linux/drivers/irqchip/irq-gic-v2m.c
Ray Jui 74c967aaff irqchip/gic-v2m: Add workaround for Broadcom NS2 GICv2m erratum
Alex Barba <alex.barba@broadcom.com> discovered Broadcom NS2 GICv2m
implementation has an erratum where the MSI data needs to be the SPI
number subtracted by an offset of 32, for the correct MSI interrupt
to be triggered.

Here we are adding the workaround based on readings from the MSI_IIDR
register, which contains a value unique to Broadcom NS2 GICv2m

Reported-by: Alex Barba <alex.barba@broadcom.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-05-11 10:12:40 +01:00

525 lines
13 KiB
C

/*
* ARM GIC v2m MSI(-X) support
* Support for Message Signaled Interrupts for systems that
* implement ARM Generic Interrupt Controller: GICv2m.
*
* Copyright (C) 2014 Advanced Micro Devices, Inc.
* Authors: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
* Harish Kasiviswanathan <harish.kasiviswanathan@amd.com>
* Brandon Anderson <brandon.anderson@amd.com>
*
* 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.
*/
#define pr_fmt(fmt) "GICv2m: " fmt
#include <linux/acpi.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/kernel.h>
#include <linux/msi.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
/*
* MSI_TYPER:
* [31:26] Reserved
* [25:16] lowest SPI assigned to MSI
* [15:10] Reserved
* [9:0] Numer of SPIs assigned to MSI
*/
#define V2M_MSI_TYPER 0x008
#define V2M_MSI_TYPER_BASE_SHIFT 16
#define V2M_MSI_TYPER_BASE_MASK 0x3FF
#define V2M_MSI_TYPER_NUM_MASK 0x3FF
#define V2M_MSI_SETSPI_NS 0x040
#define V2M_MIN_SPI 32
#define V2M_MAX_SPI 1019
#define V2M_MSI_IIDR 0xFCC
#define V2M_MSI_TYPER_BASE_SPI(x) \
(((x) >> V2M_MSI_TYPER_BASE_SHIFT) & V2M_MSI_TYPER_BASE_MASK)
#define V2M_MSI_TYPER_NUM_SPI(x) ((x) & V2M_MSI_TYPER_NUM_MASK)
/* APM X-Gene with GICv2m MSI_IIDR register value */
#define XGENE_GICV2M_MSI_IIDR 0x06000170
/* Broadcom NS2 GICv2m MSI_IIDR register value */
#define BCM_NS2_GICV2M_MSI_IIDR 0x0000013f
/* List of flags for specific v2m implementation */
#define GICV2M_NEEDS_SPI_OFFSET 0x00000001
static LIST_HEAD(v2m_nodes);
static DEFINE_SPINLOCK(v2m_lock);
struct v2m_data {
struct list_head entry;
struct fwnode_handle *fwnode;
struct resource res; /* GICv2m resource */
void __iomem *base; /* GICv2m virt address */
u32 spi_start; /* The SPI number that MSIs start */
u32 nr_spis; /* The number of SPIs for MSIs */
u32 spi_offset; /* offset to be subtracted from SPI number */
unsigned long *bm; /* MSI vector bitmap */
u32 flags; /* v2m flags for specific implementation */
};
static void gicv2m_mask_msi_irq(struct irq_data *d)
{
pci_msi_mask_irq(d);
irq_chip_mask_parent(d);
}
static void gicv2m_unmask_msi_irq(struct irq_data *d)
{
pci_msi_unmask_irq(d);
irq_chip_unmask_parent(d);
}
static struct irq_chip gicv2m_msi_irq_chip = {
.name = "MSI",
.irq_mask = gicv2m_mask_msi_irq,
.irq_unmask = gicv2m_unmask_msi_irq,
.irq_eoi = irq_chip_eoi_parent,
.irq_write_msi_msg = pci_msi_domain_write_msg,
};
static struct msi_domain_info gicv2m_msi_domain_info = {
.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
MSI_FLAG_PCI_MSIX),
.chip = &gicv2m_msi_irq_chip,
};
static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
{
struct v2m_data *v2m = irq_data_get_irq_chip_data(data);
phys_addr_t addr = v2m->res.start + V2M_MSI_SETSPI_NS;
msg->address_hi = upper_32_bits(addr);
msg->address_lo = lower_32_bits(addr);
msg->data = data->hwirq;
if (v2m->flags & GICV2M_NEEDS_SPI_OFFSET)
msg->data -= v2m->spi_offset;
}
static struct irq_chip gicv2m_irq_chip = {
.name = "GICv2m",
.irq_mask = irq_chip_mask_parent,
.irq_unmask = irq_chip_unmask_parent,
.irq_eoi = irq_chip_eoi_parent,
.irq_set_affinity = irq_chip_set_affinity_parent,
.irq_compose_msi_msg = gicv2m_compose_msi_msg,
};
static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain,
unsigned int virq,
irq_hw_number_t hwirq)
{
struct irq_fwspec fwspec;
struct irq_data *d;
int err;
if (is_of_node(domain->parent->fwnode)) {
fwspec.fwnode = domain->parent->fwnode;
fwspec.param_count = 3;
fwspec.param[0] = 0;
fwspec.param[1] = hwirq - 32;
fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
} else if (is_fwnode_irqchip(domain->parent->fwnode)) {
fwspec.fwnode = domain->parent->fwnode;
fwspec.param_count = 2;
fwspec.param[0] = hwirq;
fwspec.param[1] = IRQ_TYPE_EDGE_RISING;
} else {
return -EINVAL;
}
err = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
if (err)
return err;
/* Configure the interrupt line to be edge */
d = irq_domain_get_irq_data(domain->parent, virq);
d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
return 0;
}
static void gicv2m_unalloc_msi(struct v2m_data *v2m, unsigned int hwirq)
{
int pos;
pos = hwirq - v2m->spi_start;
if (pos < 0 || pos >= v2m->nr_spis) {
pr_err("Failed to teardown msi. Invalid hwirq %d\n", hwirq);
return;
}
spin_lock(&v2m_lock);
__clear_bit(pos, v2m->bm);
spin_unlock(&v2m_lock);
}
static int gicv2m_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
unsigned int nr_irqs, void *args)
{
struct v2m_data *v2m = NULL, *tmp;
int hwirq, offset, err = 0;
spin_lock(&v2m_lock);
list_for_each_entry(tmp, &v2m_nodes, entry) {
offset = find_first_zero_bit(tmp->bm, tmp->nr_spis);
if (offset < tmp->nr_spis) {
__set_bit(offset, tmp->bm);
v2m = tmp;
break;
}
}
spin_unlock(&v2m_lock);
if (!v2m)
return -ENOSPC;
hwirq = v2m->spi_start + offset;
err = gicv2m_irq_gic_domain_alloc(domain, virq, hwirq);
if (err) {
gicv2m_unalloc_msi(v2m, hwirq);
return err;
}
irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
&gicv2m_irq_chip, v2m);
return 0;
}
static void gicv2m_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 v2m_data *v2m = irq_data_get_irq_chip_data(d);
BUG_ON(nr_irqs != 1);
gicv2m_unalloc_msi(v2m, d->hwirq);
irq_domain_free_irqs_parent(domain, virq, nr_irqs);
}
static const struct irq_domain_ops gicv2m_domain_ops = {
.alloc = gicv2m_irq_domain_alloc,
.free = gicv2m_irq_domain_free,
};
static bool is_msi_spi_valid(u32 base, u32 num)
{
if (base < V2M_MIN_SPI) {
pr_err("Invalid MSI base SPI (base:%u)\n", base);
return false;
}
if ((num == 0) || (base + num > V2M_MAX_SPI)) {
pr_err("Number of SPIs (%u) exceed maximum (%u)\n",
num, V2M_MAX_SPI - V2M_MIN_SPI + 1);
return false;
}
return true;
}
static struct irq_chip gicv2m_pmsi_irq_chip = {
.name = "pMSI",
};
static struct msi_domain_ops gicv2m_pmsi_ops = {
};
static struct msi_domain_info gicv2m_pmsi_domain_info = {
.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
.ops = &gicv2m_pmsi_ops,
.chip = &gicv2m_pmsi_irq_chip,
};
static void gicv2m_teardown(void)
{
struct v2m_data *v2m, *tmp;
list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) {
list_del(&v2m->entry);
kfree(v2m->bm);
iounmap(v2m->base);
of_node_put(to_of_node(v2m->fwnode));
if (is_fwnode_irqchip(v2m->fwnode))
irq_domain_free_fwnode(v2m->fwnode);
kfree(v2m);
}
}
static int gicv2m_allocate_domains(struct irq_domain *parent)
{
struct irq_domain *inner_domain, *pci_domain, *plat_domain;
struct v2m_data *v2m;
v2m = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
if (!v2m)
return 0;
inner_domain = irq_domain_create_tree(v2m->fwnode,
&gicv2m_domain_ops, v2m);
if (!inner_domain) {
pr_err("Failed to create GICv2m domain\n");
return -ENOMEM;
}
inner_domain->bus_token = DOMAIN_BUS_NEXUS;
inner_domain->parent = parent;
pci_domain = pci_msi_create_irq_domain(v2m->fwnode,
&gicv2m_msi_domain_info,
inner_domain);
plat_domain = platform_msi_create_irq_domain(v2m->fwnode,
&gicv2m_pmsi_domain_info,
inner_domain);
if (!pci_domain || !plat_domain) {
pr_err("Failed to create MSI domains\n");
if (plat_domain)
irq_domain_remove(plat_domain);
if (pci_domain)
irq_domain_remove(pci_domain);
irq_domain_remove(inner_domain);
return -ENOMEM;
}
return 0;
}
static int __init gicv2m_init_one(struct fwnode_handle *fwnode,
u32 spi_start, u32 nr_spis,
struct resource *res)
{
int ret;
struct v2m_data *v2m;
v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL);
if (!v2m) {
pr_err("Failed to allocate struct v2m_data.\n");
return -ENOMEM;
}
INIT_LIST_HEAD(&v2m->entry);
v2m->fwnode = fwnode;
memcpy(&v2m->res, res, sizeof(struct resource));
v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res));
if (!v2m->base) {
pr_err("Failed to map GICv2m resource\n");
ret = -ENOMEM;
goto err_free_v2m;
}
if (spi_start && nr_spis) {
v2m->spi_start = spi_start;
v2m->nr_spis = nr_spis;
} else {
u32 typer = readl_relaxed(v2m->base + V2M_MSI_TYPER);
v2m->spi_start = V2M_MSI_TYPER_BASE_SPI(typer);
v2m->nr_spis = V2M_MSI_TYPER_NUM_SPI(typer);
}
if (!is_msi_spi_valid(v2m->spi_start, v2m->nr_spis)) {
ret = -EINVAL;
goto err_iounmap;
}
/*
* APM X-Gene GICv2m implementation has an erratum where
* the MSI data needs to be the offset from the spi_start
* in order to trigger the correct MSI interrupt. This is
* different from the standard GICv2m implementation where
* the MSI data is the absolute value within the range from
* spi_start to (spi_start + num_spis).
*
* Broadom NS2 GICv2m implementation has an erratum where the MSI data
* is 'spi_number - 32'
*/
switch (readl_relaxed(v2m->base + V2M_MSI_IIDR)) {
case XGENE_GICV2M_MSI_IIDR:
v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
v2m->spi_offset = v2m->spi_start;
break;
case BCM_NS2_GICV2M_MSI_IIDR:
v2m->flags |= GICV2M_NEEDS_SPI_OFFSET;
v2m->spi_offset = 32;
break;
}
v2m->bm = kzalloc(sizeof(long) * BITS_TO_LONGS(v2m->nr_spis),
GFP_KERNEL);
if (!v2m->bm) {
ret = -ENOMEM;
goto err_iounmap;
}
list_add_tail(&v2m->entry, &v2m_nodes);
pr_info("range%pR, SPI[%d:%d]\n", res,
v2m->spi_start, (v2m->spi_start + v2m->nr_spis - 1));
return 0;
err_iounmap:
iounmap(v2m->base);
err_free_v2m:
kfree(v2m);
return ret;
}
static struct of_device_id gicv2m_device_id[] = {
{ .compatible = "arm,gic-v2m-frame", },
{},
};
static int __init gicv2m_of_init(struct fwnode_handle *parent_handle,
struct irq_domain *parent)
{
int ret = 0;
struct device_node *node = to_of_node(parent_handle);
struct device_node *child;
for (child = of_find_matching_node(node, gicv2m_device_id); child;
child = of_find_matching_node(child, gicv2m_device_id)) {
u32 spi_start = 0, nr_spis = 0;
struct resource res;
if (!of_find_property(child, "msi-controller", NULL))
continue;
ret = of_address_to_resource(child, 0, &res);
if (ret) {
pr_err("Failed to allocate v2m resource.\n");
break;
}
if (!of_property_read_u32(child, "arm,msi-base-spi",
&spi_start) &&
!of_property_read_u32(child, "arm,msi-num-spis", &nr_spis))
pr_info("DT overriding V2M MSI_TYPER (base:%u, num:%u)\n",
spi_start, nr_spis);
ret = gicv2m_init_one(&child->fwnode, spi_start, nr_spis, &res);
if (ret) {
of_node_put(child);
break;
}
}
if (!ret)
ret = gicv2m_allocate_domains(parent);
if (ret)
gicv2m_teardown();
return ret;
}
#ifdef CONFIG_ACPI
static int acpi_num_msi;
static struct fwnode_handle *gicv2m_get_fwnode(struct device *dev)
{
struct v2m_data *data;
if (WARN_ON(acpi_num_msi <= 0))
return NULL;
/* We only return the fwnode of the first MSI frame. */
data = list_first_entry_or_null(&v2m_nodes, struct v2m_data, entry);
if (!data)
return NULL;
return data->fwnode;
}
static int __init
acpi_parse_madt_msi(struct acpi_subtable_header *header,
const unsigned long end)
{
int ret;
struct resource res;
u32 spi_start = 0, nr_spis = 0;
struct acpi_madt_generic_msi_frame *m;
struct fwnode_handle *fwnode;
m = (struct acpi_madt_generic_msi_frame *)header;
if (BAD_MADT_ENTRY(m, end))
return -EINVAL;
res.start = m->base_address;
res.end = m->base_address + SZ_4K - 1;
res.flags = IORESOURCE_MEM;
if (m->flags & ACPI_MADT_OVERRIDE_SPI_VALUES) {
spi_start = m->spi_base;
nr_spis = m->spi_count;
pr_info("ACPI overriding V2M MSI_TYPER (base:%u, num:%u)\n",
spi_start, nr_spis);
}
fwnode = irq_domain_alloc_fwnode((void *)m->base_address);
if (!fwnode) {
pr_err("Unable to allocate GICv2m domain token\n");
return -EINVAL;
}
ret = gicv2m_init_one(fwnode, spi_start, nr_spis, &res);
if (ret)
irq_domain_free_fwnode(fwnode);
return ret;
}
static int __init gicv2m_acpi_init(struct irq_domain *parent)
{
int ret;
if (acpi_num_msi > 0)
return 0;
acpi_num_msi = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_MSI_FRAME,
acpi_parse_madt_msi, 0);
if (acpi_num_msi <= 0)
goto err_out;
ret = gicv2m_allocate_domains(parent);
if (ret)
goto err_out;
pci_msi_register_fwnode_provider(&gicv2m_get_fwnode);
return 0;
err_out:
gicv2m_teardown();
return -EINVAL;
}
#else /* CONFIG_ACPI */
static int __init gicv2m_acpi_init(struct irq_domain *parent)
{
return -EINVAL;
}
#endif /* CONFIG_ACPI */
int __init gicv2m_init(struct fwnode_handle *parent_handle,
struct irq_domain *parent)
{
if (is_of_node(parent_handle))
return gicv2m_of_init(parent_handle, parent);
return gicv2m_acpi_init(parent);
}