */
+ cppc_ss = pcc_channel->con_priv;
+
+ if (!cppc_ss) {
+ pr_err("No PCC subspace found for CPPC\n");
+ return -ENODEV;
+ }
+
+ /*
+ * This is the shared communication region
+ * for the OS and Platform to communicate over.
+ */
+ comm_base_addr = cppc_ss->base_address;
+ len = cppc_ss->length;
+ pcc_cmd_delay = cppc_ss->min_turnaround_time;
+
+ pcc_comm_addr = acpi_os_ioremap(comm_base_addr, len);
+ if (!pcc_comm_addr) {
+ pr_err("Failed to ioremap PCC comm region mem\n");
+ return -ENOMEM;
+ }
+
+ /* Set flag so that we dont come here for each CPU. */
+ pcc_channel_acquired = true;
+ }
+
+ return 0;
+}
+
+/*
+ * An example CPC table looks like the following.
+ *
+ * Name(_CPC, Package()
+ * {
+ * 17,
+ * NumEntries
+ * 1,
+ * // Revision
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x120, 2)},
+ * // Highest Performance
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x124, 2)},
+ * // Nominal Performance
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x128, 2)},
+ * // Lowest Nonlinear Performance
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x12C, 2)},
+ * // Lowest Performance
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x130, 2)},
+ * // Guaranteed Performance Register
+ * ResourceTemplate(){Register(PCC, 32, 0, 0x110, 2)},
+ * // Desired Performance Register
+ * ResourceTemplate(){Register(SystemMemory, 0, 0, 0, 0)},
+ * ..
+ * ..
+ * ..
+ *
+ * }
+ * Each Register() encodes how to access that specific register.
+ * e.g. a sample PCC entry has the following encoding:
+ *
+ * Register (
+ * PCC,
+ * AddressSpaceKeyword
+ * 8,
+ * //RegisterBitWidth
+ * 8,
+ * //RegisterBitOffset
+ * 0x30,
+ * //RegisterAddress
+ * 9
+ * //AccessSize (subspace ID)
+ * 0
+ * )
+ * }
+ */
+
+/**
+ * acpi_cppc_processor_probe - Search for per CPU _CPC objects.
+ * @pr: Ptr to acpi_processor containing this CPUs logical Id.
+ *
+ * Return: 0 for success or negative value for err.
+ */
+int acpi_cppc_processor_probe(struct acpi_processor *pr)
+{
+ struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
+ union acpi_object *out_obj, *cpc_obj;
+ struct cpc_desc *cpc_ptr;
+ struct cpc_reg *gas_t;
+ acpi_handle handle = pr->handle;
+ unsigned int num_ent, i, cpc_rev;
+ acpi_status status;
+ int ret = -EFAULT;
+
+ /* Parse the ACPI _CPC table for this cpu. */
+ status = acpi_evaluate_object_typed(handle, "_CPC", NULL, &output,
+ ACPI_TYPE_PACKAGE);
+ if (ACPI_FAILURE(status)) {
+ ret = -ENODEV;
+ goto out_buf_free;
+ }
+
+ out_obj = (union acpi_object *) output.pointer;
+
+ cpc_ptr = kzalloc(sizeof(struct cpc_desc), GFP_KERNEL);
+ if (!cpc_ptr) {
+ ret = -ENOMEM;
+ goto out_buf_free;
+ }
+
+ /* First entry is NumEntries. */
+ cpc_obj = &out_obj->package.elements[0];
+ if (cpc_obj->type == ACPI_TYPE_INTEGER) {
+ num_ent = cpc_obj->integer.value;
+ } else {
+ pr_debug("Unexpected entry type(%d) for NumEntries\n",
+ cpc_obj->type);
+ goto out_free;
+ }
+
+ /* Only support CPPCv2. Bail otherwise. */
+ if (num_ent != CPPC_NUM_ENT) {
+ pr_debug("Firmware exports %d entries. Expected: %d\n",
+ num_ent, CPPC_NUM_ENT);
+ goto out_free;
+ }
+
+ /* Second entry should be revision. */
+ cpc_obj = &out_obj->package.elements[1];
+ if (cpc_obj->type == ACPI_TYPE_INTEGER) {
+ cpc_rev = cpc_obj->integer.value;
+ } else {
+ pr_debug("Unexpected entry type(%d) for Revision\n",
+ cpc_obj->type);
+ goto out_free;
+ }
+
+ if (cpc_rev != CPPC_REV) {
+ pr_debug("Firmware exports revision:%d. Expected:%d\n",
+ cpc_rev, CPPC_REV);
+ goto out_free;
+ }
+
+ /* Iterate through remaining entries in _CPC */
+ for (i = 2; i < num_ent; i++) {
+ cpc_obj = &out_obj->package.elements[i];
+
+ if (cpc_obj->type == ACPI_TYPE_INTEGER) {
+ cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_INTEGER;
+ cpc_ptr->cpc_regs[i-2].cpc_entry.int_value = cpc_obj->integer.value;
+ } else if (cpc_obj->type == ACPI_TYPE_BUFFER) {
+ gas_t = (struct cpc_reg *)
+ cpc_obj->buffer.pointer;
+
+ /*
+ * The PCC Subspace index is encoded inside
+ * the CPC table entries. The same PCC index
+ * will be used for all the PCC entries,
+ * so extract it only once.
+ */
+ if (gas_t->space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+ if (pcc_subspace_idx < 0)
+ pcc_subspace_idx = gas_t->access_width;
+ else if (pcc_subspace_idx != gas_t->access_width) {
+ pr_debug("Mismatched PCC ids.\n");
+ goto out_free;
+ }
+ } else if (gas_t->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
+ /* Support only PCC and SYS MEM type regs */
+ pr_debug("Unsupported register type: %d\n", gas_t->space_id);
+ goto out_free;
+ }
+
+ cpc_ptr->cpc_regs[i-2].type = ACPI_TYPE_BUFFER;
+ memcpy(&cpc_ptr->cpc_regs[i-2].cpc_entry.reg, gas_t, sizeof(*gas_t));
+ } else {
+ pr_debug("Err in entry:%d in CPC table of CPU:%d \n", i, pr->id);
+ goto out_free;
+ }
+ }
+ /* Store CPU Logical ID */
+ cpc_ptr->cpu_id = pr->id;
+
+ /* Plug it into this CPUs CPC descriptor. */
+ per_cpu(cpc_desc_ptr, pr->id) = cpc_ptr;
+
+ /* Parse PSD data for this CPU */
+ ret = acpi_get_psd(cpc_ptr, handle);
+ if (ret)
+ goto out_free;
+
+ /* Register PCC channel once for all CPUs. */
+ if (!pcc_channel_acquired) {
+ ret = register_pcc_channel(pcc_subspace_idx);
+ if (ret)
+ goto out_free;
+ }
+
+ /* Everything looks okay */
+ pr_debug("Parsed CPC struct for CPU: %d\n", pr->id);
+
+ kfree(output.pointer);
+ return 0;
+
+out_free:
+ kfree(cpc_ptr);
+
+out_buf_free:
+ kfree(output.pointer);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(acpi_cppc_processor_probe);
+
+/**
+ * acpi_cppc_processor_exit - Cleanup CPC structs.
+ * @pr: Ptr to acpi_processor containing this CPUs logical Id.
+ *
+ * Return: Void
+ */
+void acpi_cppc_processor_exit(struct acpi_processor *pr)
+{
+ struct cpc_desc *cpc_ptr;
+ cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
+ kfree(cpc_ptr);
+}
+EXPORT_SYMBOL_GPL(acpi_cppc_processor_exit);
+
+static u64 get_phys_addr(struct cpc_reg *reg)
+{
+ /* PCC communication addr space begins at byte offset 0x8. */
+ if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
+ return (u64)comm_base_addr + 0x8 + reg->address;
+ else
+ return reg->address;
+}
+
+static void cpc_read(struct cpc_reg *reg, u64 *val)
+{
+ u64 addr = get_phys_addr(reg);
+
+ acpi_os_read_memory((acpi_physical_address)addr,
+ val, reg->bit_width);
+}
+
+static void cpc_write(struct cpc_reg *reg, u64 val)
+{
+ u64 addr = get_phys_addr(reg);
+
+ acpi_os_write_memory((acpi_physical_address)addr,
+ val, reg->bit_width);
+}
+
+/**
+ * cppc_get_perf_caps - Get a CPUs performance capabilities.
+ * @cpunum: CPU from which to get capabilities info.
+ * @perf_caps: ptr to cppc_perf_caps. See cppc_acpi.h
+ *
+ * Return: 0 for success with perf_caps populated else -ERRNO.
+ */
+int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
+{
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
+ struct cpc_register_resource *highest_reg, *lowest_reg, *ref_perf,
+ *nom_perf;
+ u64 high, low, ref, nom;
+ int ret = 0;
+
+ if (!cpc_desc) {
+ pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
+ return -ENODEV;
+ }
+
+ highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF];
+ lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF];
+ ref_perf = &cpc_desc->cpc_regs[REFERENCE_PERF];
+ nom_perf = &cpc_desc->cpc_regs[NOMINAL_PERF];
+
+ spin_lock(&pcc_lock);
+
+ /* Are any of the regs PCC ?*/
+ if ((highest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (lowest_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (ref_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (nom_perf->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
+ /* Ring doorbell once to update PCC subspace */
+ if (send_pcc_cmd(CMD_READ)) {
+ ret = -EIO;
+ goto out_err;
+ }
+ }
+
+ cpc_read(&highest_reg->cpc_entry.reg, &high);
+ perf_caps->highest_perf = high;
+
+ cpc_read(&lowest_reg->cpc_entry.reg, &low);
+ perf_caps->lowest_perf = low;
+
+ cpc_read(&ref_perf->cpc_entry.reg, &ref);
+ perf_caps->reference_perf = ref;
+
+ cpc_read(&nom_perf->cpc_entry.reg, &nom);
+ perf_caps->nominal_perf = nom;
+
+ if (!ref)
+ perf_caps->reference_perf = perf_caps->nominal_perf;
+
+ if (!high || !low || !nom)
+ ret = -EFAULT;
+
+out_err:
+ spin_unlock(&pcc_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
+
+/**
+ * cppc_get_perf_ctrs - Read a CPUs performance feedback counters.
+ * @cpunum: CPU from which to read counters.
+ * @perf_fb_ctrs: ptr to cppc_perf_fb_ctrs. See cppc_acpi.h
+ *
+ * Return: 0 for success with perf_fb_ctrs populated else -ERRNO.
+ */
+int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
+{
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpunum);
+ struct cpc_register_resource *delivered_reg, *reference_reg;
+ u64 delivered, reference;
+ int ret = 0;
+
+ if (!cpc_desc) {
+ pr_debug("No CPC descriptor for CPU:%d\n", cpunum);
+ return -ENODEV;
+ }
+
+ delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR];
+ reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR];
+
+ spin_lock(&pcc_lock);
+
+ /* Are any of the regs PCC ?*/
+ if ((delivered_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) ||
+ (reference_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM)) {
+ /* Ring doorbell once to update PCC subspace */
+ if (send_pcc_cmd(CMD_READ)) {
+ ret = -EIO;
+ goto out_err;
+ }
+ }
+
+ cpc_read(&delivered_reg->cpc_entry.reg, &delivered);
+ cpc_read(&reference_reg->cpc_entry.reg, &reference);
+
+ if (!delivered || !reference) {
+ ret = -EFAULT;
+ goto out_err;
+ }
+
+ perf_fb_ctrs->delivered = delivered;
+ perf_fb_ctrs->reference = reference;
+
+ perf_fb_ctrs->delivered -= perf_fb_ctrs->prev_delivered;
+ perf_fb_ctrs->reference -= perf_fb_ctrs->prev_reference;
+
+ perf_fb_ctrs->prev_delivered = delivered;
+ perf_fb_ctrs->prev_reference = reference;
+
+out_err:
+ spin_unlock(&pcc_lock);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
+
+/**
+ * cppc_set_perf - Set a CPUs performance controls.
+ * @cpu: CPU for which to set performance controls.
+ * @perf_ctrls: ptr to cppc_perf_ctrls. See cppc_acpi.h
+ *
+ * Return: 0 for success, -ERRNO otherwise.
+ */
+int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
+{
+ struct cpc_desc *cpc_desc = per_cpu(cpc_desc_ptr, cpu);
+ struct cpc_register_resource *desired_reg;
+ int ret = 0;
+
+ if (!cpc_desc) {
+ pr_debug("No CPC descriptor for CPU:%d\n", cpu);
+ return -ENODEV;
+ }
+
+ desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF];
+
+ spin_lock(&pcc_lock);
+
+ /*
+ * Skip writing MIN/MAX until Linux knows how to come up with
+ * useful values.
+ */
+ cpc_write(&desired_reg->cpc_entry.reg, perf_ctrls->desired_perf);
+
+ /* Is this a PCC reg ?*/
+ if (desired_reg->cpc_entry.reg.space_id == ACPI_ADR_SPACE_PLATFORM_COMM) {
+ /* Ring doorbell so Remote can get our perf request. */
+ if (send_pcc_cmd(CMD_WRITE))
+ ret = -EIO;
+ }
+
+ spin_unlock(&pcc_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(cppc_set_perf);
--- /dev/null
+/*
+ * CPPC (Collaborative Processor Performance Control) driver for
+ * interfacing with the CPUfreq layer and governors. See
+ * cppc_acpi.c for CPPC specific methods.
+ *
+ * (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.
+ */
+
+#define pr_fmt(fmt) "CPPC Cpufreq:" fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/cpu.h>
+#include <linux/cpufreq.h>
+#include <linux/vmalloc.h>
+
+#include <acpi/cppc_acpi.h>
+
+/*
+ * These structs contain information parsed from per CPU
+ * ACPI _CPC structures.
+ * e.g. For each CPU the highest, lowest supported
+ * performance capabilities, desired performance level
+ * requested etc.
+ */
+static struct cpudata **all_cpu_data;
+
+static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cpudata *cpu;
+ struct cpufreq_freqs freqs;
+ int ret = 0;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ cpu->perf_ctrls.desired_perf = target_freq;
+ freqs.old = policy->cur;
+ freqs.new = target_freq;
+
+ cpufreq_freq_transition_begin(policy, &freqs);
+ ret = cppc_set_perf(cpu->cpu, &cpu->perf_ctrls);
+ cpufreq_freq_transition_end(policy, &freqs, ret != 0);
+
+ if (ret)
+ pr_debug("Failed to set target on CPU:%d. ret:%d\n",
+ cpu->cpu, ret);
+
+ return ret;
+}
+
+static int cppc_verify_policy(struct cpufreq_policy *policy)
+{
+ cpufreq_verify_within_cpu_limits(policy);
+ return 0;
+}
+
+static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
+{
+ int cpu_num = policy->cpu;
+ struct cpudata *cpu = all_cpu_data[cpu_num];
+ int ret;
+
+ cpu->perf_ctrls.desired_perf = cpu->perf_caps.lowest_perf;
+
+ ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
+ if (ret)
+ pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
+ cpu->perf_caps.lowest_perf, cpu_num, ret);
+}
+
+static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpudata *cpu;
+ unsigned int cpu_num = policy->cpu;
+ int ret = 0;
+
+ cpu = all_cpu_data[policy->cpu];
+
+ cpu->cpu = cpu_num;
+ ret = cppc_get_perf_caps(policy->cpu, &cpu->perf_caps);
+
+ if (ret) {
+ pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
+ cpu_num, ret);
+ return ret;
+ }
+
+ policy->min = cpu->perf_caps.lowest_perf;
+ policy->max = cpu->perf_caps.highest_perf;
+ policy->cpuinfo.min_freq = policy->min;
+ policy->cpuinfo.max_freq = policy->max;
+
+ if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
+ cpumask_copy(policy->cpus, cpu->shared_cpu_map);
+ else {
+ /* Support only SW_ANY for now. */
+ pr_debug("Unsupported CPU co-ord type\n");
+ return -EFAULT;
+ }
+
+ cpumask_set_cpu(policy->cpu, policy->cpus);
+ cpu->cur_policy = policy;
+
+ /* Set policy->cur to max now. The governors will adjust later. */
+ policy->cur = cpu->perf_ctrls.desired_perf = cpu->perf_caps.highest_perf;
+
+ ret = cppc_set_perf(cpu_num, &cpu->perf_ctrls);
+ if (ret)
+ pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
+ cpu->perf_caps.highest_perf, cpu_num, ret);
+
+ return ret;
+}
+
+static struct cpufreq_driver cppc_cpufreq_driver = {
+ .flags = CPUFREQ_CONST_LOOPS,
+ .verify = cppc_verify_policy,
+ .target = cppc_cpufreq_set_target,
+ .init = cppc_cpufreq_cpu_init,
+ .stop_cpu = cppc_cpufreq_stop_cpu,
+ .name = "cppc_cpufreq",
+};
+
+static int __init cppc_cpufreq_init(void)
+{
+ int i, ret = 0;
+ struct cpudata *cpu;
+
+ if (acpi_disabled)
+ return -ENODEV;
+
+ all_cpu_data = kzalloc(sizeof(void *) * num_possible_cpus(), GFP_KERNEL);
+ if (!all_cpu_data)
+ return -ENOMEM;
+
+ for_each_possible_cpu(i) {
+ all_cpu_data[i] = kzalloc(sizeof(struct cpudata), GFP_KERNEL);
+ if (!all_cpu_data[i])
+ goto out;
+
+ cpu = all_cpu_data[i];
+ if (!zalloc_cpumask_var(&cpu->shared_cpu_map, GFP_KERNEL))
+ goto out;
+ }
+
+ ret = acpi_get_psd_map(all_cpu_data);
+ if (ret) {
+ pr_debug("Error parsing PSD data. Aborting cpufreq registration.\n");
+ goto out;
+ }
+
+ ret = cpufreq_register_driver(&cppc_cpufreq_driver);
+ if (ret)
+ goto out;
+
+ return ret;
+
+out:
+ for_each_possible_cpu(i)
+ if (all_cpu_data[i])
+ kfree(all_cpu_data[i]);
+
+ kfree(all_cpu_data);
+ return -ENODEV;
+}
+
+late_initcall(cppc_cpufreq_init);
projects / karo-tx-linux.git / commitdiff