[PATCH v14 0/5] Add Error Disconnect Recover (EDR) support

[PATCH v14 0/5] Add Error Disconnect Recover (EDR) support

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

This patchset adds support for following features:

1. Error Disconnect Recover (EDR) support.
2. _OSC based negotiation support for DPC.

You can find EDR spec in the following link.

https://members.pcisig.com/wg/PCI-SIG/document/12614

Changes since v13:
 * Moved all EDR related code to edr.c
 * Addressed Bjorns comments.

Changes since v12:
 * Addressed Bjorns comments.
 * Added check for CONFIG_PCIE_EDR before requesting DPC control from firmware.
 * Removed ff_check parameter from AER APIs.
 * Used macros for _OST return status values in DPC driver.

Changes since v11:
 * Allowed error recovery to proceed after successful reset_link().
 * Used correct ACPI handle for sending EDR status.
 * Rebased on top of v5.5-rc5

Changes since v10:
 * Added "edr_enabled" member to dpc priv structure, which is used to cache EDR
   enabling status based on status of pcie_ports_dpc_native and FF mode.
 * Changed type of _DSM argument from Integer to Package in acpi_enable_dpc_port()
   function to fix ACPI related boot warnings.
 * Rebased on top of v5.5-rc3

Changes since v9:
 * Removed caching of pcie_aer_get_firmware_first() in dpc driver.
 * Added proper spec reference in git log for patch 5 & 7.
 * Added new function parameter "ff_check" to pci_cleanup_aer_uncorrect_error_status(),
   pci_aer_clear_fatal_status() and pci_cleanup_aer_error_status_regs() functions.
 * Rebased on top of v5.4-rc5

Changes since v8:
 * Rebased on top of v5.4-rc1

Changes since v7:
 * Updated DSM version number to match the spec.

Changes since v6:
 * Modified the order of patches to enable EDR only after all necessary support is added in kernel.
 * Addressed Bjorn comments.

Changes since v5:
 * Addressed Keith's comments.
 * Added additional check for FF mode in pci_aer_init().
 * Updated commit history of "PCI/DPC: Add support for DPC recovery on NON_FATAL errors" patch.

Changes since v4:
 * Rebased on top of v5.3-rc1
 * Fixed lock/unlock issue in edr_handle_event().
 * Merged "Update error status after reset_link()" patch into this patchset.

Changes since v3:
 * Moved EDR related ACPI functions/definitions to pci-acpi.c
 * Modified commit history in few patches to include spec reference.
 * Added support to handle DPC triggered by NON_FATAL errors.
 * Added edr_lock to protect PCI device receiving duplicate EDR notifications.
 * Addressed Bjorn comments.

Changes since v2:
 * Split EDR support patch into multiple patches.
 * Addressed Bjorn comments.

Changes since v1:
 * Rebased on top of v5.1-rc1

Kuppuswamy Sathyanarayanan (5):
  PCI/ERR: Update error status after reset_link()
  PCI/DPC: Remove pcie_device reference from dpc_dev structure
  PCI/EDR: Export AER, DPC and error recovery functions
  PCI/DPC: Add Error Disconnect Recover (EDR) support
  PCI/ACPI: Enable EDR support

 drivers/acpi/pci_root.c   |  16 +++
 drivers/pci/pci-acpi.c    |   3 +
 drivers/pci/pci.h         |   8 ++
 drivers/pci/pcie/Kconfig  |  10 ++
 drivers/pci/pcie/Makefile |   1 +
 drivers/pci/pcie/aer.c    |  39 ++++--
 drivers/pci/pcie/dpc.c    |  92 ++++++++------
 drivers/pci/pcie/dpc.h    |  20 +++
 drivers/pci/pcie/edr.c    | 259 ++++++++++++++++++++++++++++++++++++++
 drivers/pci/pcie/err.c    |  35 ++++--
 drivers/pci/probe.c       |   1 +
 include/linux/acpi.h      |   6 +-
 include/linux/pci-acpi.h  |   8 ++
 include/linux/pci.h       |   1 +
 14 files changed, 441 insertions(+), 58 deletions(-)
 create mode 100644 drivers/pci/pcie/dpc.h
 create mode 100644 drivers/pci/pcie/edr.c

-- 
2.21.0

[PATCH v14 1/5] PCI/ERR: Update error status after reset_link()

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Commit bdb5ac85777d ("PCI/ERR: Handle fatal error recovery") uses
reset_link() to recover from fatal errors. But during fatal error
recovery, if the initial value of error status is
PCI_ERS_RESULT_DISCONNECT or PCI_ERS_RESULT_NO_AER_DRIVER then
even after successful recovery (using reset_link()) pcie_do_recovery()
will report the recovery result as failure. So update the status of
error after reset_link().

Fixes: bdb5ac85777d ("PCI/ERR: Handle fatal error recovery")
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Keith Busch <keith.busch@intel.com>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Keith Busch <keith.busch@intel.com>
---
 drivers/pci/pcie/err.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index b0e6048a9208..71639055511e 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -204,9 +204,11 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 	else
 		pci_walk_bus(bus, report_normal_detected, &status);
 
-	if (state == pci_channel_io_frozen &&
-	    reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED)
-		goto failed;
+	if (state == pci_channel_io_frozen) {
+		status = reset_link(dev, service);
+		if (status != PCI_ERS_RESULT_RECOVERED)
+			goto failed;
+	}
 
 	if (status == PCI_ERS_RESULT_CAN_RECOVER) {
 		status = PCI_ERS_RESULT_RECOVERED;
-- 
2.21.0

[PATCH v14 2/5] PCI/DPC: Remove pcie_device reference from dpc_dev structure

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

Currently the only use of pcie_device member in dpc_dev structure is to
get the associated pci_dev reference. Since none of the users of
dpc_dev need reference to pcie_device, just remove it and replace it
with associated pci_dev pointer reference.

Removing pcie_device reference will help if we have need to call DPC
driver functions outside PCIe port drivers.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/pcie/dpc.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index e06f42f58d3d..99fca8400956 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -18,7 +18,7 @@
 #include "../pci.h"
 
 struct dpc_dev {
-	struct pcie_device	*dev;
+	struct pci_dev		*pdev;
 	u16			cap_pos;
 	bool			rp_extensions;
 	u8			rp_log_size;
@@ -101,7 +101,7 @@ void pci_restore_dpc_state(struct pci_dev *dev)
 static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
 {
 	unsigned long timeout = jiffies + HZ;
-	struct pci_dev *pdev = dpc->dev->port;
+	struct pci_dev *pdev = dpc->pdev;
 	u16 cap = dpc->cap_pos, status;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
@@ -149,7 +149,7 @@ static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
 
 static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
 {
-	struct pci_dev *pdev = dpc->dev->port;
+	struct pci_dev *pdev = dpc->pdev;
 	u16 cap = dpc->cap_pos, dpc_status, first_error;
 	u32 status, mask, sev, syserr, exc, dw0, dw1, dw2, dw3, log, prefix;
 	int i;
@@ -228,7 +228,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
 {
 	struct aer_err_info info;
 	struct dpc_dev *dpc = context;
-	struct pci_dev *pdev = dpc->dev->port;
+	struct pci_dev *pdev = dpc->pdev;
 	u16 cap = dpc->cap_pos, status, source, reason, ext_reason;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
@@ -267,7 +267,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
 static irqreturn_t dpc_irq(int irq, void *context)
 {
 	struct dpc_dev *dpc = (struct dpc_dev *)context;
-	struct pci_dev *pdev = dpc->dev->port;
+	struct pci_dev *pdev = dpc->pdev;
 	u16 cap = dpc->cap_pos, status;
 
 	pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status);
@@ -299,7 +299,7 @@ static int dpc_probe(struct pcie_device *dev)
 		return -ENOMEM;
 
 	dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
-	dpc->dev = dev;
+	dpc->pdev = pdev;
 	set_service_data(dev, dpc);
 
 	status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
-- 
2.21.0

[PATCH v14 3/5] PCI/EDR: Export AER, DPC and error recovery functions

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

This is a preparatory patch for adding EDR support.

As per the Downstream Port Containment Related Enhancements ECN to the
PCI Firmware Specification r3.2, sec 4.5.1, table 4-6, If DPC is
controlled by firmware, firmware is responsible for initializing
Downstream Port Containment Extended Capability Structures per firmware
policy. Further, the OS is permitted to read or write DPC Control and
Status registers of a port while processing an Error Disconnect Recover
notification from firmware on that port. Error Disconnect Recover
notification processing begins with the Error Disconnect Recover notify
from Firmware, and ends when the OS releases DPC by clearing the DPC
Trigger Status bit.Firmware can read DPC Trigger Status bit to determine
the ownership of DPC Control and Status registers. Firmware is not
permitted to write to DPC Control and Status registers if DPC Trigger
Status is set i.e. the link is in DPC state. Outside of the Error
Disconnect Recover notification processing window, the OS is not
permitted to modify DPC Control or Status registers; only firmware
is allowed to.

To add EDR support we need to re-use some of the existing DPC,
AER and pCIE error recovery functions. So add necessary interfaces.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/pci.h      |  8 ++++
 drivers/pci/pcie/aer.c | 39 ++++++++++++++------
 drivers/pci/pcie/dpc.c | 84 +++++++++++++++++++++++++-----------------
 drivers/pci/pcie/dpc.h | 20 ++++++++++
 drivers/pci/pcie/err.c | 29 ++++++++++++---
 5 files changed, 130 insertions(+), 50 deletions(-)
 create mode 100644 drivers/pci/pcie/dpc.h

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index a0a53bd05a0b..e26e298b4fec 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -440,6 +440,9 @@ struct aer_err_info {
 
 int aer_get_device_error_info(struct pci_dev *dev, struct aer_err_info *info);
 void aer_print_error(struct pci_dev *dev, struct aer_err_info *info);
+int pci_aer_clear_err_uncor_status(struct pci_dev *dev);
+void pci_aer_clear_err_fatal_status(struct pci_dev *dev);
+int pci_aer_clear_err_status_regs(struct pci_dev *dev);
 #endif	/* CONFIG_PCIEAER */
 
 #ifdef CONFIG_PCIE_DPC
@@ -546,6 +549,11 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
 /* PCI error reporting and recovery */
 void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 		      u32 service);
+pci_ers_result_t pcie_do_recovery_common(struct pci_dev *dev,
+				enum pci_channel_state state,
+				u32 service,
+				pci_ers_result_t (*reset_cb)(void *cb_data),
+				void *cb_data);
 
 bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
 #ifdef CONFIG_PCIEASPM
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 1ca86f2e0166..b9625533bc7f 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -376,7 +376,7 @@ void pci_aer_clear_device_status(struct pci_dev *dev)
 	pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta);
 }
 
-int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
+int pci_aer_clear_err_uncor_status(struct pci_dev *dev)
 {
 	int pos;
 	u32 status, sev;
@@ -385,9 +385,6 @@ int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
 	if (!pos)
 		return -EIO;
 
-	if (pcie_aer_get_firmware_first(dev))
-		return -EIO;
-
 	/* Clear status bits for ERR_NONFATAL errors only */
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev);
@@ -397,9 +394,17 @@ int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
 
 	return 0;
 }
+
+int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
+{
+	if (pcie_aer_get_firmware_first(dev))
+		return -EIO;
+
+	return pci_aer_clear_err_uncor_status(dev);
+}
 EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
 
-void pci_aer_clear_fatal_status(struct pci_dev *dev)
+void pci_aer_clear_err_fatal_status(struct pci_dev *dev)
 {
 	int pos;
 	u32 status, sev;
@@ -408,9 +413,6 @@ void pci_aer_clear_fatal_status(struct pci_dev *dev)
 	if (!pos)
 		return;
 
-	if (pcie_aer_get_firmware_first(dev))
-		return;
-
 	/* Clear status bits for ERR_FATAL errors only */
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_SEVER, &sev);
@@ -419,7 +421,15 @@ void pci_aer_clear_fatal_status(struct pci_dev *dev)
 		pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
 }
 
-int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
+void pci_aer_clear_fatal_status(struct pci_dev *dev)
+{
+	if (pcie_aer_get_firmware_first(dev))
+		return;
+
+	return pci_aer_clear_err_fatal_status(dev);
+}
+
+int pci_aer_clear_err_status_regs(struct pci_dev *dev)
 {
 	int pos;
 	u32 status;
@@ -432,9 +442,6 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
 	if (!pos)
 		return -EIO;
 
-	if (pcie_aer_get_firmware_first(dev))
-		return -EIO;
-
 	port_type = pci_pcie_type(dev);
 	if (port_type == PCI_EXP_TYPE_ROOT_PORT) {
 		pci_read_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, &status);
@@ -450,6 +457,14 @@ int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
 	return 0;
 }
 
+int pci_cleanup_aer_error_status_regs(struct pci_dev *dev)
+{
+	if (pcie_aer_get_firmware_first(dev))
+		return -EIO;
+
+	return pci_aer_clear_err_status_regs(dev);
+}
+
 void pci_save_aer_state(struct pci_dev *dev)
 {
 	struct pci_cap_saved_state *save_state;
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 99fca8400956..acae12dbf9ff 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -15,15 +15,9 @@
 #include <linux/pci.h>
 
 #include "portdrv.h"
+#include "dpc.h"
 #include "../pci.h"
 
-struct dpc_dev {
-	struct pci_dev		*pdev;
-	u16			cap_pos;
-	bool			rp_extensions;
-	u8			rp_log_size;
-};
-
 static const char * const rp_pio_error_string[] = {
 	"Configuration Request received UR Completion",	 /* Bit Position 0  */
 	"Configuration Request received CA Completion",	 /* Bit Position 1  */
@@ -117,36 +111,44 @@ static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
 	return 0;
 }
 
-static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
+pci_ers_result_t dpc_reset_link_common(struct dpc_dev *dpc)
 {
-	struct dpc_dev *dpc;
 	u16 cap;
 
-	/*
-	 * DPC disables the Link automatically in hardware, so it has
-	 * already been reset by the time we get here.
-	 */
-	dpc = to_dpc_dev(pdev);
 	cap = dpc->cap_pos;
 
 	/*
 	 * Wait until the Link is inactive, then clear DPC Trigger Status
 	 * to allow the Port to leave DPC.
 	 */
-	pcie_wait_for_link(pdev, false);
+	pcie_wait_for_link(dpc->pdev, false);
 
 	if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
 		return PCI_ERS_RESULT_DISCONNECT;
 
-	pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
+	pci_write_config_word(dpc->pdev, cap + PCI_EXP_DPC_STATUS,
 			      PCI_EXP_DPC_STATUS_TRIGGER);
 
-	if (!pcie_wait_for_link(pdev, true))
+	if (!pcie_wait_for_link(dpc->pdev, true))
 		return PCI_ERS_RESULT_DISCONNECT;
 
 	return PCI_ERS_RESULT_RECOVERED;
 }
 
+static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
+{
+	struct dpc_dev *dpc;
+
+	/*
+	 * DPC disables the Link automatically in hardware, so it has
+	 * already been reset by the time we get here.
+	 */
+	dpc = to_dpc_dev(pdev);
+
+	return dpc_reset_link_common(dpc);
+
+}
+
 static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
 {
 	struct pci_dev *pdev = dpc->pdev;
@@ -224,10 +226,9 @@ static int dpc_get_aer_uncorrect_severity(struct pci_dev *dev,
 	return 1;
 }
 
-static irqreturn_t dpc_handler(int irq, void *context)
+void dpc_process_error(struct dpc_dev *dpc)
 {
 	struct aer_err_info info;
-	struct dpc_dev *dpc = context;
 	struct pci_dev *pdev = dpc->pdev;
 	u16 cap = dpc->cap_pos, status, source, reason, ext_reason;
 
@@ -257,6 +258,14 @@ static irqreturn_t dpc_handler(int irq, void *context)
 		pci_cleanup_aer_uncorrect_error_status(pdev);
 		pci_aer_clear_fatal_status(pdev);
 	}
+}
+
+static irqreturn_t dpc_handler(int irq, void *context)
+{
+	struct dpc_dev *dpc = context;
+	struct pci_dev *pdev = dpc->pdev;
+
+	dpc_process_error(dpc);
 
 	/* We configure DPC so it only triggers on ERR_FATAL */
 	pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC);
@@ -282,6 +291,25 @@ static irqreturn_t dpc_irq(int irq, void *context)
 	return IRQ_HANDLED;
 }
 
+void dpc_dev_init(struct pci_dev *pdev, struct dpc_dev *dpc)
+{
+	dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
+	dpc->pdev = pdev;
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &dpc->cap);
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &dpc->ctl);
+
+	dpc->rp_extensions = (dpc->cap & PCI_EXP_DPC_CAP_RP_EXT);
+	if (dpc->rp_extensions) {
+		dpc->rp_log_size =
+			(dpc->cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8;
+		if (dpc->rp_log_size < 4 || dpc->rp_log_size > 9) {
+			pci_err(pdev, "RP PIO log size %u is invalid\n",
+				dpc->rp_log_size);
+			dpc->rp_log_size = 0;
+		}
+	}
+}
+
 #define FLAG(x, y) (((x) & (y)) ? '+' : '-')
 static int dpc_probe(struct pcie_device *dev)
 {
@@ -298,8 +326,8 @@ static int dpc_probe(struct pcie_device *dev)
 	if (!dpc)
 		return -ENOMEM;
 
-	dpc->cap_pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_DPC);
-	dpc->pdev = pdev;
+	dpc_dev_init(pdev, dpc);
+
 	set_service_data(dev, dpc);
 
 	status = devm_request_threaded_irq(device, dev->irq, dpc_irq,
@@ -311,18 +339,8 @@ static int dpc_probe(struct pcie_device *dev)
 		return status;
 	}
 
-	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CAP, &cap);
-	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, &ctl);
-
-	dpc->rp_extensions = (cap & PCI_EXP_DPC_CAP_RP_EXT);
-	if (dpc->rp_extensions) {
-		dpc->rp_log_size = (cap & PCI_EXP_DPC_RP_PIO_LOG_SIZE) >> 8;
-		if (dpc->rp_log_size < 4 || dpc->rp_log_size > 9) {
-			pci_err(pdev, "RP PIO log size %u is invalid\n",
-				dpc->rp_log_size);
-			dpc->rp_log_size = 0;
-		}
-	}
+	ctl = dpc->ctl;
+	cap = dpc->cap;
 
 	ctl = (ctl & 0xfff4) | PCI_EXP_DPC_CTL_EN_FATAL | PCI_EXP_DPC_CTL_INT_EN;
 	pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_CTL, ctl);
diff --git a/drivers/pci/pcie/dpc.h b/drivers/pci/pcie/dpc.h
new file mode 100644
index 000000000000..2d82bc917fcb
--- /dev/null
+++ b/drivers/pci/pcie/dpc.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DRIVERS_PCIE_DPC_H
+#define DRIVERS_PCIE_DPC_H
+
+#include <linux/pci.h>
+
+struct dpc_dev {
+	struct pci_dev		*pdev;
+	u16			cap_pos;
+	bool			rp_extensions;
+	u8			rp_log_size;
+	u16			ctl;
+	u16			cap;
+};
+
+pci_ers_result_t dpc_reset_link_common(struct dpc_dev *dpc);
+void dpc_process_error(struct dpc_dev *dpc);
+void dpc_dev_init(struct pci_dev *pdev, struct dpc_dev *dpc);
+
+#endif /* DRIVERS_PCIE_DPC_H */
diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 71639055511e..2fa6369d8ea0 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -158,11 +158,18 @@ static pci_ers_result_t default_reset_link(struct pci_dev *dev)
 	return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
 }
 
-static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
+static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service,
+				   pci_ers_result_t (*reset_cb)(void *cb_data),
+				   void *cb_data)
 {
 	pci_ers_result_t status;
 	struct pcie_port_service_driver *driver = NULL;
 
+	if (reset_cb) {
+		status = reset_cb(cb_data);
+		goto done;
+	}
+
 	driver = pcie_port_find_service(dev, service);
 	if (driver && driver->reset_link) {
 		status = driver->reset_link(dev);
@@ -174,6 +181,7 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
 		return PCI_ERS_RESULT_DISCONNECT;
 	}
 
+done:
 	if (status != PCI_ERS_RESULT_RECOVERED) {
 		pci_printk(KERN_DEBUG, dev, "link reset at upstream device %s failed\n",
 			pci_name(dev));
@@ -183,8 +191,11 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
 	return status;
 }
 
-void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
-		      u32 service)
+pci_ers_result_t pcie_do_recovery_common(struct pci_dev *dev,
+				enum pci_channel_state state,
+				u32 service,
+				pci_ers_result_t (*reset_cb)(void *cb_data),
+				void *cb_data)
 {
 	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
 	struct pci_bus *bus;
@@ -205,7 +216,7 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 		pci_walk_bus(bus, report_normal_detected, &status);
 
 	if (state == pci_channel_io_frozen) {
-		status = reset_link(dev, service);
+		status = reset_link(dev, service, reset_cb, cb_data);
 		if (status != PCI_ERS_RESULT_RECOVERED)
 			goto failed;
 	}
@@ -236,11 +247,19 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 	pci_aer_clear_device_status(dev);
 	pci_cleanup_aer_uncorrect_error_status(dev);
 	pci_info(dev, "AER: Device recovery successful\n");
-	return;
+	return status;
 
 failed:
 	pci_uevent_ers(dev, PCI_ERS_RESULT_DISCONNECT);
 
 	/* TODO: Should kernel panic here? */
 	pci_info(dev, "AER: Device recovery failed\n");
+
+	return status;
+}
+
+void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
+		      u32 service)
+{
+	pcie_do_recovery_common(dev, state, service, NULL, NULL);
 }
-- 
2.21.0

[PATCH v14 4/5] PCI/DPC: Add Error Disconnect Recover (EDR) support

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

As per ACPI specification r6.3, sec 5.6.6, when firmware owns Downstream
Port Containment (DPC), its expected to use the "Error Disconnect
Recover" (EDR) notification to alert OSPM of a DPC event and if OS
supports EDR, its expected to handle the software state invalidation and
port recovery in OS, and also let firmware know the recovery status via
_OST ACPI call. Related _OST status codes can be found in ACPI
specification r6.3, sec 6.3.5.2.

Also, as per PCI firmware specification r3.2 Downstream Port Containment
Related Enhancements ECN, sec 4.5.1, table 4-6, If DPC is controlled by
firmware (firmware first mode), firmware is responsible for
configuring the DPC and OS is responsible for error recovery. Also, OS
is allowed to modify DPC registers only during the EDR notification
window.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
---
 drivers/pci/pci-acpi.c    |   3 +
 drivers/pci/pcie/Kconfig  |  10 ++
 drivers/pci/pcie/Makefile |   1 +
 drivers/pci/pcie/edr.c    | 257 ++++++++++++++++++++++++++++++++++++++
 include/linux/pci-acpi.h  |   8 ++
 5 files changed, 279 insertions(+)
 create mode 100644 drivers/pci/pcie/edr.c

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 0c02d500158f..6af5d6a04990 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1258,6 +1258,7 @@ static void pci_acpi_setup(struct device *dev)
 
 	acpi_pci_wakeup(pci_dev, false);
 	acpi_device_power_add_dependent(adev, dev);
+	pci_acpi_add_edr_notifier(pci_dev);
 }
 
 static void pci_acpi_cleanup(struct device *dev)
@@ -1276,6 +1277,8 @@ static void pci_acpi_cleanup(struct device *dev)
 
 		device_set_wakeup_capable(dev, false);
 	}
+
+	pci_acpi_remove_edr_notifier(pci_dev);
 }
 
 static bool pci_acpi_bus_match(struct device *dev)
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 6e3c04b46fb1..772b1f4cb19e 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -140,3 +140,13 @@ config PCIE_BW
 	  This enables PCI Express Bandwidth Change Notification.  If
 	  you know link width or rate changes occur only to correct
 	  unreliable links, you may answer Y.
+
+config PCIE_EDR
+	bool "PCI Express Error Disconnect Recover support"
+	depends on PCIE_DPC && ACPI
+	help
+	  This option adds Error Disconnect Recover support as specified
+	  in the Downstream Port Containment Related Enhancements ECN to
+	  the PCI Firmware Specification r3.2.  Enable this if you want to
+	  support hybrid DPC model which uses both firmware and OS to
+	  implement DPC.
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index efb9d2e71e9e..68da9280ff11 100644
--- a/drivers/pci/pcie/Makefile
+++ b/drivers/pci/pcie/Makefile
@@ -13,3 +13,4 @@ obj-$(CONFIG_PCIE_PME)		+= pme.o
 obj-$(CONFIG_PCIE_DPC)		+= dpc.o
 obj-$(CONFIG_PCIE_PTM)		+= ptm.o
 obj-$(CONFIG_PCIE_BW)		+= bw_notification.o
+obj-$(CONFIG_PCIE_EDR)		+= edr.o
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
new file mode 100644
index 000000000000..b3e9103585a1
--- /dev/null
+++ b/drivers/pci/pcie/edr.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PCI DPC Error Disconnect Recover support driver
+ * Author: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
+ *
+ * Copyright (C) 2020 Intel Corp.
+ */
+
+#define dev_fmt(fmt) "EDR: " fmt
+
+#include <linux/pci.h>
+#include <linux/pci-acpi.h>
+
+#include "portdrv.h"
+#include "dpc.h"
+#include "../pci.h"
+
+#define EDR_PORT_ENABLE_DSM		0x0C
+#define EDR_PORT_LOCATE_DSM		0x0D
+#define EDR_OST_SUCCESS			0x80
+#define EDR_OST_FAILED			0x81
+
+/*
+ * _DSM wrapper function to enable/disable DPC port.
+ * @pdev   : PCI device structure.
+ * @enable: status of DPC port (0 or 1).
+ *
+ * returns 0 on success or errno on failure.
+ */
+static int acpi_enable_dpc_port(struct pci_dev *pdev, bool enable)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	union acpi_object *obj, argv4, req;
+	int status = 0;
+
+	req.type = ACPI_TYPE_INTEGER;
+	req.integer.value = enable;
+
+	argv4.type = ACPI_TYPE_PACKAGE;
+	argv4.package.count = 1;
+	argv4.package.elements = &req;
+
+	/*
+	 * Per the Downstream Port Containment Related Enhancements ECN to
+	 * the PCI Firmware Specification r3.2, sec 4.6.12,
+	 * EDR_PORT_ENABLE_DSM is optional.  Return success if it's not
+	 * implemented.
+	 */
+	obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
+				EDR_PORT_ENABLE_DSM, &argv4);
+	if (!obj)
+		return 0;
+
+	if (obj->type != ACPI_TYPE_INTEGER || obj->integer.value != enable)
+		status = -EIO;
+
+	ACPI_FREE(obj);
+
+	return status;
+}
+
+/*
+ * _DSM wrapper function to locate DPC port.
+ * @pdev   : Device which received EDR event.
+ *
+ * returns pci_dev or NULL.
+ */
+static struct pci_dev *acpi_locate_dpc_port(struct pci_dev *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	union acpi_object *obj;
+	u16 port;
+
+	obj = acpi_evaluate_dsm(adev->handle, &pci_acpi_dsm_guid, 5,
+				EDR_PORT_LOCATE_DSM, NULL);
+	if (!obj)
+		return pci_dev_get(pdev);
+
+	if (obj->type != ACPI_TYPE_INTEGER) {
+		ACPI_FREE(obj);
+		return NULL;
+	}
+
+	/*
+	 * Firmware returns DPC port BDF details in following format:
+	 *	15:8 = bus
+	 *	 7:3 = device
+	 *	 2:0 = function
+	 */
+	port = obj->integer.value;
+
+	ACPI_FREE(obj);
+
+	return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
+					   PCI_BUS_NUM(port), port & 0xff);
+}
+
+/*
+ * _OST wrapper function to let firmware know the status of EDR event.
+ * @pdev   : Device used to send _OST.
+ * @edev   : Device which experienced EDR event.
+ * @status: Status of EDR event.
+ */
+static int acpi_send_edr_status(struct pci_dev *pdev, struct pci_dev *edev,
+				u16 status)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	u32 ost_status;
+
+	pci_dbg(pdev, "Sending EDR status :%#x\n", status);
+
+	ost_status =  PCI_DEVID(edev->bus->number, edev->devfn);
+	ost_status = (ost_status << 16) | status;
+
+	status = acpi_evaluate_ost(adev->handle,
+				   ACPI_NOTIFY_DISCONNECT_RECOVER,
+				   ost_status, NULL);
+	if (ACPI_FAILURE(status))
+		return -EINVAL;
+
+	return 0;
+}
+
+pci_ers_result_t edr_dpc_reset_link(void *cb_data)
+{
+	return dpc_reset_link_common(cb_data);
+}
+
+static void edr_handle_event(acpi_handle handle, u32 event, void *data)
+{
+	struct dpc_dev *dpc = data, ndpc;
+	struct pci_dev *pdev = dpc->pdev;
+	pci_ers_result_t estate = PCI_ERS_RESULT_DISCONNECT;
+	u16 status;
+
+	pci_info(pdev, "ACPI event %#x received\n", event);
+
+	if (event != ACPI_NOTIFY_DISCONNECT_RECOVER)
+		return;
+
+	/*
+	 * Check if _DSM(0xD) is available, and if present locate the
+	 * port which issued EDR event.
+	 */
+	pdev = acpi_locate_dpc_port(pdev);
+	if (!pdev) {
+		pci_err(dpc->pdev, "No valid port found\n");
+		return;
+	}
+
+	if (pdev != dpc->pdev) {
+		pci_warn(pdev, "Initializing dpc again\n");
+		dpc_dev_init(pdev, &ndpc);
+		dpc= &ndpc;
+	}
+
+	/*
+	 * If port does not support DPC, just send the OST:
+	 */
+	if (!dpc->cap_pos)
+		goto send_ost;
+
+	/* Check if there is a valid DPC trigger */
+	pci_read_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS, &status);
+	if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) {
+		pci_err(pdev, "Invalid DPC trigger %#010x\n", status);
+		goto send_ost;
+	}
+
+	dpc_process_error(dpc);
+
+	/* Clear AER registers */
+	pci_aer_clear_err_uncor_status(pdev);
+	pci_aer_clear_err_fatal_status(pdev);
+	pci_aer_clear_err_status_regs(pdev);
+
+	/*
+	 * Irrespective of whether the DPC event is triggered by
+	 * ERR_FATAL or ERR_NONFATAL, since the link is already down,
+	 * use the FATAL error recovery path for both cases.
+	 */
+	estate = pcie_do_recovery_common(pdev, pci_channel_io_frozen, -1,
+					 edr_dpc_reset_link, dpc);
+send_ost:
+
+	/* Use ACPI handle of DPC event device for sending EDR status */
+	dpc = data;
+
+	/*
+	 * If recovery is successful, send _OST(0xF, BDF << 16 | 0x80)
+	 * to firmware. If not successful, send _OST(0xF, BDF << 16 | 0x81).
+	 */
+	if (estate == PCI_ERS_RESULT_RECOVERED)
+		acpi_send_edr_status(dpc->pdev, pdev, EDR_OST_SUCCESS);
+	else
+		acpi_send_edr_status(dpc->pdev, pdev, EDR_OST_FAILED);
+
+	pci_dev_put(pdev);
+}
+
+int pci_acpi_add_edr_notifier(struct pci_dev *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct dpc_dev *dpc;
+	acpi_status astatus;
+	int status;
+
+	/*
+	 * Per the Downstream Port Containment Related Enhancements ECN to
+	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-6, EDR support
+	 * can only be enabled if DPC is controlled by firmware.
+	 *
+	 * TODO: Remove dependency on ACPI FIRMWARE_FIRST bit to
+	 * determine ownership of DPC between firmware or OS.
+	 */
+	if (!pcie_aer_get_firmware_first(pdev) || pcie_ports_dpc_native)
+		return -ENODEV;
+
+	if (!adev)
+		return 0;
+
+	dpc = devm_kzalloc(&pdev->dev, sizeof(*dpc), GFP_KERNEL);
+	if (!dpc)
+		return -ENOMEM;
+
+	dpc_dev_init(pdev, dpc);
+
+	astatus = acpi_install_notify_handler(adev->handle,
+					      ACPI_SYSTEM_NOTIFY,
+					      edr_handle_event, dpc);
+	if (ACPI_FAILURE(astatus)) {
+		pci_err(pdev, "Install ACPI_SYSTEM_NOTIFY handler failed\n");
+		return -EBUSY;
+	}
+
+	status = acpi_enable_dpc_port(pdev, true);
+	if (status) {
+		pci_warn(pdev, "Enable DPC port failed\n");
+		acpi_remove_notify_handler(adev->handle,
+					   ACPI_SYSTEM_NOTIFY,
+					   edr_handle_event);
+		return status;
+	}
+
+	return 0;
+}
+
+void pci_acpi_remove_edr_notifier(struct pci_dev *pdev)
+{
+	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+
+	if (!adev)
+		return;
+
+	acpi_remove_notify_handler(adev->handle, ACPI_SYSTEM_NOTIFY,
+				   edr_handle_event);
+}
diff --git a/include/linux/pci-acpi.h b/include/linux/pci-acpi.h
index 62b7fdcc661c..a430e5fc50f3 100644
--- a/include/linux/pci-acpi.h
+++ b/include/linux/pci-acpi.h
@@ -112,6 +112,14 @@ extern const guid_t pci_acpi_dsm_guid;
 #define RESET_DELAY_DSM			0x08
 #define FUNCTION_DELAY_DSM		0x09
 
+#ifdef CONFIG_PCIE_EDR
+int pci_acpi_add_edr_notifier(struct pci_dev *pdev);
+void pci_acpi_remove_edr_notifier(struct pci_dev *pdev);
+#else
+static inline int pci_acpi_add_edr_notifier(struct pci_dev *pdev) { return 0; }
+static inline void pci_acpi_remove_edr_notifier(struct pci_dev *pdev) { }
+#endif /* CONFIG_PCIE_EDR */
+
 #else	/* CONFIG_ACPI */
 static inline void acpi_pci_add_bus(struct pci_bus *bus) { }
 static inline void acpi_pci_remove_bus(struct pci_bus *bus) { }
-- 
2.21.0

[PATCH v14 5/5] PCI/ACPI: Enable EDR support

[sathyanarayanan.kuppuswamy]

From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>

As per PCI firmware specification r3.2 Downstream Port Containment
Related Enhancements ECN, sec 4.5.1, OS must implement following steps
to enable/use EDR feature.

1. OS can use bit 7 of _OSC Control Field to negotiate control over
Downstream Port Containment (DPC) configuration of PCIe port. After _OSC
negotiation, firmware will Set this bit to grant OS control over PCIe
DPC configuration and Clear it if this feature was requested and denied,
or was not requested.

2. Also, if OS supports EDR, it should expose its support to BIOS by
setting bit 7 of _OSC Support Field. And if OS sets bit 7 of _OSC
Control Field it must also expose support for EDR by setting bit 7 of
_OSC Support Field.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Acked-by: Keith Busch <keith.busch@intel.com>
Tested-by: Huong Nguyen <huong.nguyen@dell.com>
Tested-by: Austin Bolen <Austin.Bolen@dell.com>
---
 drivers/acpi/pci_root.c | 16 ++++++++++++++++
 drivers/pci/pcie/edr.c  |  4 +++-
 drivers/pci/probe.c     |  1 +
 include/linux/acpi.h    |  6 ++++--
 include/linux/pci.h     |  1 +
 5 files changed, 25 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/pci_root.c b/drivers/acpi/pci_root.c
index d1e666ef3fcc..ad1be5941a00 100644
--- a/drivers/acpi/pci_root.c
+++ b/drivers/acpi/pci_root.c
@@ -131,6 +131,7 @@ static struct pci_osc_bit_struct pci_osc_support_bit[] = {
 	{ OSC_PCI_CLOCK_PM_SUPPORT, "ClockPM" },
 	{ OSC_PCI_SEGMENT_GROUPS_SUPPORT, "Segments" },
 	{ OSC_PCI_MSI_SUPPORT, "MSI" },
+	{ OSC_PCI_EDR_SUPPORT, "EDR" },
 	{ OSC_PCI_HPX_TYPE_3_SUPPORT, "HPX-Type3" },
 };
 
@@ -141,6 +142,7 @@ static struct pci_osc_bit_struct pci_osc_control_bit[] = {
 	{ OSC_PCI_EXPRESS_AER_CONTROL, "AER" },
 	{ OSC_PCI_EXPRESS_CAPABILITY_CONTROL, "PCIeCapability" },
 	{ OSC_PCI_EXPRESS_LTR_CONTROL, "LTR" },
+	{ OSC_PCI_EXPRESS_DPC_CONTROL, "DPC" },
 };
 
 static void decode_osc_bits(struct acpi_pci_root *root, char *msg, u32 word,
@@ -440,6 +442,8 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 		support |= OSC_PCI_ASPM_SUPPORT | OSC_PCI_CLOCK_PM_SUPPORT;
 	if (pci_msi_enabled())
 		support |= OSC_PCI_MSI_SUPPORT;
+	if (IS_ENABLED(CONFIG_PCIE_EDR))
+		support |= OSC_PCI_EDR_SUPPORT;
 
 	decode_osc_support(root, "OS supports", support);
 	status = acpi_pci_osc_support(root, support);
@@ -487,6 +491,16 @@ static void negotiate_os_control(struct acpi_pci_root *root, int *no_aspm,
 			control |= OSC_PCI_EXPRESS_AER_CONTROL;
 	}
 
+	/*
+	 * Per the Downstream Port Containment Related Enhancements ECN to
+	 * the PCI Firmware Spec, r3.2, sec 4.5.1, table 4-5,
+	 * OSC_PCI_EXPRESS_DPC_CONTROL indicates the OS supports both DPC
+	 * and EDR. So use CONFIG_PCIE_EDR for requesting DPC control which
+	 * will only be turned on if both EDR and DPC is enabled.
+	 */
+	if (IS_ENABLED(CONFIG_PCIE_EDR))
+		control |= OSC_PCI_EXPRESS_DPC_CONTROL;
+
 	requested = control;
 	status = acpi_pci_osc_control_set(handle, &control,
 					  OSC_PCI_EXPRESS_CAPABILITY_CONTROL);
@@ -916,6 +930,8 @@ struct pci_bus *acpi_pci_root_create(struct acpi_pci_root *root,
 		host_bridge->native_pme = 0;
 	if (!(root->osc_control_set & OSC_PCI_EXPRESS_LTR_CONTROL))
 		host_bridge->native_ltr = 0;
+	if (!(root->osc_control_set & OSC_PCI_EXPRESS_DPC_CONTROL))
+		host_bridge->native_dpc = 0;
 
 	/*
 	 * Evaluate the "PCI Boot Configuration" _DSM Function.  If it
diff --git a/drivers/pci/pcie/edr.c b/drivers/pci/pcie/edr.c
index b3e9103585a1..e7dfe401db5c 100644
--- a/drivers/pci/pcie/edr.c
+++ b/drivers/pci/pcie/edr.c
@@ -201,6 +201,7 @@ static void edr_handle_event(acpi_handle handle, u32 event, void *data)
 int pci_acpi_add_edr_notifier(struct pci_dev *pdev)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct pci_host_bridge *host = pci_find_host_bridge(pdev->bus);
 	struct dpc_dev *dpc;
 	acpi_status astatus;
 	int status;
@@ -213,7 +214,8 @@ int pci_acpi_add_edr_notifier(struct pci_dev *pdev)
 	 * TODO: Remove dependency on ACPI FIRMWARE_FIRST bit to
 	 * determine ownership of DPC between firmware or OS.
 	 */
-	if (!pcie_aer_get_firmware_first(pdev) || pcie_ports_dpc_native)
+	if (!pcie_aer_get_firmware_first(pdev) || pcie_ports_dpc_native ||
+	    (host->native_dpc))
 		return -ENODEV;
 
 	if (!adev)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 512cb4312ddd..c9a9c5b42e72 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -598,6 +598,7 @@ static void pci_init_host_bridge(struct pci_host_bridge *bridge)
 	bridge->native_shpc_hotplug = 1;
 	bridge->native_pme = 1;
 	bridge->native_ltr = 1;
+	bridge->native_dpc = 1;
 }
 
 struct pci_host_bridge *pci_alloc_host_bridge(size_t priv)
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 0f37a7d5fa77..0a7aaa452a98 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -515,8 +515,9 @@ extern bool osc_pc_lpi_support_confirmed;
 #define OSC_PCI_CLOCK_PM_SUPPORT		0x00000004
 #define OSC_PCI_SEGMENT_GROUPS_SUPPORT		0x00000008
 #define OSC_PCI_MSI_SUPPORT			0x00000010
+#define OSC_PCI_EDR_SUPPORT			0x00000080
 #define OSC_PCI_HPX_TYPE_3_SUPPORT		0x00000100
-#define OSC_PCI_SUPPORT_MASKS			0x0000011f
+#define OSC_PCI_SUPPORT_MASKS			0x0000019f
 
 /* PCI Host Bridge _OSC: Capabilities DWORD 3: Control Field */
 #define OSC_PCI_EXPRESS_NATIVE_HP_CONTROL	0x00000001
@@ -525,7 +526,8 @@ extern bool osc_pc_lpi_support_confirmed;
 #define OSC_PCI_EXPRESS_AER_CONTROL		0x00000008
 #define OSC_PCI_EXPRESS_CAPABILITY_CONTROL	0x00000010
 #define OSC_PCI_EXPRESS_LTR_CONTROL		0x00000020
-#define OSC_PCI_CONTROL_MASKS			0x0000003f
+#define OSC_PCI_EXPRESS_DPC_CONTROL		0x00000080
+#define OSC_PCI_CONTROL_MASKS			0x000000bf
 
 #define ACPI_GSB_ACCESS_ATTRIB_QUICK		0x00000002
 #define ACPI_GSB_ACCESS_ATTRIB_SEND_RCV         0x00000004
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c393dff2d66f..d0739e90f4e7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -510,6 +510,7 @@ struct pci_host_bridge {
 	unsigned int	native_shpc_hotplug:1;	/* OS may use SHPC hotplug */
 	unsigned int	native_pme:1;		/* OS may use PCIe PME */
 	unsigned int	native_ltr:1;		/* OS may use PCIe LTR */
+	unsigned int	native_dpc:1;		/* OS may use PCIe DPC */
 	unsigned int	preserve_config:1;	/* Preserve FW resource setup */
 
 	/* Resource alignment requirements */
-- 
2.21.0

Re: [PATCH v14 0/5] Add Error Disconnect Recover (EDR) support

[Bjorn Helgaas]

On Fri, Feb 07, 2020 at 04:03:30PM -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote:
> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
> 
> This patchset adds support for following features:
> 
> 1. Error Disconnect Recover (EDR) support.
> 2. _OSC based negotiation support for DPC.
> 
> You can find EDR spec in the following link.
> 
> https://members.pcisig.com/wg/PCI-SIG/document/12614

Hi Sathy,

Bad timing!  Linus tagged v5.6-rc1 on Feb 9, shortly after you posted
this.  Would you mind refreshing this so it applies on my "master"
branch (v5.6-rc1)?

> Changes since v13:
>  * Moved all EDR related code to edr.c
>  * Addressed Bjorns comments.
> 
> Changes since v12:
>  * Addressed Bjorns comments.
>  * Added check for CONFIG_PCIE_EDR before requesting DPC control from firmware.
>  * Removed ff_check parameter from AER APIs.
>  * Used macros for _OST return status values in DPC driver.
> 
> Changes since v11:
>  * Allowed error recovery to proceed after successful reset_link().
>  * Used correct ACPI handle for sending EDR status.
>  * Rebased on top of v5.5-rc5
> 
> Changes since v10:
>  * Added "edr_enabled" member to dpc priv structure, which is used to cache EDR
>    enabling status based on status of pcie_ports_dpc_native and FF mode.
>  * Changed type of _DSM argument from Integer to Package in acpi_enable_dpc_port()
>    function to fix ACPI related boot warnings.
>  * Rebased on top of v5.5-rc3
> 
> Changes since v9:
>  * Removed caching of pcie_aer_get_firmware_first() in dpc driver.
>  * Added proper spec reference in git log for patch 5 & 7.
>  * Added new function parameter "ff_check" to pci_cleanup_aer_uncorrect_error_status(),
>    pci_aer_clear_fatal_status() and pci_cleanup_aer_error_status_regs() functions.
>  * Rebased on top of v5.4-rc5
> 
> Changes since v8:
>  * Rebased on top of v5.4-rc1
> 
> Changes since v7:
>  * Updated DSM version number to match the spec.
> 
> Changes since v6:
>  * Modified the order of patches to enable EDR only after all necessary support is added in kernel.
>  * Addressed Bjorn comments.
> 
> Changes since v5:
>  * Addressed Keith's comments.
>  * Added additional check for FF mode in pci_aer_init().
>  * Updated commit history of "PCI/DPC: Add support for DPC recovery on NON_FATAL errors" patch.
> 
> Changes since v4:
>  * Rebased on top of v5.3-rc1
>  * Fixed lock/unlock issue in edr_handle_event().
>  * Merged "Update error status after reset_link()" patch into this patchset.
> 
> Changes since v3:
>  * Moved EDR related ACPI functions/definitions to pci-acpi.c
>  * Modified commit history in few patches to include spec reference.
>  * Added support to handle DPC triggered by NON_FATAL errors.
>  * Added edr_lock to protect PCI device receiving duplicate EDR notifications.
>  * Addressed Bjorn comments.
> 
> Changes since v2:
>  * Split EDR support patch into multiple patches.
>  * Addressed Bjorn comments.
> 
> Changes since v1:
>  * Rebased on top of v5.1-rc1
> 
> Kuppuswamy Sathyanarayanan (5):
>   PCI/ERR: Update error status after reset_link()
>   PCI/DPC: Remove pcie_device reference from dpc_dev structure
>   PCI/EDR: Export AER, DPC and error recovery functions
>   PCI/DPC: Add Error Disconnect Recover (EDR) support
>   PCI/ACPI: Enable EDR support
> 
>  drivers/acpi/pci_root.c   |  16 +++
>  drivers/pci/pci-acpi.c    |   3 +
>  drivers/pci/pci.h         |   8 ++
>  drivers/pci/pcie/Kconfig  |  10 ++
>  drivers/pci/pcie/Makefile |   1 +
>  drivers/pci/pcie/aer.c    |  39 ++++--
>  drivers/pci/pcie/dpc.c    |  92 ++++++++------
>  drivers/pci/pcie/dpc.h    |  20 +++
>  drivers/pci/pcie/edr.c    | 259 ++++++++++++++++++++++++++++++++++++++
>  drivers/pci/pcie/err.c    |  35 ++++--
>  drivers/pci/probe.c       |   1 +
>  include/linux/acpi.h      |   6 +-
>  include/linux/pci-acpi.h  |   8 ++
>  include/linux/pci.h       |   1 +
>  14 files changed, 441 insertions(+), 58 deletions(-)
>  create mode 100644 drivers/pci/pcie/dpc.h
>  create mode 100644 drivers/pci/pcie/edr.c
> 
> -- 
> 2.21.0
> 

Re: [PATCH v14 0/5] Add Error Disconnect Recover (EDR) support

[Kuppuswamy Sathyanarayanan]

Hi Bjorn,

On 2/12/20 6:38 AM, Bjorn Helgaas wrote:
> On Fri, Feb 07, 2020 at 04:03:30PM -0800, sathyanarayanan.kuppuswamy@linux.intel.com wrote:
>> From: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
>>
>> This patchset adds support for following features:
>>
>> 1. Error Disconnect Recover (EDR) support.
>> 2. _OSC based negotiation support for DPC.
>>
>> You can find EDR spec in the following link.
>>
>> https://members.pcisig.com/wg/PCI-SIG/document/12614
> Hi Sathy,
>
> Bad timing!  Linus tagged v5.6-rc1 on Feb 9, shortly after you posted
> this.  Would you mind refreshing this so it applies on my "master"
> branch (v5.6-rc1)?
Sure.
>
>> Changes since v13:
>>   * Moved all EDR related code to edr.c
>>   * Addressed Bjorns comments.
>>
>> Changes since v12:
>>   * Addressed Bjorns comments.
>>   * Added check for CONFIG_PCIE_EDR before requesting DPC control from firmware.
>>   * Removed ff_check parameter from AER APIs.
>>   * Used macros for _OST return status values in DPC driver.
>>
>> Changes since v11:
>>   * Allowed error recovery to proceed after successful reset_link().
>>   * Used correct ACPI handle for sending EDR status.
>>   * Rebased on top of v5.5-rc5
>>
>> Changes since v10:
>>   * Added "edr_enabled" member to dpc priv structure, which is used to cache EDR
>>     enabling status based on status of pcie_ports_dpc_native and FF mode.
>>   * Changed type of _DSM argument from Integer to Package in acpi_enable_dpc_port()
>>     function to fix ACPI related boot warnings.
>>   * Rebased on top of v5.5-rc3
>>
>> Changes since v9:
>>   * Removed caching of pcie_aer_get_firmware_first() in dpc driver.
>>   * Added proper spec reference in git log for patch 5 & 7.
>>   * Added new function parameter "ff_check" to pci_cleanup_aer_uncorrect_error_status(),
>>     pci_aer_clear_fatal_status() and pci_cleanup_aer_error_status_regs() functions.
>>   * Rebased on top of v5.4-rc5
>>
>> Changes since v8:
>>   * Rebased on top of v5.4-rc1
>>
>> Changes since v7:
>>   * Updated DSM version number to match the spec.
>>
>> Changes since v6:
>>   * Modified the order of patches to enable EDR only after all necessary support is added in kernel.
>>   * Addressed Bjorn comments.
>>
>> Changes since v5:
>>   * Addressed Keith's comments.
>>   * Added additional check for FF mode in pci_aer_init().
>>   * Updated commit history of "PCI/DPC: Add support for DPC recovery on NON_FATAL errors" patch.
>>
>> Changes since v4:
>>   * Rebased on top of v5.3-rc1
>>   * Fixed lock/unlock issue in edr_handle_event().
>>   * Merged "Update error status after reset_link()" patch into this patchset.
>>
>> Changes since v3:
>>   * Moved EDR related ACPI functions/definitions to pci-acpi.c
>>   * Modified commit history in few patches to include spec reference.
>>   * Added support to handle DPC triggered by NON_FATAL errors.
>>   * Added edr_lock to protect PCI device receiving duplicate EDR notifications.
>>   * Addressed Bjorn comments.
>>
>> Changes since v2:
>>   * Split EDR support patch into multiple patches.
>>   * Addressed Bjorn comments.
>>
>> Changes since v1:
>>   * Rebased on top of v5.1-rc1
>>
>> Kuppuswamy Sathyanarayanan (5):
>>    PCI/ERR: Update error status after reset_link()
>>    PCI/DPC: Remove pcie_device reference from dpc_dev structure
>>    PCI/EDR: Export AER, DPC and error recovery functions
>>    PCI/DPC: Add Error Disconnect Recover (EDR) support
>>    PCI/ACPI: Enable EDR support
>>
>>   drivers/acpi/pci_root.c   |  16 +++
>>   drivers/pci/pci-acpi.c    |   3 +
>>   drivers/pci/pci.h         |   8 ++
>>   drivers/pci/pcie/Kconfig  |  10 ++
>>   drivers/pci/pcie/Makefile |   1 +
>>   drivers/pci/pcie/aer.c    |  39 ++++--
>>   drivers/pci/pcie/dpc.c    |  92 ++++++++------
>>   drivers/pci/pcie/dpc.h    |  20 +++
>>   drivers/pci/pcie/edr.c    | 259 ++++++++++++++++++++++++++++++++++++++
>>   drivers/pci/pcie/err.c    |  35 ++++--
>>   drivers/pci/probe.c       |   1 +
>>   include/linux/acpi.h      |   6 +-
>>   include/linux/pci-acpi.h  |   8 ++
>>   include/linux/pci.h       |   1 +
>>   14 files changed, 441 insertions(+), 58 deletions(-)
>>   create mode 100644 drivers/pci/pcie/dpc.h
>>   create mode 100644 drivers/pci/pcie/edr.c
>>
>> -- 
>> 2.21.0
>>
-- 
Sathyanarayanan Kuppuswamy
Linux kernel developer