From 1d86abf1f89672a70f2ab65f6000299feb1f1781 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:49:56 +0100 Subject: PCI: aardvark: Replace custom PCIE_CORE_INT_* macros with PCI_INTERRUPT_* MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Header file linux/pci.h defines enum pci_interrupt_pin with corresponding PCI_INTERRUPT_* values. Link: https://lore.kernel.org/r/20220110015018.26359-2-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi Reviewed-by: Bjorn Helgaas --- drivers/pci/controller/pci-aardvark.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 4f5b44827d21..01f66a78347a 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -38,10 +38,6 @@ #define PCIE_CORE_ERR_CAPCTL_ECRC_CHK_TX_EN BIT(6) #define PCIE_CORE_ERR_CAPCTL_ECRC_CHCK BIT(7) #define PCIE_CORE_ERR_CAPCTL_ECRC_CHCK_RCV BIT(8) -#define PCIE_CORE_INT_A_ASSERT_ENABLE 1 -#define PCIE_CORE_INT_B_ASSERT_ENABLE 2 -#define PCIE_CORE_INT_C_ASSERT_ENABLE 3 -#define PCIE_CORE_INT_D_ASSERT_ENABLE 4 /* PIO registers base address and register offsets */ #define PIO_BASE_ADDR 0x4000 #define PIO_CTRL (PIO_BASE_ADDR + 0x0) @@ -959,7 +955,7 @@ static int advk_sw_pci_bridge_init(struct advk_pcie *pcie) bridge->conf.pref_mem_limit = cpu_to_le16(PCI_PREF_RANGE_TYPE_64); /* Support interrupt A for MSI feature */ - bridge->conf.intpin = PCIE_CORE_INT_A_ASSERT_ENABLE; + bridge->conf.intpin = PCI_INTERRUPT_INTA; /* Aardvark HW provides PCIe Capability structure in version 2 */ bridge->pcie_conf.cap = cpu_to_le16(2); -- cgit v1.2.3 From 805dfc18dd3d4dd97a987d4406593b5a225b1253 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:49:57 +0100 Subject: PCI: aardvark: Fix reading MSI interrupt number MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In advk_pcie_handle_msi() it is expected that when bit i in the W1C register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is updated to contain the MSI number corresponding to index i. Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG always contains the number of the last received MSI, overall. Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt number. Since Aardvark already forbids more than 32 interrupts and uses own allocated hwirq numbers, the msi_idx already corresponds to the received MSI number. Link: https://lore.kernel.org/r/20220110015018.26359-3-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 01f66a78347a..3cf36baa215a 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1384,7 +1384,6 @@ static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie) static void advk_pcie_handle_msi(struct advk_pcie *pcie) { u32 msi_val, msi_mask, msi_status, msi_idx; - u16 msi_data; msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG); msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG); @@ -1394,13 +1393,9 @@ static void advk_pcie_handle_msi(struct advk_pcie *pcie) if (!(BIT(msi_idx) & msi_status)) continue; - /* - * msi_idx contains bits [4:0] of the msi_data and msi_data - * contains 16bit MSI interrupt number - */ advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG); - msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK; - generic_handle_irq(msi_data); + if (generic_handle_domain_irq(pcie->msi_inner_domain, msi_idx) == -EINVAL) + dev_err_ratelimited(&pcie->pdev->dev, "unexpected MSI 0x%02x\n", msi_idx); } advk_writel(pcie, PCIE_ISR0_MSI_INT_PENDING, -- cgit v1.2.3 From b0b0b8b897f8e12b2368e868bd7cdc5742d5c5a9 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:49:58 +0100 Subject: PCI: aardvark: Fix support for MSI interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Aardvark hardware supports Multi-MSI and MSI_FLAG_MULTI_PCI_MSI is already set for the MSI chip. But when allocating MSI interrupt numbers for Multi-MSI, the numbers need to be properly aligned, otherwise endpoint devices send MSI interrupt with incorrect numbers. Fix this issue by using function bitmap_find_free_region() instead of bitmap_find_next_zero_area(). To ensure that aligned MSI interrupt numbers are used by endpoint devices, we cannot use Linux virtual irq numbers (as they are random and not properly aligned). Instead we need to use the aligned hwirq numbers. This change fixes receiving MSI interrupts on Armada 3720 boards and allows using NVMe disks which use Multi-MSI feature with 3 interrupts. Without this NVMe disks freeze booting as linux nvme-core.c is waiting 60s for an interrupt. Link: https://lore.kernel.org/r/20220110015018.26359-4-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 16 ++++++---------- 1 file changed, 6 insertions(+), 10 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 3cf36baa215a..3a7f4c3757ce 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1180,7 +1180,7 @@ static void advk_msi_irq_compose_msi_msg(struct irq_data *data, msg->address_lo = lower_32_bits(msi_msg); msg->address_hi = upper_32_bits(msi_msg); - msg->data = data->irq; + msg->data = data->hwirq; } static int advk_msi_set_affinity(struct irq_data *irq_data, @@ -1197,15 +1197,11 @@ static int advk_msi_irq_domain_alloc(struct irq_domain *domain, int hwirq, i; mutex_lock(&pcie->msi_used_lock); - hwirq = bitmap_find_next_zero_area(pcie->msi_used, MSI_IRQ_NUM, - 0, nr_irqs, 0); - if (hwirq >= MSI_IRQ_NUM) { - mutex_unlock(&pcie->msi_used_lock); - return -ENOSPC; - } - - bitmap_set(pcie->msi_used, hwirq, nr_irqs); + hwirq = bitmap_find_free_region(pcie->msi_used, MSI_IRQ_NUM, + order_base_2(nr_irqs)); mutex_unlock(&pcie->msi_used_lock); + if (hwirq < 0) + return -ENOSPC; for (i = 0; i < nr_irqs; i++) irq_domain_set_info(domain, virq + i, hwirq + i, @@ -1223,7 +1219,7 @@ static void advk_msi_irq_domain_free(struct irq_domain *domain, struct advk_pcie *pcie = domain->host_data; mutex_lock(&pcie->msi_used_lock); - bitmap_clear(pcie->msi_used, d->hwirq, nr_irqs); + bitmap_release_region(pcie->msi_used, d->hwirq, order_base_2(nr_irqs)); mutex_unlock(&pcie->msi_used_lock); } -- cgit v1.2.3 From 1571d67dc190e50c6c56e8f88cdc39f7cc53166e Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:49:59 +0100 Subject: PCI: aardvark: Rewrite IRQ code to chained IRQ handler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rewrite the code to use irq_set_chained_handler_and_data() handler with chained_irq_enter() and chained_irq_exit() processing instead of using devm_request_irq(). advk_pcie_irq_handler() reads IRQ status bits and calls other functions based on which bits are set. These functions then read its own IRQ status bits and calls other aardvark functions based on these bits. Finally generic_handle_domain_irq() with translated linux IRQ numbers are called. Link: https://lore.kernel.org/r/20220110015018.26359-5-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 48 +++++++++++++++++++---------------- 1 file changed, 26 insertions(+), 22 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 3a7f4c3757ce..d7ee7a22c206 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -268,6 +268,7 @@ struct advk_pcie { u32 actions; } wins[OB_WIN_COUNT]; u8 wins_count; + int irq; struct irq_domain *irq_domain; struct irq_chip irq_chip; raw_spinlock_t irq_lock; @@ -1428,21 +1429,26 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) } } -static irqreturn_t advk_pcie_irq_handler(int irq, void *arg) +static void advk_pcie_irq_handler(struct irq_desc *desc) { - struct advk_pcie *pcie = arg; - u32 status; + struct advk_pcie *pcie = irq_desc_get_handler_data(desc); + struct irq_chip *chip = irq_desc_get_chip(desc); + u32 val, mask, status; - status = advk_readl(pcie, HOST_CTRL_INT_STATUS_REG); - if (!(status & PCIE_IRQ_CORE_INT)) - return IRQ_NONE; + chained_irq_enter(chip, desc); - advk_pcie_handle_int(pcie); + val = advk_readl(pcie, HOST_CTRL_INT_STATUS_REG); + mask = advk_readl(pcie, HOST_CTRL_INT_MASK_REG); + status = val & ((~mask) & PCIE_IRQ_ALL_MASK); - /* Clear interrupt */ - advk_writel(pcie, PCIE_IRQ_CORE_INT, HOST_CTRL_INT_STATUS_REG); + if (status & PCIE_IRQ_CORE_INT) { + advk_pcie_handle_int(pcie); - return IRQ_HANDLED; + /* Clear interrupt */ + advk_writel(pcie, PCIE_IRQ_CORE_INT, HOST_CTRL_INT_STATUS_REG); + } + + chained_irq_exit(chip, desc); } static void __maybe_unused advk_pcie_disable_phy(struct advk_pcie *pcie) @@ -1509,7 +1515,7 @@ static int advk_pcie_probe(struct platform_device *pdev) struct advk_pcie *pcie; struct pci_host_bridge *bridge; struct resource_entry *entry; - int ret, irq; + int ret; bridge = devm_pci_alloc_host_bridge(dev, sizeof(struct advk_pcie)); if (!bridge) @@ -1595,17 +1601,9 @@ static int advk_pcie_probe(struct platform_device *pdev) if (IS_ERR(pcie->base)) return PTR_ERR(pcie->base); - irq = platform_get_irq(pdev, 0); - if (irq < 0) - return irq; - - ret = devm_request_irq(dev, irq, advk_pcie_irq_handler, - IRQF_SHARED | IRQF_NO_THREAD, "advk-pcie", - pcie); - if (ret) { - dev_err(dev, "Failed to register interrupt\n"); - return ret; - } + pcie->irq = platform_get_irq(pdev, 0); + if (pcie->irq < 0) + return pcie->irq; pcie->reset_gpio = devm_gpiod_get_from_of_node(dev, dev->of_node, "reset-gpios", 0, @@ -1654,11 +1652,14 @@ static int advk_pcie_probe(struct platform_device *pdev) return ret; } + irq_set_chained_handler_and_data(pcie->irq, advk_pcie_irq_handler, pcie); + bridge->sysdata = pcie; bridge->ops = &advk_pcie_ops; ret = pci_host_probe(bridge); if (ret < 0) { + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); advk_pcie_remove_msi_irq_domain(pcie); advk_pcie_remove_irq_domain(pcie); return ret; @@ -1706,6 +1707,9 @@ static int advk_pcie_remove(struct platform_device *pdev) advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG); advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG); + /* Remove IRQ handler */ + irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); + /* Remove IRQ domains */ advk_pcie_remove_msi_irq_domain(pcie); advk_pcie_remove_irq_domain(pcie); -- cgit v1.2.3 From 51f96e287c6f003d3bb29672811c757c5fbf0028 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:00 +0100 Subject: PCI: aardvark: Check return value of generic_handle_domain_irq() when processing INTx IRQ MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit It is possible that we receive spurious INTx interrupt. Check for the return value of generic_handle_domain_irq() when processing INTx IRQ. Link: https://lore.kernel.org/r/20220110015018.26359-6-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index d7ee7a22c206..0fb3847bdc4e 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1425,7 +1425,9 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) advk_writel(pcie, PCIE_ISR1_INTX_ASSERT(i), PCIE_ISR1_REG); - generic_handle_domain_irq(pcie->irq_domain, i); + if (generic_handle_domain_irq(pcie->irq_domain, i) == -EINVAL) + dev_err_ratelimited(&pcie->pdev->dev, "unexpected INT%c IRQ\n", + (char)i + 'A'); } } -- cgit v1.2.3 From c3cb8e51839adc0aaef478c47665443d02f5aa07 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 10 Jan 2022 02:50:01 +0100 Subject: PCI: aardvark: Make MSI irq_chip structures static driver structures MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In [1] it was agreed that we should use struct irq_chip as a global static struct in the driver. Even though the structure currently contains a dynamic member (parent_device), In [2] the plans to kill it and make the structure completely static were set out. Convert Aardvark's priv->msi_bottom_irq_chip and priv->msi_irq_chip to static driver structure. [1] https://lore.kernel.org/linux-pci/877dbcvngf.wl-maz@kernel.org/ [2] https://lore.kernel.org/linux-pci/874k6gvkhz.wl-maz@kernel.org/ Link: https://lore.kernel.org/r/20220110015018.26359-7-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 0fb3847bdc4e..6128192a7cb7 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -274,8 +274,6 @@ struct advk_pcie { raw_spinlock_t irq_lock; struct irq_domain *msi_domain; struct irq_domain *msi_inner_domain; - struct irq_chip msi_bottom_irq_chip; - struct irq_chip msi_irq_chip; struct msi_domain_info msi_domain_info; DECLARE_BITMAP(msi_used, MSI_IRQ_NUM); struct mutex msi_used_lock; @@ -1190,6 +1188,12 @@ static int advk_msi_set_affinity(struct irq_data *irq_data, return -EINVAL; } +static struct irq_chip advk_msi_bottom_irq_chip = { + .name = "MSI", + .irq_compose_msi_msg = advk_msi_irq_compose_msi_msg, + .irq_set_affinity = advk_msi_set_affinity, +}; + static int advk_msi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq, unsigned int nr_irqs, void *args) @@ -1206,7 +1210,7 @@ static int advk_msi_irq_domain_alloc(struct irq_domain *domain, for (i = 0; i < nr_irqs; i++) irq_domain_set_info(domain, virq + i, hwirq + i, - &pcie->msi_bottom_irq_chip, + &advk_msi_bottom_irq_chip, domain->host_data, handle_simple_irq, NULL, NULL); @@ -1276,29 +1280,23 @@ static const struct irq_domain_ops advk_pcie_irq_domain_ops = { .xlate = irq_domain_xlate_onecell, }; +static struct irq_chip advk_msi_irq_chip = { + .name = "advk-MSI", +}; + static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; struct device_node *node = dev->of_node; - struct irq_chip *bottom_ic, *msi_ic; struct msi_domain_info *msi_di; phys_addr_t msi_msg_phys; mutex_init(&pcie->msi_used_lock); - bottom_ic = &pcie->msi_bottom_irq_chip; - - bottom_ic->name = "MSI"; - bottom_ic->irq_compose_msi_msg = advk_msi_irq_compose_msi_msg; - bottom_ic->irq_set_affinity = advk_msi_set_affinity; - - msi_ic = &pcie->msi_irq_chip; - msi_ic->name = "advk-MSI"; - msi_di = &pcie->msi_domain_info; msi_di->flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI; - msi_di->chip = msi_ic; + msi_di->chip = &advk_msi_irq_chip; msi_msg_phys = virt_to_phys(&pcie->msi_msg); -- cgit v1.2.3 From 26bcd54e4a5cd51ec12d06fdc30e22863ed4c422 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 10 Jan 2022 02:50:02 +0100 Subject: PCI: aardvark: Make msi_domain_info structure a static driver structure MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make Aardvark's msi_domain_info structure into a private driver structure. Domain info is same for every potential instatination of a controller. Link: https://lore.kernel.org/r/20220110015018.26359-8-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 6128192a7cb7..060fa451bb40 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -274,7 +274,6 @@ struct advk_pcie { raw_spinlock_t irq_lock; struct irq_domain *msi_domain; struct irq_domain *msi_inner_domain; - struct msi_domain_info msi_domain_info; DECLARE_BITMAP(msi_used, MSI_IRQ_NUM); struct mutex msi_used_lock; u16 msi_msg; @@ -1284,20 +1283,20 @@ static struct irq_chip advk_msi_irq_chip = { .name = "advk-MSI", }; +static struct msi_domain_info advk_msi_domain_info = { + .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | + MSI_FLAG_MULTI_PCI_MSI, + .chip = &advk_msi_irq_chip, +}; + static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; struct device_node *node = dev->of_node; - struct msi_domain_info *msi_di; phys_addr_t msi_msg_phys; mutex_init(&pcie->msi_used_lock); - msi_di = &pcie->msi_domain_info; - msi_di->flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | - MSI_FLAG_MULTI_PCI_MSI; - msi_di->chip = &advk_msi_irq_chip; - msi_msg_phys = virt_to_phys(&pcie->msi_msg); advk_writel(pcie, lower_32_bits(msi_msg_phys), @@ -1313,7 +1312,8 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) pcie->msi_domain = pci_msi_create_irq_domain(of_node_to_fwnode(node), - msi_di, pcie->msi_inner_domain); + &advk_msi_domain_info, + pcie->msi_inner_domain); if (!pcie->msi_domain) { irq_domain_remove(pcie->msi_inner_domain); return -ENOMEM; -- cgit v1.2.3 From 222af78532fa299cd9b1008e49c347b7f5a45c17 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 10 Jan 2022 02:50:03 +0100 Subject: PCI: aardvark: Use dev_fwnode() instead of of_node_to_fwnode(dev->of_node) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Use simple dev_fwnode(dev) instead of struct device_node *node = dev->of_node; of_node_to_fwnode(node) especially since the node variable is not used elsewhere in the function. Link: https://lore.kernel.org/r/20220110015018.26359-9-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 060fa451bb40..bf2a99a5a576 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1292,7 +1292,6 @@ static struct msi_domain_info advk_msi_domain_info = { static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; - struct device_node *node = dev->of_node; phys_addr_t msi_msg_phys; mutex_init(&pcie->msi_used_lock); @@ -1311,7 +1310,7 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) return -ENOMEM; pcie->msi_domain = - pci_msi_create_irq_domain(of_node_to_fwnode(node), + pci_msi_create_irq_domain(dev_fwnode(dev), &advk_msi_domain_info, pcie->msi_inner_domain); if (!pcie->msi_domain) { -- cgit v1.2.3 From 4689c0916320f112a8a33f2689d3addc3262f02c Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:04 +0100 Subject: PCI: aardvark: Refactor unmasking summary MSI interrupt MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Refactor the masking of ISR0/1 Sources and unmasking of summary MSI interrupt so that it corresponds to the comments: - first mask all ISR0/1 - then unmask all MSIs - then unmask summary MSI interrupt Link: https://lore.kernel.org/r/20220110015018.26359-10-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index bf2a99a5a576..99a9b1836f26 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -571,15 +571,17 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG); /* Disable All ISR0/1 Sources */ - reg = PCIE_ISR0_ALL_MASK; - reg &= ~PCIE_ISR0_MSI_INT_PENDING; - advk_writel(pcie, reg, PCIE_ISR0_MASK_REG); - + advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_MASK_REG); advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG); /* Unmask all MSIs */ advk_writel(pcie, ~(u32)PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG); + /* Unmask summary MSI interrupt */ + reg = advk_readl(pcie, PCIE_ISR0_MASK_REG); + reg &= ~PCIE_ISR0_MSI_INT_PENDING; + 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); -- cgit v1.2.3 From e77d9c90691071769cd2b86ef097f7d07167dc3b Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:05 +0100 Subject: PCI: aardvark: Add support for masking MSI interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We should not unmask MSIs at setup, but only when kernel asks for them to be unmasked. At setup, mask all MSIs, and implement IRQ chip callbacks for masking and unmasking particular MSIs. Link: https://lore.kernel.org/r/20220110015018.26359-11-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 54 +++++++++++++++++++++++++++++++---- 1 file changed, 49 insertions(+), 5 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 99a9b1836f26..35f78bfc0dc7 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -274,6 +274,7 @@ struct advk_pcie { raw_spinlock_t irq_lock; struct irq_domain *msi_domain; struct irq_domain *msi_inner_domain; + raw_spinlock_t msi_irq_lock; DECLARE_BITMAP(msi_used, MSI_IRQ_NUM); struct mutex msi_used_lock; u16 msi_msg; @@ -570,12 +571,10 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_REG); advk_writel(pcie, PCIE_IRQ_ALL_MASK, HOST_CTRL_INT_STATUS_REG); - /* Disable All ISR0/1 Sources */ + /* Disable All ISR0/1 and MSI Sources */ advk_writel(pcie, PCIE_ISR0_ALL_MASK, PCIE_ISR0_MASK_REG); advk_writel(pcie, PCIE_ISR1_ALL_MASK, PCIE_ISR1_MASK_REG); - - /* Unmask all MSIs */ - advk_writel(pcie, ~(u32)PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG); + advk_writel(pcie, PCIE_MSI_ALL_MASK, PCIE_MSI_MASK_REG); /* Unmask summary MSI interrupt */ reg = advk_readl(pcie, PCIE_ISR0_MASK_REG); @@ -1189,10 +1188,52 @@ static int advk_msi_set_affinity(struct irq_data *irq_data, return -EINVAL; } +static void advk_msi_irq_mask(struct irq_data *d) +{ + struct advk_pcie *pcie = d->domain->host_data; + irq_hw_number_t hwirq = irqd_to_hwirq(d); + unsigned long flags; + u32 mask; + + raw_spin_lock_irqsave(&pcie->msi_irq_lock, flags); + mask = advk_readl(pcie, PCIE_MSI_MASK_REG); + mask |= BIT(hwirq); + advk_writel(pcie, mask, PCIE_MSI_MASK_REG); + raw_spin_unlock_irqrestore(&pcie->msi_irq_lock, flags); +} + +static void advk_msi_irq_unmask(struct irq_data *d) +{ + struct advk_pcie *pcie = d->domain->host_data; + irq_hw_number_t hwirq = irqd_to_hwirq(d); + unsigned long flags; + u32 mask; + + raw_spin_lock_irqsave(&pcie->msi_irq_lock, flags); + mask = advk_readl(pcie, PCIE_MSI_MASK_REG); + mask &= ~BIT(hwirq); + advk_writel(pcie, mask, PCIE_MSI_MASK_REG); + raw_spin_unlock_irqrestore(&pcie->msi_irq_lock, flags); +} + +static void advk_msi_top_irq_mask(struct irq_data *d) +{ + pci_msi_mask_irq(d); + irq_chip_mask_parent(d); +} + +static void advk_msi_top_irq_unmask(struct irq_data *d) +{ + pci_msi_unmask_irq(d); + irq_chip_unmask_parent(d); +} + static struct irq_chip advk_msi_bottom_irq_chip = { .name = "MSI", .irq_compose_msi_msg = advk_msi_irq_compose_msi_msg, .irq_set_affinity = advk_msi_set_affinity, + .irq_mask = advk_msi_irq_mask, + .irq_unmask = advk_msi_irq_unmask, }; static int advk_msi_irq_domain_alloc(struct irq_domain *domain, @@ -1282,7 +1323,9 @@ static const struct irq_domain_ops advk_pcie_irq_domain_ops = { }; static struct irq_chip advk_msi_irq_chip = { - .name = "advk-MSI", + .name = "advk-MSI", + .irq_mask = advk_msi_top_irq_mask, + .irq_unmask = advk_msi_top_irq_unmask, }; static struct msi_domain_info advk_msi_domain_info = { @@ -1296,6 +1339,7 @@ static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) struct device *dev = &pcie->pdev->dev; phys_addr_t msi_msg_phys; + raw_spin_lock_init(&pcie->msi_irq_lock); mutex_init(&pcie->msi_used_lock); msi_msg_phys = virt_to_phys(&pcie->msi_msg); -- cgit v1.2.3 From 46ad3dc4171b5ee1d12267d70112563d5760210a Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:06 +0100 Subject: PCI: aardvark: Fix setting MSI address MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MSI address for receiving MSI interrupts needs to be correctly set before enabling processing of MSI interrupts. Move code for setting PCIE_MSI_ADDR_LOW_REG and PCIE_MSI_ADDR_HIGH_REG from advk_pcie_init_msi_irq_domain() to advk_pcie_setup_hw(), before enabling PCIE_CORE_CTRL2_MSI_ENABLE. After this we can remove the now unused member msi_msg, which was used only for MSI doorbell address. MSI address can be any address which cannot be used to DMA to. So change it to the address of the main struct advk_pcie. Link: https://lore.kernel.org/r/20220110015018.26359-12-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi Acked-by: Marc Zyngier Cc: stable@vger.kernel.org # f21a8b1b6837 ("PCI: aardvark: Move to MSI handling using generic MSI support") --- drivers/pci/controller/pci-aardvark.c | 21 +++++++++------------ 1 file changed, 9 insertions(+), 12 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 35f78bfc0dc7..b20973fae24d 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -277,7 +277,6 @@ struct advk_pcie { raw_spinlock_t msi_irq_lock; DECLARE_BITMAP(msi_used, MSI_IRQ_NUM); struct mutex msi_used_lock; - u16 msi_msg; int link_gen; struct pci_bridge_emul bridge; struct gpio_desc *reset_gpio; @@ -472,6 +471,7 @@ static void advk_pcie_disable_ob_win(struct advk_pcie *pcie, u8 win_num) static void advk_pcie_setup_hw(struct advk_pcie *pcie) { + phys_addr_t msi_addr; u32 reg; int i; @@ -560,6 +560,11 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie) reg |= LANE_COUNT_1; advk_writel(pcie, reg, PCIE_CORE_CTRL0_REG); + /* Set MSI address */ + msi_addr = virt_to_phys(pcie); + advk_writel(pcie, lower_32_bits(msi_addr), PCIE_MSI_ADDR_LOW_REG); + advk_writel(pcie, upper_32_bits(msi_addr), PCIE_MSI_ADDR_HIGH_REG); + /* Enable MSI */ reg = advk_readl(pcie, PCIE_CORE_CTRL2_REG); reg |= PCIE_CORE_CTRL2_MSI_ENABLE; @@ -1175,10 +1180,10 @@ static void advk_msi_irq_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) { struct advk_pcie *pcie = irq_data_get_irq_chip_data(data); - phys_addr_t msi_msg = virt_to_phys(&pcie->msi_msg); + phys_addr_t msi_addr = virt_to_phys(pcie); - msg->address_lo = lower_32_bits(msi_msg); - msg->address_hi = upper_32_bits(msi_msg); + msg->address_lo = lower_32_bits(msi_addr); + msg->address_hi = upper_32_bits(msi_addr); msg->data = data->hwirq; } @@ -1337,18 +1342,10 @@ static struct msi_domain_info advk_msi_domain_info = { static int advk_pcie_init_msi_irq_domain(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; - phys_addr_t msi_msg_phys; raw_spin_lock_init(&pcie->msi_irq_lock); mutex_init(&pcie->msi_used_lock); - msi_msg_phys = virt_to_phys(&pcie->msi_msg); - - advk_writel(pcie, lower_32_bits(msi_msg_phys), - PCIE_MSI_ADDR_LOW_REG); - advk_writel(pcie, upper_32_bits(msi_msg_phys), - PCIE_MSI_ADDR_HIGH_REG); - pcie->msi_inner_domain = irq_domain_add_linear(NULL, MSI_IRQ_NUM, &advk_msi_domain_ops, pcie); -- cgit v1.2.3 From 754e449889b22fc3c34235e8836f08f51121d307 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:07 +0100 Subject: PCI: aardvark: Enable MSI-X support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit According to PCI 3.0 specification, sending both MSI and MSI-X interrupts is done by DWORD memory write operation to doorbell message address. The write operation for MSI has zero upper 16 bits and the MSI interrupt number in the lower 16 bits, while the write operation for MSI-X contains a 32-bit value from MSI-X table. Since the driver only uses interrupt numbers from range 0..31, the upper 16 bits of the DWORD memory write operation to doorbell message address are zero even for MSI-X interrupts. Thus we can enable MSI-X interrupts. Testing proves that kernel can correctly receive MSI-X interrupts from PCIe cards which supports both MSI and MSI-X interrupts. Link: https://lore.kernel.org/r/20220110015018.26359-13-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index b20973fae24d..45ff2a62e1a8 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1335,7 +1335,7 @@ static struct irq_chip advk_msi_irq_chip = { static struct msi_domain_info advk_msi_domain_info = { .flags = MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | - MSI_FLAG_MULTI_PCI_MSI, + MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX, .chip = &advk_msi_irq_chip, }; -- cgit v1.2.3 From 3ebfefa396ebee21061fd5fa36073368ed2cd467 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:08 +0100 Subject: PCI: aardvark: Add support for ERR interrupt on emulated bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ERR interrupt is triggered when corresponding bit is unmasked in both ISR0 and PCI_EXP_DEVCTL registers. Unmasking ERR bits in PCI_EXP_DEVCTL register is not enough. This means that currently the ERR interrupt is never triggered. Unmask ERR bits in ISR0 register at driver probe time. ERR interrupt is not triggered until ERR bits are unmasked also in PCI_EXP_DEVCTL register, which is done by AER driver. So it is safe to unconditionally unmask all ERR bits in aardvark probe. Aardvark HW sets PCI_ERR_ROOT_AER_IRQ to zero and when corresponding bits in ISR0 and PCI_EXP_DEVCTL are enabled, the HW triggers a generic interrupt on GIC. Chain this interrupt to PCIe interrupt 0 with generic_handle_domain_irq() to allow processing of ERR interrupts. Link: https://lore.kernel.org/r/20220110015018.26359-14-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 45ff2a62e1a8..0d61305488f5 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -98,6 +98,10 @@ #define PCIE_MSG_PM_PME_MASK BIT(7) #define PCIE_ISR0_MASK_REG (CONTROL_BASE_ADDR + 0x44) #define PCIE_ISR0_MSI_INT_PENDING BIT(24) +#define PCIE_ISR0_CORR_ERR BIT(11) +#define PCIE_ISR0_NFAT_ERR BIT(12) +#define PCIE_ISR0_FAT_ERR BIT(13) +#define PCIE_ISR0_ERR_MASK GENMASK(13, 11) #define PCIE_ISR0_INTX_ASSERT(val) BIT(16 + (val)) #define PCIE_ISR0_INTX_DEASSERT(val) BIT(20 + (val)) #define PCIE_ISR0_ALL_MASK GENMASK(31, 0) @@ -778,11 +782,15 @@ advk_pci_bridge_emul_base_conf_read(struct pci_bridge_emul *bridge, case PCI_INTERRUPT_LINE: { /* * From the whole 32bit register we support reading from HW only - * one bit: PCI_BRIDGE_CTL_BUS_RESET. + * two bits: PCI_BRIDGE_CTL_BUS_RESET and PCI_BRIDGE_CTL_SERR. * Other bits are retrieved only from emulated config buffer. */ __le32 *cfgspace = (__le32 *)&bridge->conf; u32 val = le32_to_cpu(cfgspace[PCI_INTERRUPT_LINE / 4]); + if (advk_readl(pcie, PCIE_ISR0_MASK_REG) & PCIE_ISR0_ERR_MASK) + val &= ~(PCI_BRIDGE_CTL_SERR << 16); + else + val |= PCI_BRIDGE_CTL_SERR << 16; if (advk_readl(pcie, PCIE_CORE_CTRL1_REG) & HOT_RESET_GEN) val |= PCI_BRIDGE_CTL_BUS_RESET << 16; else @@ -808,6 +816,19 @@ advk_pci_bridge_emul_base_conf_write(struct pci_bridge_emul *bridge, break; case PCI_INTERRUPT_LINE: + /* + * According to Figure 6-3: Pseudo Logic Diagram for Error + * Message Controls in PCIe base specification, SERR# Enable bit + * in Bridge Control register enable receiving of ERR_* messages + */ + if (mask & (PCI_BRIDGE_CTL_SERR << 16)) { + u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG); + if (new & (PCI_BRIDGE_CTL_SERR << 16)) + val &= ~PCIE_ISR0_ERR_MASK; + else + val |= PCIE_ISR0_ERR_MASK; + advk_writel(pcie, val, PCIE_ISR0_MASK_REG); + } if (mask & (PCI_BRIDGE_CTL_BUS_RESET << 16)) { u32 val = advk_readl(pcie, PCIE_CORE_CTRL1_REG); if (new & (PCI_BRIDGE_CTL_BUS_RESET << 16)) @@ -1453,6 +1474,18 @@ 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 ERR interrupt */ + if (isr0_status & PCIE_ISR0_ERR_MASK) { + advk_writel(pcie, PCIE_ISR0_ERR_MASK, PCIE_ISR0_REG); + + /* + * Aardvark HW returns zero for PCI_ERR_ROOT_AER_IRQ, so use + * PCIe interrupt 0 + */ + if (generic_handle_domain_irq(pcie->irq_domain, 0) == -EINVAL) + dev_err_ratelimited(&pcie->pdev->dev, "unhandled ERR IRQ\n"); + } + /* Process MSI interrupts */ if (isr0_status & PCIE_ISR0_MSI_INT_PENDING) advk_pcie_handle_msi(pcie); -- cgit v1.2.3 From 735f5ae49e1b44742cc63ca9b5c1ffde3e94ba91 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:09 +0100 Subject: PCI: aardvark: Fix reading PCI_EXP_RTSTA_PME bit on emulated bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The emulated bridge returns incorrect value for PCI_EXP_RTSTA register during readout in advk_pci_bridge_emul_pcie_conf_read() function: the correct bit is BIT(16), but we are setting BIT(23), because the code does *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16 where PCIE_MSG_PM_PME_MASK is BIT(7). The code should probably have been something like *value = (!!(isr0 & PCIE_MSG_PM_PME_MASK)) << 16, but we are better of using an if() and using the proper macro for this bit. Link: https://lore.kernel.org/r/20220110015018.26359-15-kabel@kernel.org Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space") Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 0d61305488f5..2b50c9e2339a 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -867,7 +867,9 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge, case PCI_EXP_RTSTA: { u32 isr0 = advk_readl(pcie, PCIE_ISR0_REG); u32 msglog = advk_readl(pcie, PCIE_MSG_LOG_REG); - *value = (isr0 & PCIE_MSG_PM_PME_MASK) << 16 | (msglog >> 16); + *value = msglog >> 16; + if (isr0 & PCIE_MSG_PM_PME_MASK) + *value |= PCI_EXP_RTSTA_PME; return PCI_BRIDGE_EMUL_HANDLED; } -- cgit v1.2.3 From 7122bcb33295228c882c0aa32a04b2547beba2c3 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:10 +0100 Subject: PCI: aardvark: Optimize writing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME on emulated bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit To optimize advk_pci_bridge_emul_pcie_conf_write() code, touch PCIE_ISR0_REG and PCIE_ISR0_MASK_REG registers only when it is really needed, when processing PCI_EXP_RTCTL_PMEIE and PCI_EXP_RTSTA_PME bits. Link: https://lore.kernel.org/r/20220110015018.26359-16-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 2b50c9e2339a..2ae43992cd06 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -925,19 +925,21 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge, advk_pcie_wait_for_retrain(pcie); break; - case PCI_EXP_RTCTL: { + case PCI_EXP_RTCTL: /* Only mask/unmask PME interrupt */ - u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) & - ~PCIE_MSG_PM_PME_MASK; - if ((new & PCI_EXP_RTCTL_PMEIE) == 0) - val |= PCIE_MSG_PM_PME_MASK; - advk_writel(pcie, val, PCIE_ISR0_MASK_REG); + 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); + } break; - } case PCI_EXP_RTSTA: - new = (new & PCI_EXP_RTSTA_PME) >> 9; - advk_writel(pcie, new, PCIE_ISR0_REG); + if (new & PCI_EXP_RTSTA_PME) + advk_writel(pcie, PCIE_MSG_PM_PME_MASK, PCIE_ISR0_REG); break; case PCI_EXP_DEVCTL: -- cgit v1.2.3 From 0fc75d87454195885bd1a81fc7e6ce92572b6109 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:11 +0100 Subject: PCI: aardvark: Add support for PME interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently enabling PCI_EXP_RTSTA_PME bit in PCI_EXP_RTCTL register does nothing. This is because PCIe PME driver expects to receive PCIe interrupt defined in PCI_EXP_FLAGS_IRQ register, but aardvark hardware does not trigger PCIe INTx/MSI interrupt for PME event, rather it triggers custom aardvark interrupt which this driver is not processing yet. Fix this issue by handling PME interrupt in advk_pcie_handle_int() and chaining it to PCIe interrupt 0 with generic_handle_domain_irq() (since aardvark sets PCI_EXP_FLAGS_IRQ to zero). With this change PCIe PME driver finally starts receiving PME interrupt. Link: https://lore.kernel.org/r/20220110015018.26359-17-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 2ae43992cd06..8020dfb8f00e 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1478,6 +1478,18 @@ 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. + */ + if (generic_handle_domain_irq(pcie->irq_domain, 0) == -EINVAL) + dev_err_ratelimited(&pcie->pdev->dev, "unhandled PME IRQ\n"); + } + /* Process ERR interrupt */ if (isr0_status & PCIE_ISR0_ERR_MASK) { advk_writel(pcie, PCIE_ISR0_ERR_MASK, PCIE_ISR0_REG); -- cgit v1.2.3 From 273ddd86d67694e3639e3bfe337a96d8861798b8 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:12 +0100 Subject: 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. Link: https://lore.kernel.org/r/20220110015018.26359-18-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 91 +++++++++++++++++++---------------- 1 file changed, 50 insertions(+), 41 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 8020dfb8f00e..bd587f9395f8 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -590,6 +590,11 @@ 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); @@ -856,22 +861,11 @@ 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); @@ -925,22 +919,19 @@ 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: @@ -1443,6 +1434,32 @@ 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; + + 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; + + if (generic_handle_domain_irq(pcie->irq_domain, 0) == -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; @@ -1478,17 +1495,9 @@ 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. - */ - if (generic_handle_domain_irq(pcie->irq_domain, 0) == -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) { -- cgit v1.2.3 From 815bc313686783e3a1823ec0efc332c70e6bd976 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:13 +0100 Subject: PCI: aardvark: Use separate INTA interrupt for emulated root bridge MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Emulated root bridge currently provides only one Legacy INTA interrupt which is used for reporting PCIe PME and ERR events and handled by kernel PCIe PME and AER drivers. Aardvark HW reports these PME and ERR events separately, so there is no need to mix real INTA interrupt and emulated INTA interrupt for PCIe PME and AER drivers. Register a new advk-RP (as in Root Port) irq chip and a new irq domain for emulated root bridge and use this new separate irq domain for providing INTA interrupt from emulated root bridge for PME and ERR events. The real INTA interrupt from real devices is now separate. A custom map_irq callback function on PCI host bridge structure is used to allocate IRQ mapping for emulated root bridge from new irq domain. Original callback of_irq_parse_and_map_pci() is used for all other devices as before. Link: https://lore.kernel.org/r/20220110015018.26359-19-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 69 ++++++++++++++++++++++++++++++++++- 1 file changed, 67 insertions(+), 2 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index bd587f9395f8..58a5ba852be1 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -273,6 +273,7 @@ struct advk_pcie { } wins[OB_WIN_COUNT]; u8 wins_count; int irq; + struct irq_domain *rp_irq_domain; struct irq_domain *irq_domain; struct irq_chip irq_chip; raw_spinlock_t irq_lock; @@ -1434,6 +1435,44 @@ static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie) irq_domain_remove(pcie->irq_domain); } +static struct irq_chip advk_rp_irq_chip = { + .name = "advk-RP", +}; + +static int advk_pcie_rp_irq_map(struct irq_domain *h, + unsigned int virq, irq_hw_number_t hwirq) +{ + struct advk_pcie *pcie = h->host_data; + + irq_set_chip_and_handler(virq, &advk_rp_irq_chip, handle_simple_irq); + irq_set_chip_data(virq, pcie); + + return 0; +} + +static const struct irq_domain_ops advk_pcie_rp_irq_domain_ops = { + .map = advk_pcie_rp_irq_map, + .xlate = irq_domain_xlate_onecell, +}; + +static int advk_pcie_init_rp_irq_domain(struct advk_pcie *pcie) +{ + pcie->rp_irq_domain = irq_domain_add_linear(NULL, 1, + &advk_pcie_rp_irq_domain_ops, + pcie); + if (!pcie->rp_irq_domain) { + dev_err(&pcie->pdev->dev, "Failed to add Root Port IRQ domain\n"); + return -ENOMEM; + } + + return 0; +} + +static void advk_pcie_remove_rp_irq_domain(struct advk_pcie *pcie) +{ + irq_domain_remove(pcie->rp_irq_domain); +} + static void advk_pcie_handle_pme(struct advk_pcie *pcie) { u32 requester = advk_readl(pcie, PCIE_MSG_LOG_REG) >> 16; @@ -1455,7 +1494,7 @@ static void advk_pcie_handle_pme(struct advk_pcie *pcie) if (!(le16_to_cpu(pcie->bridge.pcie_conf.rootctl) & PCI_EXP_RTCTL_PMEIE)) return; - if (generic_handle_domain_irq(pcie->irq_domain, 0) == -EINVAL) + if (generic_handle_domain_irq(pcie->rp_irq_domain, 0) == -EINVAL) dev_err_ratelimited(&pcie->pdev->dev, "unhandled PME IRQ\n"); } } @@ -1507,7 +1546,7 @@ static void advk_pcie_handle_int(struct advk_pcie *pcie) * Aardvark HW returns zero for PCI_ERR_ROOT_AER_IRQ, so use * PCIe interrupt 0 */ - if (generic_handle_domain_irq(pcie->irq_domain, 0) == -EINVAL) + if (generic_handle_domain_irq(pcie->rp_irq_domain, 0) == -EINVAL) dev_err_ratelimited(&pcie->pdev->dev, "unhandled ERR IRQ\n"); } @@ -1551,6 +1590,21 @@ static void advk_pcie_irq_handler(struct irq_desc *desc) chained_irq_exit(chip, desc); } +static int advk_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) +{ + struct advk_pcie *pcie = dev->bus->sysdata; + + /* + * Emulated root bridge has its own emulated irq chip and irq domain. + * Argument pin is the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD) and + * hwirq for irq_create_mapping() is indexed from zero. + */ + if (pci_is_root_bus(dev->bus)) + return irq_create_mapping(pcie->rp_irq_domain, pin - 1); + else + return of_irq_parse_and_map_pci(dev, slot, pin); +} + static void __maybe_unused advk_pcie_disable_phy(struct advk_pcie *pcie) { phy_power_off(pcie->phy); @@ -1752,14 +1806,24 @@ static int advk_pcie_probe(struct platform_device *pdev) return ret; } + ret = advk_pcie_init_rp_irq_domain(pcie); + if (ret) { + dev_err(dev, "Failed to initialize irq\n"); + advk_pcie_remove_msi_irq_domain(pcie); + advk_pcie_remove_irq_domain(pcie); + return ret; + } + irq_set_chained_handler_and_data(pcie->irq, advk_pcie_irq_handler, pcie); bridge->sysdata = pcie; bridge->ops = &advk_pcie_ops; + bridge->map_irq = advk_pcie_map_irq; ret = pci_host_probe(bridge); if (ret < 0) { irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); + advk_pcie_remove_rp_irq_domain(pcie); advk_pcie_remove_msi_irq_domain(pcie); advk_pcie_remove_irq_domain(pcie); return ret; @@ -1811,6 +1875,7 @@ static int advk_pcie_remove(struct platform_device *pdev) irq_set_chained_handler_and_data(pcie->irq, NULL, NULL); /* Remove IRQ domains */ + advk_pcie_remove_rp_irq_domain(pcie); advk_pcie_remove_msi_irq_domain(pcie); advk_pcie_remove_irq_domain(pcie); -- cgit v1.2.3 From b08e5b53d17be58eb2311d6790a84fe2c200ee47 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:14 +0100 Subject: PCI: aardvark: Remove irq_mask_ack() callback for INTx interrupts MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Callback for irq_mask_ack() is the same as for irq_mask(). As there is no special handling for irq_ack(), there is no need to define irq_mask_ack() too. Link: https://lore.kernel.org/r/20220110015018.26359-20-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi Acked-by: Marc Zyngier --- drivers/pci/controller/pci-aardvark.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 58a5ba852be1..faf4f55c462d 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1413,7 +1413,6 @@ static int advk_pcie_init_irq_domain(struct advk_pcie *pcie) } irq_chip->irq_mask = advk_pcie_irq_mask; - irq_chip->irq_mask_ack = advk_pcie_irq_mask; irq_chip->irq_unmask = advk_pcie_irq_unmask; pcie->irq_domain = -- cgit v1.2.3 From befa71000160b39c1bf6cdfca6837bb5e9d372d7 Mon Sep 17 00:00:00 2001 From: Pali Rohár Date: Mon, 10 Jan 2022 02:50:15 +0100 Subject: PCI: aardvark: Don't mask irq when mapping MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit By default, all Legacy INTx interrupts are masked, so there is no need to mask this interrupt during irq_map() callback. Link: https://lore.kernel.org/r/20220110015018.26359-21-kabel@kernel.org Signed-off-by: Pali Rohár Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 1 - 1 file changed, 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index faf4f55c462d..955ce7ef0407 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1330,7 +1330,6 @@ static int advk_pcie_irq_map(struct irq_domain *h, { struct advk_pcie *pcie = h->host_data; - advk_pcie_irq_mask(irq_get_irq_data(virq)); irq_set_status_flags(virq, IRQ_LEVEL); irq_set_chip_and_handler(virq, &pcie->irq_chip, handle_level_irq); -- cgit v1.2.3 From 0c36ab437e1d94b6628b006a1d48f05ea3b0b222 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 10 Jan 2022 02:50:16 +0100 Subject: PCI: aardvark: Drop __maybe_unused from advk_pcie_disable_phy() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This function is now always used in driver remove method, drop the __maybe_unused attribute. Link: https://lore.kernel.org/r/20220110015018.26359-22-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 955ce7ef0407..3cbaffe892a4 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1603,7 +1603,7 @@ static int advk_pcie_map_irq(const struct pci_dev *dev, u8 slot, u8 pin) return of_irq_parse_and_map_pci(dev, slot, pin); } -static void __maybe_unused advk_pcie_disable_phy(struct advk_pcie *pcie) +static void advk_pcie_disable_phy(struct advk_pcie *pcie) { phy_power_off(pcie->phy); phy_exit(pcie->phy); -- cgit v1.2.3 From 92f4ffecc4170ce29e67a1f8d51c168c3de95fb2 Mon Sep 17 00:00:00 2001 From: Marek Behún Date: Mon, 10 Jan 2022 02:50:17 +0100 Subject: PCI: aardvark: Update comment about link going down after link-up MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Update the comment about what happens when link goes down after we have checked for link-up. If a PIO request is done while link-down, we have a serious problem. Link: https://lore.kernel.org/r/20220110015018.26359-23-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Lorenzo Pieralisi --- drivers/pci/controller/pci-aardvark.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/pci/controller/pci-aardvark.c') diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index 3cbaffe892a4..5be382b19d9a 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -998,8 +998,12 @@ static bool advk_pcie_valid_device(struct advk_pcie *pcie, struct pci_bus *bus, return false; /* - * If the link goes down after we check for link-up, nothing bad - * happens but the config access times out. + * If the link goes down after we check for link-up, we have a problem: + * if a PIO request is executed while link-down, the whole controller + * gets stuck in a non-functional state, and even after link comes up + * again, PIO requests won't work anymore, and a reset of the whole PCIe + * controller is needed. Therefore we need to prevent sending PIO + * requests while the link is down. */ if (!pci_is_root_bus(bus) && !advk_pcie_link_up(pcie)) return false; -- cgit v1.2.3