diff options
Diffstat (limited to 'target/linux/generic/pending-5.10/850-0017-PCI-aardvark-Fix-support-for-PME-requester-on-emulat.patch')
| -rw-r--r-- | target/linux/generic/pending-5.10/850-0017-PCI-aardvark-Fix-support-for-PME-requester-on-emulat.patch | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.10/850-0017-PCI-aardvark-Fix-support-for-PME-requester-on-emulat.patch b/target/linux/generic/pending-5.10/850-0017-PCI-aardvark-Fix-support-for-PME-requester-on-emulat.patch new file mode 100644 index 0000000000..692d4ee555 --- /dev/null +++ b/target/linux/generic/pending-5.10/850-0017-PCI-aardvark-Fix-support-for-PME-requester-on-emulat.patch @@ -0,0 +1,178 @@ +From 68727b545332327b4c2f9c0f8d006be8970e7832 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org> +Date: Fri, 19 Feb 2021 14:22:22 +0100 +Subject: [PATCH] PCI: aardvark: Fix support for PME requester on emulated + bridge +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Enable aardvark PME interrupt unconditionally by unmasking it and read PME +requester ID to emulated bridge config space immediately after receiving +interrupt. + +PME requester ID is stored in the PCIE_MSG_LOG_REG register, which contains +the last inbound message. So when new inbound message is received by HW +(including non-PM), the content in PCIE_MSG_LOG_REG register is replaced by +a new value. + +PCIe specification mandates that subsequent PMEs are kept pending until the +PME Status Register bit is cleared by software by writing a 1b. + +Support for masking/unmasking PME interrupt on emulated bridge via +PCI_EXP_RTCTL_PMEIE bit is now implemented only in emulated bridge config +space, to ensure that we do not miss any aardvark PME interrupt. + +Reading of PCI_EXP_RTCAP and PCI_EXP_RTSTA registers is simplified as final +value is now always stored into emulated bridge config space by the +interrupt handler, so there is no need to implement support for these +registers in read_pcie callback. + +Clearing of W1C bit PCI_EXP_RTSTA_PME is now also simplified as it is done +by pci-bridge-emul.c code for emulated bridge config space. So there is no +need to implement support for clearing this bit in write_pcie callback. + +Signed-off-by: Pali Rohár <pali@kernel.org> +Signed-off-by: Marek Behún <kabel@kernel.org> +--- + drivers/pci/controller/pci-aardvark.c | 94 +++++++++++++++------------ + 1 file changed, 52 insertions(+), 42 deletions(-) + +diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c +index e2b66b0e8fb3..85a632537b70 100644 +--- a/drivers/pci/controller/pci-aardvark.c ++++ b/drivers/pci/controller/pci-aardvark.c +@@ -597,6 +597,11 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) + reg &= ~PCIE_ISR0_MSI_INT_PENDING; + advk_writel(pcie, reg, PCIE_ISR0_MASK_REG); + ++ /* Unmask PME interrupt for processing of PME requester */ ++ reg = advk_readl(pcie, PCIE_ISR0_MASK_REG); ++ reg &= ~PCIE_MSG_PM_PME_MASK; ++ advk_writel(pcie, reg, PCIE_ISR0_MASK_REG); ++ + /* Enable summary interrupt for GIC SPI source */ + reg = PCIE_IRQ_ALL_MASK & (~PCIE_IRQ_ENABLE_INTS_MASK); + advk_writel(pcie, reg, HOST_CTRL_INT_MASK_REG); +@@ -863,22 +868,11 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, + *value = PCI_EXP_SLTSTA_PDS << 16; + return PCI_BRIDGE_EMUL_HANDLED; + +- case PCI_EXP_RTCTL: { +- u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG); +- *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE; +- *value |= le16_to_cpu(bridge->pcie_conf.rootctl) & PCI_EXP_RTCTL_CRSSVE; +- *value |= PCI_EXP_RTCAP_CRSVIS << 16; +- return PCI_BRIDGE_EMUL_HANDLED; +- } +- +- case PCI_EXP_RTSTA: { +- u32 isr0 = advk_readl(pcie, PCIE_ISR0_REG); +- u32 msglog = advk_readl(pcie, PCIE_MSG_LOG_REG); +- *value = msglog >> 16; +- if (isr0 & PCIE_MSG_PM_PME_MASK) +- *value |= PCI_EXP_RTSTA_PME; +- return PCI_BRIDGE_EMUL_HANDLED; +- } ++ /* ++ * PCI_EXP_RTCTL and PCI_EXP_RTSTA are also supported, but do not need ++ * to be handled here, because their values are stored in emulated ++ * config space buffer, and we read them from there when needed. ++ */ + + case PCI_EXP_LNKCAP: { + u32 val = advk_readl(pcie, PCIE_CORE_PCIEXP_CAP + reg); +@@ -933,22 +927,19 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, + advk_pcie_wait_for_retrain(pcie); + break; + +- case PCI_EXP_RTCTL: +- /* Only mask/unmask PME interrupt */ +- if (mask & PCI_EXP_RTCTL_PMEIE) { +- u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG); +- if (new & PCI_EXP_RTCTL_PMEIE) +- val &= ~PCIE_MSG_PM_PME_MASK; +- else +- val |= PCIE_MSG_PM_PME_MASK; +- advk_writel(pcie, val, PCIE_ISR0_MASK_REG); +- } ++ case PCI_EXP_RTCTL: { ++ u16 rootctl = le16_to_cpu(bridge->pcie_conf.rootctl); ++ /* Only emulation of PMEIE and CRSSVE bits is provided */ ++ rootctl &= PCI_EXP_RTCTL_PMEIE | PCI_EXP_RTCTL_CRSSVE; ++ bridge->pcie_conf.rootctl = cpu_to_le16(rootctl); + break; ++ } + +- case PCI_EXP_RTSTA: +- if (new & PCI_EXP_RTSTA_PME) +- advk_writel(pcie, PCIE_MSG_PM_PME_MASK, PCIE_ISR0_REG); +- break; ++ /* ++ * PCI_EXP_RTSTA is also supported, but does not need to be handled ++ * here, because its value is stored in emulated config space buffer, ++ * and we write it there when needed. ++ */ + + case PCI_EXP_DEVCTL: + case PCI_EXP_DEVCTL2: +@@ -1450,6 +1441,34 @@ static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie) + irq_domain_remove(pcie->irq_domain); + } + ++static void advk_pcie_handle_pme(struct advk_pcie *pcie) ++{ ++ u32 requester = advk_readl(pcie, PCIE_MSG_LOG_REG) >> 16; ++ int virq; ++ ++ advk_writel(pcie, PCIE_MSG_PM_PME_MASK, PCIE_ISR0_REG); ++ ++ /* ++ * PCIE_MSG_LOG_REG contains the last inbound message, so store ++ * the requester ID only when PME was not asserted yet. ++ * Also do not trigger PME interrupt when PME is still asserted. ++ */ ++ if (!(le32_to_cpu(pcie->bridge.pcie_conf.rootsta) & PCI_EXP_RTSTA_PME)) { ++ pcie->bridge.pcie_conf.rootsta = cpu_to_le32(requester | PCI_EXP_RTSTA_PME); ++ ++ /* ++ * Trigger PME interrupt only if PMEIE bit in Root Control is set. ++ * Aardvark HW returns zero for PCI_EXP_FLAGS_IRQ, so use PCIe interrupt 0. ++ */ ++ if (!(le16_to_cpu(pcie->bridge.pcie_conf.rootctl) & PCI_EXP_RTCTL_PMEIE)) ++ return; ++ ++ virq = irq_find_mapping(pcie->irq_domain, 0); ++ if (generic_handle_irq(virq) == -EINVAL) ++ dev_err_ratelimited(&pcie->pdev->dev, "unhandled PME IRQ\n"); ++ } ++} ++ + static void advk_pcie_handle_msi(struct advk_pcie *pcie) + { + u32 msi_val, msi_mask, msi_status, msi_idx; +@@ -1489,18 +1508,9 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) + isr1_mask = advk_readl(pcie, PCIE_ISR1_MASK_REG); + isr1_status = isr1_val & ((~isr1_mask) & PCIE_ISR1_ALL_MASK); + +- /* Process PME interrupt */ +- if (isr0_status & PCIE_MSG_PM_PME_MASK) { +- /* +- * Do not clear PME interrupt bit in ISR0, it is cleared by IRQ +- * receiver by writing to the PCI_EXP_RTSTA register of emulated +- * root bridge. Aardvark HW returns zero for PCI_EXP_FLAGS_IRQ, +- * so use PCIe interrupt 0. +- */ +- virq = irq_find_mapping(pcie->irq_domain, 0); +- if (generic_handle_irq(virq) == -EINVAL) +- dev_err_ratelimited(&pcie->pdev->dev, "unhandled PME IRQ\n"); +- } ++ /* Process PME interrupt as the first one to do not miss PME requester id */ ++ if (isr0_status & PCIE_MSG_PM_PME_MASK) ++ advk_pcie_handle_pme(pcie); + + /* Process ERR interrupt */ + if (isr0_status & PCIE_ISR0_ERR_MASK) { +-- +2.34.1 + |