[PATCH v1 2/6] intel_pmc_core: Add PCH IP Power Gating Status

From: Rajneesh Bhardwaj
Date: Fri Oct 07 2016 - 06:32:56 EST


This patch adds the support for reading the power gating status of various
devices present on Sunrise Point PCH. This is intended to be used for
debugging purpose while tuning the platform for power optimizations and
also to understand which devices (on PCH) are blocking the system to enter
a low power state.

Power Management Controller on Sunrise Point PCH provides access to "PGD
PFET Enable Ack Status Registers (ppfear)". This patch reads and decodes
this register and dumps the output in formatted manner showing various
devices present on the PCH and their "Power Gating" status.

Further documentation can be found in Intel 7th Gen Core family mobile u/y
processor io datasheet volume 2.

Sample output (stripped and not in order):

cat /sys/kernel/debug/pmc_core/pch_ip_power_gating_status
PMC State: Not Power gated
OPI-DMI State: Not Power gated
XHCI State: Power gated
LPSS State: Power gated
CSME_PSF State: Not power gated

Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj@xxxxxxxxx>
---
drivers/platform/x86/intel_pmc_core.c | 122 ++++++++++++++++++++++++++++++++--
drivers/platform/x86/intel_pmc_core.h | 67 +++++++++++++++++++
2 files changed, 184 insertions(+), 5 deletions(-)

diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index fcb0643..d5efd6d 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -32,11 +32,65 @@

static struct pmc_dev pmc;

+static const struct pmc_bit_map spt_pfear_map[] = {
+ {"PMC", SPT_PMC_BIT_PMC},
+ {"OPI-DMI", SPT_PMC_BIT_OPI},
+ {"SPI / eSPI", SPT_PMC_BIT_SPI},
+ {"XHCI", SPT_PMC_BIT_XHCI},
+ {"SPA", SPT_PMC_BIT_SPA},
+ {"SPB", SPT_PMC_BIT_SPB},
+ {"SPC", SPT_PMC_BIT_SPC},
+ {"GBE", SPT_PMC_BIT_GBE},
+ {"SATA", SPT_PMC_BIT_SATA},
+ {"HDA-PGD0", SPT_PMC_BIT_HDA_PGD0},
+ {"HDA-PGD1", SPT_PMC_BIT_HDA_PGD1},
+ {"HDA-PGD2", SPT_PMC_BIT_HDA_PGD2},
+ {"HDA-PGD3", SPT_PMC_BIT_HDA_PGD3},
+ {"RSVD", SPT_PMC_BIT_RSVD_0B},
+ {"LPSS", SPT_PMC_BIT_LPSS},
+ {"LPC", SPT_PMC_BIT_LPC},
+ {"SMB", SPT_PMC_BIT_SMB},
+ {"ISH", SPT_PMC_BIT_ISH},
+ {"P2SB", SPT_PMC_BIT_P2SB},
+ {"DFX", SPT_PMC_BIT_DFX},
+ {"SCC", SPT_PMC_BIT_SCC},
+ {"RSVD", SPT_PMC_BIT_RSVD_0C},
+ {"FUSE", SPT_PMC_BIT_FUSE},
+ {"CAMERA", SPT_PMC_BIT_CAMREA},
+ {"RSVD", SPT_PMC_BIT_RSVD_0D},
+ {"USB3-OTG", SPT_PMC_BIT_USB3_OTG},
+ {"EXI", SPT_PMC_BIT_EXI},
+ {"CSE", SPT_PMC_BIT_CSE},
+ {"CSME_KVM", SPT_PMC_BIT_CSME_KVM},
+ {"CSME_PMT", SPT_PMC_BIT_CSME_PMT},
+ {"CSME_CLINK", SPT_PMC_BIT_CSME_CLINK},
+ {"CSME_PTIO", SPT_PMC_BIT_CSME_PTIO},
+ {"CSME_USBR", SPT_PMC_BIT_CSME_USBR},
+ {"CSME_SUSRAM", SPT_PMC_BIT_CSME_SUSRAM},
+ {"CSME_SMT", SPT_PMC_BIT_CSME_SMT},
+ {"RSVD", SPT_PMC_BIT_RSVD_1A},
+ {"CSME_SMS2", SPT_PMC_BIT_CSME_SMS2},
+ {"CSME_SMS1", SPT_PMC_BIT_CSME_SMS1},
+ {"CSME_RTC", SPT_PMC_BIT_CSME_RTC},
+ {"CSME_PSF", SPT_PMC_BIT_CSME_PSF},
+ {},
+};
+
+static const struct pmc_reg_map spt_reg_map = {
+ .pfear_sts = spt_pfear_map,
+};
+
static const struct pci_device_id pmc_pci_ids[] = {
- { PCI_VDEVICE(INTEL, SPT_PMC_PCI_DEVICE_ID), (kernel_ulong_t)NULL },
+ { PCI_VDEVICE(INTEL, SPT_PMC_PCI_DEVICE_ID),
+ (kernel_ulong_t)&spt_reg_map },
{ 0, },
};

+static inline u8 pmc_core_reg_read_byte(struct pmc_dev *pmcdev, int offset)
+{
+ return readb(pmcdev->regbase + offset);
+}
+
static inline u32 pmc_core_reg_read(struct pmc_dev *pmcdev, int reg_offset)
{
return readl(pmcdev->regbase + reg_offset);
@@ -90,6 +144,45 @@ static int pmc_core_dev_state_get(void *data, u64 *val)

DEFINE_DEBUGFS_ATTRIBUTE(pmc_core_dev_state, pmc_core_dev_state_get, NULL, "%llu\n");

+#if IS_ENABLED(CONFIG_DEBUG_FS)
+static void pmc_core_display_map(struct seq_file *s, int index,
+ u8 pf_reg, const struct pmc_bit_map *pf_map)
+{
+ seq_printf(s, "PCH IP: %-2d - %-32s\tState: %s\n",
+ index, pf_map[index].name,
+ pf_map[index].bit_mask & pf_reg ? "Off" : "On");
+}
+
+static int pmc_core_ppfear_sts_show(struct seq_file *s, void *unused)
+{
+ struct pmc_dev *pmcdev = s->private;
+ const struct pmc_bit_map *map = pmcdev->map->pfear_sts;
+ u8 pf_regs[NUM_ENTRIES];
+ int index, iter;
+
+ iter = SPT_PMC_XRAM_PPFEAR0A;
+
+ for (index = 0; index < NUM_ENTRIES; index++, iter++)
+ pf_regs[index] = pmc_core_reg_read_byte(pmcdev, iter);
+
+ for (index = 0; map[index].name; index++)
+ pmc_core_display_map(s, index, pf_regs[index / 8], map);
+
+ return 0;
+}
+
+static int pmc_core_ppfear_sts_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pmc_core_ppfear_sts_show, inode->i_private);
+}
+
+static const struct file_operations pmc_core_ppfear_ops = {
+ .open = pmc_core_ppfear_sts_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
static void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
{
debugfs_remove_recursive(pmcdev->dbgfs_dir);
@@ -106,14 +199,31 @@ static int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
pmcdev->dbgfs_dir = dir;
file = debugfs_create_file("slp_s0_residency_usec", S_IFREG | S_IRUGO,
dir, pmcdev, &pmc_core_dev_state);
+ if (!file)
+ goto err;

- if (!file) {
- pmc_core_dbgfs_unregister(pmcdev);
- return -ENODEV;
- }
+ file = debugfs_create_file("pch_ip_power_gating_status",
+ S_IFREG | S_IRUGO, dir, pmcdev,
+ &pmc_core_ppfear_ops);
+ if (!file)
+ goto err;

return 0;
+
+err:
+ pmc_core_dbgfs_unregister(pmcdev);
+ return -ENODEV;
+}
+#else
+static inline int pmc_core_dbgfs_register(struct pmc_dev *pmcdev)
+{
+ return 0;
+}
+
+static inline void pmc_core_dbgfs_unregister(struct pmc_dev *pmcdev)
+{
}
+#endif /* CONFIG_DEBUG_FS */

static const struct x86_cpu_id intel_pmc_core_ids[] = {
{ X86_VENDOR_INTEL, 6, INTEL_FAM6_SKYLAKE_MOBILE, X86_FEATURE_MWAIT,
@@ -128,6 +238,7 @@ static int pmc_core_probe(struct pci_dev *dev, const struct pci_device_id *id)
struct device *ptr_dev = &dev->dev;
struct pmc_dev *pmcdev = &pmc;
const struct x86_cpu_id *cpu_id;
+ const struct pmc_reg_map *map = (struct pmc_reg_map *)id->driver_data;
int err;

cpu_id = x86_match_cpu(intel_pmc_core_ids);
@@ -164,6 +275,7 @@ static int pmc_core_probe(struct pci_dev *dev, const struct pci_device_id *id)
if (err < 0)
dev_warn(&dev->dev, "PMC Core: debugfs register failed.\n");

+ pmcdev->map = map;
pmc.has_slp_s0_res = true;
return 0;
}
diff --git a/drivers/platform/x86/intel_pmc_core.h b/drivers/platform/x86/intel_pmc_core.h
index cde31ec..d034cd3 100644
--- a/drivers/platform/x86/intel_pmc_core.h
+++ b/drivers/platform/x86/intel_pmc_core.h
@@ -29,6 +29,70 @@
#define SPT_PMC_MMIO_REG_LEN 0x1000
#define SPT_PMC_SLP_S0_RES_COUNTER_STEP 0x64
#define PMC_BASE_ADDR_MASK ~(SPT_PMC_MMIO_REG_LEN - 1)
+#define NUM_ENTRIES 5
+
+/* Sunrise Point: PGD PFET Enable Ack Status Registers */
+enum ppfear_regs {
+ SPT_PMC_XRAM_PPFEAR0A = 0x590,
+ SPT_PMC_XRAM_PPFEAR0B,
+ SPT_PMC_XRAM_PPFEAR0C,
+ SPT_PMC_XRAM_PPFEAR0D,
+ SPT_PMC_XRAM_PPFEAR1A,
+};
+
+#define SPT_PMC_BIT_PMC BIT(0)
+#define SPT_PMC_BIT_OPI BIT(1)
+#define SPT_PMC_BIT_SPI BIT(2)
+#define SPT_PMC_BIT_XHCI BIT(3)
+#define SPT_PMC_BIT_SPA BIT(4)
+#define SPT_PMC_BIT_SPB BIT(5)
+#define SPT_PMC_BIT_SPC BIT(6)
+#define SPT_PMC_BIT_GBE BIT(7)
+
+#define SPT_PMC_BIT_SATA BIT(0)
+#define SPT_PMC_BIT_HDA_PGD0 BIT(1)
+#define SPT_PMC_BIT_HDA_PGD1 BIT(2)
+#define SPT_PMC_BIT_HDA_PGD2 BIT(3)
+#define SPT_PMC_BIT_HDA_PGD3 BIT(4)
+#define SPT_PMC_BIT_RSVD_0B BIT(5)
+#define SPT_PMC_BIT_LPSS BIT(6)
+#define SPT_PMC_BIT_LPC BIT(7)
+
+#define SPT_PMC_BIT_SMB BIT(0)
+#define SPT_PMC_BIT_ISH BIT(1)
+#define SPT_PMC_BIT_P2SB BIT(2)
+#define SPT_PMC_BIT_DFX BIT(3)
+#define SPT_PMC_BIT_SCC BIT(4)
+#define SPT_PMC_BIT_RSVD_0C BIT(5)
+#define SPT_PMC_BIT_FUSE BIT(6)
+#define SPT_PMC_BIT_CAMREA BIT(7)
+
+#define SPT_PMC_BIT_RSVD_0D BIT(0)
+#define SPT_PMC_BIT_USB3_OTG BIT(1)
+#define SPT_PMC_BIT_EXI BIT(2)
+#define SPT_PMC_BIT_CSE BIT(3)
+#define SPT_PMC_BIT_CSME_KVM BIT(4)
+#define SPT_PMC_BIT_CSME_PMT BIT(5)
+#define SPT_PMC_BIT_CSME_CLINK BIT(6)
+#define SPT_PMC_BIT_CSME_PTIO BIT(7)
+
+#define SPT_PMC_BIT_CSME_USBR BIT(0)
+#define SPT_PMC_BIT_CSME_SUSRAM BIT(1)
+#define SPT_PMC_BIT_CSME_SMT BIT(2)
+#define SPT_PMC_BIT_RSVD_1A BIT(3)
+#define SPT_PMC_BIT_CSME_SMS2 BIT(4)
+#define SPT_PMC_BIT_CSME_SMS1 BIT(5)
+#define SPT_PMC_BIT_CSME_RTC BIT(6)
+#define SPT_PMC_BIT_CSME_PSF BIT(7)
+
+struct pmc_bit_map {
+ const char *name;
+ u32 bit_mask;
+};
+
+struct pmc_reg_map {
+ const struct pmc_bit_map *pfear_sts;
+};

/**
* struct pmc_dev - pmc device structure
@@ -44,7 +108,10 @@
struct pmc_dev {
u32 base_addr;
void __iomem *regbase;
+ const struct pmc_reg_map *map;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
struct dentry *dbgfs_dir;
+#endif /* CONFIG_DEBUG_FS */
bool has_slp_s0_res;
};

--
1.9.1