--- /dev/null
+From 1a90ecdfae1c0cf1b242276f6f0e3d98b5877f14 Mon Sep 17 00:00:00 2001
+From: Jim Quinlan <james.quinlan@broadcom.com>
+Date: Mon, 16 Dec 2019 12:01:10 +0100
+Subject: [PATCH] PCI: brcmstb: Add MSI support
+
+commit 40ca1bf580ef24df30702032ba5e40dfdcaa200b upstream.
+
+This adds MSI support to the Broadcom STB PCIe host controller. The MSI
+controller is physically located within the PCIe block, however, there
+is no reason why the MSI controller could not be moved elsewhere in the
+future. MSIX is not supported by the HW.
+
+Since the internal Brcmstb MSI controller is intertwined with the PCIe
+controller, it is not its own platform device but rather part of the
+PCIe platform device.
+
+Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>
+Co-developed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
+Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
+Reviewed-by: Marc Zyngier <maz@kernel.org>
+Reviewed-by: Andrew Murray <andrew.murray@arm.com>
+---
+ drivers/pci/controller/Kconfig | 1 +
+ drivers/pci/controller/pcie-brcmstb.c | 262 +++++++++++++++++++++++++-
+ 2 files changed, 262 insertions(+), 1 deletion(-)
+
+--- a/drivers/pci/controller/Kconfig
++++ b/drivers/pci/controller/Kconfig
+@@ -285,6 +285,7 @@ config PCIE_BRCMSTB
+ tristate "Broadcom Brcmstb PCIe host controller"
+ depends on ARCH_BCM2835 || COMPILE_TEST
+ depends on OF
++ depends on PCI_MSI_IRQ_DOMAIN
+ help
+ Say Y here to enable PCIe host controller support for
+ Broadcom STB based SoCs, like the Raspberry Pi 4.
+--- a/drivers/pci/controller/pcie-brcmstb.c
++++ b/drivers/pci/controller/pcie-brcmstb.c
+@@ -2,6 +2,7 @@
+ /* Copyright (C) 2009 - 2019 Broadcom */
+
+ #include <linux/bitfield.h>
++#include <linux/bitops.h>
+ #include <linux/clk.h>
+ #include <linux/compiler.h>
+ #include <linux/delay.h>
+@@ -9,11 +10,13 @@
+ #include <linux/interrupt.h>
+ #include <linux/io.h>
+ #include <linux/ioport.h>
++#include <linux/irqchip/chained_irq.h>
+ #include <linux/irqdomain.h>
+ #include <linux/kernel.h>
+ #include <linux/list.h>
+ #include <linux/log2.h>
+ #include <linux/module.h>
++#include <linux/msi.h>
+ #include <linux/of_address.h>
+ #include <linux/of_irq.h>
+ #include <linux/of_pci.h>
+@@ -67,6 +70,12 @@
+ #define PCIE_MISC_RC_BAR3_CONFIG_LO 0x403c
+ #define PCIE_MISC_RC_BAR3_CONFIG_LO_SIZE_MASK 0x1f
+
++#define PCIE_MISC_MSI_BAR_CONFIG_LO 0x4044
++#define PCIE_MISC_MSI_BAR_CONFIG_HI 0x4048
++
++#define PCIE_MISC_MSI_DATA_CONFIG 0x404c
++#define PCIE_MISC_MSI_DATA_CONFIG_VAL 0xffe06540
++
+ #define PCIE_MISC_PCIE_CTRL 0x4064
+ #define PCIE_MISC_PCIE_CTRL_PCIE_L23_REQUEST_MASK 0x1
+
+@@ -114,6 +123,11 @@
+
+ /* PCIe parameters */
+ #define BRCM_NUM_PCIE_OUT_WINS 0x4
++#define BRCM_INT_PCI_MSI_NR 32
++
++/* MSI target adresses */
++#define BRCM_MSI_TARGET_ADDR_LT_4GB 0x0fffffffcULL
++#define BRCM_MSI_TARGET_ADDR_GT_4GB 0xffffffffcULL
+
+ /* MDIO registers */
+ #define MDIO_PORT0 0x0
+@@ -135,6 +149,19 @@
+ #define SSC_STATUS_SSC_MASK 0x400
+ #define SSC_STATUS_PLL_LOCK_MASK 0x800
+
++struct brcm_msi {
++ struct device *dev;
++ void __iomem *base;
++ struct device_node *np;
++ struct irq_domain *msi_domain;
++ struct irq_domain *inner_domain;
++ struct mutex lock; /* guards the alloc/free operations */
++ u64 target_addr;
++ int irq;
++ /* used indicates which MSI interrupts have been alloc'd */
++ unsigned long used;
++};
++
+ /* Internal PCIe Host Controller Information.*/
+ struct brcm_pcie {
+ struct device *dev;
+@@ -144,6 +171,8 @@ struct brcm_pcie {
+ struct device_node *np;
+ bool ssc;
+ int gen;
++ u64 msi_target_addr;
++ struct brcm_msi *msi;
+ };
+
+ /*
+@@ -309,6 +338,215 @@ static void brcm_pcie_set_outbound_win(s
+ writel(tmp, pcie->base + PCIE_MEM_WIN0_LIMIT_HI(win));
+ }
+
++static struct irq_chip brcm_msi_irq_chip = {
++ .name = "BRCM STB PCIe MSI",
++ .irq_ack = irq_chip_ack_parent,
++ .irq_mask = pci_msi_mask_irq,
++ .irq_unmask = pci_msi_unmask_irq,
++};
++
++static struct msi_domain_info brcm_msi_domain_info = {
++ /* Multi MSI is supported by the controller, but not by this driver */
++ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
++ .chip = &brcm_msi_irq_chip,
++};
++
++static void brcm_pcie_msi_isr(struct irq_desc *desc)
++{
++ struct irq_chip *chip = irq_desc_get_chip(desc);
++ unsigned long status, virq;
++ struct brcm_msi *msi;
++ struct device *dev;
++ u32 bit;
++
++ chained_irq_enter(chip, desc);
++ msi = irq_desc_get_handler_data(desc);
++ dev = msi->dev;
++
++ status = readl(msi->base + PCIE_MSI_INTR2_STATUS);
++ for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
++ virq = irq_find_mapping(msi->inner_domain, bit);
++ if (virq)
++ generic_handle_irq(virq);
++ else
++ dev_dbg(dev, "unexpected MSI\n");
++ }
++
++ chained_irq_exit(chip, desc);
++}
++
++static void brcm_msi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
++{
++ struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
++
++ msg->address_lo = lower_32_bits(msi->target_addr);
++ msg->address_hi = upper_32_bits(msi->target_addr);
++ msg->data = (0xffff & PCIE_MISC_MSI_DATA_CONFIG_VAL) | data->hwirq;
++}
++
++static int brcm_msi_set_affinity(struct irq_data *irq_data,
++ const struct cpumask *mask, bool force)
++{
++ return -EINVAL;
++}
++
++static void brcm_msi_ack_irq(struct irq_data *data)
++{
++ struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
++
++ writel(1 << data->hwirq, msi->base + PCIE_MSI_INTR2_CLR);
++}
++
++
++static struct irq_chip brcm_msi_bottom_irq_chip = {
++ .name = "BRCM STB MSI",
++ .irq_compose_msi_msg = brcm_msi_compose_msi_msg,
++ .irq_set_affinity = brcm_msi_set_affinity,
++ .irq_ack = brcm_msi_ack_irq,
++};
++
++static int brcm_msi_alloc(struct brcm_msi *msi)
++{
++ int hwirq;
++
++ mutex_lock(&msi->lock);
++ hwirq = bitmap_find_free_region(&msi->used, BRCM_INT_PCI_MSI_NR, 0);
++ mutex_unlock(&msi->lock);
++
++ return hwirq;
++}
++
++static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq)
++{
++ mutex_lock(&msi->lock);
++ bitmap_release_region(&msi->used, hwirq, 0);
++ mutex_unlock(&msi->lock);
++}
++
++static int brcm_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
++ unsigned int nr_irqs, void *args)
++{
++ struct brcm_msi *msi = domain->host_data;
++ int hwirq;
++
++ hwirq = brcm_msi_alloc(msi);
++
++ if (hwirq < 0)
++ return hwirq;
++
++ irq_domain_set_info(domain, virq, (irq_hw_number_t)hwirq,
++ &brcm_msi_bottom_irq_chip, domain->host_data,
++ handle_edge_irq, NULL, NULL);
++ return 0;
++}
++
++static void brcm_irq_domain_free(struct irq_domain *domain,
++ unsigned int virq, unsigned int nr_irqs)
++{
++ struct irq_data *d = irq_domain_get_irq_data(domain, virq);
++ struct brcm_msi *msi = irq_data_get_irq_chip_data(d);
++
++ brcm_msi_free(msi, d->hwirq);
++}
++
++static const struct irq_domain_ops msi_domain_ops = {
++ .alloc = brcm_irq_domain_alloc,
++ .free = brcm_irq_domain_free,
++};
++
++static int brcm_allocate_domains(struct brcm_msi *msi)
++{
++ struct fwnode_handle *fwnode = of_node_to_fwnode(msi->np);
++ struct device *dev = msi->dev;
++
++ msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
++ &msi_domain_ops, msi);
++ if (!msi->inner_domain) {
++ dev_err(dev, "failed to create IRQ domain\n");
++ return -ENOMEM;
++ }
++
++ msi->msi_domain = pci_msi_create_irq_domain(fwnode,
++ &brcm_msi_domain_info,
++ msi->inner_domain);
++ if (!msi->msi_domain) {
++ dev_err(dev, "failed to create MSI domain\n");
++ irq_domain_remove(msi->inner_domain);
++ return -ENOMEM;
++ }
++
++ return 0;
++}
++
++static void brcm_free_domains(struct brcm_msi *msi)
++{
++ irq_domain_remove(msi->msi_domain);
++ irq_domain_remove(msi->inner_domain);
++}
++
++static void brcm_msi_remove(struct brcm_pcie *pcie)
++{
++ struct brcm_msi *msi = pcie->msi;
++
++ if (!msi)
++ return;
++ irq_set_chained_handler(msi->irq, NULL);
++ irq_set_handler_data(msi->irq, NULL);
++ brcm_free_domains(msi);
++}
++
++static void brcm_msi_set_regs(struct brcm_msi *msi)
++{
++ writel(0xffffffff, msi->base + PCIE_MSI_INTR2_MASK_CLR);
++
++ /*
++ * The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
++ * enable, which we set to 1.
++ */
++ writel(lower_32_bits(msi->target_addr) | 0x1,
++ msi->base + PCIE_MISC_MSI_BAR_CONFIG_LO);
++ writel(upper_32_bits(msi->target_addr),
++ msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);
++
++ writel(PCIE_MISC_MSI_DATA_CONFIG_VAL,
++ msi->base + PCIE_MISC_MSI_DATA_CONFIG);
++}
++
++static int brcm_pcie_enable_msi(struct brcm_pcie *pcie)
++{
++ struct brcm_msi *msi;
++ int irq, ret;
++ struct device *dev = pcie->dev;
++
++ irq = irq_of_parse_and_map(dev->of_node, 1);
++ if (irq <= 0) {
++ dev_err(dev, "cannot map MSI interrupt\n");
++ return -ENODEV;
++ }
++
++ msi = devm_kzalloc(dev, sizeof(struct brcm_msi), GFP_KERNEL);
++ if (!msi)
++ return -ENOMEM;
++
++ mutex_init(&msi->lock);
++ msi->dev = dev;
++ msi->base = pcie->base;
++ msi->np = pcie->np;
++ msi->target_addr = pcie->msi_target_addr;
++ msi->irq = irq;
++
++ ret = brcm_allocate_domains(msi);
++ if (ret)
++ return ret;
++
++ irq_set_chained_handler_and_data(msi->irq, brcm_pcie_msi_isr, msi);
++
++ brcm_msi_set_regs(msi);
++ pcie->msi = msi;
++
++ return 0;
++}
++
+ /* The controller is capable of serving in both RC and EP roles */
+ static bool brcm_pcie_rc_mode(struct brcm_pcie *pcie)
+ {
+@@ -497,6 +735,18 @@ static int brcm_pcie_setup(struct brcm_p
+ PCIE_MISC_MISC_CTRL_SCB0_SIZE_MASK);
+ writel(tmp, base + PCIE_MISC_MISC_CTRL);
+
++ /*
++ * We ideally want the MSI target address to be located in the 32bit
++ * addressable memory area. Some devices might depend on it. This is
++ * possible either when the inbound window is located above the lower
++ * 4GB or when the inbound area is smaller than 4GB (taking into
++ * account the rounding-up we're forced to perform).
++ */
++ if (rc_bar2_offset >= SZ_4G || (rc_bar2_size + rc_bar2_offset) < SZ_4G)
++ pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
++ else
++ pcie->msi_target_addr = BRCM_MSI_TARGET_ADDR_GT_4GB;
++
+ /* disable the PCIe->GISB memory window (RC_BAR1) */
+ tmp = readl(base + PCIE_MISC_RC_BAR1_CONFIG_LO);
+ tmp &= ~PCIE_MISC_RC_BAR1_CONFIG_LO_SIZE_MASK;
+@@ -646,6 +896,7 @@ static void brcm_pcie_turn_off(struct br
+
+ static void __brcm_pcie_remove(struct brcm_pcie *pcie)
+ {
++ brcm_msi_remove(pcie);
+ brcm_pcie_turn_off(pcie);
+ clk_disable_unprepare(pcie->clk);
+ clk_put(pcie->clk);
+@@ -664,7 +915,7 @@ static int brcm_pcie_remove(struct platf
+
+ static int brcm_pcie_probe(struct platform_device *pdev)
+ {
+- struct device_node *np = pdev->dev.of_node;
++ struct device_node *np = pdev->dev.of_node, *msi_np;
+ struct pci_host_bridge *bridge;
+ struct brcm_pcie *pcie;
+ struct pci_bus *child;
+@@ -708,6 +959,15 @@ static int brcm_pcie_probe(struct platfo
+ if (ret)
+ goto fail;
+
++ msi_np = of_parse_phandle(pcie->np, "msi-parent", 0);
++ if (pci_msi_enabled() && msi_np == pcie->np) {
++ ret = brcm_pcie_enable_msi(pcie);
++ if (ret) {
++ dev_err(pcie->dev, "probe of internal MSI failed");
++ goto fail;
++ }
++ }
++
+ bridge->dev.parent = &pdev->dev;
+ bridge->busnr = 0;
+ bridge->ops = &brcm_pcie_ops;
projects / openwrt / staging / luka.git / blobdiff