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[PATCH V2 1/9] PCI: Introduce PCIe TPH support framework

Wei Huang posted 9 patches 1 year, 8 months ago
There is a newer version of this series
[PATCH V2 1/9] PCI: Introduce PCIe TPH support framework
Posted by Wei Huang 1 year, 8 months ago 
This patch implements the framework for PCIe TPH support. It introduces
tph.c source file, along with CONFIG_PCIE_TPH, to Linux PCIe subsystem.
A new member, named tph_cap, is also introduced in pci_dev to cache TPH
capability offset.

Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Signed-off-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com> 
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
---
 drivers/pci/pci.h         |  6 ++++++
 drivers/pci/pcie/Kconfig  | 10 ++++++++++
 drivers/pci/pcie/Makefile |  1 +
 drivers/pci/pcie/tph.c    | 28 ++++++++++++++++++++++++++++
 drivers/pci/probe.c       |  1 +
 include/linux/pci.h       |  4 ++++
 6 files changed, 50 insertions(+)
 create mode 100644 drivers/pci/pcie/tph.c

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index fd44565c4756..b371b5b45f86 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -506,6 +506,12 @@ static inline int pci_iov_bus_range(struct pci_bus *bus)
 
 #endif /* CONFIG_PCI_IOV */
 
+#ifdef CONFIG_PCIE_TPH
+void pcie_tph_init(struct pci_dev *dev);
+#else
+static inline void pcie_tph_init(struct pci_dev *dev) {}
+#endif
+
 #ifdef CONFIG_PCIE_PTM
 void pci_ptm_init(struct pci_dev *dev);
 void pci_save_ptm_state(struct pci_dev *dev);
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 17919b99fa66..d22857325b3e 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -155,3 +155,13 @@ config PCIE_EDR
 	  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.
+
+config PCIE_TPH
+	bool "TLP Processing Hints"
+	default n
+	help
+	  This option adds support for PCIE TLP Processing Hints (TPH).
+	  TPH allows endpoint devices to provide optimization hints, such as
+	  desired caching behavior, for requests that target memory space.
+	  These hints, called steering tags, can empower the system hardware
+	  to optimize the utilization of platform resources.
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index 6461aa93fe76..3542b42ea0b9 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_EDR)		+= edr.o
+obj-$(CONFIG_PCIE_TPH)		+= tph.o
diff --git a/drivers/pci/pcie/tph.c b/drivers/pci/pcie/tph.c
new file mode 100644
index 000000000000..5f0cc06b74bb
--- /dev/null
+++ b/drivers/pci/pcie/tph.c
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * TPH (TLP Processing Hints) support
+ *
+ * Copyright (C) 2024 Advanced Micro Devices, Inc.
+ *     Eric Van Tassell <Eric.VanTassell@amd.com>
+ *     Wei Huang <wei.huang2@amd.com>
+ */
+
+#define pr_fmt(fmt) "TPH: " fmt
+#define dev_fmt pr_fmt
+
+#include <linux/acpi.h>
+#include <uapi/linux/pci_regs.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+#include <linux/msi.h>
+#include <linux/pci-acpi.h>
+
+#include "../pci.h"
+
+void pcie_tph_init(struct pci_dev *dev)
+{
+	dev->tph_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
+}
+
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 15168881ec94..1f1ae55a5f83 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2484,6 +2484,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_dpc_init(dev);		/* Downstream Port Containment */
 	pci_rcec_init(dev);		/* Root Complex Event Collector */
 	pci_doe_init(dev);		/* Data Object Exchange */
+	pcie_tph_init(dev);             /* TLP Processing Hints */
 
 	pcie_report_downtraining(dev);
 	pci_init_reset_methods(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 5bece7fd11f8..d75a88ec5136 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -530,6 +530,10 @@ struct pci_dev {
 
 	/* These methods index pci_reset_fn_methods[] */
 	u8 reset_methods[PCI_NUM_RESET_METHODS]; /* In priority order */
+
+#ifdef CONFIG_PCIE_TPH
+	u16 tph_cap; /* TPH capability offset */
+#endif
 };
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
-- 
2.44.0
Re: [PATCH V2 1/9] PCI: Introduce PCIe TPH support framework
Posted by Bjorn Helgaas 1 year, 8 months ago 
On Fri, May 31, 2024 at 04:38:33PM -0500, Wei Huang wrote:
> This patch implements the framework for PCIe TPH support. It introduces
> tph.c source file, along with CONFIG_PCIE_TPH, to Linux PCIe subsystem.
> A new member, named tph_cap, is also introduced in pci_dev to cache TPH
> capability offset.

s/This patch implements/Implement/
s/It introduces/Introduce/
s/is also introduced/Add tph_cap .../

https://chris.beams.io/posts/git-commit/
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/submitting-patches.rst?id=v6.9#n94

> +	  This option adds support for PCIE TLP Processing Hints (TPH).
> +	  TPH allows endpoint devices to provide optimization hints, such as
> +	  desired caching behavior, for requests that target memory space.
> +	  These hints, called steering tags, can empower the system hardware
> +	  to optimize the utilization of platform resources.

s/PCIE TLP/PCIe TLP/ to match context.

> +++ b/drivers/pci/pcie/tph.c

> +#define pr_fmt(fmt) "TPH: " fmt
> +#define dev_fmt pr_fmt

Add when used.

> +void pcie_tph_init(struct pci_dev *dev)
> +{
> +	dev->tph_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
> +}
> +

  $ git am m/v2_20240531_wei_huang2_pcie_tph_and_cache_direct_injection_support.mbx
  Applying: PCI: Introduce PCIe TPH support framework
  .git/rebase-apply/patch:88: new blank line at EOF.
  +
  warning: 1 line adds whitespace errors.
Re: [PATCH V2 1/9] PCI: Introduce PCIe TPH support framework
Posted by Jonathan Cameron 1 year, 8 months ago 
On Fri, 31 May 2024 16:38:33 -0500
Wei Huang <wei.huang2@amd.com> wrote:

> This patch implements the framework for PCIe TPH support. It introduces
> tph.c source file, along with CONFIG_PCIE_TPH, to Linux PCIe subsystem.
> A new member, named tph_cap, is also introduced in pci_dev to cache TPH
> capability offset.
> 
> Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com>
> Signed-off-by: Eric Van Tassell <Eric.VanTassell@amd.com>
> Signed-off-by: Wei Huang <wei.huang2@amd.com>
> Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
> Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com> 
> Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>


One trivial comment inline.
With that fixed.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> diff --git a/drivers/pci/pcie/tph.c b/drivers/pci/pcie/tph.c
> new file mode 100644
> index 000000000000..5f0cc06b74bb
> --- /dev/null
> +++ b/drivers/pci/pcie/tph.c
> @@ -0,0 +1,28 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * TPH (TLP Processing Hints) support
> + *
> + * Copyright (C) 2024 Advanced Micro Devices, Inc.
> + *     Eric Van Tassell <Eric.VanTassell@amd.com>
> + *     Wei Huang <wei.huang2@amd.com>
> + */
> +
> +#define pr_fmt(fmt) "TPH: " fmt
> +#define dev_fmt pr_fmt
> +
> +#include <linux/acpi.h>
> +#include <uapi/linux/pci_regs.h>
> +#include <linux/kernel.h>
> +#include <linux/errno.h>
> +#include <linux/msi.h>
> +#include <linux/pci.h>
> +#include <linux/msi.h>
> +#include <linux/pci-acpi.h>

Introduce headers as you first use them.  That way we can more
easily see if there are unused ones in this list.


> +
> +#include "../pci.h"
> +
> +void pcie_tph_init(struct pci_dev *dev)
> +{
> +	dev->tph_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
> +}
> +
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 15168881ec94..1f1ae55a5f83 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2484,6 +2484,7 @@ static void pci_init_capabilities(struct pci_dev *dev)
>  	pci_dpc_init(dev);		/* Downstream Port Containment */
>  	pci_rcec_init(dev);		/* Root Complex Event Collector */
>  	pci_doe_init(dev);		/* Data Object Exchange */
> +	pcie_tph_init(dev);             /* TLP Processing Hints */
>  
>  	pcie_report_downtraining(dev);
>  	pci_init_reset_methods(dev);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 5bece7fd11f8..d75a88ec5136 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -530,6 +530,10 @@ struct pci_dev {
>  
>  	/* These methods index pci_reset_fn_methods[] */
>  	u8 reset_methods[PCI_NUM_RESET_METHODS]; /* In priority order */
> +
> +#ifdef CONFIG_PCIE_TPH
> +	u16 tph_cap; /* TPH capability offset */
> +#endif
>  };
>  
>  static inline struct pci_dev *pci_physfn(struct pci_dev *dev)

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