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irqchip/gic-v3: Add PCI/MSI support to the GICv3 MBI sub-driver 

You would hope that if you have a GICv3 in your system, you'd use the ITS,
as it provides a large interrupt ID space and device isolation. Sadly,
some SoC integrations are less than perfect, and the ITS is not usesable on
those.

The only solution for these systems is to use the MBI interface, and
rely on a very small number of possible vectors.

This patch thus adds minimal support for PCI/MSI on top of the GICv3
MBI driver. Please don't use it if you can avoid it.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lkml.kernel.org/r/20180508121438.11301-9-marc.zyngier@arm.com
This commit is contained in:
Marc Zyngier 2018-05-08 13:14:37 +01:00 committed by Thomas Gleixner
parent 505287525c
commit 3898535149
1 changed files with 59 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
drivers/irqchip/irq-gic-v3-mbi.c
View File

@ -12,6 +12,7 @@
#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>
@ -144,6 +145,55 @@ static void mbi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
iommu_dma_map_msi_msg(data->irq, msg);
}
#ifdef CONFIG_PCI_MSI
/* PCI-specific irqchip */
static void mbi_mask_msi_irq(struct irq_data *d)
{
pci_msi_mask_irq(d);
irq_chip_mask_parent(d);
}
static void mbi_unmask_msi_irq(struct irq_data *d)
{
pci_msi_unmask_irq(d);
irq_chip_unmask_parent(d);
}
static struct irq_chip mbi_msi_irq_chip = {
.name = "MSI",
.irq_mask = mbi_mask_msi_irq,
.irq_unmask = mbi_unmask_msi_irq,
.irq_eoi = irq_chip_eoi_parent,
.irq_compose_msi_msg = mbi_compose_msi_msg,
.irq_write_msi_msg = pci_msi_domain_write_msg,
};
static struct msi_domain_info mbi_msi_domain_info = {
.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
MSI_FLAG_PCI_MSIX | MSI_FLAG_MULTI_PCI_MSI),
.chip = &mbi_msi_irq_chip,
};
static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
struct irq_domain **pci_domain)
{
*pci_domain = pci_msi_create_irq_domain(nexus_domain->parent->fwnode,
&mbi_msi_domain_info,
nexus_domain);
if (!*pci_domain)
return -ENOMEM;
return 0;
}
#else
static int mbi_allocate_pci_domain(struct irq_domain *nexus_domain,
struct irq_domain **pci_domain)
{
*pci_domain = NULL;
return 0;
}
#endif
static void mbi_compose_mbi_msg(struct irq_data *data, struct msi_msg *msg)
{
mbi_compose_msi_msg(data, msg);
@ -175,7 +225,8 @@ static struct msi_domain_info mbi_pmsi_domain_info = {
static int mbi_allocate_domains(struct irq_domain *parent)
{
struct irq_domain *nexus_domain, *plat_domain;
struct irq_domain *nexus_domain, *pci_domain, *plat_domain;
int err;
nexus_domain = irq_domain_create_tree(parent->fwnode,
&mbi_domain_ops, NULL);
@ -185,12 +236,17 @@ static int mbi_allocate_domains(struct irq_domain *parent)
irq_domain_update_bus_token(nexus_domain, DOMAIN_BUS_NEXUS);
nexus_domain->parent = parent;
err = mbi_allocate_pci_domain(nexus_domain, &pci_domain);
plat_domain = platform_msi_create_irq_domain(parent->fwnode,
&mbi_pmsi_domain_info,
nexus_domain);
if (!plat_domain) {
irq_domain_remove(plat_domain);
if (err || !plat_domain) {
if (plat_domain)
irq_domain_remove(plat_domain);
if (pci_domain)
irq_domain_remove(pci_domain);
irq_domain_remove(nexus_domain);
return -ENOMEM;
}