Merge "msm: pcie: provide APIs to prevent and allow PCIe ASPM L1" (ab477afb) · Commits · e / devices / android_kernel_xiaomi_nabu

drivers/pci/host/pci-msm.c

+103 −20

Original line number	Diff line number	Diff line
		@@ -714,6 +714,8 @@ struct msm_pcie_dev_t {
		struct mutex recovery_lock;
		spinlock_t wakeup_lock;
		spinlock_t irq_lock;
		struct mutex aspm_lock;
		int prevent_l1;
		ulong linkdown_counter;
		ulong link_turned_on_counter;
		ulong link_turned_off_counter;
		@@ -1370,6 +1372,8 @@ static void msm_pcie_show_status(struct msm_pcie_dev_t *dev)
		dev->linkdown_counter);
		PCIE_DBG_FS(dev, "wake_counter: %lu\n",
		dev->wake_counter);
		PCIE_DBG_FS(dev, "prevent_l1: %d\n",
		dev->prevent_l1);
		PCIE_DBG_FS(dev, "target_link_speed: 0x%x\n",
		dev->target_link_speed);
		PCIE_DBG_FS(dev, "link_turned_on_counter: %lu\n",
		@@ -6151,20 +6155,6 @@ static int msm_pcie_link_retrain(struct msm_pcie_dev_t *pcie_dev,
		u32 cnt_max = 1000; /* 100ms timeout */
		u32 link_status_lbms_mask = PCI_EXP_LNKSTA_LBMS << PCI_EXP_LNKCTL;

		cnt = 0;
		/* confirm link is in L0 */
		while (((readl_relaxed(pcie_dev->parf + PCIE20_PARF_LTSSM) &
		MSM_PCIE_LTSSM_MASK)) != MSM_PCIE_LTSSM_L0) {
		if (unlikely(cnt++ >= cnt_max)) {
		PCIE_ERR(pcie_dev,
		"PCIe: RC%d: failed to transition to L0\n",
		pcie_dev->rc_idx);
		return -EIO;
		}

		usleep_range(100, 105);
		}

		/* link retrain */
		msm_pcie_config_clear_set_dword(pci_dev,
		pci_dev->pcie_cap + PCI_EXP_LNKCTL,
		@@ -6213,6 +6203,99 @@ static int msm_pcie_set_link_width(struct msm_pcie_dev_t *pcie_dev,
		return 0;
		}

		void msm_pcie_allow_l1(struct pci_dev *pci_dev)
		{
		struct pci_dev *root_pci_dev;
		struct msm_pcie_dev_t *pcie_dev;

		root_pci_dev = pci_find_pcie_root_port(pci_dev);
		if (!root_pci_dev)
		return;

		pcie_dev = PCIE_BUS_PRIV_DATA(root_pci_dev->bus);

		mutex_lock(&pcie_dev->aspm_lock);
		if (unlikely(--pcie_dev->prevent_l1 < 0))
		PCIE_ERR(pcie_dev,
		"PCIe: RC%d: %02x:%02x.%01x: unbalanced prevent_l1: %d < 0\n",
		pcie_dev->rc_idx, pci_dev->bus->number,
		PCI_SLOT(pci_dev->devfn), PCI_FUNC(pci_dev->devfn),
		pcie_dev->prevent_l1);

		if (pcie_dev->prevent_l1) {
		mutex_unlock(&pcie_dev->aspm_lock);
		return;
		}

		msm_pcie_write_mask(pcie_dev->parf + PCIE20_PARF_PM_CTRL, BIT(5), 0);
		/* enable L1 */
		msm_pcie_write_mask(pcie_dev->dm_core +
		(root_pci_dev->pcie_cap + PCI_EXP_LNKCTL),
		0, PCI_EXP_LNKCTL_ASPM_L1);

		PCIE_DBG2(pcie_dev, "PCIe: RC%d: %02x:%02x.%01x: exit\n",
		pcie_dev->rc_idx, pci_dev->bus->number,
		PCI_SLOT(pci_dev->devfn), PCI_FUNC(pci_dev->devfn));
		mutex_unlock(&pcie_dev->aspm_lock);
		}
		EXPORT_SYMBOL(msm_pcie_allow_l1);

		int msm_pcie_prevent_l1(struct pci_dev *pci_dev)
		{
		struct pci_dev *root_pci_dev;
		struct msm_pcie_dev_t *pcie_dev;
		u32 cnt = 0;
		u32 cnt_max = 1000; /* 100ms timeout */
		int ret = 0;

		root_pci_dev = pci_find_pcie_root_port(pci_dev);
		if (!root_pci_dev)
		return -ENODEV;

		pcie_dev = PCIE_BUS_PRIV_DATA(root_pci_dev->bus);

		/* disable L1 */
		mutex_lock(&pcie_dev->aspm_lock);
		if (pcie_dev->prevent_l1++) {
		mutex_unlock(&pcie_dev->aspm_lock);
		return 0;
		}

		msm_pcie_write_mask(pcie_dev->dm_core +
		(root_pci_dev->pcie_cap + PCI_EXP_LNKCTL),
		PCI_EXP_LNKCTL_ASPM_L1, 0);
		msm_pcie_write_mask(pcie_dev->parf + PCIE20_PARF_PM_CTRL, 0, BIT(5));

		/* confirm link is in L0 */
		while (((readl_relaxed(pcie_dev->parf + PCIE20_PARF_LTSSM) &
		MSM_PCIE_LTSSM_MASK)) != MSM_PCIE_LTSSM_L0) {
		if (unlikely(cnt++ >= cnt_max)) {
		PCIE_ERR(pcie_dev,
		"PCIe: RC%d: %02x:%02x.%01x: failed to transition to L0\n",
		pcie_dev->rc_idx, pci_dev->bus->number,
		PCI_SLOT(pci_dev->devfn),
		PCI_FUNC(pci_dev->devfn));
		ret = -EIO;
		goto err;
		}

		usleep_range(100, 105);
		}

		PCIE_DBG2(pcie_dev, "PCIe: RC%d: %02x:%02x.%01x: exit\n",
		pcie_dev->rc_idx, pci_dev->bus->number,
		PCI_SLOT(pci_dev->devfn), PCI_FUNC(pci_dev->devfn));
		mutex_unlock(&pcie_dev->aspm_lock);

		return 0;
		err:
		mutex_unlock(&pcie_dev->aspm_lock);
		msm_pcie_allow_l1(pci_dev);

		return ret;
		}
		EXPORT_SYMBOL(msm_pcie_prevent_l1);

		int msm_pcie_set_link_bandwidth(struct pci_dev *pci_dev, u16 target_link_speed,
		u16 target_link_width)
		{
		@@ -6262,9 +6345,10 @@ int msm_pcie_set_link_bandwidth(struct pci_dev *pci_dev, u16 target_link_speed,
		PCI_EXP_LNKSTA_CLS,
		target_link_speed);

		/* disable link L1. Need to be in L0 for gen switch */
		msm_pcie_config_l1(pcie_dev, root_pci_dev, false);
		msm_pcie_write_mask(pcie_dev->parf + PCIE20_PARF_PM_CTRL, 0, BIT(5));
		/* need to be in L0 for gen switch */
		ret = msm_pcie_prevent_l1(root_pci_dev);
		if (ret)
		return ret;

		if (target_link_speed > current_link_speed)
		msm_pcie_scale_link_bandwidth(pcie_dev, target_link_speed);
		@@ -6287,9 +6371,7 @@ int msm_pcie_set_link_bandwidth(struct pci_dev *pci_dev, u16 target_link_speed,
		if (target_link_speed < current_link_speed)
		msm_pcie_scale_link_bandwidth(pcie_dev, target_link_speed);
		out:
		/* re-enable link L1 */
		msm_pcie_write_mask(pcie_dev->parf + PCIE20_PARF_PM_CTRL, BIT(5), 0);
		msm_pcie_config_l1(pcie_dev, root_pci_dev, true);
		msm_pcie_allow_l1(root_pci_dev);

		return ret;
		}
		@@ -6553,6 +6635,7 @@ static int __init pcie_init(void)
		mutex_init(&msm_pcie_dev[i].setup_lock);
		mutex_init(&msm_pcie_dev[i].clk_lock);
		mutex_init(&msm_pcie_dev[i].recovery_lock);
		mutex_init(&msm_pcie_dev[i].aspm_lock);
		spin_lock_init(&msm_pcie_dev[i].wakeup_lock);
		spin_lock_init(&msm_pcie_dev[i].irq_lock);
		msm_pcie_dev[i].drv_ready = false;

include/linux/msm_pcie.h

+29 −0

Original line number	Diff line number	Diff line
		@@ -81,6 +81,26 @@ static inline int msm_msi_init(struct device *dev)

		#ifdef CONFIG_PCI_MSM

		/**
		* msm_pcie_allow_l1 - allow PCIe link to re-enter L1
		* @pci_dev: client's pci device structure
		*
		* This function gives PCIe clients the control to allow the link to re-enter
		* L1. Should only be used after msm_pcie_prevent_l1 has been called.
		*/
		void msm_pcie_allow_l1(struct pci_dev *pci_dev);

		/**
		* msm_pcie_request_not_enter_l1 - keeps PCIe link out of L1
		* @pci_dev: client's pci device structure
		*
		* This function gives PCIe clients the control to exit and prevent the link
		* from entering L1.
		*
		* Return 0 on success, negative value on error
		*/
		int msm_pcie_prevent_l1(struct pci_dev *pci_dev);

		/**
		* msm_pcie_set_link_bandwidth - updates the number of lanes and speed of PCIe
		* link.
		@@ -218,6 +238,15 @@ static inline int msm_pcie_pm_control(enum msm_pcie_pm_opt pm_opt, u32 busnr,
		return -ENODEV;
		}

		static inline void msm_pcie_request_allow_l1(struct pci_dev *pci_dev)
		{
		}

		static inline int msm_pcie_request_not_enter_l1(struct pci_dev *pci_dev)
		{
		return -ENODEV;
		}

		static inline int msm_pcie_l1ss_timeout_disable(struct pci_dev *pci_dev)
		{
		return -ENODEV;