tmakin/tegra-linux-noble
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

iommu: Always register bus notifiers

Browse Source 
The number of bus types that the IOMMU subsystem deals with is small and
manageable, so pull that list into core code as a first step towards
cleaning up all the boilerplate bus-awareness from drivers. Calling
iommu_probe_device() before bus->iommu_ops is set will simply return
-ENODEV and not break the notifier call chain, so there should be no
harm in proactively registering all our bus notifiers at init time.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Niklas Schnelle <schnelle@linux.ibm.com> # s390
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/7462347bf938bd6eedb629a3a318434f6516e712.1660572783.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Robin Murphy
2022-08-15 17:20:05 +01:00
committed by Joerg Roedel
parent 927a5fdd94
commit c13dbc1e24
1 changed files with 37 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/iommu/iommu.c
+37 -35
View File
@@ -6,6 +6,7 @@
#define pr_fmt(fmt) "iommu: " fmt
#include <linux/amba/bus.h>
#include <linux/device.h>
#include <linux/dma-iommu.h>
#include <linux/kernel.h>
@@ -16,11 +17,13 @@
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/errno.h>
#include <linux/host1x_context_bus.h>
#include <linux/iommu.h>
#include <linux/idr.h>
#include <linux/err.h>
#include <linux/pci.h>
#include <linux/bitops.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/fsl/mc.h>
#include <linux/module.h>
@@ -75,6 +78,8 @@ static const char * const iommu_group_resv_type_string[] = {
#define IOMMU_CMD_LINE_DMA_API BIT(0)
#define IOMMU_CMD_LINE_STRICT BIT(1)
static int iommu_bus_notifier(struct notifier_block *nb,
unsigned long action, void *data);
static int iommu_alloc_default_domain(struct iommu_group *group,
struct device *dev);
static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,
@@ -103,6 +108,22 @@ struct iommu_group_attribute iommu_group_attr_##_name = \
static LIST_HEAD(iommu_device_list);
static DEFINE_SPINLOCK(iommu_device_lock);
static struct bus_type * const iommu_buses[] = {
&platform_bus_type,
#ifdef CONFIG_PCI
&pci_bus_type,
#endif
#ifdef CONFIG_ARM_AMBA
&amba_bustype,
#endif
#ifdef CONFIG_FSL_MC_BUS
&fsl_mc_bus_type,
#endif
#ifdef CONFIG_TEGRA_HOST1X_CONTEXT_BUS
&host1x_context_device_bus_type,
#endif
};
/*
* Use a function instead of an array here because the domain-type is a
* bit-field, so an array would waste memory.
@@ -126,6 +147,8 @@ static const char *iommu_domain_type_str(unsigned int t)
static int __init iommu_subsys_init(void)
{
struct notifier_block *nb;
if (!(iommu_cmd_line & IOMMU_CMD_LINE_DMA_API)) {
if (IS_ENABLED(CONFIG_IOMMU_DEFAULT_PASSTHROUGH))
iommu_set_default_passthrough(false);
@@ -152,6 +175,15 @@ static int __init iommu_subsys_init(void)
(iommu_cmd_line & IOMMU_CMD_LINE_STRICT) ?
"(set via kernel command line)" : "");
nb = kcalloc(ARRAY_SIZE(iommu_buses), sizeof(*nb), GFP_KERNEL);
if (!nb)
return -ENOMEM;
for (int i = 0; i < ARRAY_SIZE(iommu_buses); i++) {
nb[i].notifier_call = iommu_bus_notifier;
bus_register_notifier(iommu_buses[i], &nb[i]);
}
return 0;
}
subsys_initcall(iommu_subsys_init);
@@ -1774,39 +1806,6 @@ int bus_iommu_probe(struct bus_type *bus)
return ret;
}
static int iommu_bus_init(struct bus_type *bus, const struct iommu_ops *ops)
{
struct notifier_block *nb;
int err;
nb = kzalloc(sizeof(struct notifier_block), GFP_KERNEL);
if (!nb)
return -ENOMEM;
nb->notifier_call = iommu_bus_notifier;
err = bus_register_notifier(bus, nb);
if (err)
goto out_free;
err = bus_iommu_probe(bus);
if (err)
goto out_err;
return 0;
out_err:
/* Clean up */
bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
bus_unregister_notifier(bus, nb);
out_free:
kfree(nb);
return err;
}
/**
* bus_set_iommu - set iommu-callbacks for the bus
* @bus: bus.
@@ -1835,9 +1834,12 @@ int bus_set_iommu(struct bus_type *bus, const struct iommu_ops *ops)
bus->iommu_ops = ops;
/* Do IOMMU specific setup for this bus-type */
err = iommu_bus_init(bus, ops);
if (err)
err = bus_iommu_probe(bus);
if (err) {
/* Clean up */
bus_for_each_dev(bus, NULL, NULL, remove_iommu_group);
bus->iommu_ops = NULL;
}
return err;
}