[PATCH V5 5/8] pseries/drc-info: Search new DRC properties for CPU indexes

[Michael Bringmann]

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]

Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>
---
diff --git a/arch/powerpc/platforms/pseries/pseries_energy.c b/arch/powerpc/platforms/pseries/pseries_energy.c
index 9276779..10c4200 100644
--- a/arch/powerpc/platforms/pseries/pseries_energy.c
+++ b/arch/powerpc/platforms/pseries/pseries_energy.c
@@ -35,10 +35,68 @@ 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 *fdi_p, unsigned long int *nsl_p,
+			unsigned long int *si_p, unsigned long int *ldi_p)
+{
+	char *drc_type, *drc_name, *pc;
+	u32 fdi, nsl, si, ldi;
+
+	fdi = nsl = si = ldi = 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 = (char *)pc;
+	pc += (strlen(drc_name) + 1);
+
+	/* Get drc-index-start:encode-int */
+	memcpy(&fdi, pc, 4);
+	fdi = be32_to_cpu(fdi);
+	pc += 4;
+
+	/* Get/skip drc-name-suffix-start:encode-int */
+	pc += 4;
+
+	/* Get number-sequential-elements:encode-int */
+	memcpy(&nsl, pc, 4);
+	nsl = be32_to_cpu(nsl);
+	pc += 4;
+
+	/* Get sequential-increment:encode-int */
+	memcpy(&si, pc, 4);
+	si = be32_to_cpu(si);
+	pc += 4;
+
+	/* Get/skip drc-power-domain:encode-int */
+	pc += 4;
+
+	/* Should now know end of current entry */
+	ldi = fdi + ((nsl-1)*si);
+
+	(*info) = (int *)pc;
+
+	if (dtype)
+		*dtype = drc_type;
+	if (dname)
+		*dname = drc_name;
+	if (fdi_p)
+		*fdi_p = fdi;
+	if (nsl_p)
+		*nsl_p = nsl;
+	if (si_p)
+		*si_p = si;
+	if (ldi_p)
+		*ldi_p = ldi;
+}
+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 +104,54 @@ 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, iw = i, fdi = 0;
+		unsigned long int ldi = 0, nsl = 0, si = 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, &fdi,
+					&nsl, &si, &ldi);
+			if (strcmp(dtype, "CPU"))
+				goto err;
+
+			if (iw < ldi)
+				break;
+
+			WARN_ON(((iw-fdi)%si) != 0);
+		}
+		WARN_ON((nsl == 0) | (si == 0));
+
+		ret = ldi + (iw*si);
+	} 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 +172,51 @@ 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 fdi = 0, ldi = 0, nsl = 0, si = 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, &fdi,
+					&nsl, &si, &ldi);
+			if (strcmp(dtype, "CPU"))
+				goto err;
+
+			WARN_ON(drc_index < fdi);
+			if (drc_index > ldi)
+				continue;
+
+			WARN_ON(((drc_index-fdi)%si) != 0);
+
+			ret = ((drc_index-fdi)/si);
 			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);