linux/drivers/pci/of_property.c
Herve Codina dc12273fa3 PCI: of_property: Add interrupt-controller property in PCI device nodes
PCI devices and bridges DT nodes created during the PCI scan are created
with the interrupt-map property set to handle interrupts.

In order to set this interrupt-map property at a specific level, a
phandle to the parent interrupt controller is needed. On systems that
are not fully described by a device-tree, the parent interrupt
controller may be unavailable (i.e. not described by the device-tree).

As mentioned in the [1], avoiding the use of the interrupt-map property
and considering a PCI device as an interrupt controller itself avoid the
use of a parent interrupt phandle.

In that case, the PCI device itself as an interrupt controller is
responsible for routing the interrupts described in the device-tree
world (DT overlay) to the PCI interrupts.

Add the 'interrupt-controller' property in the PCI device DT node.

[1]: https://lore.kernel.org/lkml/CAL_Jsq+je7+9ATR=B6jXHjEJHjn24vQFs4Tvi9=vhDeK9n42Aw@mail.gmail.com/

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lore.kernel.org/r/20240527161450.326615-18-herve.codina@bootlin.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
2024-07-08 17:40:30 -06:00

393 lines
9.3 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
*/
#include <linux/pci.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/bitfield.h>
#include <linux/bits.h>
#include "pci.h"
#define OF_PCI_ADDRESS_CELLS 3
#define OF_PCI_SIZE_CELLS 2
#define OF_PCI_MAX_INT_PIN 4
struct of_pci_addr_pair {
u32 phys_addr[OF_PCI_ADDRESS_CELLS];
u32 size[OF_PCI_SIZE_CELLS];
};
/*
* Each entry in the ranges table is a tuple containing the child address,
* the parent address, and the size of the region in the child address space.
* Thus, for PCI, in each entry parent address is an address on the primary
* side and the child address is the corresponding address on the secondary
* side.
*/
struct of_pci_range {
u32 child_addr[OF_PCI_ADDRESS_CELLS];
u32 parent_addr[OF_PCI_ADDRESS_CELLS];
u32 size[OF_PCI_SIZE_CELLS];
};
#define OF_PCI_ADDR_SPACE_IO 0x1
#define OF_PCI_ADDR_SPACE_MEM32 0x2
#define OF_PCI_ADDR_SPACE_MEM64 0x3
#define OF_PCI_ADDR_FIELD_NONRELOC BIT(31)
#define OF_PCI_ADDR_FIELD_SS GENMASK(25, 24)
#define OF_PCI_ADDR_FIELD_PREFETCH BIT(30)
#define OF_PCI_ADDR_FIELD_BUS GENMASK(23, 16)
#define OF_PCI_ADDR_FIELD_DEV GENMASK(15, 11)
#define OF_PCI_ADDR_FIELD_FUNC GENMASK(10, 8)
#define OF_PCI_ADDR_FIELD_REG GENMASK(7, 0)
enum of_pci_prop_compatible {
PROP_COMPAT_PCI_VVVV_DDDD,
PROP_COMPAT_PCICLASS_CCSSPP,
PROP_COMPAT_PCICLASS_CCSS,
PROP_COMPAT_NUM,
};
static void of_pci_set_address(struct pci_dev *pdev, u32 *prop, u64 addr,
u32 reg_num, u32 flags, bool reloc)
{
prop[0] = FIELD_PREP(OF_PCI_ADDR_FIELD_BUS, pdev->bus->number) |
FIELD_PREP(OF_PCI_ADDR_FIELD_DEV, PCI_SLOT(pdev->devfn)) |
FIELD_PREP(OF_PCI_ADDR_FIELD_FUNC, PCI_FUNC(pdev->devfn));
prop[0] |= flags | reg_num;
if (!reloc) {
prop[0] |= OF_PCI_ADDR_FIELD_NONRELOC;
prop[1] = upper_32_bits(addr);
prop[2] = lower_32_bits(addr);
}
}
static int of_pci_get_addr_flags(struct resource *res, u32 *flags)
{
u32 ss;
if (res->flags & IORESOURCE_IO)
ss = OF_PCI_ADDR_SPACE_IO;
else if (res->flags & IORESOURCE_MEM_64)
ss = OF_PCI_ADDR_SPACE_MEM64;
else if (res->flags & IORESOURCE_MEM)
ss = OF_PCI_ADDR_SPACE_MEM32;
else
return -EINVAL;
*flags = 0;
if (res->flags & IORESOURCE_PREFETCH)
*flags |= OF_PCI_ADDR_FIELD_PREFETCH;
*flags |= FIELD_PREP(OF_PCI_ADDR_FIELD_SS, ss);
return 0;
}
static int of_pci_prop_bus_range(struct pci_dev *pdev,
struct of_changeset *ocs,
struct device_node *np)
{
u32 bus_range[] = { pdev->subordinate->busn_res.start,
pdev->subordinate->busn_res.end };
return of_changeset_add_prop_u32_array(ocs, np, "bus-range", bus_range,
ARRAY_SIZE(bus_range));
}
static int of_pci_prop_ranges(struct pci_dev *pdev, struct of_changeset *ocs,
struct device_node *np)
{
struct of_pci_range *rp;
struct resource *res;
int i, j, ret;
u32 flags, num;
u64 val64;
if (pci_is_bridge(pdev)) {
num = PCI_BRIDGE_RESOURCE_NUM;
res = &pdev->resource[PCI_BRIDGE_RESOURCES];
} else {
num = PCI_STD_NUM_BARS;
res = &pdev->resource[PCI_STD_RESOURCES];
}
rp = kcalloc(num, sizeof(*rp), GFP_KERNEL);
if (!rp)
return -ENOMEM;
for (i = 0, j = 0; j < num; j++) {
if (!resource_size(&res[j]))
continue;
if (of_pci_get_addr_flags(&res[j], &flags))
continue;
val64 = res[j].start;
of_pci_set_address(pdev, rp[i].parent_addr, val64, 0, flags,
false);
if (pci_is_bridge(pdev)) {
memcpy(rp[i].child_addr, rp[i].parent_addr,
sizeof(rp[i].child_addr));
} else {
/*
* For endpoint device, the lower 64-bits of child
* address is always zero.
*/
rp[i].child_addr[0] = j;
}
val64 = resource_size(&res[j]);
rp[i].size[0] = upper_32_bits(val64);
rp[i].size[1] = lower_32_bits(val64);
i++;
}
ret = of_changeset_add_prop_u32_array(ocs, np, "ranges", (u32 *)rp,
i * sizeof(*rp) / sizeof(u32));
kfree(rp);
return ret;
}
static int of_pci_prop_reg(struct pci_dev *pdev, struct of_changeset *ocs,
struct device_node *np)
{
struct of_pci_addr_pair reg = { 0 };
/* configuration space */
of_pci_set_address(pdev, reg.phys_addr, 0, 0, 0, true);
return of_changeset_add_prop_u32_array(ocs, np, "reg", (u32 *)&reg,
sizeof(reg) / sizeof(u32));
}
static int of_pci_prop_interrupts(struct pci_dev *pdev,
struct of_changeset *ocs,
struct device_node *np)
{
int ret;
u8 pin;
ret = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
if (ret != 0)
return ret;
if (!pin)
return 0;
return of_changeset_add_prop_u32(ocs, np, "interrupts", (u32)pin);
}
static int of_pci_prop_intr_ctrl(struct pci_dev *pdev, struct of_changeset *ocs,
struct device_node *np)
{
int ret;
u8 pin;
ret = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
if (ret != 0)
return ret;
if (!pin)
return 0;
ret = of_changeset_add_prop_u32(ocs, np, "#interrupt-cells", 1);
if (ret)
return ret;
return of_changeset_add_prop_bool(ocs, np, "interrupt-controller");
}
static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,
struct device_node *np)
{
u32 i, addr_sz[OF_PCI_MAX_INT_PIN] = { 0 }, map_sz = 0;
struct of_phandle_args out_irq[OF_PCI_MAX_INT_PIN];
__be32 laddr[OF_PCI_ADDRESS_CELLS] = { 0 };
u32 int_map_mask[] = { 0xffff00, 0, 0, 7 };
struct device_node *pnode;
struct pci_dev *child;
u32 *int_map, *mapp;
int ret;
u8 pin;
pnode = pci_device_to_OF_node(pdev->bus->self);
if (!pnode)
pnode = pci_bus_to_OF_node(pdev->bus);
if (!pnode) {
pci_err(pdev, "failed to get parent device node");
return -EINVAL;
}
laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
i = pin - 1;
out_irq[i].np = pnode;
out_irq[i].args_count = 1;
out_irq[i].args[0] = pin;
ret = of_irq_parse_raw(laddr, &out_irq[i]);
if (ret) {
out_irq[i].np = NULL;
pci_dbg(pdev, "parse irq %d failed, ret %d", pin, ret);
continue;
}
of_property_read_u32(out_irq[i].np, "#address-cells",
&addr_sz[i]);
}
list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
i = pci_swizzle_interrupt_pin(child, pin) - 1;
if (!out_irq[i].np)
continue;
map_sz += 5 + addr_sz[i] + out_irq[i].args_count;
}
}
/*
* Parsing interrupt failed for all pins. In this case, it does not
* need to generate interrupt-map property.
*/
if (!map_sz)
return 0;
int_map = kcalloc(map_sz, sizeof(u32), GFP_KERNEL);
if (!int_map)
return -ENOMEM;
mapp = int_map;
list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
i = pci_swizzle_interrupt_pin(child, pin) - 1;
if (!out_irq[i].np)
continue;
*mapp = (child->bus->number << 16) |
(child->devfn << 8);
mapp += OF_PCI_ADDRESS_CELLS;
*mapp = pin;
mapp++;
*mapp = out_irq[i].np->phandle;
mapp++;
if (addr_sz[i]) {
ret = of_property_read_u32_array(out_irq[i].np,
"reg", mapp,
addr_sz[i]);
if (ret)
goto failed;
}
mapp += addr_sz[i];
memcpy(mapp, out_irq[i].args,
out_irq[i].args_count * sizeof(u32));
mapp += out_irq[i].args_count;
}
}
ret = of_changeset_add_prop_u32_array(ocs, np, "interrupt-map", int_map,
map_sz);
if (ret)
goto failed;
ret = of_changeset_add_prop_u32(ocs, np, "#interrupt-cells", 1);
if (ret)
goto failed;
ret = of_changeset_add_prop_u32_array(ocs, np, "interrupt-map-mask",
int_map_mask,
ARRAY_SIZE(int_map_mask));
if (ret)
goto failed;
kfree(int_map);
return 0;
failed:
kfree(int_map);
return ret;
}
static int of_pci_prop_compatible(struct pci_dev *pdev,
struct of_changeset *ocs,
struct device_node *np)
{
const char *compat_strs[PROP_COMPAT_NUM] = { 0 };
int i, ret;
compat_strs[PROP_COMPAT_PCI_VVVV_DDDD] =
kasprintf(GFP_KERNEL, "pci%x,%x", pdev->vendor, pdev->device);
compat_strs[PROP_COMPAT_PCICLASS_CCSSPP] =
kasprintf(GFP_KERNEL, "pciclass,%06x", pdev->class);
compat_strs[PROP_COMPAT_PCICLASS_CCSS] =
kasprintf(GFP_KERNEL, "pciclass,%04x", pdev->class >> 8);
ret = of_changeset_add_prop_string_array(ocs, np, "compatible",
compat_strs, PROP_COMPAT_NUM);
for (i = 0; i < PROP_COMPAT_NUM; i++)
kfree(compat_strs[i]);
return ret;
}
int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
struct device_node *np)
{
int ret;
/*
* The added properties will be released when the
* changeset is destroyed.
*/
if (pci_is_bridge(pdev)) {
ret = of_changeset_add_prop_string(ocs, np, "device_type",
"pci");
if (ret)
return ret;
ret = of_pci_prop_bus_range(pdev, ocs, np);
if (ret)
return ret;
ret = of_pci_prop_intr_map(pdev, ocs, np);
if (ret)
return ret;
} else {
ret = of_pci_prop_intr_ctrl(pdev, ocs, np);
if (ret)
return ret;
}
ret = of_pci_prop_ranges(pdev, ocs, np);
if (ret)
return ret;
ret = of_changeset_add_prop_u32(ocs, np, "#address-cells",
OF_PCI_ADDRESS_CELLS);
if (ret)
return ret;
ret = of_changeset_add_prop_u32(ocs, np, "#size-cells",
OF_PCI_SIZE_CELLS);
if (ret)
return ret;
ret = of_pci_prop_reg(pdev, ocs, np);
if (ret)
return ret;
ret = of_pci_prop_compatible(pdev, ocs, np);
if (ret)
return ret;
ret = of_pci_prop_interrupts(pdev, ocs, np);
if (ret)
return ret;
return 0;
}