This is very much a PoC for one potential way to support
CDAT on Switch Upstream Ports.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
---
drivers/pci/pcie/Kconfig | 5 ++
drivers/pci/pcie/Makefile | 1 +
drivers/pci/pcie/cdat.c | 127 ++++++++++++++++++++++++++++++++
drivers/pci/pcie/portdrv.h | 9 ++-
drivers/pci/pcie/portdrv_core.c | 43 ++++++++++-
drivers/pci/pcie/portdrv_pci.c | 2 +
6 files changed, 183 insertions(+), 4 deletions(-)
create mode 100644 drivers/pci/pcie/cdat.c
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index 788ac8df3f9d..7d90c05bf0ac 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -142,3 +142,8 @@ 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_CDAT
+ bool "CDAT hacks"
+ help
+ It's a dirty hack.
diff --git a/drivers/pci/pcie/Makefile b/drivers/pci/pcie/Makefile
index 5783a2f79e6a..4925394e8d4b 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_CDAT) += cdat.o
diff --git a/drivers/pci/pcie/cdat.c b/drivers/pci/pcie/cdat.c
new file mode 100644
index 000000000000..04165c1b8174
--- /dev/null
+++ b/drivers/pci/pcie/cdat.c
@@ -0,0 +1,127 @@
+//HACK
+#include <linux/pci.h>
+#include <linux/pci-doe.h>
+#include "../../cxl/cxlpci.h"
+#include "../../cxl/cdat.h"
+#include "portdrv.h"
+
+struct cdat {
+ struct pci_doe_mb *doe_mb;
+ struct device *dev;
+};
+
+#define CDAT_DOE_REQ(entry_handle) \
+ (FIELD_PREP(CXL_DOE_TABLE_ACCESS_REQ_CODE, \
+ CXL_DOE_TABLE_ACCESS_REQ_CODE_READ) | \
+ FIELD_PREP(CXL_DOE_TABLE_ACCESS_TABLE_TYPE, \
+ CXL_DOE_TABLE_ACCESS_TABLE_TYPE_CDATA) | \
+ FIELD_PREP(CXL_DOE_TABLE_ACCESS_ENTRY_HANDLE, (entry_handle)))
+
+static void cdat_doe_task_complete(struct pci_doe_task *task)
+{
+ complete(task->private);
+}
+
+static int cdat_get_length(struct cdat *cdat, size_t *length)
+{
+ u32 cdat_request_pl = CDAT_DOE_REQ(0);
+ u32 cdat_response_pl[32];
+ DECLARE_COMPLETION_ONSTACK(c);
+ struct pci_doe_task task = {
+ .prot.vid = PCI_DVSEC_VENDOR_ID_CXL,
+ .prot.type = CXL_DOE_PROTOCOL_TABLE_ACCESS,
+ .request_pl = &cdat_request_pl,
+ .request_pl_sz = sizeof(cdat_request_pl),
+ .response_pl = cdat_response_pl,
+ .response_pl_sz = sizeof(cdat_response_pl),
+ .complete = cdat_doe_task_complete,
+ .private = &c,
+ };
+ int rc;
+
+ rc = pci_doe_submit_task(cdat->doe_mb, &task);
+ if (rc < 0) {
+ dev_err(cdat->dev, "DOE submit failed: %d", rc);
+ return rc;
+ }
+ wait_for_completion(&c);
+
+ if (task.rv < 1)
+ return -EIO;
+
+ *length = cdat_response_pl[1];
+ dev_info(cdat->dev, "CDAT length %lu\n", *length);
+
+ return 0;
+}
+
+static int cdat_probe(struct pcie_device *dev)
+{
+ struct device *device = &dev->device;
+ struct cdat *cdat;
+ u16 off;
+ size_t length;
+ int rc;
+
+ /* probably not necessary */
+ if ((pci_pcie_type(dev->port) != PCI_EXP_TYPE_UPSTREAM))
+ return -ENODEV;
+
+ cdat = devm_kzalloc(device, sizeof(*cdat), GFP_KERNEL);
+ if (!cdat)
+ return -ENOMEM;
+
+ cdat->dev = device;
+ /* Terrible though it is lets go find the cap again */
+ pci_doe_for_each_off(dev->port, off) {
+ bool supports_cdat;
+ struct pci_doe_mb *doe_mb;
+
+ doe_mb = pci_doe_create_mb(dev->port, off, true);
+ if (IS_ERR(doe_mb)) {
+ dev_err(device,
+ "Failed to create the DOE mailbox state machine\n");
+ continue;
+ }
+ supports_cdat = pci_doe_supports_prot(doe_mb, PCI_DVSEC_VENDOR_ID_CXL,
+ CXL_DOE_PROTOCOL_TABLE_ACCESS);
+ if (supports_cdat) {
+ cdat->doe_mb = doe_mb;
+ break;
+ }
+ pci_doe_destroy_mb(doe_mb);
+ }
+ if (!cdat->doe_mb)
+ return -ENODEV;
+
+ rc = cdat_get_length(cdat, &length);
+ if (rc) {
+ dev_err(device, "Failed to get cdat length\n");
+ return rc;
+ }
+ printk("CDAT length is %lu\n", length);
+ /* this is a PoC so that'll do for now */
+ dev_set_drvdata(device, cdat);
+ return 0;
+}
+
+static void cdat_remove(struct pcie_device *dev)
+{
+ /* Mess with driver remove later */
+ struct cdat *cdat = dev_get_drvdata(&dev->device);
+
+ pci_doe_destroy_mb(cdat->doe_mb);
+}
+
+static struct pcie_port_service_driver cdat_driver = {
+ .name = "cdat",
+ .port_type = PCIE_ANY_PORT, //fixme -upstream only
+ .service = PCIE_PORT_SERVICE_CDAT,
+ .probe = cdat_probe,
+ .remove = cdat_remove,
+};
+
+int __init pcie_cdat_init(void)
+{
+ return pcie_port_service_register(&cdat_driver);
+}
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 0ef4bf5f811d..d35b973f5b67 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -22,8 +22,10 @@
#define PCIE_PORT_SERVICE_DPC (1 << PCIE_PORT_SERVICE_DPC_SHIFT)
#define PCIE_PORT_SERVICE_BWNOTIF_SHIFT 4 /* Bandwidth notification */
#define PCIE_PORT_SERVICE_BWNOTIF (1 << PCIE_PORT_SERVICE_BWNOTIF_SHIFT)
+#define PCIE_PORT_SERVICE_CDAT_SHIFT 5 /* CXL CDAT Table DOE */
+#define PCIE_PORT_SERVICE_CDAT (1 << PCIE_PORT_SERVICE_CDAT_SHIFT)
-#define PCIE_PORT_DEVICE_MAXSERVICES 5
+#define PCIE_PORT_DEVICE_MAXSERVICES 6
extern bool pcie_ports_dpc_native;
@@ -53,6 +55,11 @@ int pcie_dpc_init(void);
static inline int pcie_dpc_init(void) { return 0; }
#endif
+#ifdef CONFIG_PCIE_CDAT
+int pcie_cdat_init(void);
+#else
+static inline int pcie_cdat_init(void) { return 0; }
+#endif
/* Port Type */
#define PCIE_ANY_PORT (~0)
diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 604feeb84ee4..161545b30014 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/pci.h>
+#include <linux/pci-doe.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
@@ -17,6 +18,7 @@
#include <linux/aer.h>
#include "../pci.h"
+#include "../../cxl/cxlpci.h"
#include "portdrv.h"
struct portdrv_service_data {
@@ -43,10 +45,12 @@ static void release_pcie_device(struct device *dev)
* required to accommodate the largest Message Number.
*/
static int pcie_message_numbers(struct pci_dev *dev, int mask,
- u32 *pme, u32 *aer, u32 *dpc)
+ u32 *pme, u32 *aer, u32 *dpc, u32 *cdat)
{
u32 nvec = 0, pos;
+ u16 off = 0;
u16 reg16;
+ u32 reg32;
/*
* The Interrupt Message Number indicates which vector is used, i.e.,
@@ -86,6 +90,18 @@ static int pcie_message_numbers(struct pci_dev *dev, int mask,
}
}
+#ifdef CONFIG_PCIE_CDAT
+ pci_doe_for_each_off(dev, off) {
+ pci_read_config_dword(dev, off + PCI_DOE_CAP, ®32);
+
+ if (!FIELD_GET(PCI_DOE_CAP_INT, reg32))
+ return -EOPNOTSUPP;
+
+ *cdat = FIELD_GET(PCI_DOE_CAP_IRQ, reg32);
+ nvec = max(nvec, *cdat + 1);
+ }
+#endif
+
return nvec;
}
@@ -101,7 +117,7 @@ static int pcie_message_numbers(struct pci_dev *dev, int mask,
static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
{
int nr_entries, nvec, pcie_irq;
- u32 pme = 0, aer = 0, dpc = 0;
+ u32 pme = 0, aer = 0, dpc = 0, cdat = 0;
/* Allocate the maximum possible number of MSI/MSI-X vectors */
nr_entries = pci_alloc_irq_vectors(dev, 1, PCIE_PORT_MAX_MSI_ENTRIES,
@@ -110,7 +126,7 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
return nr_entries;
/* See how many and which Interrupt Message Numbers we actually use */
- nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc);
+ nvec = pcie_message_numbers(dev, mask, &pme, &aer, &dpc, &cdat);
if (nvec > nr_entries) {
pci_free_irq_vectors(dev);
return -EIO;
@@ -151,6 +167,9 @@ static int pcie_port_enable_irq_vec(struct pci_dev *dev, int *irqs, int mask)
if (mask & PCIE_PORT_SERVICE_DPC)
irqs[PCIE_PORT_SERVICE_DPC_SHIFT] = pci_irq_vector(dev, dpc);
+ if (mask & PCIE_PORT_SERVICE_CDAT)
+ irqs[PCIE_PORT_SERVICE_CDAT_SHIFT] = pci_irq_vector(dev, cdat);
+
return 0;
}
@@ -207,6 +226,7 @@ static int get_port_device_capability(struct pci_dev *dev)
{
struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);
int services = 0;
+ u16 off = 0;
if (dev->is_hotplug_bridge &&
(pcie_ports_native || host->native_pcie_hotplug)) {
@@ -264,6 +284,23 @@ static int get_port_device_capability(struct pci_dev *dev)
if (linkcap & PCI_EXP_LNKCAP_LBNC)
services |= PCIE_PORT_SERVICE_BWNOTIF;
}
+ /* Run the DOE in poll mode to query protocol */
+ pci_doe_for_each_off(dev, off) {
+ bool supports_cdat;
+ struct pci_doe_mb *doe_mb;
+
+ doe_mb = pci_doe_create_mb(dev, off, false);
+ if (IS_ERR(doe_mb)) {
+ pci_err(dev, "Failed to create the DOE mailbox state machine\n");
+ continue;
+ }
+ supports_cdat = pci_doe_supports_prot(doe_mb, PCI_DVSEC_VENDOR_ID_CXL,
+ CXL_DOE_PROTOCOL_TABLE_ACCESS);
+ pci_doe_destroy_mb(doe_mb);
+ if (supports_cdat) {
+ services |= PCIE_PORT_SERVICE_CDAT;
+ }
+ }
return services;
}
diff --git a/drivers/pci/pcie/portdrv_pci.c b/drivers/pci/pcie/portdrv_pci.c
index 4b8801656ffb..b4ec0cab7eb9 100644
--- a/drivers/pci/pcie/portdrv_pci.c
+++ b/drivers/pci/pcie/portdrv_pci.c
@@ -8,6 +8,7 @@
*/
#include <linux/pci.h>
+#include <linux/pci-doe.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/pm.h>
@@ -235,6 +236,7 @@ static void __init pcie_init_services(void)
pcie_pme_init();
pcie_dpc_init();
pcie_hp_init();
+ pcie_cdat_init();
}
static int __init pcie_portdrv_init(void)
--
2.32.0
