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sconfig: Allow to specify device operations

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Currently we only have runtime mechanisms to assign device operations to
a node in our devicetree (with one exception: the root device). The most
common method is to map PCI IDs to the device operations with a `struct
pci_driver`. Another accustomed way is to let a chip driver assign them.

For very common drivers, e.g. those in soc/intel/common/blocks/, the PCI
ID lists grew very large and are incredibly error-prone. Often, IDs are
missing and sometimes IDs are added almost mechanically without checking
the code for compatibility. Maintaining these lists in a central place
also reduces flexibility.

Now, for onboard devices it is actually unnecessary to assign the device
operations at runtime. We already know exactly what operations should be
assigned. And since we are using chipset devicetrees, we have a perfect
place to put that information.

This patch adds a simple mechanism to `sconfig`. It allows us to speci-
fy operations per device, e.g.

  device pci 00.0 alias system_agent on
          ops system_agent_ops
  end

The operations are given as a C identifier. In this example, we simply
assume that a global `struct device_operations system_agent_ops` exists.

Change-Id: I2833d2f2450fde3206c33393f58b86fd4280b566
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/66483
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
This commit is contained in:
Nico Huber
2022-08-06 19:02:59 +02:00
committed by Felix Held
parent f1ba7d6c8f
commit c0fc38eed8
7 changed files with 401 additions and 332 deletions
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47
util/sconfig/main.c
View File

@ -148,6 +148,9 @@ struct queue_entry {
struct queue_entry *prev;
};
/* Global list of all `struct device_operations` identifiers to declare. */
static struct identifier *device_operations;
#define S_ALLOC(_s) s_alloc(__func__, _s)
static void *s_alloc(const char *f, size_t s)
@ -696,6 +699,30 @@ static int emit_fw_config_probe(FILE *fil, struct device *dev)
return 0;
}
/* Enqueue identifier to list with head `*it`, if not already present. */
void add_identifier(struct identifier **it, const char *id)
{
for (; *it != NULL; it = &(*it)->next) {
if (!strcmp((*it)->id, id))
return;
}
*it = S_ALLOC(sizeof(**it));
(*it)->id = id;
}
void add_device_ops(struct bus *bus, char *ops_id)
{
if (bus->dev->ops_id) {
printf("ERROR: Device operations may only be specified once,\n"
" found '%s', '%s'.\n", bus->dev->ops_id, ops_id);
exit(1);
}
add_identifier(&device_operations, ops_id);
bus->dev->ops_id = ops_id;
}
/*
* Allocate a new bus for the provided device.
* - If this is the first bus being allocated under this device, then its id
@ -1262,10 +1289,13 @@ static void pass1(FILE *fil, FILE *head, struct device *ptr, struct device *next
fprintf(fil, "#if !DEVTREE_EARLY\n");
/*
* ops field is set to default_dev_ops_root only for the root
* device. For all other devices, it is set by the driver at runtime.
* ops field can be set in the devicetree. If unspecified, it is set
* to default_dev_ops_root only for the root device, other devices
* get it set by the driver at runtime.
*/
if (ptr == &base_root_dev)
if (ptr->ops_id)
fprintf(fil, "\t.ops = &%s,\n", ptr->ops_id);
else if (ptr == &base_root_dev)
fprintf(fil, "\t.ops = &default_dev_ops_root,\n");
else
fprintf(fil, "\t.ops = NULL,\n");
@ -1477,6 +1507,12 @@ static void emit_chip_configs(FILE *fil)
}
}
static void emit_identifiers(FILE *fil, const char *decl, const struct identifier *it)
{
for (; it != NULL; it = it->next)
fprintf(fil, "extern %s %s;\n", decl, it->id);
}
static void inherit_subsystem_ids(FILE *file, FILE *head, struct device *dev,
struct device *next)
{
@ -1854,6 +1890,10 @@ static void update_device(struct device *base_dev, struct device *override_dev)
*/
override_dev->chip_instance->base_chip_instance = get_chip_instance(base_dev);
/* Allow to override the ops of a device */
if (override_dev->ops_id)
base_dev->ops_id = override_dev->ops_id;
/*
* Now that the device properties are all copied over, look at each bus
* of the override device and run override_devicetree in a recursive
@ -1970,6 +2010,7 @@ static void generate_outputc(FILE *f, const char *static_header)
fprintf(f, "#include <fw_config.h>\n");
fprintf(f, "#include <%s>\n", static_header);
emit_chip_headers(f, chip_header.next);
emit_identifiers(f, "struct device_operations", device_operations);
fprintf(f, "\n#define STORAGE static __maybe_unused DEVTREE_CONST\n\n");
walk_device_tree(NULL, NULL, &base_root_dev, inherit_subsystem_ids);