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cppc_cpufreq: replace per-cpu data array with a list 

The cppc_cpudata per-cpu storage was inefficient (1) additional to causing
functional issues (2) when CPUs are hotplugged out, due to per-cpu data
being improperly initialised.

(1) The amount of information needed for CPPC performance control in its
    cpufreq driver depends on the domain (PSD) coordination type:

    ANY:    One set of CPPC control and capability data (e.g desired
            performance, highest/lowest performance, etc) applies to all
            CPUs in the domain.

    ALL:    Same as ANY. To be noted that this type is not currently
            supported. When supported, information about which CPUs
            belong to a domain is needed in order for frequency change
            requests to be sent to each of them.

    HW:     It's necessary to store CPPC control and capability
            information for all the CPUs. HW will then coordinate the
            performance state based on their limitations and requests.

    NONE:   Same as HW. No HW coordination is expected.

    Despite this, the previous initialisation code would indiscriminately
    allocate memory for all CPUs (all_cpu_data) and unnecessarily
    duplicate performance capabilities and the domain sharing mask and type
    for each possible CPU.

(2) With the current per-cpu structure, when having ANY coordination,
    the cppc_cpudata cpu information is not initialised (will remain 0)
    for all CPUs in a policy, other than policy->cpu. When policy->cpu is
    hotplugged out, the driver will incorrectly use the uninitialised (0)
    value of the other CPUs when making frequency changes. Additionally,
    the previous values stored in the perf_ctrls.desired_perf will be
    lost when policy->cpu changes.

Therefore replace the array of per cpu data with a list. The memory for
each structure is allocated at policy init, where a single structure
can be allocated per policy, not per cpu. In order to accommodate the
struct list_head node in the cppc_cpudata structure, the now unused cpu
and cur_policy variables are removed.

For example, on a arm64 Juno platform with 6 CPUs: (0, 1, 2, 3) in PSD1,
(4, 5) in PSD2 - ANY coordination, the memory allocation comparison shows:

Before patch:

 - ANY coordination:
   total    slack      req alloc/free  caller
       0        0        0     0/1     _kernel_size_le_hi32+0x0xffff800008ff7810
       0        0        0     0/6     _kernel_size_le_hi32+0x0xffff800008ff7808
     128       80       48     1/0     _kernel_size_le_hi32+0x0xffff800008ffc070
     768        0      768     6/0     _kernel_size_le_hi32+0x0xffff800008ffc0e4

After patch:

 - ANY coordination:
    total    slack      req alloc/free  caller
     256        0      256     2/0     _kernel_size_le_hi32+0x0xffff800008fed410
       0        0        0     0/2     _kernel_size_le_hi32+0x0xffff800008fed274

Additional notes:
 - A pointer to the policy's cppc_cpudata is stored in policy->driver_data
 - Driver registration is skipped if _CPC entries are not present.

Signed-off-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
Ionela Voinescu 2020-12-14 12:38:23 +00:00 committed by Rafael J. Wysocki
parent cfdc589f4b
commit a28b2bfc09
3 changed files with 154 additions and 167 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

141
drivers/acpi/cppc_acpi.c
View File

@ -413,109 +413,88 @@ static int acpi_get_psd(struct cpc_desc *cpc_ptr, acpi_handle handle)
return result;
}
bool acpi_cpc_valid(void)
{
struct cpc_desc *cpc_ptr;
int cpu;
for_each_possible_cpu(cpu) {
cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
if (!cpc_ptr)
return false;
}
return true;
}
EXPORT_SYMBOL_GPL(acpi_cpc_valid);
/**
* acpi_get_psd_map - Map the CPUs in a common freq domain.
* @all_cpu_data: Ptrs to CPU specific CPPC data including PSD info.
* acpi_get_psd_map - Map the CPUs in the freq domain of a given cpu
* @cpu: Find all CPUs that share a domain with cpu.
* @cpu_data: Pointer 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 acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *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;
struct acpi_psd_package *match_pdomain;
struct acpi_psd_package *pdomain;
int count_target, i;
/*
* Now that we have _PSD data from all CPUs, let's setup P-state
* domain info.
*/
cpc_ptr = per_cpu(cpc_desc_ptr, cpu);
if (!cpc_ptr)
return -EFAULT;
pdomain = &(cpc_ptr->domain_info);
cpumask_set_cpu(cpu, cpu_data->shared_cpu_map);
if (pdomain->num_processors <= 1)
return 0;
/* Validate the Domain info */
count_target = pdomain->num_processors;
if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ALL)
cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ALL;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_HW_ALL)
cpu_data->shared_type = CPUFREQ_SHARED_TYPE_HW;
else if (pdomain->coord_type == DOMAIN_COORD_TYPE_SW_ANY)
cpu_data->shared_type = CPUFREQ_SHARED_TYPE_ANY;
for_each_possible_cpu(i) {
if (cpumask_test_cpu(i, covered_cpus))
if (i == cpu)
continue;
pr = all_cpu_data[i];
cpc_ptr = per_cpu(cpc_desc_ptr, i);
if (!cpc_ptr) {
retval = -EFAULT;
goto err_ret;
}
match_cpc_ptr = per_cpu(cpc_desc_ptr, i);
if (!match_cpc_ptr)
goto err_fault;
pdomain = &(cpc_ptr->domain_info);
cpumask_set_cpu(i, pr->shared_cpu_map);
cpumask_set_cpu(i, covered_cpus);
if (pdomain->num_processors <= 1)
match_pdomain = &(match_cpc_ptr->domain_info);
if (match_pdomain->domain != pdomain->domain)
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;
/* Here i and cpu are in the same domain */
if (match_pdomain->num_processors != count_target)
goto err_fault;
for_each_possible_cpu(j) {
if (i == j)
continue;
if (pdomain->coord_type != match_pdomain->coord_type)
goto err_fault;
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_cpu(j, pr->shared_cpu_map) {
if (i == j)
continue;
match_pr = all_cpu_data[j];
match_pr->shared_type = pr->shared_type;
cpumask_copy(match_pr->shared_cpu_map,
pr->shared_cpu_map);
}
cpumask_set_cpu(i, cpu_data->shared_cpu_map);
}
goto out;
err_ret:
for_each_possible_cpu(i) {
pr = all_cpu_data[i];
return 0;
/* Assume no coordination on any error parsing domain info */
cpumask_clear(pr->shared_cpu_map);
cpumask_set_cpu(i, pr->shared_cpu_map);
pr->shared_type = CPUFREQ_SHARED_TYPE_NONE;
}
out:
free_cpumask_var(covered_cpus);
return retval;
err_fault:
/* Assume no coordination on any error parsing domain info */
cpumask_clear(cpu_data->shared_cpu_map);
cpumask_set_cpu(cpu, cpu_data->shared_cpu_map);
cpu_data->shared_type = CPUFREQ_SHARED_TYPE_NONE;
return -EFAULT;
}
EXPORT_SYMBOL_GPL(acpi_get_psd_map);

174
drivers/cpufreq/cppc_cpufreq.c
View File

@ -30,13 +30,13 @@
#define DMI_PROCESSOR_MAX_SPEED 0x14
/*
* 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.
* This list contains information parsed from per CPU ACPI _CPC and _PSD
* structures: e.g. the highest and lowest supported performance, capabilities,
* desired performance, level requested etc. Depending on the share_type, not
* all CPUs will have an entry in the list.
*/
static struct cppc_cpudata **all_cpu_data;
static LIST_HEAD(cpu_data_list);
static bool boost_supported;
struct cppc_workaround_oem_info {
@ -148,8 +148,9 @@ static unsigned int cppc_cpufreq_khz_to_perf(struct cppc_cpudata *cpu_data,
static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
unsigned int target_freq,
unsigned int relation)
{
struct cppc_cpudata *cpu_data = all_cpu_data[policy->cpu];
struct cppc_cpudata *cpu_data = policy->driver_data;
unsigned int cpu = policy->cpu;
struct cpufreq_freqs freqs;
u32 desired_perf;
@ -183,7 +184,7 @@ static int cppc_verify_policy(struct cpufreq_policy_data *policy)
static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
{
struct cppc_cpudata *cpu_data = all_cpu_data[policy->cpu];
struct cppc_cpudata *cpu_data = policy->driver_data;
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
unsigned int cpu = policy->cpu;
int ret;
@ -194,6 +195,12 @@ static void cppc_cpufreq_stop_cpu(struct cpufreq_policy *policy)
if (ret)
pr_debug("Err setting perf value:%d on CPU:%d. ret:%d\n",
caps->lowest_perf, cpu, ret);
/* Remove CPU node from list and free driver data for policy */
free_cpumask_var(cpu_data->shared_cpu_map);
list_del(&cpu_data->node);
kfree(policy->driver_data);
policy->driver_data = NULL;
}
/*
@ -239,25 +246,61 @@ static unsigned int cppc_cpufreq_get_transition_delay_us(unsigned int cpu)
}
#endif
static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
static struct cppc_cpudata *cppc_cpufreq_get_cpu_data(unsigned int cpu)
{
struct cppc_cpudata *cpu_data = all_cpu_data[policy->cpu];
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
unsigned int cpu = policy->cpu;
int i, ret = 0;
struct cppc_cpudata *cpu_data;
int ret;
cpu_data->cpu = cpu;
ret = cppc_get_perf_caps(cpu, caps);
cpu_data = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
if (!cpu_data)
goto out;
if (!zalloc_cpumask_var(&cpu_data->shared_cpu_map, GFP_KERNEL))
goto free_cpu;
ret = acpi_get_psd_map(cpu, cpu_data);
if (ret) {
pr_debug("Err reading CPU%d perf capabilities. ret:%d\n",
cpu, ret);
return ret;
pr_debug("Err parsing CPU%d PSD data: ret:%d\n", cpu, ret);
goto free_mask;
}
ret = cppc_get_perf_caps(cpu, &cpu_data->perf_caps);
if (ret) {
pr_debug("Err reading CPU%d perf caps: ret:%d\n", cpu, ret);
goto free_mask;
}
/* Convert the lowest and nominal freq from MHz to KHz */
caps->lowest_freq *= 1000;
caps->nominal_freq *= 1000;
cpu_data->perf_caps.lowest_freq *= 1000;
cpu_data->perf_caps.nominal_freq *= 1000;
list_add(&cpu_data->node, &cpu_data_list);
return cpu_data;
free_mask:
free_cpumask_var(cpu_data->shared_cpu_map);
free_cpu:
kfree(cpu_data);
out:
return NULL;
}
static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
{
unsigned int cpu = policy->cpu;
struct cppc_cpudata *cpu_data;
struct cppc_perf_caps *caps;
int ret;
cpu_data = cppc_cpufreq_get_cpu_data(cpu);
if (!cpu_data) {
pr_err("Error in acquiring _CPC/_PSD data for CPU%d.\n", cpu);
return -ENODEV;
}
caps = &cpu_data->perf_caps;
policy->driver_data = cpu_data;
/*
* Set min to lowest nonlinear perf to avoid any efficiency penalty (see
@ -287,16 +330,12 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
/* Nothing to be done - we'll have a policy for each CPU */
break;
case CPUFREQ_SHARED_TYPE_ANY:
/* All CPUs in the domain will share a policy */
/*
* All CPUs in the domain will share a policy and all cpufreq
* operations will use a single cppc_cpudata structure stored
* in policy->driver_data.
*/
cpumask_copy(policy->cpus, cpu_data->shared_cpu_map);
for_each_cpu(i, policy->cpus) {
if (unlikely(i == cpu))
continue;
memcpy(&all_cpu_data[i]->perf_caps, caps,
sizeof(cpu_data->perf_caps));
}
break;
default:
pr_debug("Unsupported CPU co-ord type: %d\n",
@ -304,8 +343,6 @@ static int cppc_cpufreq_cpu_init(struct cpufreq_policy *policy)
return -EFAULT;
}
cpu_data->cur_policy = policy;
/*
* If 'highest_perf' is greater than 'nominal_perf', we assume CPU Boost
* is supported.
@ -360,9 +397,12 @@ static int cppc_get_rate_from_fbctrs(struct cppc_cpudata *cpu_data,
static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
{
struct cppc_perf_fb_ctrs fb_ctrs_t0 = {0}, fb_ctrs_t1 = {0};
struct cppc_cpudata *cpu_data = all_cpu_data[cpu];
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
struct cppc_cpudata *cpu_data = policy->driver_data;
int ret;
cpufreq_cpu_put(policy);
ret = cppc_get_perf_ctrs(cpu, &fb_ctrs_t0);
if (ret)
return ret;
@ -378,7 +418,7 @@ static unsigned int cppc_cpufreq_get_rate(unsigned int cpu)
static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
{
struct cppc_cpudata *cpu_data = all_cpu_data[policy->cpu];
struct cppc_cpudata *cpu_data = policy->driver_data;
struct cppc_perf_caps *caps = &cpu_data->perf_caps;
int ret;
@ -404,9 +444,9 @@ static int cppc_cpufreq_set_boost(struct cpufreq_policy *policy, int state)
static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
{
unsigned int cpu = policy->cpu;
struct cppc_cpudata *cpu_data = policy->driver_data;
return cpufreq_show_cpus(all_cpu_data[cpu]->shared_cpu_map, buf);
return cpufreq_show_cpus(cpu_data->shared_cpu_map, buf);
}
cpufreq_freq_attr_ro(freqdomain_cpus);
@ -435,10 +475,13 @@ static struct cpufreq_driver cppc_cpufreq_driver = {
*/
static unsigned int hisi_cppc_cpufreq_get_rate(unsigned int cpu)
{
struct cppc_cpudata *cpu_data = all_cpu_data[cpu];
struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
struct cppc_cpudata *cpu_data = policy->driver_data;
u64 desired_perf;
int ret;
cpufreq_cpu_put(policy);
ret = cppc_get_desired_perf(cpu, &desired_perf);
if (ret < 0)
return -EIO;
@ -471,68 +514,33 @@ static void cppc_check_hisi_workaround(void)
static int __init cppc_cpufreq_init(void)
{
struct cppc_cpudata *cpu_data;
int i, ret = 0;
if (acpi_disabled)
if ((acpi_disabled) || !acpi_cpc_valid())
return -ENODEV;
all_cpu_data = kcalloc(num_possible_cpus(), sizeof(void *),
GFP_KERNEL);
if (!all_cpu_data)
return -ENOMEM;
for_each_possible_cpu(i) {
all_cpu_data[i] = kzalloc(sizeof(struct cppc_cpudata), GFP_KERNEL);
if (!all_cpu_data[i])
goto out;
cpu_data = all_cpu_data[i];
if (!zalloc_cpumask_var(&cpu_data->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;
}
INIT_LIST_HEAD(&cpu_data_list);
cppc_check_hisi_workaround();
ret = cpufreq_register_driver(&cppc_cpufreq_driver);
if (ret)
goto out;
return cpufreq_register_driver(&cppc_cpufreq_driver);
}
return ret;
static inline void free_cpu_data(void)
{
struct cppc_cpudata *iter, *tmp;
out:
for_each_possible_cpu(i) {
cpu_data = all_cpu_data[i];
if (!cpu_data)
break;
free_cpumask_var(cpu_data->shared_cpu_map);
kfree(cpu_data);
list_for_each_entry_safe(iter, tmp, &cpu_data_list, node) {
free_cpumask_var(iter->shared_cpu_map);
list_del(&iter->node);
kfree(iter);
}
kfree(all_cpu_data);
return -ENODEV;
}
static void __exit cppc_cpufreq_exit(void)
{
struct cppc_cpudata *cpu_data;
int i;
cpufreq_unregister_driver(&cppc_cpufreq_driver);
for_each_possible_cpu(i) {
cpu_data = all_cpu_data[i];
free_cpumask_var(cpu_data->shared_cpu_map);
kfree(cpu_data);
}
kfree(all_cpu_data);
free_cpu_data();
}
module_exit(cppc_cpufreq_exit);

6
include/acpi/cppc_acpi.h
View File

@ -124,11 +124,10 @@ struct cppc_perf_fb_ctrs {
/* Per CPU container for runtime CPPC management. */
struct cppc_cpudata {
int cpu;
struct list_head node;
struct cppc_perf_caps perf_caps;
struct cppc_perf_ctrls perf_ctrls;
struct cppc_perf_fb_ctrs perf_fb_ctrs;
struct cpufreq_policy *cur_policy;
unsigned int shared_type;
cpumask_var_t shared_cpu_map;
};
@ -137,7 +136,8 @@ extern int cppc_get_desired_perf(int cpunum, u64 *desired_perf);
extern int cppc_get_perf_ctrs(int cpu, struct cppc_perf_fb_ctrs *perf_fb_ctrs);
extern int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls);
extern int cppc_get_perf_caps(int cpu, struct cppc_perf_caps *caps);
extern int acpi_get_psd_map(struct cppc_cpudata **);
extern bool acpi_cpc_valid(void);
extern int acpi_get_psd_map(unsigned int cpu, struct cppc_cpudata *cpu_data);
extern unsigned int cppc_get_transition_latency(int cpu);
extern bool cpc_ffh_supported(void);
extern int cpc_read_ffh(int cpunum, struct cpc_reg *reg, u64 *val);