On Tue, Oct 24, 2017 at 02:15:47PM -0400, Jim Quinlan wrote:
> This commit adds MSI to the Broadcom STB PCIe host controller. It does
> not add MSIX since that functionality is not in the HW. 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.
>
> 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 <[email protected]>
> ---
> drivers/pci/host/Kconfig | 12 ++
> drivers/pci/host/Makefile | 1 +
> drivers/pci/host/pci-brcmstb-msi.c | 318
> +++++++++++++++++++++++++++++++++++++
> drivers/pci/host/pci-brcmstb.c | 72 +++++++--
> drivers/pci/host/pci-brcmstb.h | 26 +++
> 5 files changed, 419 insertions(+), 10 deletions(-)
> create mode 100644 drivers/pci/host/pci-brcmstb-msi.c
>
> diff --git a/drivers/pci/host/Kconfig b/drivers/pci/host/Kconfig
> index b9b4f11..54aa5d2 100644
> --- a/drivers/pci/host/Kconfig
> +++ b/drivers/pci/host/Kconfig
> @@ -228,4 +228,16 @@ config PCI_BRCMSTB
> default ARCH_BRCMSTB || BMIPS_GENERIC
> help
> Adds support for Broadcom Settop Box PCIe host controller.
> + To compile this driver as a module, choose m here.
> +
> +config PCI_BRCMSTB_MSI
> + bool "Broadcom Brcmstb PCIe MSI support"
> + depends on ARCH_BRCMSTB || BMIPS_GENERIC
> + depends on OF
> + depends on PCI_MSI
> + default PCI_BRCMSTB
> + help
> + Say Y here if you want to enable MSI support for Broadcom's iProc
> + PCIe controller
Is there any reason *not* to enable MSI? Most drivers just include
MSI support in the base driver, in the same file and under the same
config symbol.
> +
> endmenu
> diff --git a/drivers/pci/host/Makefile b/drivers/pci/host/Makefile
> index c283321..1026d6f 100644
> --- a/drivers/pci/host/Makefile
> +++ b/drivers/pci/host/Makefile
> @@ -23,6 +23,7 @@ obj-$(CONFIG_PCIE_TANGO_SMP8759) += pcie-tango.o
> obj-$(CONFIG_VMD) += vmd.o
> obj-$(CONFIG_PCI_BRCMSTB) += brcmstb-pci.o
> brcmstb-pci-objs := pci-brcmstb.o pci-brcmstb-dma.o
> +obj-$(CONFIG_PCI_BRCMSTB_MSI) += pci-brcmstb-msi.o
>
> # The following drivers are for devices that use the generic ACPI
> # pci_root.c driver but don't support standard ECAM config access.
> diff --git a/drivers/pci/host/pci-brcmstb-msi.c
> b/drivers/pci/host/pci-brcmstb-msi.c
> new file mode 100644
> index 0000000..c805e2f
> --- /dev/null
> +++ b/drivers/pci/host/pci-brcmstb-msi.c
> @@ -0,0 +1,318 @@
> +/*
> + * Copyright (C) 2015-2017 Broadcom
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
Remove last blank line of comment and add a blank line between comment
and #includes.
> +#include <linux/bitops.h>
> +#include <linux/compiler.h>
> +#include <linux/init.h>
> +#include <linux/interrupt.h>
> +#include <linux/io.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/msi.h>
> +#include <linux/of_irq.h>
> +#include <linux/of_pci.h>
> +#include <linux/of_platform.h>
> +#include <linux/pci.h>
> +#include <linux/types.h>
> +
> +#include "pci-brcmstb.h"
> +
> +#define PCIE_MISC_MSI_DATA_CONFIG 0x404c
> +#define PCIE_MSI_INTR2_BASE 0x4500
> +#define PCIE_MISC_MSI_BAR_CONFIG_LO 0x4044
> +#define PCIE_MISC_MSI_BAR_CONFIG_HI 0x4048
> +
> +/* Offsets from PCIE_INTR2_CPU_BASE and PCIE_MSI_INTR2_BASE */
> +#define STATUS 0x0
> +#define SET 0x4
> +#define CLR 0x8
> +#define MASK_STATUS 0xc
> +#define MASK_SET 0x10
> +#define MASK_CLR 0x14
> +
> +struct brcm_msi {
> + struct irq_domain *msi_domain;
> + struct irq_domain *inner_domain;
> + struct mutex lock; /* guards the alloc/free operations */
> + u64 target_addr;
> + int irq;
> + /* intr_base is the base pointer for interrupt status/set/clr regs */
> + void __iomem *intr_base;
> + /* intr_legacy_mask indicates how many bits are MSI interrupts */
> + u32 intr_legacy_mask;
> + /* intr_legacy_offset indicates bit position of MSI_01. It is
> + * to map the register bit position to a hwirq that starts at 0.
> + */
> + u32 intr_legacy_offset;
> + /* used indicates which MSI interrupts have been alloc'd */
> + unsigned long used;
> +
> + void __iomem *base;
> + struct device *dev;
> + struct device_node *dn;
> + unsigned int rev;
> +};
> +
> +static struct irq_chip brcm_msi_irq_chip = {
> + .name = "Brcm_MSI",
> + .irq_mask = pci_msi_mask_irq,
> + .irq_unmask = pci_msi_unmask_irq,
> +};
> +
> +static struct msi_domain_info brcm_msi_domain_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
> + MSI_FLAG_PCI_MSIX),
> + .chip = &brcm_msi_irq_chip,
> +};
> +
> +static void brcm_pcie_msi_isr(struct irq_desc *desc)
> +{
> + struct irq_chip *chip = irq_desc_get_chip(desc);
> + struct brcm_msi *msi;
> + unsigned long status, virq;
> + u32 mask, bit, hwirq;
> +
> + chained_irq_enter(chip, desc);
> + msi = irq_desc_get_handler_data(desc);
> + mask = msi->intr_legacy_mask;
> +
> + while ((status = bcm_readl(msi->intr_base + STATUS) & mask)) {
> + for_each_set_bit(bit, &status, BRCM_INT_PCI_MSI_NR) {
> + /* clear the interrupt */
> + bcm_writel(1 << bit, msi->intr_base + CLR);
> +
> + /* Account for legacy interrupt offset */
> + hwirq = bit - msi->intr_legacy_offset;
> +
> + virq = irq_find_mapping(msi->inner_domain, hwirq);
> + if (virq) {
> + if (msi->used & (1 << hwirq))
> + generic_handle_irq(virq);
> + else
> + dev_info(msi->dev, "unhandled MSI %d\n",
> + hwirq);
> + } else {
> + /* Unknown MSI, just clear it */
> + dev_dbg(msi->dev, "unexpected MSI\n");
Use a local "struct device *dev" to avoid repeating the "msi->dev"
here and elsewhere.
> + }
> + }
> + }
> + chained_irq_exit(chip, desc);
> +}
> +
> +static void brcm_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct brcm_msi *msi = irq_data_get_irq_chip_data(data);
> + u32 temp;
> +
> + msg->address_lo = lower_32_bits(msi->target_addr);
> + msg->address_hi = upper_32_bits(msi->target_addr);
> + temp = bcm_readl(msi->base + PCIE_MISC_MSI_DATA_CONFIG);
> + msg->data = ((temp >> 16) & (temp & 0xffff)) | data->hwirq;
> +}
> +
> +static int brcm_msi_set_affinity(struct irq_data *irq_data,
> + const struct cpumask *mask, bool force)
> +{
> + return -EINVAL;
> +}
> +
> +static struct irq_chip brcm_msi_bottom_irq_chip = {
> + .name = "Brcm MSI",
Why the different name from brcm_msi_irq_chip above ("Brcm_MSI" vs
"Brcm MSI")? If the "_" signifies something, it should be made more
explicit.
> + .irq_compose_msi_msg = brcm_compose_msi_msg,
> + .irq_set_affinity = brcm_msi_set_affinity,
> +};
> +
> +static int brcm_msi_alloc(struct brcm_msi *msi)
> +{
> + int bit, hwirq;
> +
> + mutex_lock(&msi->lock);
> + bit = ~msi->used ? ffz(msi->used) : -1;
> +
> + if (bit >= 0 && bit < BRCM_INT_PCI_MSI_NR) {
> + msi->used |= (1 << bit);
> + hwirq = bit - msi->intr_legacy_offset;
> + } else {
> + hwirq = -ENOSPC;
> + }
> +
> + mutex_unlock(&msi->lock);
> + return hwirq;
> +}
> +
> +static void brcm_msi_free(struct brcm_msi *msi, unsigned long hwirq)
> +{
> + mutex_lock(&msi->lock);
> + msi->used &= ~(1 << (hwirq + msi->intr_legacy_offset));
> + 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_simple_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);
> +}
> +
> +void brcm_msi_set_regs(struct brcm_msi *msi)
> +{
> + u32 data_val, msi_lo, msi_hi;
> +
> + if (msi->rev >= BRCM_PCIE_HW_REV_33) {
> + /* ffe0 -- least sig 5 bits are 0 indicating 32 msgs
> + * 6540 -- this is our arbitrary unique data value
> + */
Multi-line comment style.
> + data_val = 0xffe06540;
> + } else {
> + /* fff8 -- least sig 3 bits are 0 indicating 8 msgs
> + * 6540 -- this is our arbitrary unique data value
> + */
> + data_val = 0xfff86540;
> + }
> +
> + /* Make sure we are not masking MSIs. Note that MSIs can be masked,
> + * but that occurs on the PCIe EP device
> + */
> + bcm_writel(0xffffffff & msi->intr_legacy_mask,
> + msi->intr_base + MASK_CLR);
> +
> + msi_lo = lower_32_bits(msi->target_addr);
> + msi_hi = upper_32_bits(msi->target_addr);
> + /* The 0 bit of PCIE_MISC_MSI_BAR_CONFIG_LO is repurposed to MSI
> + * enable, which we set to 1.
> + */
> + bcm_writel(msi_lo | 1, msi->base + PCIE_MISC_MSI_BAR_CONFIG_LO);
> + bcm_writel(msi_hi, msi->base + PCIE_MISC_MSI_BAR_CONFIG_HI);
> + bcm_writel(data_val, msi->base + PCIE_MISC_MSI_DATA_CONFIG);
> +}
> +EXPORT_SYMBOL(brcm_msi_set_regs);
> +
> +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->dn);
> +
> + msi->inner_domain = irq_domain_add_linear(NULL, BRCM_INT_PCI_MSI_NR,
> + &msi_domain_ops, msi);
> + if (!msi->inner_domain) {
> + dev_err(msi->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(msi->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);
> +}
> +
> +void brcm_msi_remove(struct brcm_msi *msi)
> +{
> + if (!msi)
> + return;
> + irq_set_chained_handler(msi->irq, NULL);
> + irq_set_handler_data(msi->irq, NULL);
> + brcm_free_domains(msi);
> +}
> +EXPORT_SYMBOL(brcm_msi_remove);
> +
> +int brcm_msi_probe(struct platform_device *pdev, struct brcm_info *info)
> +{
> + struct brcm_msi *msi;
> + int irq, ret;
> +
> + irq = irq_of_parse_and_map(pdev->dev.of_node, 1);
> + if (irq <= 0) {
> + dev_err(&pdev->dev, "cannot map msi intr\n");
> + return -ENODEV;
> + }
> +
> + msi = devm_kzalloc(&pdev->dev, sizeof(struct brcm_msi), GFP_KERNEL);
> + if (!msi)
> + return -ENOMEM;
> +
> + msi->dev = &pdev->dev;
> + msi->base = info->base;
> + msi->rev = info->rev;
> + msi->dn = pdev->dev.of_node;
> + msi->target_addr = info->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);
> +
> + if (msi->rev >= BRCM_PCIE_HW_REV_33) {
> + msi->intr_base = msi->base + PCIE_MSI_INTR2_BASE;
> + /* This version of PCIe hw has only 32 intr bits
> + * starting at bit position 0.
> + */
> + msi->intr_legacy_mask = 0xffffffff;
> + msi->intr_legacy_offset = 0x0;
> + msi->used = 0x0;
> +
> + } else {
> + msi->intr_base = msi->base + PCIE_INTR2_CPU_BASE;
> + /* This version of PCIe hw has only 8 intr bits starting
> + * at bit position 24.
> + */
> + msi->intr_legacy_mask = 0xff000000;
> + msi->intr_legacy_offset = 24;
> + msi->used = 0x00ffffff;
> + }
> +
> + brcm_msi_set_regs(msi);
> + info->msi = msi;
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(brcm_msi_probe);
> diff --git a/drivers/pci/host/pci-brcmstb.c b/drivers/pci/host/pci-brcmstb.c
> index f5d80e6..99900d9 100644
> --- a/drivers/pci/host/pci-brcmstb.c
> +++ b/drivers/pci/host/pci-brcmstb.c
> @@ -22,6 +22,7 @@
> #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>
> @@ -327,10 +328,13 @@ struct brcm_pcie {
> int num_out_wins;
> bool ssc;
> int gen;
> + u64 msi_target_addr;
> struct brcm_window out_wins[BRCM_NUM_PCI_OUT_WINS];
> struct list_head resources;
> struct device *dev;
> struct list_head pwr_supplies;
> + struct brcm_msi *msi;
> + bool msi_internal;
> unsigned int rev;
> unsigned int num;
> bool bridge_setup_done;
> @@ -763,6 +767,7 @@ static void brcm_pcie_setup_prep(struct brcm_pcie *pcie)
> void __iomem *base = pcie->base;
> unsigned int scb_size_val;
> u64 rc_bar2_size = 0, rc_bar2_offset = 0, total_mem_size = 0;
> + u64 msi_target_addr;
> u32 tmp, burst;
> int i;
>
> @@ -806,14 +811,17 @@ static void brcm_pcie_setup_prep(struct brcm_pcie *pcie)
> /* The PCI host controller by design must set the inbound
> * viewport to be a contiguous arrangement of all of the
> * system's memory. In addition, its size mut be a power of
> - * two. To further complicate matters, the viewport must
> - * start on a pci-address that is aligned on a multiple of its
> - * size. If a portion of the viewport does not represent
> - * system memory -- e.g. 3GB of memory requires a 4GB viewport
> - * -- we can map the outbound memory in or after 3GB and even
> - * though the viewport will overlap the outbound memory the
> - * controller will know to send outbound memory downstream and
> - * everything else upstream.
> + * two. Further, the MSI target address must NOT be placed
> + * inside this region, as the decoding logic will consider its
> + * address to be inbound memory traffic. To further
> + * complicate matters, the viewport must start on a
> + * pci-address that is aligned on a multiple of its size.
> + * If a portion of the viewport does not represent system
> + * memory -- e.g. 3GB of memory requires a 4GB viewport --
> + * we can map the outbound memory in or after 3GB and even
> + * though the viewport will overlap the outbound memory
> + * the controller will know to send outbound memory downstream
> + * and everything else upstream.
> */
> rc_bar2_size = roundup_pow_of_two_64(total_mem_size);
>
> @@ -828,6 +836,14 @@ static void brcm_pcie_setup_prep(struct brcm_pcie *pcie)
> if (total_mem_size <= 0xc0000000ULL &&
> rc_bar2_size <= 0x100000000ULL) {
> rc_bar2_offset = 0;
> + /* If the viewport is less then 4GB we can fit
> + * the MSI target address under 4GB. Otherwise
> + * put it right below 64GB.
> + */
> + msi_target_addr =
> + (rc_bar2_size == 0x100000000ULL)
> + ? BRCM_MSI_TARGET_ADDR_GT_4GB
> + : BRCM_MSI_TARGET_ADDR_LT_4GB;
> } else {
> /* The system memory is 4GB or larger so we
> * cannot start the inbound region at location
> @@ -836,15 +852,24 @@ static void brcm_pcie_setup_prep(struct brcm_pcie *pcie)
> * start it at the 1x multiple of its size
> */
> rc_bar2_offset = rc_bar2_size;
> - }
>
> + /* Since we are starting the viewport at 4GB or
> + * higher, put the MSI target address below 4GB
> + */
> + msi_target_addr = BRCM_MSI_TARGET_ADDR_LT_4GB;
> + }
> } else {
> /* Set simple configuration based on memory sizes
> * only. We always start the viewport at address 0,
> * and set the MSI target address accordingly.
> */
> rc_bar2_offset = 0;
> +
> + msi_target_addr = (rc_bar2_size >= 0x100000000ULL)
> + ? BRCM_MSI_TARGET_ADDR_GT_4GB
> + : BRCM_MSI_TARGET_ADDR_LT_4GB;
> }
> + pcie->msi_target_addr = msi_target_addr;
>
> tmp = lower_32_bits(rc_bar2_offset);
> tmp = INSERT_FIELD(tmp, PCIE_MISC_RC_BAR2_CONFIG_LO, SIZE,
> @@ -1053,6 +1078,9 @@ static int brcm_pcie_resume(struct device *dev)
> if (ret)
> return ret;
>
> + if (pcie->msi && pcie->msi_internal)
> + brcm_msi_set_regs(pcie->msi);
> +
> pcie->suspended = false;
>
> return 0;
> @@ -1116,6 +1144,7 @@ static void
> __attribute__((__section__("pci_fixup_early")))
>
> static void _brcm_pcie_remove(struct brcm_pcie *pcie)
> {
> + brcm_msi_remove(pcie->msi);
> turn_off(pcie);
> clk_disable_unprepare(pcie->clk);
> clk_put(pcie->clk);
> @@ -1125,7 +1154,7 @@ static void _brcm_pcie_remove(struct brcm_pcie *pcie)
>
> static int brcm_pcie_probe(struct platform_device *pdev)
> {
> - struct device_node *dn = pdev->dev.of_node;
> + struct device_node *dn = pdev->dev.of_node, *msi_dn;
> struct property *pp;
> const struct of_device_id *of_id;
> const struct pcie_cfg_data *data;
> @@ -1244,6 +1273,29 @@ static int brcm_pcie_probe(struct platform_device
> *pdev)
> if (ret)
> goto fail;
>
> + msi_dn = of_parse_phandle(pcie->dn, "msi-parent", 0);
> + /* Use the internal MSI if no msi-parent property */
> + if (!msi_dn)
> + msi_dn = pcie->dn;
> +
> + if (IS_ENABLED(CONFIG_PCI_MSI) && pci_msi_enabled()
> + && msi_dn == pcie->dn) {
> + struct brcm_info info;
> +
> + info.rev = pcie->rev;
> + info.msi_target_addr = pcie->msi_target_addr;
> + info.base = pcie->base;
> +
> + ret = brcm_msi_probe(pdev, &info);
> + if (ret)
> + dev_err(pcie->dev,
> + "probe of internal MSI failed: %d)", ret);
> + else
> + pcie->msi_internal = true;
> +
> + pcie->msi = info.msi;
> + }
> +
> list_splice_init(&pcie->resources, &bridge->windows);
> bridge->dev.parent = &pdev->dev;
> bridge->busnr = 0;
> diff --git a/drivers/pci/host/pci-brcmstb.h b/drivers/pci/host/pci-brcmstb.h
> index c3b148a..f969c2a 100644
> --- a/drivers/pci/host/pci-brcmstb.h
> +++ b/drivers/pci/host/pci-brcmstb.h
> @@ -27,6 +27,32 @@
> extern struct of_pci_range *dma_ranges;
> extern int num_dma_ranges;
>
> +struct brcm_msi;
> +struct brcm_info;
> +struct platform_device;
> +
> +#ifdef CONFIG_PCI_BRCMSTB_MSI
> +int brcm_msi_probe(struct platform_device *pdev, struct brcm_info *info);
> +void brcm_msi_set_regs(struct brcm_msi *chip);
> +void brcm_msi_remove(struct brcm_msi *chip);
> +#else
> +static inline int brcm_msi_probe(struct platform_device *pdev,
> + struct brcm_info *info)
> +{
> + return -ENODEV;
> +}
> +
> +static inline void brcm_msi_set_regs(struct brcm_msi *chip) {}
> +static inline void brcm_msi_remove(struct brcm_msi *chip) {}
> +#endif /* CONFIG_PCI_BRCMSTB_MSI */
> +
> +struct brcm_info {
> + int rev;
> + u64 msi_target_addr;
> + void __iomem *base;
> + struct brcm_msi *msi;
> +};
> +
> #if defined(CONFIG_MIPS)
> /* Broadcom MIPs HW implicitly does the swapping if necessary */
> #define bcm_readl(a) __raw_readl(a)
> --
> 1.9.0.138.g2de3478
>
