Nouveau - Jan 2017 - [PATCH v4 0/3] Expose power budget cap via hwmon

There is an optinal header field in the power budget table we can use to
read out the power cap of the GPU.

The meaning of this header field was confirmed with nvidia-smi -q:

The rows "Min Power Limit", "Power Limit" and "Max
Power Limit" are set
to the "min", "avg" and "max" values from the
referenced power budget
entry respectively.

We should have this in the kernel before actually using it to catch errors
and see how reliable this is, but as it seems it works on all GPUs as
expected on Kepler und Maxwells with the power cap field set in the vbios.

This series keeps things really simple for now until we figure out more
about the power budget table and are able to parse the power cap for vbios
without that field set.

v3: big rework of the actual vbios parsing to prevent memory leakage and
    silly memory handling
v4: little reworks

Karol Herbst (3):
  nvbios/power_budget: Add basic power budget parsing
  subdev/iccsense: Parse max and crit power level
  hwmon: expose power_max and power_crit

 .../include/nvkm/subdev/bios/power_budget.h        |  26 +++++
 drm/nouveau/include/nvkm/subdev/iccsense.h         |   3 +
 drm/nouveau/nouveau_hwmon.c                        |  44 +++++++
 drm/nouveau/nvkm/subdev/bios/Kbuild                |   1 +
 drm/nouveau/nvkm/subdev/bios/power_budget.c        | 126 +++++++++++++++++++++
 drm/nouveau/nvkm/subdev/iccsense/base.c            |  20 +++-
 6 files changed, 218 insertions(+), 2 deletions(-)
 create mode 100644 drm/nouveau/include/nvkm/subdev/bios/power_budget.h
 create mode 100644 drm/nouveau/nvkm/subdev/bios/power_budget.c

-- 
2.11.0

v2: Set entry to 0xff if not found
    Add cap entry for ver 0x30 tables
    Rework to fix memory leak
v3: More error checks
    Simplify check for invalid entries
v4: disable for ver 0x10 for now
    move assignments after the second last return

Signed-off-by: Karol Herbst <karolherbst at gmail.com>
---
 .../include/nvkm/subdev/bios/power_budget.h        |  26 +++++
 drm/nouveau/nvkm/subdev/bios/Kbuild                |   1 +
 drm/nouveau/nvkm/subdev/bios/power_budget.c        | 126 +++++++++++++++++++++
 3 files changed, 153 insertions(+)
 create mode 100644 drm/nouveau/include/nvkm/subdev/bios/power_budget.h
 create mode 100644 drm/nouveau/nvkm/subdev/bios/power_budget.c

diff --git a/drm/nouveau/include/nvkm/subdev/bios/power_budget.h
b/drm/nouveau/include/nvkm/subdev/bios/power_budget.h
new file mode 100644
index 00000000..f5f4a14c
--- /dev/null
+++ b/drm/nouveau/include/nvkm/subdev/bios/power_budget.h
@@ -0,0 +1,26 @@
+#ifndef __NVBIOS_POWER_BUDGET_H__
+#define __NVBIOS_POWER_BUDGET_H__
+
+#include <nvkm/subdev/bios.h>
+
+struct nvbios_power_budget_entry {
+	u32 min_w;
+	u32 avg_w;
+	u32 max_w;
+};
+
+struct nvbios_power_budget {
+	u32 offset;
+	u8  ver;
+	u8  hlen;
+	u8  elen;
+	u8  ecount;
+	u8  cap_entry;
+};
+
+int nvbios_power_budget_header(struct nvkm_bios *,
+                               struct nvbios_power_budget *);
+int nvbios_power_budget_entry(struct nvkm_bios *, struct nvbios_power_budget *,
+                              u8 idx, struct nvbios_power_budget_entry *);
+
+#endif
diff --git a/drm/nouveau/nvkm/subdev/bios/Kbuild
b/drm/nouveau/nvkm/subdev/bios/Kbuild
index be57220a..6b4f1e06 100644
--- a/drm/nouveau/nvkm/subdev/bios/Kbuild
+++ b/drm/nouveau/nvkm/subdev/bios/Kbuild
@@ -19,6 +19,7 @@ nvkm-y += nvkm/subdev/bios/pcir.o
 nvkm-y += nvkm/subdev/bios/perf.o
 nvkm-y += nvkm/subdev/bios/pll.o
 nvkm-y += nvkm/subdev/bios/pmu.o
+nvkm-y += nvkm/subdev/bios/power_budget.o
 nvkm-y += nvkm/subdev/bios/ramcfg.o
 nvkm-y += nvkm/subdev/bios/rammap.o
 nvkm-y += nvkm/subdev/bios/shadow.o
diff --git a/drm/nouveau/nvkm/subdev/bios/power_budget.c
b/drm/nouveau/nvkm/subdev/bios/power_budget.c
new file mode 100644
index 00000000..617bfffc
--- /dev/null
+++ b/drm/nouveau/nvkm/subdev/bios/power_budget.c
@@ -0,0 +1,126 @@
+/*
+ * Copyright 2016 Karol Herbst
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
"Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Karol Herbst
+ */
+#include <subdev/bios.h>
+#include <subdev/bios/bit.h>
+#include <subdev/bios/power_budget.h>
+
+static u32
+nvbios_power_budget_table(struct nvkm_bios *bios, u8 *ver, u8 *hdr, u8 *cnt,
+			  u8 *len)
+{
+	struct bit_entry bit_P;
+	u32 power_budget;
+
+	if (bit_entry(bios, 'P', &bit_P) || bit_P.version != 2 ||
+	    bit_P.length < 0x2c)
+		return 0;
+
+	power_budget = nvbios_rd32(bios, bit_P.offset + 0x2c);
+	if (!power_budget)
+		return 0;
+
+	*ver = nvbios_rd08(bios, power_budget);
+	switch (*ver) {
+	case 0x20:
+	case 0x30:
+		*hdr = nvbios_rd08(bios, power_budget + 0x1);
+		*len = nvbios_rd08(bios, power_budget + 0x2);
+		*cnt = nvbios_rd08(bios, power_budget + 0x3);
+		return power_budget;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+int
+nvbios_power_budget_header(struct nvkm_bios *bios,
+                           struct nvbios_power_budget *budget)
+{
+	struct nvkm_subdev *subdev = &bios->subdev;
+	u8 ver, hdr, cnt, len, cap_entry;
+	u32 header;
+
+	if (!bios || !budget)
+		return -EINVAL;
+
+	header = nvbios_power_budget_table(bios, &ver, &hdr, &cnt,
&len);
+	if (!header || !cnt)
+		return -ENODEV;
+
+	switch (ver) {
+	case 0x20:
+		cap_entry = nvbios_rd08(bios, header + 0x9);
+		break;
+	case 0x30:
+		cap_entry = nvbios_rd08(bios, header + 0xa);
+		break;
+	default:
+		cap_entry = 0xff;
+	}
+
+	if (cap_entry >= cnt && cap_entry != 0xff) {
+		nvkm_warn(subdev,
+		          "invalid cap_entry in power budget table found\n");
+		budget->cap_entry = 0xff;
+		return -EINVAL;
+	}
+
+	budget->offset = header;
+	budget->ver = ver;
+	budget->hlen = hdr;
+	budget->elen = len;
+	budget->ecount = cnt;
+
+	budget->cap_entry = cap_entry;
+
+	return 0;
+}
+
+int
+nvbios_power_budget_entry(struct nvkm_bios *bios,
+                          struct nvbios_power_budget *budget,
+                          u8 idx, struct nvbios_power_budget_entry *entry)
+{
+	u32 entry_offset;
+
+	if (!bios || !budget || !budget->offset || idx >= budget->ecount
+		|| !entry)
+		return -EINVAL;
+
+	entry_offset = budget->offset + budget->hlen + idx * budget->elen;
+
+	if (budget->ver >= 0x20) {
+		entry->min_w = nvbios_rd32(bios, entry_offset + 0x2);
+		entry->avg_w = nvbios_rd32(bios, entry_offset + 0x6);
+		entry->max_w = nvbios_rd32(bios, entry_offset + 0xa);
+	} else {
+		entry->min_w = 0;
+		entry->max_w = nvbios_rd32(bios, entry_offset + 0x2);
+		entry->avg_w = entry->max_w;
+	}
+
+	return 0;
+}
-- 
2.11.0

Signed-off-by: Karol Herbst <karolherbst at gmail.com>
---
 drm/nouveau/include/nvkm/subdev/iccsense.h |  3 +++
 drm/nouveau/nvkm/subdev/iccsense/base.c    | 20 ++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/drm/nouveau/include/nvkm/subdev/iccsense.h
b/drm/nouveau/include/nvkm/subdev/iccsense.h
index 3c2ddd97..b7a9b041 100644
--- a/drm/nouveau/include/nvkm/subdev/iccsense.h
+++ b/drm/nouveau/include/nvkm/subdev/iccsense.h
@@ -8,6 +8,9 @@ struct nvkm_iccsense {
 	bool data_valid;
 	struct list_head sensors;
 	struct list_head rails;
+
+	u32 power_w_max;
+	u32 power_w_crit;
 };
 
 int gf100_iccsense_new(struct nvkm_device *, int index, struct nvkm_iccsense
**);
diff --git a/drm/nouveau/nvkm/subdev/iccsense/base.c
b/drm/nouveau/nvkm/subdev/iccsense/base.c
index f0af2a38..fecfa6af 100644
--- a/drm/nouveau/nvkm/subdev/iccsense/base.c
+++ b/drm/nouveau/nvkm/subdev/iccsense/base.c
@@ -26,6 +26,7 @@
 #include <subdev/bios.h>
 #include <subdev/bios/extdev.h>
 #include <subdev/bios/iccsense.h>
+#include <subdev/bios/power_budget.h>
 #include <subdev/i2c.h>
 
 static bool
@@ -216,10 +217,25 @@ nvkm_iccsense_oneinit(struct nvkm_subdev *subdev)
 {
 	struct nvkm_iccsense *iccsense = nvkm_iccsense(subdev);
 	struct nvkm_bios *bios = subdev->device->bios;
+	struct nvbios_power_budget budget;
 	struct nvbios_iccsense stbl;
-	int i;
+	int i, ret;
 
-	if (!bios || nvbios_iccsense_parse(bios, &stbl) || !stbl.nr_entry)
+	if (!bios)
+		return 0;
+
+	ret = nvbios_power_budget_header(bios, &budget);
+	if (!ret && budget.cap_entry != 0xff) {
+		struct nvbios_power_budget_entry entry;
+		ret = nvbios_power_budget_entry(bios, &budget,
+		                                budget.cap_entry, &entry);
+		if (!ret) {
+			iccsense->power_w_max  = entry.avg_w;
+			iccsense->power_w_crit = entry.max_w;
+		}
+	}
+
+	if (nvbios_iccsense_parse(bios, &stbl) || !stbl.nr_entry)
 		return 0;
 
 	iccsense->data_valid = true;
-- 
2.11.0

Signed-off-by: Karol Herbst <karolherbst at gmail.com>
---
 drm/nouveau/nouveau_hwmon.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/drm/nouveau/nouveau_hwmon.c b/drm/nouveau/nouveau_hwmon.c
index d762b8af..23b1670c 100644
--- a/drm/nouveau/nouveau_hwmon.c
+++ b/drm/nouveau/nouveau_hwmon.c
@@ -596,6 +596,32 @@ nouveau_hwmon_get_power1_input(struct device *d, struct
device_attribute *a,
 static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO,
 			  nouveau_hwmon_get_power1_input, NULL, 0);
 
+static ssize_t
+nouveau_hwmon_get_power1_max(struct device *d, struct device_attribute *a,
+			     char *buf)
+{
+	struct drm_device *dev = dev_get_drvdata(d);
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
+	return sprintf(buf, "%i\n", iccsense->power_w_max);
+}
+
+static SENSOR_DEVICE_ATTR(power1_max, S_IRUGO,
+			  nouveau_hwmon_get_power1_max, NULL, 0);
+
+static ssize_t
+nouveau_hwmon_get_power1_crit(struct device *d, struct device_attribute *a,
+			      char *buf)
+{
+	struct drm_device *dev = dev_get_drvdata(d);
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	struct nvkm_iccsense *iccsense = nvxx_iccsense(&drm->client.device);
+	return sprintf(buf, "%i\n", iccsense->power_w_crit);
+}
+
+static SENSOR_DEVICE_ATTR(power1_crit, S_IRUGO,
+			  nouveau_hwmon_get_power1_crit, NULL, 0);
+
 static struct attribute *hwmon_default_attributes[] = {
 	&sensor_dev_attr_name.dev_attr.attr,
 	&sensor_dev_attr_update_rate.dev_attr.attr,
@@ -639,6 +665,12 @@ static struct attribute *hwmon_power_attributes[] = {
 	NULL
 };
 
+static struct attribute *hwmon_power_caps_attributes[] = {
+	&sensor_dev_attr_power1_max.dev_attr.attr,
+	&sensor_dev_attr_power1_crit.dev_attr.attr,
+	NULL
+};
+
 static const struct attribute_group hwmon_default_attrgroup = {
 	.attrs = hwmon_default_attributes,
 };
@@ -657,6 +689,9 @@ static const struct attribute_group hwmon_in0_attrgroup = {
 static const struct attribute_group hwmon_power_attrgroup = {
 	.attrs = hwmon_power_attributes,
 };
+static const struct attribute_group hwmon_power_caps_attrgroup = {
+	.attrs = hwmon_power_caps_attributes,
+};
 #endif
 
 int
@@ -728,8 +763,16 @@ nouveau_hwmon_init(struct drm_device *dev)
 	if (iccsense && iccsense->data_valid &&
!list_empty(&iccsense->rails)) {
 		ret = sysfs_create_group(&hwmon_dev->kobj,
 					 &hwmon_power_attrgroup);
+
 		if (ret)
 			goto error;
+
+		if (iccsense->power_w_max && iccsense->power_w_crit) {
+			ret = sysfs_create_group(&hwmon_dev->kobj,
+						 &hwmon_power_caps_attrgroup);
+			if (ret)
+				goto error;
+		}
 	}
 
 	hwmon->hwmon = hwmon_dev;
@@ -759,6 +802,7 @@ nouveau_hwmon_fini(struct drm_device *dev)
 		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_fan_rpm_attrgroup);
 		sysfs_remove_group(&hwmon->hwmon->kobj, &hwmon_in0_attrgroup);
 		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_attrgroup);
+		sysfs_remove_group(&hwmon->hwmon->kobj,
&hwmon_power_caps_attrgroup);
 
 		hwmon_device_unregister(hwmon->hwmon);
 	}
-- 
2.11.0