From: Bjorn Helgaas <bhelgaas@google.com>
To: Myron Stowe <myron.stowe@redhat.com>
Cc: linux-pci@vger.kernel.org, yinghai@kernel.org,
linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 01/15] PCI, acpiphp: Separate out hot-add support of pci host bridge
Date: Fri, 7 Dec 2012 12:32:46 -0700 [thread overview]
Message-ID: <CAErSpo6MEtx6hsYhY=h0+eXqQcnZuG2vq=z_8Oz8tnksKZd7DA@mail.gmail.com> (raw)
In-Reply-To: <20121207062500.11051.44198.stgit@amt.stowe>
On Thu, Dec 6, 2012 at 11:25 PM, Myron Stowe <myron.stowe@redhat.com> wrote:
> From: Yinghai Lu <yinghai@kernel.org>
>
> It causes confusion.
I completely agree that acpiphp causes confusion :)
> We may only need acpi hp for pci host bridge.
>
> Split host bridge hot-add support to pci_root_hp, and keep acpiphp simple.
>
> -v2: put back pci_root_hp change in one patch
> -v3: add pcibios_resource_survey_bus() calling
> -v4: remove not needed code with remove_bridge
> -v5: put back support for acpiphp support for slots just on root bus.
> -v6: change some functions to *_p2p_* to make it more clean.
> -v7: split hot_added change out.
>
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> Signed-off-by: Myron Stowe <myron.stowe@redhat.com>
> ---
>
> drivers/acpi/Makefile | 1
> drivers/acpi/pci_root_hp.c | 228 ++++++++++++++++++++++++++++++++++++
> drivers/pci/hotplug/acpiphp_glue.c | 59 ++-------
> 3 files changed, 244 insertions(+), 44 deletions(-)
> create mode 100644 drivers/acpi/pci_root_hp.c
>
> diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
> index 82422fe..4edfe41 100644
> --- a/drivers/acpi/Makefile
> +++ b/drivers/acpi/Makefile
> @@ -36,6 +36,7 @@ acpi-y += processor_core.o
> acpi-y += ec.o
> acpi-$(CONFIG_ACPI_DOCK) += dock.o
> acpi-y += pci_root.o pci_link.o pci_irq.o pci_bind.o
> +acpi-$(CONFIG_HOTPLUG) += pci_root_hp.o
I absolutely, 110% agree with splitting out the host bridge hotplug
code from the PCI device hotplug code.
But I don't want to put this in a separate file; I think it should go
directly in pci_root.c. Putting it in a separate file gives the
illusion that hotplug is something we only do in unusual
circumstances. But that's wrong -- even at boot-time we should be
using the same hot-plug flow as we do later.
Plus, I want people to be forced to look at the ugliness of this code
every time they look at pci_root.c. Maybe that will help get it
cleaned up eventually.
For example, as soon as you put this code in pci_root.c instead of
pci_root_hp.c, it becomes obvious that we're keeping a list of host
bridges in both places, and we probably don't need two lists. And it
seems dubious that acpi_pci_root_hp_init() is an initcall that walks
the namespace looking for host bridges, when acpi_pci_root_add()
already exists and is called for every host bridge.
Bjorn
> acpi-y += power.o
> acpi-y += event.o
> acpi-y += sysfs.o
> diff --git a/drivers/acpi/pci_root_hp.c b/drivers/acpi/pci_root_hp.c
> new file mode 100644
> index 0000000..10c12aa
> --- /dev/null
> +++ b/drivers/acpi/pci_root_hp.c
> @@ -0,0 +1,228 @@
> +/*
> + * Separated from drivers/pci/hotplug/acpiphp_glue.c
> + * only support root bridge
> + */
> +
> +#include <linux/init.h>
> +#include <linux/module.h>
> +
> +#include <linux/kernel.h>
> +#include <linux/pci.h>
> +#include <linux/mutex.h>
> +#include <linux/slab.h>
> +#include <linux/acpi.h>
> +
> +static LIST_HEAD(acpi_root_bridge_list);
> +struct acpi_root_bridge {
> + struct list_head list;
> + acpi_handle handle;
> + u32 flags;
> +};
> +
> +/* bridge flags */
> +#define ROOT_BRIDGE_HAS_EJ0 (0x00000002)
> +#define ROOT_BRIDGE_HAS_PS3 (0x00000080)
> +
> +#define ACPI_STA_FUNCTIONING (0x00000008)
> +
> +static struct acpi_root_bridge *acpi_root_handle_to_bridge(acpi_handle handle)
> +{
> + struct acpi_root_bridge *bridge;
> +
> + list_for_each_entry(bridge, &acpi_root_bridge_list, list)
> + if (bridge->handle == handle)
> + return bridge;
> +
> + return NULL;
> +}
> +
> +/* allocate and initialize host bridge data structure */
> +static void add_acpi_root_bridge(acpi_handle handle)
> +{
> + struct acpi_root_bridge *bridge;
> + acpi_handle dummy_handle;
> + acpi_status status;
> +
> + /* if the bridge doesn't have _STA, we assume it is always there */
> + status = acpi_get_handle(handle, "_STA", &dummy_handle);
> + if (ACPI_SUCCESS(status)) {
> + unsigned long long tmp;
> +
> + status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
> + if (ACPI_FAILURE(status)) {
> + printk(KERN_DEBUG "%s: _STA evaluation failure\n",
> + __func__);
> + return;
> + }
> + if ((tmp & ACPI_STA_FUNCTIONING) == 0)
> + /* don't register this object */
> + return;
> + }
> +
> + bridge = kzalloc(sizeof(struct acpi_root_bridge), GFP_KERNEL);
> + if (!bridge)
> + return;
> +
> + bridge->handle = handle;
> +
> + if (ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &dummy_handle)))
> + bridge->flags |= ROOT_BRIDGE_HAS_EJ0;
> + if (ACPI_SUCCESS(acpi_get_handle(handle, "_PS3", &dummy_handle)))
> + bridge->flags |= ROOT_BRIDGE_HAS_PS3;
> +
> + list_add(&bridge->list, &acpi_root_bridge_list);
> +}
> +
> +struct acpi_root_hp_work {
> + struct work_struct work;
> + acpi_handle handle;
> + u32 type;
> + void *context;
> +};
> +
> +static void alloc_acpi_root_hp_work(acpi_handle handle, u32 type,
> + void *context,
> + void (*func)(struct work_struct *work))
> +{
> + struct acpi_root_hp_work *hp_work;
> + int ret;
> +
> + hp_work = kmalloc(sizeof(*hp_work), GFP_KERNEL);
> + if (!hp_work)
> + return;
> +
> + hp_work->handle = handle;
> + hp_work->type = type;
> + hp_work->context = context;
> +
> + INIT_WORK(&hp_work->work, func);
> + ret = queue_work(kacpi_hotplug_wq, &hp_work->work);
> + if (!ret)
> + kfree(hp_work);
> +}
> +
> +static void handle_root_bridge_insertion(acpi_handle handle)
> +{
> + struct acpi_device *device, *pdevice;
> + acpi_handle phandle;
> + int ret_val;
> +
> + acpi_get_parent(handle, &phandle);
> + if (acpi_bus_get_device(phandle, &pdevice)) {
> + printk(KERN_DEBUG "no parent device, assuming NULL\n");
> + pdevice = NULL;
> + }
> + if (!acpi_bus_get_device(handle, &device)) {
> + /* check if pci root_bus is removed */
> + struct acpi_pci_root *root = acpi_driver_data(device);
> + if (pci_find_bus(root->segment, root->secondary.start))
> + return;
> +
> + printk(KERN_DEBUG "bus exists... trim\n");
> + /* this shouldn't be in here, so remove
> + * the bus then re-add it...
> + */
> + ret_val = acpi_bus_trim(device, 1);
> + printk(KERN_DEBUG "acpi_bus_trim return %x\n", ret_val);
> + }
> + if (acpi_bus_add(&device, pdevice, handle, ACPI_BUS_TYPE_DEVICE)) {
> + printk(KERN_ERR "cannot add bridge to acpi list\n");
> + return;
> + }
> + if (acpi_bus_start(device))
> + printk(KERN_ERR "cannot start bridge\n");
> +}
> +
> +static void _handle_hotplug_event_root(struct work_struct *work)
> +{
> + struct acpi_root_bridge *bridge;
> + char objname[64];
> + struct acpi_buffer buffer = { .length = sizeof(objname),
> + .pointer = objname };
> + struct acpi_root_hp_work *hp_work;
> + acpi_handle handle;
> + u32 type;
> +
> + hp_work = container_of(work, struct acpi_root_hp_work, work);
> + handle = hp_work->handle;
> + type = hp_work->type;
> +
> + bridge = acpi_root_handle_to_bridge(handle);
> +
> + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
> +
> + switch (type) {
> + case ACPI_NOTIFY_BUS_CHECK:
> + /* bus enumerate */
> + printk(KERN_DEBUG "%s: Bus check notify on %s\n", __func__,
> + objname);
> + if (!bridge) {
> + handle_root_bridge_insertion(handle);
> + add_acpi_root_bridge(handle);
> + }
> +
> + break;
> +
> + case ACPI_NOTIFY_DEVICE_CHECK:
> + /* device check */
> + printk(KERN_DEBUG "%s: Device check notify on %s\n", __func__,
> + objname);
> + if (!bridge) {
> + handle_root_bridge_insertion(handle);
> + add_acpi_root_bridge(handle);
> + }
> + break;
> +
> + default:
> + printk(KERN_WARNING "notify_handler: unknown event type 0x%x for %s\n",
> + type, objname);
> + break;
> + }
> +
> + kfree(hp_work); /* allocated in handle_hotplug_event_bridge */
> +}
> +
> +static void handle_hotplug_event_root(acpi_handle handle, u32 type,
> + void *context)
> +{
> + alloc_acpi_root_hp_work(handle, type, context,
> + _handle_hotplug_event_root);
> +}
> +
> +static acpi_status __init
> +find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
> +{
> + char objname[64];
> + struct acpi_buffer buffer = { .length = sizeof(objname),
> + .pointer = objname };
> + int *count = (int *)context;
> +
> + if (!acpi_is_root_bridge(handle))
> + return AE_OK;
> +
> + (*count)++;
> +
> + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
> +
> + acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> + handle_hotplug_event_root, NULL);
> + printk(KERN_DEBUG "acpi root: %s notify handler installed\n", objname);
> +
> + add_acpi_root_bridge(handle);
> +
> + return AE_OK;
> +}
> +
> +static int __init acpi_pci_root_hp_init(void)
> +{
> + int num = 0;
> +
> + acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
> + ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
> +
> + printk(KERN_DEBUG "Found %d acpi root devices\n", num);
> +
> + return 0;
> +}
> +
> +subsys_initcall(acpi_pci_root_hp_init);
> diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c
> index 3d6d4fd..d0369dc 100644
> --- a/drivers/pci/hotplug/acpiphp_glue.c
> +++ b/drivers/pci/hotplug/acpiphp_glue.c
> @@ -543,10 +543,13 @@ static void cleanup_bridge(struct acpiphp_bridge *bridge)
> acpi_status status;
> acpi_handle handle = bridge->handle;
>
> - status = acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> + if (bridge->type != BRIDGE_TYPE_HOST) {
> + status = acpi_remove_notify_handler(handle,
> + ACPI_SYSTEM_NOTIFY,
> handle_hotplug_event_bridge);
> - if (ACPI_FAILURE(status))
> - err("failed to remove notify handler\n");
> + if (ACPI_FAILURE(status))
> + err("failed to remove notify handler\n");
> + }
>
> if ((bridge->type != BRIDGE_TYPE_HOST) &&
> ((bridge->flags & BRIDGE_HAS_EJ0) && bridge->func)) {
> @@ -630,9 +633,6 @@ static void remove_bridge(struct acpi_pci_root *root)
> bridge = acpiphp_handle_to_bridge(handle);
> if (bridge)
> cleanup_bridge(bridge);
> - else
> - acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> - handle_hotplug_event_bridge);
> }
>
> static int power_on_slot(struct acpiphp_slot *slot)
> @@ -1107,18 +1107,12 @@ static void acpiphp_sanitize_bus(struct pci_bus *bus)
> }
>
> /* Program resources in newly inserted bridge */
> -static int acpiphp_configure_bridge (acpi_handle handle)
> +static int acpiphp_configure_p2p_bridge(acpi_handle handle)
> {
> - struct pci_bus *bus;
> + struct pci_dev *pdev = acpi_get_pci_dev(handle);
> + struct pci_bus *bus = pdev->subordinate;
>
> - if (acpi_is_root_bridge(handle)) {
> - struct acpi_pci_root *root = acpi_pci_find_root(handle);
> - bus = root->bus;
> - } else {
> - struct pci_dev *pdev = acpi_get_pci_dev(handle);
> - bus = pdev->subordinate;
> - pci_dev_put(pdev);
> - }
> + pci_dev_put(pdev);
>
> pci_bus_size_bridges(bus);
> pci_bus_assign_resources(bus);
> @@ -1128,7 +1122,7 @@ static int acpiphp_configure_bridge (acpi_handle handle)
> return 0;
> }
>
> -static void handle_bridge_insertion(acpi_handle handle, u32 type)
> +static void handle_p2p_bridge_insertion(acpi_handle handle, u32 type)
> {
> struct acpi_device *device, *pdevice;
> acpi_handle phandle;
> @@ -1148,9 +1142,9 @@ static void handle_bridge_insertion(acpi_handle handle, u32 type)
> err("cannot add bridge to acpi list\n");
> return;
> }
> - if (!acpiphp_configure_bridge(handle) &&
> + if (!acpiphp_configure_p2p_bridge(handle) &&
> !acpi_bus_start(device))
> - add_bridge(handle);
> + add_p2p_bridge(handle);
> else
> err("cannot configure and start bridge\n");
>
> @@ -1236,7 +1230,7 @@ static void _handle_hotplug_event_bridge(struct work_struct *work)
>
> if (acpi_bus_get_device(handle, &device)) {
> /* This bridge must have just been physically inserted */
> - handle_bridge_insertion(handle, type);
> + handle_p2p_bridge_insertion(handle, type);
> goto out;
> }
>
> @@ -1413,21 +1407,6 @@ static void handle_hotplug_event_func(acpi_handle handle, u32 type,
> _handle_hotplug_event_func);
> }
>
> -static acpi_status
> -find_root_bridges(acpi_handle handle, u32 lvl, void *context, void **rv)
> -{
> - int *count = (int *)context;
> -
> - if (!acpi_is_root_bridge(handle))
> - return AE_OK;
> -
> - (*count)++;
> - acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
> - handle_hotplug_event_bridge, NULL);
> -
> - return AE_OK ;
> -}
> -
> static struct acpi_pci_driver acpi_pci_hp_driver = {
> .add = add_bridge,
> .remove = remove_bridge,
> @@ -1438,15 +1417,7 @@ static struct acpi_pci_driver acpi_pci_hp_driver = {
> */
> int __init acpiphp_glue_init(void)
> {
> - int num = 0;
> -
> - acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT,
> - ACPI_UINT32_MAX, find_root_bridges, NULL, &num, NULL);
> -
> - if (num <= 0)
> - return -1;
> - else
> - acpi_pci_register_driver(&acpi_pci_hp_driver);
> + acpi_pci_register_driver(&acpi_pci_hp_driver);
>
> return 0;
> }
>
next prev parent reply other threads:[~2012-12-07 19:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-07 6:24 [PATCH 00/15] PCI/ACPI: Remove "pci_root" sub-driver support Myron Stowe
2012-12-07 6:25 ` [PATCH 01/15] PCI, acpiphp: Separate out hot-add support of pci host bridge Myron Stowe
2012-12-07 19:32 ` Bjorn Helgaas [this message]
2012-12-07 21:04 ` Rafael J. Wysocki
2012-12-07 21:30 ` Yinghai Lu
2012-12-07 21:36 ` Bjorn Helgaas
2012-12-07 21:42 ` Yinghai Lu
2012-12-07 6:25 ` [PATCH 02/15] PCI/acpiphp: Fix coding style of external declarations in acpiphp.h Myron Stowe
2012-12-07 6:25 ` [PATCH 03/15] PCI/acpiphp: Leave the "acpiphp" sub-driver registered and in place Myron Stowe
2012-12-07 6:25 ` [PATCH 04/15] PCI/acpiphp: Change acpiphp_glue_init() to return void instead of 0 Myron Stowe
2012-12-07 6:25 ` [PATCH 05/15] PCI/acpiphp: Collapse initialization call chain of "acpiphp" sub-driver Myron Stowe
2012-12-07 6:25 ` [PATCH 06/15] PCI/acpiphp: Convert "acpiphp" sub-driver's functionality to built-in only Myron Stowe
2012-12-07 6:48 ` Yinghai Lu
2012-12-07 19:11 ` Myron Stowe
2012-12-07 6:25 ` [PATCH 07/15] PCI/acpiphp: Declare acpi_{add, remove}_bridge() as external functions Myron Stowe
2012-12-07 6:25 ` [PATCH 08/15] PCI/acpiphp: Collapse the initialization call chain of "acpiphp" further Myron Stowe
2012-12-07 6:25 ` [PATCH 09/15] PCI/acpiphp: Add "acpiphp" functionality statically within "pci_root" Myron Stowe
2012-12-07 6:25 ` [PATCH 10/15] PCI/acpiphp: Change acpiphp_add_bridge() to return void instead of 0 Myron Stowe
2012-12-07 6:25 ` [PATCH 11/15] PCI/ACPI: Fix latent refcount issue in acpi_pci_root_start() Myron Stowe
2012-12-07 6:26 ` [PATCH 12/15] PCI/ACPI: Move where dmi_check_system() is called from Myron Stowe
2012-12-07 6:26 ` [PATCH 13/15] PCI/ACPI: Convert "pci_slot" sub-driver's functionality to built-in only Myron Stowe
2012-12-07 6:26 ` [PATCH 14/15] PCI/ACPI: Add "pci_slot" functionality statically within "pci_root" Myron Stowe
2012-12-07 6:26 ` [PATCH 15/15] PCI/ACPI: Remove the "pci_root" driver's sub-driver infrastructure Myron Stowe
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