There are several global variables in cppc driver that are related
to PCC channel used for CPPC. This patch collects all such
information into a single consolidated structure(cppc_pcc_data).
Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
Signed-off-by: Prashanth Prakash <pprakash@xxxxxxxxxxxxxx>
---
drivers/acpi/cppc_acpi.c | 167 ++++++++++++++++++++++++-----------------------
1 file changed, 87 insertions(+), 80 deletions(-)
diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index f00fac3..80c123f 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -45,30 +45,41 @@
#include <acpi/cppc_acpi.h>
-/*
- * 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
- */
-static DECLARE_RWSEM(pcc_lock);
+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;
-/* Indicates if there are any pending/batched PCC write commands */
-static bool pending_pcc_write_cmd;
+ bool pending_pcc_write_cmd; /* Any pending/batched PCC write cmds? */
+ unsigned int pcc_write_cnt; /* Running count of PCC write commands */
-/* Wait queue for CPUs whose requests were batched */
-static DECLARE_WAIT_QUEUE_HEAD(pcc_write_wait_q);
+ /*
+ * 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;
+};
-/* Used to identify if a batched request is delivered to platform */
-static unsigned int pcc_write_cnt;
+/* Structure to represent the single PCC channel */
+static struct cppc_pcc_data pcc_data = {
+ .pcc_subspace_idx = -1,
+};
/*
* The cpc_desc structure contains the ACPI register details
@@ -79,16 +90,8 @@ static unsigned int pcc_write_cnt;
*/
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 int pcc_subspace_idx = -1;
-static bool pcc_channel_acquired;
-static ktime_t deadline;
-static unsigned int pcc_mpar, pcc_mrtt, pcc_nominal;
-
/* pcc mapped address + header size + offset within PCC subspace */
-#define GET_PCC_VADDR(offs) (pcc_comm_addr + 0x8 + (offs))
+#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 && \
@@ -181,8 +184,8 @@ static struct kobj_type cppc_ktype = {
static int check_pcc_chan(void)
{
int ret = -EIO;
- struct acpi_pcct_shared_memory __iomem *generic_comm_base = pcc_comm_addr;
- ktime_t next_deadline = ktime_add(ktime_get(), deadline);
+ 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);
/* Retry in case the remote processor was too slow to catch up. */
while (!ktime_after(ktime_get(), next_deadline)) {
@@ -213,7 +216,7 @@ 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_comm_addr;
+ (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;
@@ -228,24 +231,24 @@ static int send_pcc_cmd(u16 cmd)
* before write completion, so first send a WRITE command to
* platform
*/
- if (pending_pcc_write_cmd)
+ if (pcc_data.pending_pcc_write_cmd)
send_pcc_cmd(CMD_WRITE);
ret = check_pcc_chan();
if (ret)
goto end;
} else /* CMD_WRITE */
- pending_pcc_write_cmd = FALSE;
+ 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_mrtt) {
+ if (pcc_data.pcc_mrtt) {
time_delta = ktime_us_delta(ktime_get(), last_cmd_cmpl_time);
- if (pcc_mrtt > time_delta)
- udelay(pcc_mrtt - time_delta);
+ if (pcc_data.pcc_mrtt > time_delta)
+ udelay(pcc_data.pcc_mrtt - time_delta);
}
/*
@@ -259,7 +262,7 @@ static int send_pcc_cmd(u16 cmd)
* not send the request to the platform after hitting the MPAR limit in
* any 60s window
*/
- if (pcc_mpar) {
+ 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) {
@@ -268,7 +271,7 @@ static int send_pcc_cmd(u16 cmd)
goto end;
}
last_mpar_reset = ktime_get();
- mpar_count = pcc_mpar;
+ mpar_count = pcc_data.pcc_mpar;
}
mpar_count--;
}
@@ -280,7 +283,7 @@ static int send_pcc_cmd(u16 cmd)
writew_relaxed(0, &generic_comm_base->status);
/* Ring doorbell */
- ret = mbox_send_message(pcc_channel, &cmd);
+ 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);
@@ -299,13 +302,13 @@ static int send_pcc_cmd(u16 cmd)
* command for proper handling of MRTT, so we need to check
* for pcc_mrtt in addition to CMD_READ
*/
- if (cmd == CMD_READ || pcc_mrtt) {
+ if (cmd == CMD_READ || pcc_data.pcc_mrtt) {
ret = check_pcc_chan();
- if (pcc_mrtt)
+ if (pcc_data.pcc_mrtt)
last_cmd_cmpl_time = ktime_get();
}
- mbox_client_txdone(pcc_channel, ret);
+ mbox_client_txdone(pcc_data.pcc_channel, ret);
end:
if (cmd == CMD_WRITE) {
@@ -315,12 +318,12 @@ end:
if (!desc)
continue;
- if (desc->write_cmd_id == pcc_write_cnt)
+ if (desc->write_cmd_id == pcc_data.pcc_write_cnt)
desc->write_cmd_status = ret;
}
}
- pcc_write_cnt++;
- wake_up_all(&pcc_write_wait_q);
+ pcc_data.pcc_write_cnt++;
+ wake_up_all(&pcc_data.pcc_write_wait_q);
}
return ret;
@@ -528,10 +531,10 @@ static int register_pcc_channel(int pcc_subspace_idx)
u64 usecs_lat;
if (pcc_subspace_idx >= 0) {
- pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl,
+ pcc_data.pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl,
pcc_subspace_idx);
- if (IS_ERR(pcc_channel)) {
+ if (IS_ERR(pcc_data.pcc_channel)) {
pr_err("Failed to find PCC communication channel\n");
return -ENODEV;
}
@@ -542,7 +545,7 @@ static int register_pcc_channel(int pcc_subspace_idx)
* PCC channels) and stored pointers to the
* subspace communication region in con_priv.
*/
- cppc_ss = pcc_channel->con_priv;
+ cppc_ss = (pcc_data.pcc_channel)->con_priv;
if (!cppc_ss) {
pr_err("No PCC subspace found for CPPC\n");
@@ -555,19 +558,19 @@ static int register_pcc_channel(int pcc_subspace_idx)
* So add an arbitrary amount of wait on top of Nominal.
*/
usecs_lat = NUM_RETRIES * cppc_ss->latency;
- deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC);
- pcc_mrtt = cppc_ss->min_turnaround_time;
- pcc_mpar = cppc_ss->max_access_rate;
- pcc_nominal = cppc_ss->latency;
+ pcc_data.deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC);
+ pcc_data.pcc_mrtt = cppc_ss->min_turnaround_time;
+ pcc_data.pcc_mpar = cppc_ss->max_access_rate;
+ pcc_data.pcc_nominal = cppc_ss->latency;
- pcc_comm_addr = acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
- if (!pcc_comm_addr) {
+ pcc_data.pcc_comm_addr = acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
+ if (!pcc_data.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;
+ pcc_data.pcc_channel_acquired = true;
}
return 0;
@@ -706,9 +709,9 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
* 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) {
+ if (pcc_data.pcc_subspace_idx < 0)
+ pcc_data.pcc_subspace_idx = gas_t->access_width;
+ else if (pcc_data.pcc_subspace_idx != gas_t->access_width) {
pr_debug("Mismatched PCC ids.\n");
goto out_free;
}
@@ -743,10 +746,13 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
goto out_free;
/* Register PCC channel once for all CPUs. */
- if (!pcc_channel_acquired) {
- ret = register_pcc_channel(pcc_subspace_idx);
+ if (!pcc_data.pcc_channel_acquired) {
+ ret = register_pcc_channel(pcc_data.pcc_subspace_idx);
if (ret)
goto out_free;
+
+ init_rwsem(&pcc_data.pcc_lock);
+ init_waitqueue_head(&pcc_data.pcc_write_wait_q);
}
/* Plug PSD data into this CPUs CPC descriptor. */
@@ -924,7 +930,7 @@ 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(ref_perf) || CPC_IN_PCC(nom_perf)) {
regs_in_pcc = 1;
- down_write(&pcc_lock);
+ down_write(&pcc_data.pcc_lock);
/* Ring doorbell once to update PCC subspace */
if (send_pcc_cmd(CMD_READ) < 0) {
ret = -EIO;
@@ -946,7 +952,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
out_err:
if (regs_in_pcc)
- up_write(&pcc_lock);
+ up_write(&pcc_data.pcc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
@@ -986,7 +992,7 @@ 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)) {
- down_write(&pcc_lock);
+ down_write(&pcc_data.pcc_lock);
regs_in_pcc = 1;
/* Ring doorbell once to update PCC subspace */
if (send_pcc_cmd(CMD_READ) < 0) {
@@ -1019,7 +1025,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
perf_fb_ctrs->ctr_wrap_time = ctr_wrap_time;
out_err:
if (regs_in_pcc)
- up_write(&pcc_lock);
+ up_write(&pcc_data.pcc_lock);
return ret;
}
EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
@@ -1052,17 +1058,17 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
* achieve that goal here
*/
if (CPC_IN_PCC(desired_reg)) {
- down_read(&pcc_lock); /* BEGIN Phase-I */
+ down_read(&pcc_data.pcc_lock); /* BEGIN Phase-I */
/*
* If there are pending write commands i.e pending_pcc_write_cmd
* is TRUE, then we know OSPM owns the channel as another CPU
* has already checked for command completion bit and updated
* the corresponding CPC registers
*/
- if (!pending_pcc_write_cmd) {
+ if (!pcc_data.pending_pcc_write_cmd) {
ret = check_pcc_chan();
if (ret) {
- up_read(&pcc_lock);
+ up_read(&pcc_data.pcc_lock);
return ret;
}
/*
@@ -1070,9 +1076,9 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
* will not arrive and steal the channel during the
* transition to write lock
*/
- pending_pcc_write_cmd = TRUE;
+ pcc_data.pending_pcc_write_cmd = TRUE;
}
- cpc_desc->write_cmd_id = pcc_write_cnt;
+ cpc_desc->write_cmd_id = pcc_data.pcc_write_cnt;
cpc_desc->write_cmd_status = 0;
}
@@ -1083,7 +1089,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
cpc_write(desired_reg, perf_ctrls->desired_perf);
if (CPC_IN_PCC(desired_reg))
- up_read(&pcc_lock); /* END Phase-I */
+ up_read(&pcc_data.pcc_lock); /* END Phase-I */
/*
* This is Phase-II where we transfer the ownership of PCC to Platform
*
@@ -1131,15 +1137,15 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
* the write command before servicing the read command
*/
if (CPC_IN_PCC(desired_reg)) {
- if (down_write_trylock(&pcc_lock)) { /* BEGIN Phase-II */
+ if (down_write_trylock(&pcc_data.pcc_lock)) { /* BEGIN Phase-II */
/* Update only if there are pending write commands */
- if (pending_pcc_write_cmd)
+ if (pcc_data.pending_pcc_write_cmd)
send_pcc_cmd(CMD_WRITE);
- up_write(&pcc_lock); /* END Phase-II */
+ up_write(&pcc_data.pcc_lock); /* END Phase-II */
} else
/* Wait until pcc_write_cnt is updated by send_pcc_cmd */
- wait_event(pcc_write_wait_q,
- cpc_desc->write_cmd_id != pcc_write_cnt);
+ wait_event(pcc_data.pcc_write_wait_q,
+ cpc_desc->write_cmd_id != pcc_data.pcc_write_cnt);
/* send_pcc_cmd updates the status in case of failure */
ret = cpc_desc->write_cmd_status;
@@ -1181,10 +1187,11 @@ unsigned int cppc_get_transition_latency(int cpu_num)
if (!CPC_IN_PCC(desired_reg))
return CPUFREQ_ETERNAL;
- if (pcc_mpar)
- latency_ns = 60 * (1000 * 1000 * 1000 / pcc_mpar);
+ if (pcc_data.pcc_mpar)
+ latency_ns = 60 * (1000 * 1000 * 1000 / pcc_data.pcc_mpar);
- latency_ns = max(latency_ns, (pcc_nominal + pcc_mrtt) * 1000);
+ latency_ns = max(latency_ns, pcc_data.pcc_nominal * 1000);
+ latency_ns = max(latency_ns, pcc_data.pcc_mrtt * 1000);
return latency_ns;
}
--
Qualcomm Datacenter Technologies on behalf of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.
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