swh:1:snp:173f8deb0c56c557784b4fd217e7608ac6197844
Tip revision: f4d51dffc6c01a9e94650d95ce0104964f8ae822 authored by Linus Torvalds on 07 September 2020, 00:11:40 UTC
Linux 5.9-rc4
Linux 5.9-rc4
Tip revision: f4d51df
pcie-tango.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/irqchip/chained_irq.h>
#include <linux/irqdomain.h>
#include <linux/pci-ecam.h>
#include <linux/delay.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#define MSI_MAX 256
#define SMP8759_MUX 0x48
#define SMP8759_TEST_OUT 0x74
#define SMP8759_DOORBELL 0x7c
#define SMP8759_STATUS 0x80
#define SMP8759_ENABLE 0xa0
struct tango_pcie {
DECLARE_BITMAP(used_msi, MSI_MAX);
u64 msi_doorbell;
spinlock_t used_msi_lock;
void __iomem *base;
struct irq_domain *dom;
};
static void tango_msi_isr(struct irq_desc *desc)
{
struct irq_chip *chip = irq_desc_get_chip(desc);
struct tango_pcie *pcie = irq_desc_get_handler_data(desc);
unsigned long status, base, virq, idx, pos = 0;
chained_irq_enter(chip, desc);
spin_lock(&pcie->used_msi_lock);
while ((pos = find_next_bit(pcie->used_msi, MSI_MAX, pos)) < MSI_MAX) {
base = round_down(pos, 32);
status = readl_relaxed(pcie->base + SMP8759_STATUS + base / 8);
for_each_set_bit(idx, &status, 32) {
virq = irq_find_mapping(pcie->dom, base + idx);
generic_handle_irq(virq);
}
pos = base + 32;
}
spin_unlock(&pcie->used_msi_lock);
chained_irq_exit(chip, desc);
}
static void tango_ack(struct irq_data *d)
{
struct tango_pcie *pcie = d->chip_data;
u32 offset = (d->hwirq / 32) * 4;
u32 bit = BIT(d->hwirq % 32);
writel_relaxed(bit, pcie->base + SMP8759_STATUS + offset);
}
static void update_msi_enable(struct irq_data *d, bool unmask)
{
unsigned long flags;
struct tango_pcie *pcie = d->chip_data;
u32 offset = (d->hwirq / 32) * 4;
u32 bit = BIT(d->hwirq % 32);
u32 val;
spin_lock_irqsave(&pcie->used_msi_lock, flags);
val = readl_relaxed(pcie->base + SMP8759_ENABLE + offset);
val = unmask ? val | bit : val & ~bit;
writel_relaxed(val, pcie->base + SMP8759_ENABLE + offset);
spin_unlock_irqrestore(&pcie->used_msi_lock, flags);
}
static void tango_mask(struct irq_data *d)
{
update_msi_enable(d, false);
}
static void tango_unmask(struct irq_data *d)
{
update_msi_enable(d, true);
}
static int tango_set_affinity(struct irq_data *d, const struct cpumask *mask,
bool force)
{
return -EINVAL;
}
static void tango_compose_msi_msg(struct irq_data *d, struct msi_msg *msg)
{
struct tango_pcie *pcie = d->chip_data;
msg->address_lo = lower_32_bits(pcie->msi_doorbell);
msg->address_hi = upper_32_bits(pcie->msi_doorbell);
msg->data = d->hwirq;
}
static struct irq_chip tango_chip = {
.irq_ack = tango_ack,
.irq_mask = tango_mask,
.irq_unmask = tango_unmask,
.irq_set_affinity = tango_set_affinity,
.irq_compose_msi_msg = tango_compose_msi_msg,
};
static void msi_ack(struct irq_data *d)
{
irq_chip_ack_parent(d);
}
static void msi_mask(struct irq_data *d)
{
pci_msi_mask_irq(d);
irq_chip_mask_parent(d);
}
static void msi_unmask(struct irq_data *d)
{
pci_msi_unmask_irq(d);
irq_chip_unmask_parent(d);
}
static struct irq_chip msi_chip = {
.name = "MSI",
.irq_ack = msi_ack,
.irq_mask = msi_mask,
.irq_unmask = msi_unmask,
};
static struct msi_domain_info msi_dom_info = {
.flags = MSI_FLAG_PCI_MSIX
| MSI_FLAG_USE_DEF_DOM_OPS
| MSI_FLAG_USE_DEF_CHIP_OPS,
.chip = &msi_chip,
};
static int tango_irq_domain_alloc(struct irq_domain *dom, unsigned int virq,
unsigned int nr_irqs, void *args)
{
struct tango_pcie *pcie = dom->host_data;
unsigned long flags;
int pos;
spin_lock_irqsave(&pcie->used_msi_lock, flags);
pos = find_first_zero_bit(pcie->used_msi, MSI_MAX);
if (pos >= MSI_MAX) {
spin_unlock_irqrestore(&pcie->used_msi_lock, flags);
return -ENOSPC;
}
__set_bit(pos, pcie->used_msi);
spin_unlock_irqrestore(&pcie->used_msi_lock, flags);
irq_domain_set_info(dom, virq, pos, &tango_chip,
pcie, handle_edge_irq, NULL, NULL);
return 0;
}
static void tango_irq_domain_free(struct irq_domain *dom, unsigned int virq,
unsigned int nr_irqs)
{
unsigned long flags;
struct irq_data *d = irq_domain_get_irq_data(dom, virq);
struct tango_pcie *pcie = d->chip_data;
spin_lock_irqsave(&pcie->used_msi_lock, flags);
__clear_bit(d->hwirq, pcie->used_msi);
spin_unlock_irqrestore(&pcie->used_msi_lock, flags);
}
static const struct irq_domain_ops dom_ops = {
.alloc = tango_irq_domain_alloc,
.free = tango_irq_domain_free,
};
static int smp8759_config_read(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 *val)
{
struct pci_config_window *cfg = bus->sysdata;
struct tango_pcie *pcie = dev_get_drvdata(cfg->parent);
int ret;
/* Reads in configuration space outside devfn 0 return garbage */
if (devfn != 0)
return PCIBIOS_FUNC_NOT_SUPPORTED;
/*
* PCI config and MMIO accesses are muxed. Linux doesn't have a
* mutual exclusion mechanism for config vs. MMIO accesses, so
* concurrent accesses may cause corruption.
*/
writel_relaxed(1, pcie->base + SMP8759_MUX);
ret = pci_generic_config_read(bus, devfn, where, size, val);
writel_relaxed(0, pcie->base + SMP8759_MUX);
return ret;
}
static int smp8759_config_write(struct pci_bus *bus, unsigned int devfn,
int where, int size, u32 val)
{
struct pci_config_window *cfg = bus->sysdata;
struct tango_pcie *pcie = dev_get_drvdata(cfg->parent);
int ret;
writel_relaxed(1, pcie->base + SMP8759_MUX);
ret = pci_generic_config_write(bus, devfn, where, size, val);
writel_relaxed(0, pcie->base + SMP8759_MUX);
return ret;
}
static const struct pci_ecam_ops smp8759_ecam_ops = {
.bus_shift = 20,
.pci_ops = {
.map_bus = pci_ecam_map_bus,
.read = smp8759_config_read,
.write = smp8759_config_write,
}
};
static int tango_pcie_link_up(struct tango_pcie *pcie)
{
void __iomem *test_out = pcie->base + SMP8759_TEST_OUT;
int i;
writel_relaxed(16, test_out);
for (i = 0; i < 10; ++i) {
u32 ltssm_state = readl_relaxed(test_out) >> 8;
if ((ltssm_state & 0x1f) == 0xf) /* L0 */
return 1;
usleep_range(3000, 4000);
}
return 0;
}
static int tango_pcie_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct tango_pcie *pcie;
struct resource *res;
struct fwnode_handle *fwnode = of_node_to_fwnode(dev->of_node);
struct irq_domain *msi_dom, *irq_dom;
struct of_pci_range_parser parser;
struct of_pci_range range;
int virq, offset;
dev_warn(dev, "simultaneous PCI config and MMIO accesses may cause data corruption\n");
add_taint(TAINT_CRAP, LOCKDEP_STILL_OK);
pcie = devm_kzalloc(dev, sizeof(*pcie), GFP_KERNEL);
if (!pcie)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
pcie->base = devm_ioremap_resource(dev, res);
if (IS_ERR(pcie->base))
return PTR_ERR(pcie->base);
platform_set_drvdata(pdev, pcie);
if (!tango_pcie_link_up(pcie))
return -ENODEV;
if (of_pci_dma_range_parser_init(&parser, dev->of_node) < 0)
return -ENOENT;
if (of_pci_range_parser_one(&parser, &range) == NULL)
return -ENOENT;
range.pci_addr += range.size;
pcie->msi_doorbell = range.pci_addr + res->start + SMP8759_DOORBELL;
for (offset = 0; offset < MSI_MAX / 8; offset += 4)
writel_relaxed(0, pcie->base + SMP8759_ENABLE + offset);
virq = platform_get_irq(pdev, 1);
if (virq < 0)
return virq;
irq_dom = irq_domain_create_linear(fwnode, MSI_MAX, &dom_ops, pcie);
if (!irq_dom) {
dev_err(dev, "Failed to create IRQ domain\n");
return -ENOMEM;
}
msi_dom = pci_msi_create_irq_domain(fwnode, &msi_dom_info, irq_dom);
if (!msi_dom) {
dev_err(dev, "Failed to create MSI domain\n");
irq_domain_remove(irq_dom);
return -ENOMEM;
}
pcie->dom = irq_dom;
spin_lock_init(&pcie->used_msi_lock);
irq_set_chained_handler_and_data(virq, tango_msi_isr, pcie);
return pci_host_common_probe(pdev);
}
static const struct of_device_id tango_pcie_ids[] = {
{
.compatible = "sigma,smp8759-pcie",
.data = &smp8759_ecam_ops,
},
{ },
};
static struct platform_driver tango_pcie_driver = {
.probe = tango_pcie_probe,
.driver = {
.name = KBUILD_MODNAME,
.of_match_table = tango_pcie_ids,
.suppress_bind_attrs = true,
},
};
builtin_platform_driver(tango_pcie_driver);
/*
* The root complex advertises the wrong device class.
* Header Type 1 is for PCI-to-PCI bridges.
*/
static void tango_fixup_class(struct pci_dev *dev)
{
dev->class = PCI_CLASS_BRIDGE_PCI << 8;
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0024, tango_fixup_class);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0028, tango_fixup_class);
/*
* The root complex exposes a "fake" BAR, which is used to filter
* bus-to-system accesses. Only accesses within the range defined by this
* BAR are forwarded to the host, others are ignored.
*
* By default, the DMA framework expects an identity mapping, and DRAM0 is
* mapped at 0x80000000.
*/
static void tango_fixup_bar(struct pci_dev *dev)
{
dev->non_compliant_bars = true;
pci_write_config_dword(dev, PCI_BASE_ADDRESS_0, 0x80000000);
}
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0024, tango_fixup_bar);
DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SIGMA, 0x0028, tango_fixup_bar);