Merge tag 'platform-drivers-x86-v6.7-6' of...

Merge tag 'platform-drivers-x86-v6.7-6' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86

Pull x86 platform driver fixes from Ilpo Järvinen:

 - Intel PMC GBE LTR regression

 - P2SB / PCI deadlock fix

* tag 'platform-drivers-x86-v6.7-6' of git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86:
  platform/x86/intel/pmc: Move GBE LTR ignore to suspend callback
  platform/x86/intel/pmc: Allow reenabling LTRs
  platform/x86/intel/pmc: Add suspend callback
  platform/x86: p2sb: Allow p2sb_bar() calls during PCI device probe

drivers/platform/x86/intel/pmc/adl.c

@@ -314,16 +314,13 @@ int adl_core_init(struct pmc_dev *pmcdev)
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 	int ret;
 
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	pmc->map = &adl_reg_map;
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3);
-
 	return 0;
 }

drivers/platform/x86/intel/pmc/cnp.c

@@ -204,21 +204,35 @@ const struct pmc_reg_map cnp_reg_map = {
 	.etr3_offset = ETR3_OFFSET,
 };
 
+void cnl_suspend(struct pmc_dev *pmcdev)
+{
+	/*
+	 * Due to a hardware limitation, the GBE LTR blocks PC10
+	 * when a cable is attached. To unblock PC10 during suspend,
+	 * tell the PMC to ignore it.
+	 */
+	pmc_core_send_ltr_ignore(pmcdev, 3, 1);
+}
+
+int cnl_resume(struct pmc_dev *pmcdev)
+{
+	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
+
+	return pmc_core_resume_common(pmcdev);
+}
+
 int cnp_core_init(struct pmc_dev *pmcdev)
 {
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 	int ret;
 
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	pmc->map = &cnp_reg_map;
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3);
-
 	return 0;
 }

drivers/platform/x86/intel/pmc/core.c

@@ -460,7 +460,7 @@ static int pmc_core_pll_show(struct seq_file *s, void *unused)
 }
 DEFINE_SHOW_ATTRIBUTE(pmc_core_pll);
 
-int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value)
+int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value, int ignore)
 {
 	struct pmc *pmc;
 	const struct pmc_reg_map *map;
@@ -498,7 +498,10 @@ int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value)
 	mutex_lock(&pmcdev->lock);
 
 	reg = pmc_core_reg_read(pmc, map->ltr_ignore_offset);
-	reg |= BIT(ltr_index);
+	if (ignore)
+		reg |= BIT(ltr_index);
+	else
+		reg &= ~BIT(ltr_index);
 	pmc_core_reg_write(pmc, map->ltr_ignore_offset, reg);
 
 	mutex_unlock(&pmcdev->lock);
@@ -521,7 +524,7 @@ static ssize_t pmc_core_ltr_ignore_write(struct file *file,
 	if (err)
 		return err;
 
-	err = pmc_core_send_ltr_ignore(pmcdev, value);
+	err = pmc_core_send_ltr_ignore(pmcdev, value, 1);
 
 	return err == 0 ? count : err;
 }
@@ -1279,6 +1282,9 @@ static __maybe_unused int pmc_core_suspend(struct device *dev)
 	struct pmc_dev *pmcdev = dev_get_drvdata(dev);
 	struct pmc *pmc = pmcdev->pmcs[PMC_IDX_MAIN];
 
+	if (pmcdev->suspend)
+		pmcdev->suspend(pmcdev);
+
 	/* Check if the syspend will actually use S0ix */
 	if (pm_suspend_via_firmware())
 		return 0;

drivers/platform/x86/intel/pmc/core.h

@@ -363,6 +363,7 @@ struct pmc {
  * @s0ix_counter:	S0ix residency (step adjusted)
  * @num_lpm_modes:	Count of enabled modes
  * @lpm_en_modes:	Array of enabled modes from lowest to highest priority
+ * @suspend:		Function to perform platform specific suspend
  * @resume:		Function to perform platform specific resume
  *
  * pmc_dev contains info about power management controller device.
@@ -379,6 +380,7 @@ struct pmc_dev {
 	u64 s0ix_counter;
 	int num_lpm_modes;
 	int lpm_en_modes[LPM_MAX_NUM_MODES];
+	void (*suspend)(struct pmc_dev *pmcdev);
 	int (*resume)(struct pmc_dev *pmcdev);
 
 	bool has_die_c6;
@@ -486,7 +488,7 @@ extern const struct pmc_bit_map *mtl_ioem_lpm_maps[];
 extern const struct pmc_reg_map mtl_ioem_reg_map;
 
 extern void pmc_core_get_tgl_lpm_reqs(struct platform_device *pdev);
-extern int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value);
+int pmc_core_send_ltr_ignore(struct pmc_dev *pmcdev, u32 value, int ignore);
 
 int pmc_core_resume_common(struct pmc_dev *pmcdev);
 int get_primary_reg_base(struct pmc *pmc);
@@ -500,6 +502,9 @@ int tgl_core_init(struct pmc_dev *pmcdev);
 int adl_core_init(struct pmc_dev *pmcdev);
 int mtl_core_init(struct pmc_dev *pmcdev);
 
+void cnl_suspend(struct pmc_dev *pmcdev);
+int cnl_resume(struct pmc_dev *pmcdev);
+
 #define pmc_for_each_mode(i, mode, pmcdev)		\
 	for (i = 0, mode = pmcdev->lpm_en_modes[i];	\
 	     i < pmcdev->num_lpm_modes;			\

drivers/platform/x86/intel/pmc/mtl.c

@@ -979,6 +979,8 @@ static void mtl_d3_fixup(void)
 static int mtl_resume(struct pmc_dev *pmcdev)
 {
 	mtl_d3_fixup();
+	pmc_core_send_ltr_ignore(pmcdev, 3, 0);
+
 	return pmc_core_resume_common(pmcdev);
 }
 
@@ -989,6 +991,7 @@ int mtl_core_init(struct pmc_dev *pmcdev)
 
 	mtl_d3_fixup();
 
+	pmcdev->suspend = cnl_suspend;
 	pmcdev->resume = mtl_resume;
 
 	pmcdev->regmap_list = mtl_pmc_info_list;
@@ -1002,11 +1005,5 @@ int mtl_core_init(struct pmc_dev *pmcdev)
 			return ret;
 	}
 
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3);
-
 	return 0;
 }

drivers/platform/x86/intel/pmc/tgl.c

@@ -259,16 +259,15 @@ int tgl_core_init(struct pmc_dev *pmcdev)
 	int ret;
 
 	pmc->map = &tgl_reg_map;
+
+	pmcdev->suspend = cnl_suspend;
+	pmcdev->resume = cnl_resume;
+
 	ret = get_primary_reg_base(pmc);
 	if (ret)
 		return ret;
 
 	pmc_core_get_tgl_lpm_reqs(pmcdev->pdev);
-	/* Due to a hardware limitation, the GBE LTR blocks PC10
-	 * when a cable is attached. Tell the PMC to ignore it.
-	 */
-	dev_dbg(&pmcdev->pdev->dev, "ignoring GBE LTR\n");
-	pmc_core_send_ltr_ignore(pmcdev, 3);
 
 	return 0;
 }

drivers/platform/x86/p2sb.c

@@ -26,6 +26,21 @@ static const struct x86_cpu_id p2sb_cpu_ids[] = {
 	{}
 };
 
+/*
+ * Cache BAR0 of P2SB device functions 0 to 7.
+ * TODO: The constant 8 is the number of functions that PCI specification
+ *       defines. Same definitions exist tree-wide. Unify this definition and
+ *       the other definitions then move to include/uapi/linux/pci.h.
+ */
+#define NR_P2SB_RES_CACHE 8
+
+struct p2sb_res_cache {
+	u32 bus_dev_id;
+	struct resource res;
+};
+
+static struct p2sb_res_cache p2sb_resources[NR_P2SB_RES_CACHE];
+
 static int p2sb_get_devfn(unsigned int *devfn)
 {
 	unsigned int fn = P2SB_DEVFN_DEFAULT;
@@ -39,8 +54,16 @@ static int p2sb_get_devfn(unsigned int *devfn)
 	return 0;
 }
 
+static bool p2sb_valid_resource(struct resource *res)
+{
+	if (res->flags)
+		return true;
+
+	return false;
+}
+
 /* Copy resource from the first BAR of the device in question */
-static int p2sb_read_bar0(struct pci_dev *pdev, struct resource *mem)
+static void p2sb_read_bar0(struct pci_dev *pdev, struct resource *mem)
 {
 	struct resource *bar0 = &pdev->resource[0];
 
@@ -56,47 +79,64 @@ static int p2sb_read_bar0(struct pci_dev *pdev, struct resource *mem)
 	mem->end = bar0->end;
 	mem->flags = bar0->flags;
 	mem->desc = bar0->desc;
-
-	return 0;
 }
 
-static int p2sb_scan_and_read(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+static void p2sb_scan_and_cache_devfn(struct pci_bus *bus, unsigned int devfn)
 {
+	struct p2sb_res_cache *cache = &p2sb_resources[PCI_FUNC(devfn)];
 	struct pci_dev *pdev;
-	int ret;
 
 	pdev = pci_scan_single_device(bus, devfn);
 	if (!pdev)
-		return -ENODEV;
+		return;
 
-	ret = p2sb_read_bar0(pdev, mem);
+	p2sb_read_bar0(pdev, &cache->res);
+	cache->bus_dev_id = bus->dev.id;
 
 	pci_stop_and_remove_bus_device(pdev);
-	return ret;
+	return;
 }
 
-/**
- * p2sb_bar - Get Primary to Sideband (P2SB) bridge device BAR
- * @bus: PCI bus to communicate with
- * @devfn: PCI slot and function to communicate with
- * @mem: memory resource to be filled in
- *
- * The BIOS prevents the P2SB device from being enumerated by the PCI
- * subsystem, so we need to unhide and hide it back to lookup the BAR.
- *
- * if @bus is NULL, the bus 0 in domain 0 will be used.
- * If @devfn is 0, it will be replaced by devfn of the P2SB device.
- *
- * Caller must provide a valid pointer to @mem.
- *
- * Locking is handled by pci_rescan_remove_lock mutex.
- *
- * Return:
- * 0 on success or appropriate errno value on error.
- */
-int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+static int p2sb_scan_and_cache(struct pci_bus *bus, unsigned int devfn)
+{
+	unsigned int slot, fn;
+
+	if (PCI_FUNC(devfn) == 0) {
+		/*
+		 * When function number of the P2SB device is zero, scan it and
+		 * other function numbers, and if devices are available, cache
+		 * their BAR0s.
+		 */
+		slot = PCI_SLOT(devfn);
+		for (fn = 0; fn < NR_P2SB_RES_CACHE; fn++)
+			p2sb_scan_and_cache_devfn(bus, PCI_DEVFN(slot, fn));
+	} else {
+		/* Scan the P2SB device and cache its BAR0 */
+		p2sb_scan_and_cache_devfn(bus, devfn);
+	}
+
+	if (!p2sb_valid_resource(&p2sb_resources[PCI_FUNC(devfn)].res))
+		return -ENOENT;
+
+	return 0;
+}
+
+static struct pci_bus *p2sb_get_bus(struct pci_bus *bus)
+{
+	static struct pci_bus *p2sb_bus;
+
+	bus = bus ?: p2sb_bus;
+	if (bus)
+		return bus;
+
+	/* Assume P2SB is on the bus 0 in domain 0 */
+	p2sb_bus = pci_find_bus(0, 0);
+	return p2sb_bus;
+}
+
+static int p2sb_cache_resources(void)
 {
-	struct pci_dev *pdev_p2sb;
+	struct pci_bus *bus;
 	unsigned int devfn_p2sb;
 	u32 value = P2SBC_HIDE;
 	int ret;
@@ -106,8 +146,9 @@ int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
 	if (ret)
 		return ret;
 
-	/* if @bus is NULL, use bus 0 in domain 0 */
-	bus = bus ?: pci_find_bus(0, 0);
+	bus = p2sb_get_bus(NULL);
+	if (!bus)
+		return -ENODEV;
 
 	/*
 	 * Prevent concurrent PCI bus scan from seeing the P2SB device and
@@ -115,17 +156,16 @@ int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
 	 */
 	pci_lock_rescan_remove();
 
-	/* Unhide the P2SB device, if needed */
+	/*
+	 * The BIOS prevents the P2SB device from being enumerated by the PCI
+	 * subsystem, so we need to unhide and hide it back to lookup the BAR.
+	 * Unhide the P2SB device here, if needed.
+	 */
 	pci_bus_read_config_dword(bus, devfn_p2sb, P2SBC, &value);
 	if (value & P2SBC_HIDE)
 		pci_bus_write_config_dword(bus, devfn_p2sb, P2SBC, 0);
 
-	pdev_p2sb = pci_scan_single_device(bus, devfn_p2sb);
-	if (devfn)
-		ret = p2sb_scan_and_read(bus, devfn, mem);
-	else
-		ret = p2sb_read_bar0(pdev_p2sb, mem);
-	pci_stop_and_remove_bus_device(pdev_p2sb);
+	ret = p2sb_scan_and_cache(bus, devfn_p2sb);
 
 	/* Hide the P2SB device, if it was hidden */
 	if (value & P2SBC_HIDE)
@@ -133,12 +173,62 @@ int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
 
 	pci_unlock_rescan_remove();
 
-	if (ret)
-		return ret;
+	return ret;
+}
+
+/**
+ * p2sb_bar - Get Primary to Sideband (P2SB) bridge device BAR
+ * @bus: PCI bus to communicate with
+ * @devfn: PCI slot and function to communicate with
+ * @mem: memory resource to be filled in
+ *
+ * If @bus is NULL, the bus 0 in domain 0 will be used.
+ * If @devfn is 0, it will be replaced by devfn of the P2SB device.
+ *
+ * Caller must provide a valid pointer to @mem.
+ *
+ * Return:
+ * 0 on success or appropriate errno value on error.
+ */
+int p2sb_bar(struct pci_bus *bus, unsigned int devfn, struct resource *mem)
+{
+	struct p2sb_res_cache *cache;
+	int ret;
 
-	if (mem->flags == 0)
+	bus = p2sb_get_bus(bus);
+	if (!bus)
 		return -ENODEV;
 
+	if (!devfn) {
+		ret = p2sb_get_devfn(&devfn);
+		if (ret)
+			return ret;
+	}
+
+	cache = &p2sb_resources[PCI_FUNC(devfn)];
+	if (cache->bus_dev_id != bus->dev.id)
+		return -ENODEV;
+
+	if (!p2sb_valid_resource(&cache->res))
+		return -ENOENT;
+
+	memcpy(mem, &cache->res, sizeof(*mem));
 	return 0;
 }
 EXPORT_SYMBOL_GPL(p2sb_bar);
+
+static int __init p2sb_fs_init(void)
+{
+	p2sb_cache_resources();
+	return 0;
+}
+
+/*
+ * pci_rescan_remove_lock to avoid access to unhidden P2SB devices can
+ * not be locked in sysfs pci bus rescan path because of deadlock. To
+ * avoid the deadlock, access to P2SB devices with the lock at an early
+ * step in kernel initialization and cache required resources. This
+ * should happen after subsys_initcall which initializes PCI subsystem
+ * and before device_initcall which requires P2SB resources.
+ */
+fs_initcall(p2sb_fs_init);