[RFC,v3,1/2] pci: introduce the PCIe TLP Processing Hints API
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Commit Message
Extend the PCI driver and the library to extract the Steering Tag (ST)
for a given Processor/Processor Container and Cache ID pair and validate
a Processing Hint from a TPH _DSM associated with a root port device.
The rte_pci_device structure passed into the rte_pci_extract_tph_st()
function could be a device or a root port. If it's a device, the
function should trace it back to the root port and use its TPH _DSM to
extract STs. The implementation of rte_pci_extract_tph_st() is dependent
on the operating system.
rte_pci_extract_tph_st() should also be supplied with a
rte_tph_acpi__dsm_args, and a rte_tph_acpi__dsm_return structures.
These two structures are defined in the PCI library and comply with the
TPH _DSM argument and return encoding specified in the PCI firmware ECN
titled "Revised _DSM for Cache Locality TPH Features.". Use of
rte_init_tph_acpi__dsm_args() is recommended for initializing the
rte_tph_acpi__dsm_args struct which is capable of converting lcore ID,
the cache level into values understood by the ACPI _DSM function.
rte_tph_acpi__dsm_return struct will be initialized with the values
returned by the TPH _DSM; it is up to the caller to use these values per
the device's capabilities.
Signed-off-by: Wathsala Vithanage <wathsala.vithanage@arm.com>
Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
Reviewed-by: Dhruv Tripathi <dhruv.tripathi@arm.com>
---
drivers/bus/pci/bsd/pci.c | 12 ++++
drivers/bus/pci/linux/pci.c | 12 ++++
drivers/bus/pci/rte_bus_pci.h | 22 +++++++
drivers/bus/pci/version.map | 3 +
drivers/bus/pci/windows/pci.c | 14 +++++
lib/pci/meson.build | 2 +
lib/pci/rte_pci.h | 2 +
lib/pci/rte_pci_tph.c | 21 +++++++
lib/pci/rte_pci_tph.h | 111 ++++++++++++++++++++++++++++++++++
9 files changed, 199 insertions(+)
create mode 100644 lib/pci/rte_pci_tph.c
create mode 100644 lib/pci/rte_pci_tph.h
Comments
On Mon, 21 Oct 2024 01:52:45 +0000
Wathsala Vithanage <wathsala.vithanage@arm.com> wrote:
> Extend the PCI driver and the library to extract the Steering Tag (ST)
> for a given Processor/Processor Container and Cache ID pair and validate
> a Processing Hint from a TPH _DSM associated with a root port device.
> The rte_pci_device structure passed into the rte_pci_extract_tph_st()
> function could be a device or a root port. If it's a device, the
> function should trace it back to the root port and use its TPH _DSM to
> extract STs. The implementation of rte_pci_extract_tph_st() is dependent
> on the operating system.
>
> rte_pci_extract_tph_st() should also be supplied with a
> rte_tph_acpi__dsm_args, and a rte_tph_acpi__dsm_return structures.
> These two structures are defined in the PCI library and comply with the
> TPH _DSM argument and return encoding specified in the PCI firmware ECN
> titled "Revised _DSM for Cache Locality TPH Features.". Use of
> rte_init_tph_acpi__dsm_args() is recommended for initializing the
> rte_tph_acpi__dsm_args struct which is capable of converting lcore ID,
> the cache level into values understood by the ACPI _DSM function.
> rte_tph_acpi__dsm_return struct will be initialized with the values
> returned by the TPH _DSM; it is up to the caller to use these values per
> the device's capabilities.
>
> Signed-off-by: Wathsala Vithanage <wathsala.vithanage@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagarahalli@arm.com>
> Reviewed-by: Dhruv Tripathi <dhruv.tripathi@arm.com>
While doing review, noticed that patch has minor whitespace issue.
/home/shemminger/DPDK/main/.git/worktrees/stash/rebase-apply/patch:123: new blank line at EOF.
+
warning: 1 line adds whitespace errors.
@@ -639,3 +639,15 @@ rte_pci_ioport_unmap(struct rte_pci_ioport *p)
return ret;
}
+
+int
+rte_pci_extract_tph_st(const struct rte_pci_device *dev,
+ const struct rte_tph_acpi__dsm_args *args,
+ struct rte_tph_acpi__dsm_return *ret)
+{
+ RTE_SET_USED(dev);
+ RTE_SET_USED(args);
+ RTE_SET_USED(ret);
+ /* BSD doesn't support this feature yet! */
+ return -1;
+}
@@ -803,3 +803,15 @@ rte_pci_ioport_unmap(struct rte_pci_ioport *p)
return ret;
}
+
+int
+rte_pci_extract_tph_st(const struct rte_pci_device *dev,
+ const struct rte_tph_acpi__dsm_args *args,
+ struct rte_tph_acpi__dsm_return *ret)
+{
+ RTE_SET_USED(dev);
+ RTE_SET_USED(args);
+ RTE_SET_USED(ret);
+ /* Linux doesn't support this feature yet! */
+ return -1;
+}
@@ -312,6 +312,28 @@ void rte_pci_ioport_read(struct rte_pci_ioport *p,
void rte_pci_ioport_write(struct rte_pci_ioport *p,
const void *data, size_t len, off_t offset);
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Extract steering tag from the ACPI TPH _DSM of the root port
+ * of the device is connected to.
+ *
+ * @param device
+ * A pointer to a rte_pci_device structure describing the device
+ * to use.
+ * @param args
+ * An initialized args object for the _DSM.
+ * @param ret
+ * A pointer to a _DSM return object to store the extracted steering tag.
+ * @return
+ * 0 on success, -1 on error extracting the steeting tag.
+ */
+__rte_experimental
+int rte_pci_extract_tph_st(const struct rte_pci_device *device,
+ const struct rte_tph_acpi__dsm_args *args,
+ struct rte_tph_acpi__dsm_return *ret);
+
#ifdef __cplusplus
}
#endif
@@ -31,6 +31,9 @@ EXPERIMENTAL {
rte_pci_find_capability;
rte_pci_find_next_capability;
rte_pci_has_capability_list;
+
+ # added in 24.11
+ rte_pci_extract_tph_st;
};
INTERNAL {
@@ -500,3 +500,17 @@ rte_pci_scan(void)
return ret;
}
+
+
+int
+rte_pci_extract_tph_st(const struct rte_pci_device *dev,
+ const struct rte_tph_acpi__dsm_args *args,
+ struct rte_tph_acpi__dsm_return *ret)
+{
+ RTE_SET_USED(dev);
+ RTE_SET_USED(args);
+ RTE_SET_USED(ret);
+ /* This feature is not yet implemented for windows */
+ return -1;
+}
+
@@ -3,3 +3,5 @@
sources = files('rte_pci.c')
headers = files('rte_pci.h')
+headers = files('rte_pci_tph.h')
+headers = files('rte_pci_tph.c')
@@ -16,6 +16,8 @@
#include <inttypes.h>
#include <sys/types.h>
+#include <rte_pci_tph.h>
+
#ifdef __cplusplus
extern "C" {
#endif
new file mode 100644
@@ -0,0 +1,21 @@
+#include <errno.h>
+#include <rte_pci_tph.h>
+
+int
+rte_init_tph_acpi__dsm_args(uint16_t lcore_id, uint8_t type,
+ uint8_t cache_level, uint8_t ph,
+ struct rte_tph_acpi__dsm_args *args)
+{
+ RTE_SET_USED(lcore_id);
+ RTE_SET_USED(type);
+ RTE_SET_USED(cache_level);
+ RTE_SET_USED(ph);
+
+ if (!args)
+ return -EINVAL;
+ /* Use libhwloc or other mechanism provided by DPDK to
+ * map lcore_id and cache_level to hardware IDs for
+ * initializing args.
+ */
+ return -ENOTSUP;
+}
new file mode 100644
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright(c) 2024 Arm Ltd.
+ */
+
+#ifndef _RTE_PCI_TPH_H_
+#define _RTE_PCI_TPH_H_
+
+/**
+ * @file
+ *
+ * RTE PCI TLP Processing Hints helpers
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <rte_common.h>
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this structure may change, or be removed, without prior notice
+ *
+ * ACPI TPH _DSM input args structure.
+ * Refer to PCI-SIG ECN "Revised _DSM for Cache Locality TPH Features" for details.
+ */
+struct rte_tph_acpi__dsm_args {
+ uint32_t feature_id; /**< Always 0. */
+ struct {
+ /** APIC/PPTT Processor/Processor container ID. */
+ uint32_t uid;
+ } __rte_packed featureArg1; /**< 1st Arg. */
+ struct {
+ /** Intended ph bits just for validating. */
+ uint64_t ph : 2;
+ /** If type=1 uid is Processor container ID. */
+ uint64_t type : 1;
+ /** cache_reference is valid if cache_ref_valid=1. */
+ uint64_t cache_ref_valid : 1;
+ uint64_t reserved : 28;
+ /** PPTT cache ID of the desired target. */
+ uint64_t cache_refernce : 32;
+ } __rte_packed featureArg2; /**< 2ns Arg. */
+} __rte_packed;
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this structure may change, or be removed, without prior notice
+ *
+ * ACPI TPH _DSM return structure.
+ * Refer to PCI-SIG ECN "Revised _DSM for Cache Locality TPH Features" for details.
+ */
+struct rte_tph_acpi__dsm_return {
+ uint64_t vmem_st_valid : 1; /**< if set to 1, vmem_st (8-bit ST) is valid. */
+ /** if set to 1, vmem_ext_st (16-bit vmem ST) is valid. */
+ uint64_t vmem_ext_st_valid : 1;
+ /** if set to 1, ph bits in input args is valid. */
+ uint64_t vmem_ph_ignore : 1;
+ uint64_t reserved_1 : 5;
+ /** 8-bit volatile memory ST) */
+ uint64_t vmem_st : 8;
+ /** 16-bit volatile ST) */
+ uint64_t vmem_ext_st : 16;
+ uint64_t pmem_st_valid : 1; /**< if set to 1, pmem_st (8-bit ST) is valid. */
+ /** if set to 1, pmem_ext_st (16-bit ST) is valid. */
+ uint64_t pmem_ext_st_valid : 1;
+ /** if set to 1, ph bits in input args are valid for persistent memory. */
+ uint64_t pmem_ph_ignore : 1;
+ uint64_t reserved_2 : 5;
+ /** 8-bit persistent memory ST) */
+ uint64_t pmem_st : 8;
+ /** 16-bit persistent memory ST) */
+ uint64_t pmem_ext_st : 16;
+} __rte_packed;
+
+
+/**
+ *
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Initializes stashing hints configuration with a platform specific stashing hint
+ * that matches the lcore_id and cache_level.
+ *
+ * @param lcore_id
+ * The lcore_id of the processor of the cache stashing target. If is_container is set
+ * the target is the processor container of the CPU specified by the lcore_id.
+ * @param type
+ * If set to 1, the procssor container of the processor specified by lcore_id will be
+ * used at the stashing target. If set to 0, processor specified by the lcore_id will be
+ * used as the stashing target.
+ * @param cache_level
+ * The cache level of the processor/container specified by the lcore_id.
+ * @param ph
+ * TPH Processing Hints bits.
+ * @param args
+ * ACPI TPH _DSM object arguments structure.
+ * @return
+ * - (0) on Success.
+ * - 0 < or 0 > on Failure.
+ */
+
+int rte_init_tph_acpi__dsm_args(uint16_t lcore_id, uint8_t type,
+ uint8_t cache_level, uint8_t ph,
+ struct rte_tph_acpi__dsm_args *args);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _RTE_PCI_TPH_H_ */