[PATCHv2 2/2] ACPI / CPPC: Make cppc acpi driver aware of pcc subspace ids

[George Cherian <george.cherian@cavium.com>]

Based on ACPI 6.2 Section 8.4.7.1.9 If the PCC register space is used,
all PCC registers, for all processors in the same performance
domain (as defined by _PSD), must be defined to be in the same subspace.
Based on Section 14.1 of ACPI specification, it is possible to have a
maximum of 256 PCC subspace ids. Add support of multiple PCC subspace id
instead of using a single global pcc_data structure.

While at that fix the time_delta check in send_pcc_cmd() so that last_mpar_reset
and mpar_count is initialized properly.

Signed-off-by: George Cherian <george.cherian@cavium.com>
---
 drivers/acpi/cppc_acpi.c | 228 ++++++++++++++++++++++++++++++-----------------
 1 file changed, 144 insertions(+), 84 deletions(-)

diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
index e5b47f0..6c99f2f 100644
--- a/drivers/acpi/cppc_acpi.c
+++ b/drivers/acpi/cppc_acpi.c
@@ -75,13 +75,16 @@ struct cppc_pcc_data {
 
 	/* Wait queue for CPUs whose requests were batched */
 	wait_queue_head_t pcc_write_wait_q;
+	ktime_t last_cmd_cmpl_time;
+	ktime_t last_mpar_reset;
+	int mpar_count;
+	int refcount;
 };
 
-/* Structure to represent the single PCC channel */
-static struct cppc_pcc_data pcc_data = {
-	.pcc_subspace_idx = -1,
-	.platform_owns_pcc = true,
-};
+/* Array  to represent the PCC channel per subspace id */
+static struct cppc_pcc_data *pcc_data[MAX_PCC_SUBSPACES];
+/* The cpu_pcc_subspace_idx contains per CPU subspace id */
+static DEFINE_PER_CPU(int, cpu_pcc_subspace_idx);
 
 /*
  * The cpc_desc structure contains the ACPI register details
@@ -93,7 +96,8 @@ static struct cppc_pcc_data pcc_data = {
 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))
+#define GET_PCC_VADDR(offs, pcc_ss_id) (pcc_data[pcc_ss_id]->pcc_comm_addr + \
+						0x8 + (offs))
 
 /* Check if a CPC register is in PCC */
 #define CPC_IN_PCC(cpc) ((cpc)->type == ACPI_TYPE_BUFFER &&		\
@@ -188,13 +192,16 @@ static struct kobj_type cppc_ktype = {
 	.default_attrs = cppc_attrs,
 };
 
-static int check_pcc_chan(bool chk_err_bit)
+static int check_pcc_chan(int pcc_ss_id, 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);
+	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_data.platform_owns_pcc)
+	if (!pcc_ss_data->platform_owns_pcc)
 		return 0;
 
 	/* Retry in case the remote processor was too slow to catch up. */
@@ -219,7 +226,7 @@ static int check_pcc_chan(bool chk_err_bit)
 	}
 
 	if (likely(!ret))
-		pcc_data.platform_owns_pcc = false;
+		pcc_ss_data->platform_owns_pcc = false;
 	else
 		pr_err("PCC check channel failed. Status=%x\n", status);
 
@@ -230,13 +237,15 @@ static int check_pcc_chan(bool chk_err_bit)
  * 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)
+static int send_pcc_cmd(int pcc_ss_id, u16 cmd)
 {
 	int ret = -EIO, i;
+	struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
 	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;
+		(struct acpi_pcct_shared_memory *)pcc_ss_data->pcc_comm_addr;
+	ktime_t last_cmd_cmpl_time = pcc_ss_data->last_cmd_cmpl_time;
+	ktime_t last_mpar_reset = pcc_ss_data->last_mpar_reset;
+	int mpar_count = pcc_ss_data->mpar_count;
 	unsigned int time_delta;
 
 	/*
@@ -249,24 +258,24 @@ static int send_pcc_cmd(u16 cmd)
 		 * before write completion, so first send a WRITE command to
 		 * platform
 		 */
-		if (pcc_data.pending_pcc_write_cmd)
-			send_pcc_cmd(CMD_WRITE);
+		if (pcc_ss_data->pending_pcc_write_cmd)
+			send_pcc_cmd(pcc_ss_id, CMD_WRITE);
 
-		ret = check_pcc_chan(false);
+		ret = check_pcc_chan(pcc_ss_id, false);
 		if (ret)
 			goto end;
 	} else /* CMD_WRITE */
-		pcc_data.pending_pcc_write_cmd = FALSE;
+		pcc_ss_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) {
+	if (pcc_ss_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);
+		if (pcc_ss_data->pcc_mrtt > time_delta)
+			udelay(pcc_ss_data->pcc_mrtt - time_delta);
 	}
 
 	/*
@@ -280,16 +289,16 @@ 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_data.pcc_mpar) {
+	if (pcc_ss_data->pcc_mpar) {
 		if (mpar_count == 0) {
 			time_delta = ktime_ms_delta(ktime_get(), last_mpar_reset);
-			if (time_delta < 60 * MSEC_PER_SEC) {
+			if ((time_delta < 60 * MSEC_PER_SEC) && last_mpar_reset) {
 				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 = pcc_ss_data->pcc_mpar;
 		}
 		mpar_count--;
 	}
@@ -300,10 +309,10 @@ static int send_pcc_cmd(u16 cmd)
 	/* Flip CMD COMPLETE bit */
 	writew_relaxed(0, &generic_comm_base->status);
 
-	pcc_data.platform_owns_pcc = true;
+	pcc_ss_data->platform_owns_pcc = true;
 
 	/* Ring doorbell */
-	ret = mbox_send_message(pcc_data.pcc_channel, &cmd);
+	ret = mbox_send_message(pcc_ss_data->pcc_channel, &cmd);
 	if (ret < 0) {
 		pr_err("Err sending PCC mbox message. cmd:%d, ret:%d\n",
 				cmd, ret);
@@ -311,15 +320,15 @@ static int send_pcc_cmd(u16 cmd)
 	}
 
 	/* wait for completion and check for PCC errro bit */
-	ret = check_pcc_chan(true);
+	ret = check_pcc_chan(pcc_ss_id, true);
 
-	if (pcc_data.pcc_mrtt)
+	if (pcc_ss_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);
+	if (pcc_ss_data->pcc_channel->mbox->txdone_irq)
+		mbox_chan_txdone(pcc_ss_data->pcc_channel, ret);
 	else
-		mbox_client_txdone(pcc_data.pcc_channel, ret);
+		mbox_client_txdone(pcc_ss_data->pcc_channel, ret);
 
 end:
 	if (cmd == CMD_WRITE) {
@@ -329,12 +338,12 @@ static int send_pcc_cmd(u16 cmd)
 				if (!desc)
 					continue;
 
-				if (desc->write_cmd_id == pcc_data.pcc_write_cnt)
+				if (desc->write_cmd_id == pcc_ss_data->pcc_write_cnt)
 					desc->write_cmd_status = ret;
 			}
 		}
-		pcc_data.pcc_write_cnt++;
-		wake_up_all(&pcc_data.pcc_write_wait_q);
+		pcc_ss_data->pcc_write_cnt++;
+		wake_up_all(&pcc_ss_data->pcc_write_wait_q);
 	}
 
 	return ret;
@@ -536,16 +545,16 @@ int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data)
 }
 EXPORT_SYMBOL_GPL(acpi_get_psd_map);
 
-static int register_pcc_channel(int pcc_subspace_idx)
+static int register_pcc_channel(int pcc_ss_idx)
 {
 	struct acpi_pcct_hw_reduced *cppc_ss;
 	u64 usecs_lat;
 
-	if (pcc_subspace_idx >= 0) {
-		pcc_data.pcc_channel = pcc_mbox_request_channel(&cppc_mbox_cl,
-				pcc_subspace_idx);
+	if (pcc_ss_idx >= 0) {
+		pcc_data[pcc_ss_idx]->pcc_channel =
+			pcc_mbox_request_channel(&cppc_mbox_cl,	pcc_ss_idx);
 
-		if (IS_ERR(pcc_data.pcc_channel)) {
+		if (IS_ERR(pcc_data[pcc_ss_idx]->pcc_channel)) {
 			pr_err("Failed to find PCC communication channel\n");
 			return -ENODEV;
 		}
@@ -556,7 +565,7 @@ 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_data.pcc_channel)->con_priv;
+		cppc_ss = (pcc_data[pcc_ss_idx]->pcc_channel)->con_priv;
 
 		if (!cppc_ss) {
 			pr_err("No PCC subspace found for CPPC\n");
@@ -569,19 +578,20 @@ 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;
-		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_data.pcc_comm_addr = acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
-		if (!pcc_data.pcc_comm_addr) {
+		pcc_data[pcc_ss_idx]->deadline = ns_to_ktime(usecs_lat * NSEC_PER_USEC);
+		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;
+
+		pcc_data[pcc_ss_idx]->pcc_comm_addr =
+			acpi_os_ioremap(cppc_ss->base_address, cppc_ss->length);
+		if (!pcc_data[pcc_ss_idx]->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_data.pcc_channel_acquired = true;
+		pcc_data[pcc_ss_idx]->pcc_channel_acquired = true;
 	}
 
 	return 0;
@@ -600,6 +610,37 @@ bool __weak cpc_ffh_supported(void)
 	return false;
 }
 
+
+/**
+ * pcc_data_alloc() - Allocate the pcc_data memory for pcc subspace
+ *
+ * Check and allocate the cppc_pcc_data memory.
+ * In some processor configurations it is possible that same subspace
+ * is shared between multiple CPU's. This is seen especially in CPU's
+ * with hardware multi-threading support.
+ *
+ * Return: 0 for success, errno for failure
+ */
+int pcc_data_alloc(int pcc_ss_id)
+{
+	int loop;
+
+	if (pcc_ss_id < 0)
+		return -EINVAL;
+
+	for (loop = 0; pcc_data[loop] != NULL; loop++) {
+		if (pcc_data[loop]->pcc_subspace_idx == pcc_ss_id) {
+			pcc_data[loop]->refcount++;
+			return 0;
+		}
+	}
+
+	pcc_data[pcc_ss_id] = kzalloc(sizeof(struct cppc_pcc_data), GFP_KERNEL);
+	pcc_data[pcc_ss_id]->pcc_subspace_idx = pcc_ss_id;
+	pcc_data[pcc_ss_id]->refcount++;
+
+	return 0;
+}
 /*
  * An example CPC table looks like the following.
  *
@@ -661,6 +702,7 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 	struct device *cpu_dev;
 	acpi_handle handle = pr->handle;
 	unsigned int num_ent, i, cpc_rev;
+	unsigned int pcc_subspace_id = 0;
 	acpi_status status;
 	int ret = -EFAULT;
 
@@ -733,12 +775,10 @@ 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_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");
+				pcc_subspace_id = gas_t->access_width;
+				if (pcc_data_alloc(pcc_subspace_id))
 					goto out_free;
-				}
+				per_cpu(cpu_pcc_subspace_idx, pr->id) = pcc_subspace_id;
 			} else if (gas_t->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY) {
 				if (gas_t->address) {
 					void __iomem *addr;
@@ -771,14 +811,14 @@ int acpi_cppc_processor_probe(struct acpi_processor *pr)
 	if (ret)
 		goto out_free;
 
-	/* Register PCC channel once for all CPUs. */
-	if (!pcc_data.pcc_channel_acquired) {
-		ret = register_pcc_channel(pcc_data.pcc_subspace_idx);
+	/* Register PCC channel once for all PCC subspace id. */
+	if (!pcc_data[pcc_subspace_id]->pcc_channel_acquired) {
+		ret = register_pcc_channel(pcc_subspace_id);
 		if (ret)
 			goto out_free;
 
-		init_rwsem(&pcc_data.pcc_lock);
-		init_waitqueue_head(&pcc_data.pcc_write_wait_q);
+		init_rwsem(&pcc_data[pcc_subspace_id]->pcc_lock);
+		init_waitqueue_head(&pcc_data[pcc_subspace_id]->pcc_write_wait_q);
 	}
 
 	/* Everything looks okay */
@@ -831,6 +871,16 @@ void acpi_cppc_processor_exit(struct acpi_processor *pr)
 	struct cpc_desc *cpc_ptr;
 	unsigned int i;
 	void __iomem *addr;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, pr->id);
+
+	if (pcc_data[pcc_ss_id]->pcc_channel_acquired) {
+		pcc_data[pcc_ss_id]->refcount--;
+		if (!pcc_data[pcc_ss_id]->refcount) {
+			pcc_mbox_free_channel(pcc_data[pcc_ss_id]->pcc_channel);
+			pcc_data[pcc_ss_id]->pcc_channel_acquired = 0;
+			kfree(pcc_data[pcc_ss_id]);
+		}
+	}
 
 	cpc_ptr = per_cpu(cpc_desc_ptr, pr->id);
 	if (!cpc_ptr)
@@ -888,6 +938,7 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 {
 	int ret_val = 0;
 	void __iomem *vaddr = 0;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
 	struct cpc_reg *reg = &reg_res->cpc_entry.reg;
 
 	if (reg_res->type == ACPI_TYPE_INTEGER) {
@@ -897,7 +948,7 @@ static int cpc_read(int cpu, struct cpc_register_resource *reg_res, u64 *val)
 
 	*val = 0;
 	if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
-		vaddr = GET_PCC_VADDR(reg->address);
+		vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
 	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
@@ -932,10 +983,11 @@ static int cpc_write(int cpu, struct cpc_register_resource *reg_res, u64 val)
 {
 	int ret_val = 0;
 	void __iomem *vaddr = 0;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu);
 	struct cpc_reg *reg = &reg_res->cpc_entry.reg;
 
 	if (reg->space_id == ACPI_ADR_SPACE_PLATFORM_COMM)
-		vaddr = GET_PCC_VADDR(reg->address);
+		vaddr = GET_PCC_VADDR(reg->address, pcc_ss_id);
 	else if (reg->space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY)
 		vaddr = reg_res->sys_mem_vaddr;
 	else if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE)
@@ -980,6 +1032,8 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 	struct cpc_register_resource *highest_reg, *lowest_reg,
 		*lowest_non_linear_reg, *nominal_reg;
 	u64 high, low, nom, min_nonlinear;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
+	struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
 	int ret = 0, regs_in_pcc = 0;
 
 	if (!cpc_desc) {
@@ -996,9 +1050,9 @@ 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)) {
 		regs_in_pcc = 1;
-		down_write(&pcc_data.pcc_lock);
+		down_write(&pcc_ss_data->pcc_lock);
 		/* Ring doorbell once to update PCC subspace */
-		if (send_pcc_cmd(CMD_READ) < 0) {
+		if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
 			ret = -EIO;
 			goto out_err;
 		}
@@ -1021,7 +1075,7 @@ int cppc_get_perf_caps(int cpunum, struct cppc_perf_caps *perf_caps)
 
 out_err:
 	if (regs_in_pcc)
-		up_write(&pcc_data.pcc_lock);
+		up_write(&pcc_ss_data->pcc_lock);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cppc_get_perf_caps);
@@ -1038,6 +1092,8 @@ 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,
 		*ref_perf_reg, *ctr_wrap_reg;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpunum);
+	struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
 	u64 delivered, reference, ref_perf, ctr_wrap_time;
 	int ret = 0, regs_in_pcc = 0;
 
@@ -1061,10 +1117,10 @@ 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_data.pcc_lock);
+		down_write(&pcc_ss_data->pcc_lock);
 		regs_in_pcc = 1;
 		/* Ring doorbell once to update PCC subspace */
-		if (send_pcc_cmd(CMD_READ) < 0) {
+		if (send_pcc_cmd(pcc_ss_id, CMD_READ) < 0) {
 			ret = -EIO;
 			goto out_err;
 		}
@@ -1094,7 +1150,7 @@ int cppc_get_perf_ctrs(int cpunum, struct cppc_perf_fb_ctrs *perf_fb_ctrs)
 	perf_fb_ctrs->wraparound_time = ctr_wrap_time;
 out_err:
 	if (regs_in_pcc)
-		up_write(&pcc_data.pcc_lock);
+		up_write(&pcc_ss_data->pcc_lock);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(cppc_get_perf_ctrs);
@@ -1110,6 +1166,8 @@ 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 = pcc_data[pcc_ss_id];
 	int ret = 0;
 
 	if (!cpc_desc) {
@@ -1127,11 +1185,11 @@ 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_data.pcc_lock);	/* BEGIN Phase-I */
-		if (pcc_data.platform_owns_pcc) {
-			ret = check_pcc_chan(false);
+		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);
 			if (ret) {
-				up_read(&pcc_data.pcc_lock);
+				up_read(&pcc_ss_data->pcc_lock);
 				return ret;
 			}
 		}
@@ -1139,8 +1197,8 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 		 * Update the pending_write to make sure a PCC CMD_READ will not
 		 * arrive and steal the channel during the switch to write lock
 		 */
-		pcc_data.pending_pcc_write_cmd = true;
-		cpc_desc->write_cmd_id = pcc_data.pcc_write_cnt;
+		pcc_ss_data->pending_pcc_write_cmd = true;
+		cpc_desc->write_cmd_id = pcc_ss_data->pcc_write_cnt;
 		cpc_desc->write_cmd_status = 0;
 	}
 
@@ -1151,7 +1209,7 @@ int cppc_set_perf(int cpu, struct cppc_perf_ctrls *perf_ctrls)
 	cpc_write(cpu, desired_reg, perf_ctrls->desired_perf);
 
 	if (CPC_IN_PCC(desired_reg))
-		up_read(&pcc_data.pcc_lock);	/* END Phase-I */
+		up_read(&pcc_ss_data->pcc_lock);	/* END Phase-I */
 	/*
 	 * This is Phase-II where we transfer the ownership of PCC to Platform
 	 *
@@ -1199,15 +1257,15 @@ 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_data.pcc_lock)) {	/* BEGIN Phase-II */
+		if (down_write_trylock(&pcc_ss_data->pcc_lock)) {/* BEGIN Phase-II */
 			/* Update only if there are pending write commands */
-			if (pcc_data.pending_pcc_write_cmd)
-				send_pcc_cmd(CMD_WRITE);
-			up_write(&pcc_data.pcc_lock);		/* END Phase-II */
+			if (pcc_ss_data->pending_pcc_write_cmd)
+				send_pcc_cmd(pcc_ss_id, CMD_WRITE);
+			up_write(&pcc_ss_data->pcc_lock);	/* END Phase-II */
 		} else
 			/* Wait until pcc_write_cnt is updated by send_pcc_cmd */
-			wait_event(pcc_data.pcc_write_wait_q,
-				cpc_desc->write_cmd_id != pcc_data.pcc_write_cnt);
+			wait_event(pcc_ss_data->pcc_write_wait_q,
+				   cpc_desc->write_cmd_id != pcc_ss_data->pcc_write_cnt);
 
 		/* send_pcc_cmd updates the status in case of failure */
 		ret = cpc_desc->write_cmd_status;
@@ -1240,6 +1298,8 @@ unsigned int cppc_get_transition_latency(int cpu_num)
 	unsigned int latency_ns = 0;
 	struct cpc_desc *cpc_desc;
 	struct cpc_register_resource *desired_reg;
+	int pcc_ss_id = per_cpu(cpu_pcc_subspace_idx, cpu_num);
+	struct cppc_pcc_data *pcc_ss_data = pcc_data[pcc_ss_id];
 
 	cpc_desc = per_cpu(cpc_desc_ptr, cpu_num);
 	if (!cpc_desc)
@@ -1249,11 +1309,11 @@ unsigned int cppc_get_transition_latency(int cpu_num)
 	if (!CPC_IN_PCC(desired_reg))
 		return CPUFREQ_ETERNAL;
 
-	if (pcc_data.pcc_mpar)
-		latency_ns = 60 * (1000 * 1000 * 1000 / pcc_data.pcc_mpar);
+	if (pcc_ss_data->pcc_mpar)
+		latency_ns = 60 * (1000 * 1000 * 1000 / pcc_ss_data->pcc_mpar);
 
-	latency_ns = max(latency_ns, pcc_data.pcc_nominal * 1000);
-	latency_ns = max(latency_ns, pcc_data.pcc_mrtt * 1000);
+	latency_ns = max(latency_ns, pcc_ss_data->pcc_nominal * 1000);
+	latency_ns = max(latency_ns, pcc_ss_data->pcc_mrtt * 1000);
 
 	return latency_ns;
 }
-- 
2.1.4