[PATCH V8 5/8] pseries/drc-info: Search new DRC properties for CPU indexes

Michael Bringmann mwb at linux.vnet.ibm.com
Thu Oct 27 02:25:03 AEDT 2016


pseries/drc-info: Provide parallel routines to convert between
drc_index and CPU numbers at runtime, using the older device-tree
properties ("ibm,drc-indexes", "ibm,drc-names", "ibm,drc-types"
and "ibm,drc-power-domains"), or the new property "ibm,drc-info".

[V2: Revise contant names.]
[V3: No change.]
[V4: No change.]
[V5: Resynchronize/resubmit]
[V6: No change]
[V7: Correct mail threading]
[v8: Insert more useful variable names]

Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
---
 arch/powerpc/platforms/pseries/pseries_energy.c |  189 ++++++++++++++++++++---
 1 file changed, 165 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 164a13d..05fb5e8 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -35,10 +35,73 @@ static int sysfs_entries;
 
 /* Helper Routines to convert between drc_index to cpu numbers */
 
+void read_one_drc_info(int **info, char **dtype, char **dname,
+			unsigned long int *drc_index_start_p,
+			unsigned long int *num_sequential_elems_p,
+			unsigned long int *sequential_inc_p,
+			unsigned long int *last_drc_index_p)
+{
+	char *drc_type, *drc_name_prefix, *pc;
+	u32 drc_index_start, num_sequential_elems;
+	u32 sequential_inc, last_drc_index;
+
+	drc_index_start = num_sequential_elems = 0;
+	sequential_inc = last_drc_index = 0;
+
+	/* Get drc-type:encode-string */
+	pc = (char *)info;
+	drc_type = pc;
+	pc += (strlen(drc_type) + 1);
+
+	/* Get drc-name-prefix:encode-string */
+	drc_name_prefix = (char *)pc;
+	pc += (strlen(drc_name_prefix) + 1);
+
+	/* Get drc-index-start:encode-int */
+	memcpy(&drc_index_start, pc, 4);
+	drc_index_start = be32_to_cpu(drc_index_start);
+	pc += 4;
+
+	/* Get/skip drc-name-suffix-start:encode-int */
+	pc += 4;
+
+	/* Get number-sequential-elements:encode-int */
+	memcpy(&num_sequential_elems, pc, 4);
+	num_sequential_elems = be32_to_cpu(num_sequential_elems);
+	pc += 4;
+
+	/* Get sequential-increment:encode-int */
+	memcpy(&sequential_inc, pc, 4);
+	sequential_inc = be32_to_cpu(sequential_inc);
+	pc += 4;
+
+	/* Get/skip drc-power-domain:encode-int */
+	pc += 4;
+
+	/* Should now know end of current entry */
+	last_drc_index = drc_index_start +
+			((num_sequential_elems-1)*sequential_inc);
+
+	(*info) = (int *)pc;
+
+	if (dtype)
+		*dtype = drc_type;
+	if (dname)
+		*dname = drc_name_prefix;
+	if (drc_index_start_p)
+		*drc_index_start_p = drc_index_start;
+	if (num_sequential_elems_p)
+		*num_sequential_elems_p = num_sequential_elems;
+	if (sequential_inc_p)
+		*sequential_inc_p = sequential_inc;
+	if (last_drc_index_p)
+		*last_drc_index_p = last_drc_index;
+}
+EXPORT_SYMBOL(read_one_drc_info);
+
 static u32 cpu_to_drc_index(int cpu)
 {
 	struct device_node *dn = NULL;
-	const int *indexes;
 	int i;
 	int rc = 1;
 	u32 ret = 0;
@@ -46,18 +109,60 @@ static u32 cpu_to_drc_index(int cpu)
 	dn = of_find_node_by_path("/cpus");
 	if (dn == NULL)
 		goto err;
-	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
-	if (indexes == NULL)
-		goto err_of_node_put;
+
 	/* Convert logical cpu number to core number */
 	i = cpu_core_index_of_thread(cpu);
-	/*
-	 * The first element indexes[0] is the number of drc_indexes
-	 * returned in the list.  Hence i+1 will get the drc_index
-	 * corresponding to core number i.
-	 */
-	WARN_ON(i > indexes[0]);
-	ret = indexes[i + 1];
+
+	if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
+		int *info = (int *)4;
+		unsigned long int num_set_entries, j, check_val = i;
+		unsigned long int drc_index_start = 0;
+		unsigned long int last_drc_index = 0;
+		unsigned long int num_sequential_elems = 0;
+		unsigned long int sequential_inc = 0;
+		char *dtype;
+		char *dname;
+
+		info = (int *)of_get_property(dn, "ibm,drc-info", NULL);
+		if (info == NULL)
+			goto err_of_node_put;
+
+		num_set_entries = be32_to_cpu(*info++);
+
+		for (j = 0; j < num_set_entries; j++) {
+
+			read_one_drc_info(&info, &dtype, &dname,
+					&drc_index_start,
+					&num_sequential_elems,
+					&sequential_inc, &last_drc_index);
+			if (strcmp(dtype, "CPU"))
+				goto err;
+
+			if (check_val < last_drc_index)
+				break;
+
+			WARN_ON(((check_val-drc_index_start)%
+					sequential_inc) != 0);
+		}
+		WARN_ON((num_sequential_elems == 0) | (sequential_inc == 0));
+
+		ret = last_drc_index + (check_val*sequential_inc);
+	} else {
+		const int *indexes;
+
+		indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
+		if (indexes == NULL)
+			goto err_of_node_put;
+
+		/*
+		 * The first element indexes[0] is the number of drc_indexes
+		 * returned in the list.  Hence i+1 will get the drc_index
+		 * corresponding to core number i.
+		 */
+		WARN_ON(i > indexes[0]);
+		ret = indexes[i + 1];
+	}
+
 	rc = 0;
 
 err_of_node_put:
@@ -78,21 +183,57 @@ static int drc_index_to_cpu(u32 drc_index)
 	dn = of_find_node_by_path("/cpus");
 	if (dn == NULL)
 		goto err;
-	indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
-	if (indexes == NULL)
-		goto err_of_node_put;
-	/*
-	 * First element in the array is the number of drc_indexes
-	 * returned.  Search through the list to find the matching
-	 * drc_index and get the core number
-	 */
-	for (i = 0; i < indexes[0]; i++) {
-		if (indexes[i + 1] == drc_index)
+
+	if (firmware_has_feature(FW_FEATURE_DRC_INFO)) {
+		int *info = (int *)dn;
+		unsigned long int num_set_entries, j, ret;
+		unsigned long int drc_index_start = 0;
+		unsigned long int last_drc_index = 0;
+		unsigned long int num_sequential_elems = 0;
+		unsigned long int sequential_inc = 0;
+		char *dtype, *dname;
+
+		info = (int *)of_get_property(dn, "ibm,drc-info", NULL);
+		if (info == NULL)
+			goto err_of_node_put;
+
+		num_set_entries = be32_to_cpu(*info++);
+
+		for (j = 0; j < num_set_entries; j++) {
+			read_one_drc_info(&info, &dtype, &dname,
+					&drc_index_start,
+					&num_sequential_elems,
+					&sequential_inc, &last_drc_index);
+			if (strcmp(dtype, "CPU"))
+				goto err;
+
+			WARN_ON(drc_index < drc_index_start);
+			if (drc_index > last_drc_index)
+				continue;
+
+			WARN_ON(((drc_index-drc_index_start)%
+					sequential_inc) != 0);
+
+			ret = ((drc_index-drc_index_start)/sequential_inc);
 			break;
+		}
+	} else {
+		indexes = of_get_property(dn, "ibm,drc-indexes", NULL);
+		if (indexes == NULL)
+			goto err_of_node_put;
+		/*
+		 * First element in the array is the number of drc_indexes
+		 * returned.  Search through the list to find the matching
+		 * drc_index and get the core number
+		 */
+		for (i = 0; i < indexes[0]; i++) {
+			if (indexes[i + 1] == drc_index)
+				break;
+		}
+		/* Convert core number to logical cpu number */
+		cpu = cpu_first_thread_of_core(i);
+		rc = 0;
 	}
-	/* Convert core number to logical cpu number */
-	cpu = cpu_first_thread_of_core(i);
-	rc = 0;
 
 err_of_node_put:
 	of_node_put(dn);



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