From: ameynarkhede03@gmail.com
To: bhelgaas@google.com
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
alex.williamson@redhat.com, raphael.norwitz@nutanix.com,
Amey Narkhede <ameynarkhede03@gmail.com>
Subject: [PATCH 2/4] PCI: Add new bitmap for keeping track of supported reset mechanisms
Date: Fri, 12 Mar 2021 23:04:50 +0530 [thread overview]
Message-ID: <20210312173452.3855-3-ameynarkhede03@gmail.com> (raw)
In-Reply-To: <20210312173452.3855-1-ameynarkhede03@gmail.com>
From: Amey Narkhede <ameynarkhede03@gmail.com>
Introduce a new bitmap reset_methods in struct pci_dev
to keep track of reset mechanisms supported by the
device. Also refactor probing and reset functions
to take advantage of calling convention of reset
functions.
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
drivers/pci/pci.c | 106 ++++++++++++++++++++++++--------------------
drivers/pci/pci.h | 11 ++++-
drivers/pci/probe.c | 5 +--
include/linux/pci.h | 10 +++++
4 files changed, 79 insertions(+), 53 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4a7c084a3..407b44e85 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -40,6 +40,26 @@ const char *pci_power_names[] = {
};
EXPORT_SYMBOL_GPL(pci_power_names);
+static int pci_af_flr(struct pci_dev *dev, int probe);
+static int pci_pm_reset(struct pci_dev *dev, int probe);
+static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe);
+static int pci_parent_bus_reset(struct pci_dev *dev, int probe);
+
+/*
+ * The ordering for functions in pci_reset_fn_methods
+ * is required for bitmap positions defined
+ * in reset_methods in struct pci_dev
+ */
+const struct pci_reset_fn_method pci_reset_fn_methods[] = {
+ { .reset_fn = &pci_dev_specific_reset, .name = "device_specific" },
+ { .reset_fn = &pcie_flr, .name = "flr" },
+ { .reset_fn = &pci_af_flr, .name = "af_flr" },
+ { .reset_fn = &pci_pm_reset, .name = "pm" },
+ { .reset_fn = &pci_dev_reset_slot_function, .name = "slot" },
+ { .reset_fn = &pci_parent_bus_reset, .name = "bus" },
+ { 0 },
+};
+
int isa_dma_bridge_buggy;
EXPORT_SYMBOL(isa_dma_bridge_buggy);
@@ -5080,71 +5100,59 @@ static void pci_dev_restore(struct pci_dev *dev)
*/
int __pci_reset_function_locked(struct pci_dev *dev)
{
- int rc;
+ int i, rc = -ENOTTY;
+ const struct pci_reset_fn_method *reset;
might_sleep();
- /*
- * A reset method returns -ENOTTY if it doesn't support this device
- * and we should try the next method.
- *
- * If it returns 0 (success), we're finished. If it returns any
- * other error, we're also finished: this indicates that further
- * reset mechanisms might be broken on the device.
- */
- rc = pci_dev_specific_reset(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pcie_flr(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_af_flr(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_pm_reset(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_dev_reset_slot_function(dev, 0);
- if (rc != -ENOTTY)
- return rc;
- return pci_parent_bus_reset(dev, 0);
+ for (i = 0, reset = pci_reset_fn_methods; reset->reset_fn; i++, reset++) {
+ if (!(dev->reset_methods & (1 << i)))
+ continue;
+
+ /*
+ * A reset method returns -ENOTTY if it doesn't support this device
+ * and we should try the next method.
+ *
+ * If it returns 0 (success), we're finished. If it returns any
+ * other error, we're also finished: this indicates that further
+ * reset mechanisms might be broken on the device.
+ */
+ rc = reset->reset_fn(dev, 0);
+ if (rc != -ENOTTY)
+ return rc;
+ }
+ return rc;
}
EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
/**
- * pci_probe_reset_function - check whether the device can be safely reset
- * @dev: PCI device to reset
+ * pci_init_reset_methods - check whether device can be safely reset
+ * and store supported reset mechanisms.
+ * @dev: PCI device to check for reset mechanisms
*
* Some devices allow an individual function to be reset without affecting
* other functions in the same device. The PCI device must be responsive
- * to PCI config space in order to use this function.
+ * to reads and writes to its PCI config space in order to use this function.
*
- * Returns 0 if the device function can be reset or negative if the
- * device doesn't support resetting a single function.
+ * Stores reset mechanisms supported by device in reset_methods bitmap
+ * field of struct pci_dev
*/
-int pci_probe_reset_function(struct pci_dev *dev)
+void pci_init_reset_methods(struct pci_dev *dev)
{
- int rc;
+ int i, rc;
+ const struct pci_reset_fn_method *reset;
- might_sleep();
+ dev->reset_methods = 0;
- rc = pci_dev_specific_reset(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pcie_flr(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_af_flr(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_pm_reset(dev, 1);
- if (rc != -ENOTTY)
- return rc;
- rc = pci_dev_reset_slot_function(dev, 1);
- if (rc != -ENOTTY)
- return rc;
+ might_sleep();
- return pci_parent_bus_reset(dev, 1);
+ for (i = 0, reset = pci_reset_fn_methods; reset->reset_fn; i++, reset++) {
+ rc = reset->reset_fn(dev, 1);
+ if (!rc)
+ dev->reset_methods |= (1 << i);
+ else if (rc != -ENOTTY)
+ break;
+ }
}
/**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index ef7c46613..ec093efdc 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -39,7 +39,7 @@ enum pci_mmap_api {
int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
enum pci_mmap_api mmap_api);
-int pci_probe_reset_function(struct pci_dev *dev);
+void pci_init_reset_methods(struct pci_dev *dev);
int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
int pci_bus_error_reset(struct pci_dev *dev);
@@ -612,6 +612,15 @@ struct pci_dev_reset_methods {
int (*reset)(struct pci_dev *dev, int probe);
};
+typedef int (*pci_reset_fn_t)(struct pci_dev *, int);
+
+struct pci_reset_fn_method {
+ pci_reset_fn_t reset_fn;
+ char *name;
+};
+
+extern const struct pci_reset_fn_method pci_reset_fn_methods[];
+
#ifdef CONFIG_PCI_QUIRKS
int pci_dev_specific_reset(struct pci_dev *dev, int probe);
#else
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15abc..01dd037bd 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2403,9 +2403,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
pci_rcec_init(dev); /* Root Complex Event Collector */
pcie_report_downtraining(dev);
-
- if (pci_probe_reset_function(dev) == 0)
- dev->reset_fn = 1;
+ pci_init_reset_methods(dev);
+ dev->reset_fn = !!dev->reset_methods;
}
/*
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 621ff5224..56d6e4750 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -325,6 +325,16 @@ struct pci_dev {
unsigned int class; /* 3 bytes: (base,sub,prog-if) */
u8 revision; /* PCI revision, low byte of class word */
u8 hdr_type; /* PCI header type (`multi' flag masked out) */
+ /*
+ * bit 0 -> dev_specific
+ * bit 1 -> flr
+ * bit 2 -> af_flr
+ * bit 3 -> pm
+ * bit 4 -> slot
+ * bit 5 -> bus
+ * See pci_reset_fn_methods array in pci.c
+ */
+ u8 __bitwise reset_methods; /* bitmap for device supported reset capabilities */
#ifdef CONFIG_PCIEAER
u16 aer_cap; /* AER capability offset */
struct aer_stats *aer_stats; /* AER stats for this device */
--
2.30.2
next prev parent reply other threads:[~2021-03-12 17:37 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-12 17:34 [PATCH 0/4] Expose and manage PCI device reset ameynarkhede03
2021-03-12 17:34 ` [PATCH 1/4] PCI: Refactor pcie_flr to follow calling convention of other reset methods ameynarkhede03
2021-03-12 17:34 ` ameynarkhede03 [this message]
2021-03-14 23:51 ` [PATCH 2/4] PCI: Add new bitmap for keeping track of supported reset mechanisms Pali Rohár
2021-03-12 17:34 ` [PATCH 3/4] PCI: Remove reset_fn field from pci_dev ameynarkhede03
2021-03-14 23:52 ` Pali Rohár
2021-03-12 17:34 ` [PATCH 4/4] PCI/sysfs: Allow userspace to query and set device reset mechanism ameynarkhede03
2021-03-14 23:55 ` Pali Rohár
2021-03-15 13:43 ` Amey Narkhede
2021-03-15 13:52 ` Pali Rohár
2021-03-15 14:34 ` Alex Williamson
2021-03-15 14:52 ` Pali Rohár
2021-03-15 15:03 ` Alex Williamson
2021-03-17 19:02 ` Pali Rohár
2021-03-17 19:15 ` Alex Williamson
2021-03-17 19:24 ` Pali Rohár
2021-03-17 19:32 ` Alex Williamson
2021-03-17 19:40 ` Pali Rohár
2021-03-17 20:00 ` Alex Williamson
2021-03-17 20:13 ` Pali Rohár
2021-03-18 14:31 ` Amey Narkhede
2021-03-23 14:34 ` Pali Rohár
2021-03-23 14:44 ` Alex Williamson
2021-03-23 15:32 ` Amey Narkhede
2021-03-23 16:06 ` Alex Williamson
2021-03-23 16:15 ` Alex Williamson
2021-03-15 15:07 ` Leon Romanovsky
2021-03-15 15:33 ` Amey Narkhede
2021-03-15 16:29 ` Alex Williamson
2021-03-15 18:32 ` Raphael Norwitz
2021-03-17 4:20 ` Leon Romanovsky
2021-03-17 10:24 ` Amey Narkhede
2021-03-17 11:02 ` Leon Romanovsky
2021-03-17 11:23 ` Amey Narkhede
2021-03-17 11:47 ` Leon Romanovsky
2021-03-17 13:17 ` Amey Narkhede
2021-03-17 13:58 ` Leon Romanovsky
2021-03-17 17:31 ` Alex Williamson
2021-03-18 9:09 ` Leon Romanovsky
2021-03-18 14:22 ` Amey Narkhede
2021-03-18 14:57 ` Leon Romanovsky
2021-03-18 17:01 ` Amey Narkhede
2021-03-18 17:35 ` Leon Romanovsky
2021-03-18 17:43 ` Amey Narkhede
2021-03-18 18:14 ` Enrico Weigelt, metux IT consult
2021-03-19 13:05 ` Leon Romanovsky
2021-03-19 15:23 ` Amey Narkhede
2021-03-19 15:37 ` Leon Romanovsky
2021-03-19 15:53 ` Amey Narkhede
2021-03-18 17:58 ` Enrico Weigelt, metux IT consult
2021-03-19 13:07 ` Leon Romanovsky
2021-03-18 16:39 ` Alex Williamson
2021-03-18 17:22 ` Leon Romanovsky
2021-03-18 17:38 ` Amey Narkhede
2021-03-18 18:34 ` Enrico Weigelt, metux IT consult
2021-03-19 12:59 ` Leon Romanovsky
2021-03-19 13:48 ` Enrico Weigelt, metux IT consult
2021-03-19 15:51 ` Leon Romanovsky
2021-03-19 15:57 ` Bjorn Helgaas
2021-03-19 16:24 ` Leon Romanovsky
2021-03-19 16:23 ` Alex Williamson
2021-03-20 9:10 ` Leon Romanovsky
2021-03-20 14:59 ` Alex Williamson
2021-03-21 8:40 ` Leon Romanovsky
2021-03-21 14:57 ` Amey Narkhede
2021-03-22 17:10 ` Alex Williamson
2021-03-24 10:03 ` Leon Romanovsky
2021-03-24 14:37 ` Alex Williamson
2021-03-24 15:13 ` Leon Romanovsky
2021-03-24 17:17 ` Alex Williamson
2021-03-25 8:37 ` Leon Romanovsky
2021-03-25 14:55 ` Alex Williamson
2021-03-25 16:09 ` Leon Romanovsky
2021-03-25 17:22 ` Amey Narkhede
2021-03-25 17:36 ` Leon Romanovsky
2021-03-25 17:53 ` Alex Williamson
2021-03-26 6:40 ` Leon Romanovsky
2021-03-26 9:18 ` Krzysztof Wilczyński
2021-03-26 12:54 ` Leon Romanovsky
2021-03-26 14:20 ` Alex Williamson
2021-03-27 6:02 ` Leon Romanovsky
2021-03-25 16:26 ` Amey Narkhede
2021-03-25 16:46 ` Leon Romanovsky
2021-03-18 17:51 ` Enrico Weigelt, metux IT consult
[not found] ` <20210312112043.3f2954e3@omen.home.shazbot.org>
2021-03-12 18:40 ` [PATCH 0/4] Expose and manage PCI device reset Amey Narkhede
2021-03-12 18:58 ` Krzysztof Wilczyński
2021-03-12 19:06 ` Amey Narkhede
2021-03-12 19:20 ` Krzysztof Wilczyński
2021-03-13 2:02 ` Raphael Norwitz
2021-03-14 12:09 ` Leon Romanovsky
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