[PATCH 2/6] device/pci: add cmdmem cap to pci_dev

From: Dave Jiang <dave.jiang@intel.com>
To: vkoul@kernel.org, tglx@linutronix.de, mingo@redhat.com,
	bp@alien8.de, hpa@zytor.com, bhelgaas@google.com,
	gregkh@linuxfoundation.org, arnd@arndb.de
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
	dmaengine@vger.kernel.org, dan.j.williams@intel.com,
	ashok.raj@intel.com, fenghua.yu@intel.com,
	linux-pci@vger.kernel.org, tony.luck@intel.com,
	jing.lin@intel.com, sanjay.k.kumar@intel.com
Subject: [PATCH 2/6] device/pci: add cmdmem cap to pci_dev
Date: Mon, 30 Mar 2020 14:27:00 -0700	[thread overview]
Message-ID: <158560362090.6059.1762280705382158736.stgit@djiang5-desk3.ch.intel.com> (raw)
In-Reply-To: <158560290392.6059.16921214463585182874.stgit@djiang5-desk3.ch.intel.com>

Since the current accelerator devices do not have standard PCIe capability
enumeration for accepting ENQCMDS yet, for now an attribute of pdev->cmdmem has
been added to struct pci_dev.  Currently a PCI quirk must be used for the
devices that have such cap until the PCI cap is standardized. Add a helper
function to provide the check if a device supports the cmdmem capability.

Such capability is expected to be added to PCIe device cap enumeration in
the future.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
---
 drivers/base/core.c    |   13 +++++++++++++
 include/linux/device.h |    2 ++
 include/linux/pci.h    |    1 +
 3 files changed, 16 insertions(+)

diff --git a/drivers/base/core.c b/drivers/base/core.c
index dbb0f9130f42..cd9f5b040ed4 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -27,6 +27,7 @@
 #include <linux/netdevice.h>
 #include <linux/sched/signal.h>
 #include <linux/sysfs.h>
+#include <linux/pci.h>
 
 #include "base.h"
 #include "power/power.h"
@@ -3790,3 +3791,15 @@ int device_match_any(struct device *dev, const void *unused)
 	return 1;
 }
 EXPORT_SYMBOL_GPL(device_match_any);
+
+bool device_supports_cmdmem(struct device *dev)
+{
+	struct pci_dev *pdev;
+
+	if (!dev_is_pci(dev))
+		return false;
+
+	pdev = to_pci_dev(dev);
+	return pdev->cmdmem;
+}
+EXPORT_SYMBOL_GPL(device_supports_cmdmem);
diff --git a/include/linux/device.h b/include/linux/device.h
index fa04dfd22bbc..3e787d3de435 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -809,6 +809,8 @@ static inline bool dev_has_sync_state(struct device *dev)
 	return false;
 }
 
+extern bool device_supports_cmdmem(struct device *dev);
+
 /*
  * High level routines for use by the bus drivers
  */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 3840a541a9de..0bc5d581f20e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -422,6 +422,7 @@ struct pci_dev {
 	unsigned int	is_probed:1;		/* Device probing in progress */
 	unsigned int	link_active_reporting:1;/* Device capable of reporting link active */
 	unsigned int	no_vf_scan:1;		/* Don't scan for VFs after IOV enablement */
+	unsigned int	cmdmem:1;		/* MMIO writes support command mem region with synchronous write notification */
 	pci_dev_flags_t dev_flags;
 	atomic_t	enable_cnt;	/* pci_enable_device has been called */
 

