From 4773e77cdc9b3af93ee1ae7bcf2acf94fde17166 Mon Sep 17 00:00:00 2001 From: Prashanth Prakash Date: Wed, 4 Apr 2018 12:14:50 -0600 Subject: ACPI / CPPC: Add support for CPPC v3 CPPC V3 introduces two new entries to make it easier to convert between abstract processor performance and frequency. The two new entries are lowest frequency and nominal frequency. These are the frequencies corresponding to lowest and nominal abstract performance. Add support to read the new entries and populate them as part of the CPPC performance capabilities which can be used by cpufreq drivers Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 81 ++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 65 insertions(+), 16 deletions(-) (limited to 'drivers/acpi/cppc_acpi.c') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 735c74a4cbdb..8fa3d3a6e5b6 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -156,6 +156,9 @@ show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, highest_perf); show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_perf); show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_perf); show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_nonlinear_perf); +show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, lowest_freq); +show_cppc_data(cppc_get_perf_caps, cppc_perf_caps, nominal_freq); + show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, reference_perf); show_cppc_data(cppc_get_perf_ctrs, cppc_perf_fb_ctrs, wraparound_time); @@ -183,6 +186,8 @@ static struct attribute *cppc_attrs[] = { &lowest_perf.attr, &lowest_nonlinear_perf.attr, &nominal_perf.attr, + &nominal_freq.attr, + &lowest_freq.attr, NULL }; @@ -613,7 +618,6 @@ bool __weak cpc_ffh_supported(void) return false; } - /** * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace * @@ -641,6 +645,34 @@ int pcc_data_alloc(int pcc_ss_id) return 0; } + +/* Check if CPPC revision + num_ent combination is supported */ +static bool is_cppc_supported(int revision, int num_ent) +{ + int expected_num_ent; + + switch (revision) { + case CPPC_V2_REV: + expected_num_ent = CPPC_V2_NUM_ENT; + break; + case CPPC_V3_REV: + expected_num_ent = CPPC_V3_NUM_ENT; + break; + default: + pr_debug("Firmware exports unsupported CPPC revision: %d\n", + revision); + return false; + } + + if (expected_num_ent != num_ent) { + pr_debug("Firmware exports %d entries. Expected: %d for CPPC rev:%d\n", + num_ent, expected_num_ent, revision); + return false; + } + + return true; +} + /* * An example CPC table looks like the following. * @@ -731,14 +763,6 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) 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; - } - cpc_ptr->num_entries = num_ent; /* Second entry should be revision. */ @@ -750,12 +774,10 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) cpc_obj->type); goto out_free; } + cpc_ptr->version = cpc_rev; - if (cpc_rev != CPPC_REV) { - pr_debug("Firmware exports revision:%d. Expected:%d\n", - cpc_rev, CPPC_REV); + if (!is_cppc_supported(cpc_rev, num_ent)) goto out_free; - } /* Iterate through remaining entries in _CPC */ for (i = 2; i < num_ent; i++) { @@ -808,6 +830,18 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr) } } per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id; + + /* + * Initialize the remaining cpc_regs as unsupported. + * Example: In case FW exposes CPPC v2, the below loop will initialize + * LOWEST_FREQ and NOMINAL_FREQ regs as unsupported + */ + for (i = num_ent - 2; i < MAX_CPC_REG_ENT; i++) { + cpc_ptr->cpc_regs[i].type = ACPI_TYPE_INTEGER; + cpc_ptr->cpc_regs[i].cpc_entry.int_value = 0; + } + + /* Store CPU Logical ID */ cpc_ptr->cpu_id = pr->id; @@ -1037,8 +1071,9 @@ 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, - *lowest_non_linear_reg, *nominal_reg; - u64 high, low, nom, min_nonlinear; + *lowest_non_linear_reg, *nominal_reg, + *low_freq_reg = NULL, *nom_freq_reg = NULL; + u64 high, low, nom, min_nonlinear, low_f = 0, nom_f = 0; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); struct cppc_pcc_data *pcc_ss_data; int ret = 0, regs_in_pcc = 0; @@ -1053,10 +1088,13 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; nominal_reg = &cpc_desc->cpc_regs[NOMINAL_PERF]; + low_freq_reg = &cpc_desc->cpc_regs[LOWEST_FREQ]; + nom_freq_reg = &cpc_desc->cpc_regs[NOMINAL_FREQ]; /* Are any of the regs PCC ?*/ if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || - CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg)) { + CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || + CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) { regs_in_pcc = 1; down_write(&pcc_ss_data->pcc_lock); /* Ring doorbell once to update PCC subspace */ @@ -1081,6 +1119,17 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) if (!high || !low || !nom || !min_nonlinear) ret = -EFAULT; + /* Read optional lowest and nominal frequencies if present */ + if (CPC_SUPPORTED(low_freq_reg)) + cpc_read(cpunum, low_freq_reg, &low_f); + + if (CPC_SUPPORTED(nom_freq_reg)) + cpc_read(cpunum, nom_freq_reg, &nom_f); + + perf_caps->lowest_freq = low_f; + perf_caps->nominal_freq = nom_f; + + out_err: if (regs_in_pcc) up_write(&pcc_ss_data->pcc_lock); -- cgit From 6fa12d584dcba18f67425ce17e9317311a624f81 Mon Sep 17 00:00:00 2001 From: Prashanth Prakash Date: Wed, 4 Apr 2018 12:14:51 -0600 Subject: ACPI / CPPC: Check for valid PCC subspace only if PCC is used Changes the behavior where we return error if there are no valid PCC subspace for a given performance domain. The ACPI spec does not mandate the use PCC, so it is possible to have platforms where a PCC subspace may not be present, so we need to check for a valid PCC subspace ID only if the register is a PCC register. Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 30 +++++++++++++++++++++--------- 1 file changed, 21 insertions(+), 9 deletions(-) (limited to 'drivers/acpi/cppc_acpi.c') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 8fa3d3a6e5b6..4446fa6c820e 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -1075,15 +1075,14 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) *low_freq_reg = NULL, *nom_freq_reg = NULL; u64 high, low, nom, min_nonlinear, low_f = 0, nom_f = 0; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); - struct cppc_pcc_data *pcc_ss_data; + struct cppc_pcc_data *pcc_ss_data = NULL; int ret = 0, regs_in_pcc = 0; - if (!cpc_desc || pcc_ss_id < 0) { + if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); return -ENODEV; } - pcc_ss_data = pcc_data[pcc_ss_id]; highest_reg = &cpc_desc->cpc_regs[HIGHEST_PERF]; lowest_reg = &cpc_desc->cpc_regs[LOWEST_PERF]; lowest_non_linear_reg = &cpc_desc->cpc_regs[LOW_NON_LINEAR_PERF]; @@ -1095,6 +1094,11 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps) if (CPC_IN_PCC(highest_reg) || CPC_IN_PCC(lowest_reg) || CPC_IN_PCC(lowest_non_linear_reg) || CPC_IN_PCC(nominal_reg) || CPC_IN_PCC(low_freq_reg) || CPC_IN_PCC(nom_freq_reg)) { + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + pcc_ss_data = pcc_data[pcc_ss_id]; regs_in_pcc = 1; down_write(&pcc_ss_data->pcc_lock); /* Ring doorbell once to update PCC subspace */ @@ -1150,16 +1154,15 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) struct cpc_register_resource *delivered_reg, *reference_reg, *ref_perf_reg, *ctr_wrap_reg; int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum); - struct cppc_pcc_data *pcc_ss_data; + struct cppc_pcc_data *pcc_ss_data = NULL; u64 delivered, reference, ref_perf, ctr_wrap_time; int ret = 0, regs_in_pcc = 0; - if (!cpc_desc || pcc_ss_id < 0) { + if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpunum); return -ENODEV; } - pcc_ss_data = pcc_data[pcc_ss_id]; delivered_reg = &cpc_desc->cpc_regs[DELIVERED_CTR]; reference_reg = &cpc_desc->cpc_regs[REFERENCE_CTR]; ref_perf_reg = &cpc_desc->cpc_regs[REFERENCE_PERF]; @@ -1175,6 +1178,11 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs) /* Are any of the regs PCC ?*/ if (CPC_IN_PCC(delivered_reg) || CPC_IN_PCC(reference_reg) || CPC_IN_PCC(ctr_wrap_reg) || CPC_IN_PCC(ref_perf_reg)) { + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + pcc_ss_data = pcc_data[pcc_ss_id]; down_write(&pcc_ss_data->pcc_lock); regs_in_pcc = 1; /* Ring doorbell once to update PCC subspace */ @@ -1225,15 +1233,14 @@ 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 pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu); - struct cppc_pcc_data *pcc_ss_data; + struct cppc_pcc_data *pcc_ss_data = NULL; int ret = 0; - if (!cpc_desc || pcc_ss_id < 0) { + if (!cpc_desc) { pr_debug("No CPC descriptor for CPU:%d\n", cpu); return -ENODEV; } - pcc_ss_data = pcc_data[pcc_ss_id]; desired_reg = &cpc_desc->cpc_regs[DESIRED_PERF]; /* @@ -1244,6 +1251,11 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls) * achieve that goal here */ if (CPC_IN_PCC(desired_reg)) { + if (pcc_ss_id < 0) { + pr_debug("Invalid pcc_ss_id\n"); + return -ENODEV; + } + pcc_ss_data = pcc_data[pcc_ss_id]; down_read(&pcc_ss_data->pcc_lock); /* BEGIN Phase-I */ if (pcc_ss_data->platform_owns_pcc) { ret = check_pcc_chan(pcc_ss_id, false); -- cgit From 58e1c03536c959e0d45fde8261cb9c15da893fe6 Mon Sep 17 00:00:00 2001 From: "Prakash, Prashanth" Date: Tue, 24 Apr 2018 17:10:02 -0600 Subject: ACPI / CPPC: Fix invalid PCC channel status errors Replace the faulty PCC status register polling code with a iopoll.h macro to fix incorrect reporting of PCC check errors ("PCC check channel failed"). There were potential codepaths where we could incorrectly return PCC channel status as busy even without checking the PCC status register once or not checking the status register before breaking out of the polling loop. For example, if the thread polling PCC status register was preempted and scheduled back after we have crossed the deadline then we can report that the channel is busy even without checking the status register. Signed-off-by: Prashanth Prakash Signed-off-by: Rafael J. Wysocki --- drivers/acpi/cppc_acpi.c | 48 +++++++++++++++++++----------------------------- 1 file changed, 19 insertions(+), 29 deletions(-) (limited to 'drivers/acpi/cppc_acpi.c') diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c index 4446fa6c820e..d9ce4b162e2c 100644 --- a/drivers/acpi/cppc_acpi.c +++ b/drivers/acpi/cppc_acpi.c @@ -39,6 +39,7 @@ #include #include +#include #include #include #include @@ -49,7 +50,7 @@ struct cppc_pcc_data { struct mbox_chan *pcc_channel; void __iomem *pcc_comm_addr; bool pcc_channel_acquired; - ktime_t deadline; + unsigned int deadline_us; unsigned int pcc_mpar, pcc_mrtt, pcc_nominal; bool pending_pcc_write_cmd; /* Any pending/batched PCC write cmds? */ @@ -198,42 +199,31 @@ static struct kobj_type cppc_ktype = { static int check_pcc_chan(int pcc_ss_id, bool chk_err_bit) { - int ret = -EIO, status = 0; + int ret, status; struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id]; struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_ss_data->pcc_comm_addr; - ktime_t next_deadline = ktime_add(ktime_get(), - pcc_ss_data->deadline); if (!pcc_ss_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); - } + /* + * Poll PCC status register every 3us(delay_us) for maximum of + * deadline_us(timeout_us) until PCC command complete bit is set(cond) + */ + ret = readw_relaxed_poll_timeout(&generic_comm_base->status, status, + status & PCC_CMD_COMPLETE_MASK, 3, + pcc_ss_data->deadline_us); - if (likely(!ret)) + if (likely(!ret)) { pcc_ss_data->platform_owns_pcc = false; - else - pr_err("PCC check channel failed for ss: %d. Status=%x\n", - pcc_ss_id, status); + if (chk_err_bit && (status & PCC_ERROR_MASK)) + ret = -EIO; + } + + if (unlikely(ret)) + pr_err("PCC check channel failed for ss: %d. ret=%d\n", + pcc_ss_id, ret); return ret; } @@ -585,7 +575,7 @@ static int register_pcc_channel(int pcc_ss_idx) * So add an arbitrary amount of wait on top of Nominal. */ usecs_lat = NUM_RETRIES * cppc_ss->latency; - pcc_data[pcc_ss_idx]->deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC); + pcc_data[pcc_ss_idx]->deadline_us = usecs_lat; pcc_data[pcc_ss_idx]->pcc_mrtt = cppc_ss->min_turnaround_time; pcc_data[pcc_ss_idx]->pcc_mpar = cppc_ss->max_access_rate; pcc_data[pcc_ss_idx]->pcc_nominal = cppc_ss->latency; -- cgit