soc/amd/picasso: Add PCI driver for data fabric devices

Data fabric devices are PCI devices which support PCI configuration
space but do not require any MMIO/IO resources. This change adds a PCI
driver for the data fabric devices which only provides device
operations for adding node to SSDT and returning the ACPI name for the
device.

Signed-off-by: Furquan Shaikh <furquan@google.com>
Change-Id: I3da9287db5febf1a1d7eb1dfbed9f1348f80a588
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43314
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 169 insertions, 0 deletions

diff --git a/src/soc/amd/picasso/data_fabric.c b/src/soc/amd/picasso/data_fabric.c
new file mode 100644
index 000000000000..23cb94c83747
--- /dev/null
+++ b/src/soc/amd/picasso/data_fabric.c
@@ -0,0 +1,169 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <acpi/acpi_device.h>
+#include <console/console.h>
+#include <cpu/x86/lapic_def.h>
+#include <device/device.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <device/pci_ops.h>
+#include <soc/data_fabric.h>
+#include <soc/iomap.h>
+#include <soc/pci_devs.h>
+#include <stdbool.h>
+
+static void disable_mmio_reg(int reg)
+{
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_CONTROL(reg),
+			   IOMS0_FABRIC_ID << MMIO_DST_FABRIC_ID_SHIFT);
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_BASE(reg), 0);
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(reg), 0);
+}
+
+static bool is_mmio_reg_disabled(int reg)
+{
+	uint32_t val = pci_read_config32(SOC_DF_F0_DEV, NB_MMIO_CONTROL(reg));
+	return !(val & ((MMIO_WE | MMIO_RE)));
+}
+
+static int find_unused_mmio_reg(void)
+{
+	unsigned int i;
+
+	for (i = 0; i < NUM_NB_MMIO_REGS; i++) {
+		if (is_mmio_reg_disabled(i))
+			return i;
+	}
+	return -1;
+}
+
+void data_fabric_set_mmio_np(void)
+{
+	/*
+	 * Mark region from HPET-LAPIC or 0xfed00000-0xfee00000-1 as NP.
+	 *
+	 * AGESA has already programmed the NB MMIO routing, however nothing
+	 * is yet marked as non-posted.
+	 *
+	 * If there exists an overlapping routing base/limit pair, trim its
+	 * base or limit to avoid the new NP region.  If any pair exists
+	 * completely within HPET-LAPIC range, remove it.  If any pair surrounds
+	 * HPET-LAPIC, it must be split into two regions.
+	 *
+	 * TODO(b/156296146): Remove the settings from AGESA and allow coreboot
+	 * to own everything.  If not practical, consider erasing all settings
+	 * and have coreboot reprogram them.  At that time, make the source
+	 * below more flexible.
+	 *   * Note that the code relies on the granularity of the HPET and
+	 *     LAPIC addresses being sufficiently large that the shifted limits
+	 *     +/-1 are always equivalent to the non-shifted values +/-1.
+	 */
+
+	unsigned int i;
+	int reg;
+	uint32_t base, limit, ctrl;
+	const uint32_t np_bot = HPET_BASE_ADDRESS >> D18F0_MMIO_SHIFT;
+	const uint32_t np_top = (LOCAL_APIC_ADDR - 1) >> D18F0_MMIO_SHIFT;
+
+	for (i = 0; i < NUM_NB_MMIO_REGS; i++) {
+		/* Adjust all registers that overlap */
+		ctrl = pci_read_config32(SOC_DF_F0_DEV, NB_MMIO_CONTROL(i));
+		if (!(ctrl & (MMIO_WE | MMIO_RE)))
+			continue; /* not enabled */
+
+		base = pci_read_config32(SOC_DF_F0_DEV, NB_MMIO_BASE(i));
+		limit = pci_read_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(i));
+
+		if (base > np_top || limit < np_bot)
+			continue; /* no overlap at all */
+
+		if (base >= np_bot && limit <= np_top) {
+			disable_mmio_reg(i); /* 100% within, so remove */
+			continue;
+		}
+
+		if (base < np_bot && limit > np_top) {
+			/* Split the configured region */
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(i), np_bot - 1);
+			reg = find_unused_mmio_reg();
+			if (reg < 0) {
+				/* Although a pair could be freed later, this condition is
+				 * very unusual and deserves analysis.  Flag an error and
+				 * leave the topmost part unconfigured. */
+				printk(BIOS_ERR,
+				       "Error: Not enough NB MMIO routing registers\n");
+				continue;
+			}
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_BASE(reg), np_top + 1);
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(reg), limit);
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_CONTROL(reg), ctrl);
+			continue;
+		}
+
+		/* If still here, adjust only the base or limit */
+		if (base <= np_bot)
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(i), np_bot - 1);
+		else
+			pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_BASE(i), np_top + 1);
+	}
+
+	reg = find_unused_mmio_reg();
+	if (reg < 0) {
+		printk(BIOS_ERR, "Error: cannot configure region as NP\n");
+		return;
+	}
+
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_BASE(reg), np_bot);
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_LIMIT(reg), np_top);
+	pci_write_config32(SOC_DF_F0_DEV, NB_MMIO_CONTROL(reg),
+			   (IOMS0_FABRIC_ID << MMIO_DST_FABRIC_ID_SHIFT) | MMIO_NP | MMIO_WE
+				   | MMIO_RE);
+}
+
+static const char *data_fabric_acpi_name(const struct device *dev)
+{
+	switch (dev->device) {
+	case PCI_DEVICE_ID_AMD_FAM17H_DF0:
+		return "DFD0";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF1:
+		return "DFD1";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF2:
+		return "DFD2";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF3:
+		return "DFD3";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF4:
+		return "DFD4";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF5:
+		return "DFD5";
+	case PCI_DEVICE_ID_AMD_FAM17H_DF6:
+		return "DFD6";
+	default:
+		printk(BIOS_ERR, "%s: Unhandled device id 0x%x\n", __func__, dev->device);
+	}
+
+	return NULL;
+}
+
+static struct device_operations data_fabric_ops = {
+	.read_resources		= noop_read_resources,
+	.set_resources		= noop_set_resources,
+	.acpi_name		= data_fabric_acpi_name,
+	.acpi_fill_ssdt		= acpi_device_write_pci_dev,
+};
+
+static const unsigned short pci_device_ids[] = {
+	PCI_DEVICE_ID_AMD_FAM17H_DF0,
+	PCI_DEVICE_ID_AMD_FAM17H_DF1,
+	PCI_DEVICE_ID_AMD_FAM17H_DF2,
+	PCI_DEVICE_ID_AMD_FAM17H_DF3,
+	PCI_DEVICE_ID_AMD_FAM17H_DF4,
+	PCI_DEVICE_ID_AMD_FAM17H_DF5,
+	PCI_DEVICE_ID_AMD_FAM17H_DF6,
+	0
+};
+
+static const struct pci_driver data_fabric_driver __pci_driver = {
+	.ops			= &data_fabric_ops,
+	.vendor			= PCI_VENDOR_ID_AMD,
+	.devices		= pci_device_ids,
+};