From: Wei Huang <wei.huang2@amd.com>
To: <linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-doc@vger.kernel.org>, <netdev@vger.kernel.org>
Cc: <bhelgaas@google.com>, <corbet@lwn.net>, <davem@davemloft.net>,
<edumazet@google.com>, <kuba@kernel.org>, <pabeni@redhat.com>,
<alex.williamson@redhat.com>, <gospo@broadcom.com>,
<michael.chan@broadcom.com>, <ajit.khaparde@broadcom.com>,
<manoj.panicker2@amd.com>, <Eric.VanTassell@amd.com>,
<wei.huang2@amd.com>
Subject: [PATCH V1 3/9] PCI/TPH: Implement a command line option to disable TPH
Date: Thu, 9 May 2024 11:27:35 -0500 [thread overview]
Message-ID: <20240509162741.1937586-4-wei.huang2@amd.com> (raw)
In-Reply-To: <20240509162741.1937586-1-wei.huang2@amd.com>
Provide a kernel option, with related helper functions, to completely
disable TPH so that no TPH headers are generated.
Co-developed-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Signed-off-by: Eric Van Tassell <Eric.VanTassell@amd.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Wei Huang <wei.huang2@amd.com>
---
.../admin-guide/kernel-parameters.txt | 1 +
drivers/pci/pci-driver.c | 7 ++++-
drivers/pci/pci.c | 12 ++++++++
drivers/pci/pcie/tph.c | 30 +++++++++++++++++++
include/linux/pci-tph.h | 19 ++++++++++++
include/linux/pci.h | 1 +
6 files changed, 69 insertions(+), 1 deletion(-)
create mode 100644 include/linux/pci-tph.h
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 396137ee018d..5681600c6941 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4593,6 +4593,7 @@
nomio [S390] Do not use MIO instructions.
norid [S390] ignore the RID field and force use of
one PCI domain per PCI function
+ notph [PCIE] Do not use PCIe TPH
pcie_aspm= [PCIE] Forcibly enable or ignore PCIe Active State Power
Management.
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index af2996d0d17f..9722d070c0ca 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -21,6 +21,7 @@
#include <linux/acpi.h>
#include <linux/dma-map-ops.h>
#include <linux/iommu.h>
+#include <linux/pci-tph.h>
#include "pci.h"
#include "pcie/portdrv.h"
@@ -322,8 +323,12 @@ static long local_pci_probe(void *_ddi)
pm_runtime_get_sync(dev);
pci_dev->driver = pci_drv;
rc = pci_drv->probe(pci_dev, ddi->id);
- if (!rc)
+ if (!rc) {
+ if (pci_tph_disabled())
+ pcie_tph_disable(pci_dev);
+
return rc;
+ }
if (rc < 0) {
pci_dev->driver = NULL;
pm_runtime_put_sync(dev);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index e5f243dd4288..06f9656f95bf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -157,6 +157,9 @@ static bool pcie_ari_disabled;
/* If set, the PCIe ATS capability will not be used. */
static bool pcie_ats_disabled;
+/* If set, the PCIe TPH capability will not be used. */
+static bool pcie_tph_disabled;
+
/* If set, the PCI config space of each device is printed during boot. */
bool pci_early_dump;
@@ -166,6 +169,12 @@ bool pci_ats_disabled(void)
}
EXPORT_SYMBOL_GPL(pci_ats_disabled);
+bool pci_tph_disabled(void)
+{
+ return pcie_tph_disabled;
+}
+EXPORT_SYMBOL_GPL(pci_tph_disabled);
+
/* Disable bridge_d3 for all PCIe ports */
static bool pci_bridge_d3_disable;
/* Force bridge_d3 for all PCIe ports */
@@ -6707,6 +6716,9 @@ static int __init pci_setup(char *str)
pci_no_domains();
} else if (!strncmp(str, "noari", 5)) {
pcie_ari_disabled = true;
+ } else if (!strcmp(str, "notph")) {
+ pr_info("PCIe: TPH is disabled\n");
+ pcie_tph_disabled = true;
} else if (!strncmp(str, "cbiosize=", 9)) {
pci_cardbus_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "cbmemsize=", 10)) {
diff --git a/drivers/pci/pcie/tph.c b/drivers/pci/pcie/tph.c
index 5f0cc06b74bb..5dc533b89a33 100644
--- a/drivers/pci/pcie/tph.c
+++ b/drivers/pci/pcie/tph.c
@@ -16,11 +16,41 @@
#include <linux/errno.h>
#include <linux/msi.h>
#include <linux/pci.h>
+#include <linux/pci-tph.h>
#include <linux/msi.h>
#include <linux/pci-acpi.h>
#include "../pci.h"
+static int tph_set_reg_field_u32(struct pci_dev *dev, u8 offset, u32 mask,
+ u8 shift, u32 field)
+{
+ u32 reg_val;
+ int ret;
+
+ if (!dev->tph_cap)
+ return -EINVAL;
+
+ ret = pci_read_config_dword(dev, dev->tph_cap + offset, ®_val);
+ if (ret)
+ return ret;
+
+ reg_val &= ~mask;
+ reg_val |= (field << shift) & mask;
+
+ ret = pci_write_config_dword(dev, dev->tph_cap + offset, reg_val);
+
+ return ret;
+}
+
+int pcie_tph_disable(struct pci_dev *dev)
+{
+ return tph_set_reg_field_u32(dev, PCI_TPH_CTRL,
+ PCI_TPH_CTRL_REQ_EN_MASK,
+ PCI_TPH_CTRL_REQ_EN_SHIFT,
+ PCI_TPH_REQ_DISABLE);
+}
+
void pcie_tph_init(struct pci_dev *dev)
{
dev->tph_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_TPH);
diff --git a/include/linux/pci-tph.h b/include/linux/pci-tph.h
new file mode 100644
index 000000000000..e187d7e89e8c
--- /dev/null
+++ b/include/linux/pci-tph.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * TPH (TLP Processing Hints)
+ *
+ * Copyright (C) 2024 Advanced Micro Devices, Inc.
+ * Eric Van Tassell <Eric.VanTassell@amd.com>
+ * Wei Huang <wei.huang2@amd.com>
+ */
+#ifndef LINUX_PCI_TPH_H
+#define LINUX_PCI_TPH_H
+
+#ifdef CONFIG_PCIE_TPH
+int pcie_tph_disable(struct pci_dev *dev);
+#else
+static inline int pcie_tph_disable(struct pci_dev *dev)
+{ return -EOPNOTSUPP; }
+#endif
+
+#endif /* LINUX_PCI_TPH_H */
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 73d92c7d2c5b..63aa6f888c90 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1866,6 +1866,7 @@ static inline bool pci_aer_available(void) { return false; }
#endif
bool pci_ats_disabled(void);
+bool pci_tph_disabled(void);
#ifdef CONFIG_PCIE_PTM
int pci_enable_ptm(struct pci_dev *dev, u8 *granularity);
--
2.44.0
next prev parent reply other threads:[~2024-05-09 16:28 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-09 16:27 [PATCH V1 0/9] PCIe TPH and cache direct injection support Wei Huang
2024-05-09 16:27 ` [PATCH V1 1/9] PCI: Introduce PCIe TPH support framework Wei Huang
2024-05-09 16:27 ` [PATCH V1 2/9] PCI: Add TPH related register definition Wei Huang
2024-05-09 16:27 ` Wei Huang [this message]
2024-05-09 16:27 ` [PATCH V1 4/9] PCI/TPH: Implement a command line option to force No ST Mode Wei Huang
2024-05-09 16:27 ` [PATCH V1 5/9] PCI/TPH: Introduce API functions to get/set steering tags Wei Huang
2024-05-10 3:07 ` kernel test robot
2024-05-11 20:15 ` Simon Horman
2024-05-13 13:29 ` Wei Huang
2024-05-09 16:27 ` [PATCH V1 6/9] PCI/TPH: Retrieve steering tag from ACPI _DSM Wei Huang
2024-05-10 4:20 ` kernel test robot
2024-05-10 5:24 ` kernel test robot
2024-05-09 16:27 ` [PATCH V1 7/9] PCI/TPH: Add TPH documentation Wei Huang
2024-05-15 12:11 ` Bagas Sanjaya
2024-05-09 16:27 ` [PATCH V1 8/9] bnxt_en: Add TPH support in BNXT driver Wei Huang
2024-05-09 21:50 ` Vadim Fedorenko
2024-05-10 3:55 ` Ajit Khaparde
2024-05-10 10:35 ` Vadim Fedorenko
2024-05-10 15:23 ` Andy Gospodarek
2024-05-10 20:03 ` David Wei
2024-05-10 20:33 ` Andy Gospodarek
2024-05-10 20:33 ` Vadim Fedorenko
2024-05-10 20:37 ` Andy Gospodarek
2024-05-10 3:10 ` Somnath Kotur
2024-05-09 16:27 ` [PATCH V1 9/9] bnxt_en: Pass NQ ID to the FW when allocating RX/RX AGG rings Wei Huang
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