soc/intel/skylake: Swap PCI devfn resides in same PCI device
After FSP-S, a device on PCI function n will be function swapped
to function 0 if there is no device presnet on function 0.
It needs some modification for DT and causes mismatches between
software configuration and hardware schematic. This patch is
from d779605, which swaps the devfn of the first enabled device
in DT and function 0 resides in a PCI device.
BUG=b:80105785
BRANCH=None
TEST=Make sure the device is still enabled after coalescence with
device on bus 0 and w/o device on bus 0. Test with suspend
and resume and ensure it's consistent.
Change-Id: Ibbc5d6e979977011f5904c8bd4b2f1be16bd23dc
Signed-off-by: Gaggery Tsai <gaggery.tsai@intel.com>
Reviewed-on: https://review.coreboot.org/26479
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
diff --git a/src/soc/intel/skylake/chip_fsp20.c b/src/soc/intel/skylake/chip_fsp20.c
index bc78586..0ba70e0 100644
--- a/src/soc/intel/skylake/chip_fsp20.c
+++ b/src/soc/intel/skylake/chip_fsp20.c
@@ -19,12 +19,14 @@
#include <device/pci.h>
#include <fsp/api.h>
#include <arch/acpi.h>
+#include <arch/io.h>
#include <chip.h>
#include <compiler.h>
#include <bootstate.h>
#include <console/console.h>
#include <device/device.h>
#include <device/pci.h>
+#include <device/pci_ids.h>
#include <fsp/api.h>
#include <fsp/util.h>
#include <intelblocks/xdci.h>
@@ -39,10 +41,135 @@
#include <soc/systemagent.h>
#include <string.h>
+struct pcie_entry {
+ unsigned int devfn;
+ unsigned int func_count;
+};
+
+/*
+ * According to table 2-2 in doc#546717:
+ * PCI bus[function] ID
+ * D28:[F0 - F7] 0xA110 - 0xA117
+ * D29:[F0 - F7] 0xA118 - 0xA11F
+ * D27:[F0 - F3] 0xA167 - 0xA16A
+ */
+static const struct pcie_entry pcie_table_skl_pch_h[] = {
+ {PCH_DEVFN_PCIE1, 8},
+ {PCH_DEVFN_PCIE9, 8},
+ {PCH_DEVFN_PCIE17, 4},
+};
+
+/*
+ * According to table 2-2 in doc#564464:
+ * PCI bus[function] ID
+ * D28:[F0 - F7] 0xA290 - 0xA297
+ * D29:[F0 - F7] 0xA298 - 0xA29F
+ * D27:[F0 - F7] 0xA2E7 - 0xA2EE
+ */
+static const struct pcie_entry pcie_table_kbl_pch_h[] = {
+ {PCH_DEVFN_PCIE1, 8},
+ {PCH_DEVFN_PCIE9, 8},
+ {PCH_DEVFN_PCIE17, 8},
+};
+
+/*
+ * According to table 2-2 in doc#567995/545659:
+ * PCI bus[function] ID
+ * D28:[F0 - F7] 0x9D10 - 0x9D17
+ * D29:[F0 - F3] 0x9D18 - 0x9D1B
+ */
+static const struct pcie_entry pcie_table_skl_pch_lp[] = {
+ {PCH_DEVFN_PCIE1, 8},
+ {PCH_DEVFN_PCIE9, 4},
+};
+
+/*
+ * If the PCIe root port at function 0 is disabled,
+ * the PCIe root ports might be coalesced after FSP silicon init.
+ * The below function will swap the devfn of the first enabled device
+ * in devicetree and function 0 resides a pci device
+ * so that it won't confuse coreboot.
+ */
+static void pcie_update_device_tree(const struct pcie_entry *pcie_rp_group,
+ size_t pci_groups)
+{
+ struct device *func0;
+ unsigned int devfn, devfn0;
+ int i, group;
+ unsigned int inc = PCI_DEVFN(0, 1);
+
+ for (group = 0; group < pci_groups; group++) {
+ devfn0 = pcie_rp_group[group].devfn;
+ func0 = dev_find_slot(0, devfn0);
+ if (func0 == NULL)
+ continue;
+
+ /* No more functions if function 0 is disabled. */
+ if (pci_read_config32(func0, PCI_VENDOR_ID) == 0xffffffff)
+ continue;
+
+ devfn = devfn0 + inc;
+
+ /*
+ * Increase function by 1.
+ * Then find first enabled device to replace func0
+ * as that port was move to func0.
+ */
+ for (i = 1; i < pcie_rp_group[group].func_count;
+ i++, devfn += inc) {
+ struct device *dev = dev_find_slot(0, devfn);
+ if (dev == NULL || !dev->enabled)
+ continue;
+
+ /*
+ * Found the first enabled device in
+ * a given dev number.
+ */
+ printk(BIOS_INFO, "PCI func %d was swapped"
+ " to func 0.\n", i);
+ func0->path.pci.devfn = dev->path.pci.devfn;
+ dev->path.pci.devfn = devfn0;
+ break;
+ }
+ }
+}
+
+static void pcie_override_devicetree_after_silicon_init(void)
+{
+ uint16_t id, id_mask;
+
+ id = pci_read_config16(PCH_DEV_PCIE1, PCI_DEVICE_ID);
+ /*
+ * We may read an ID other than func 0 after FSP-S.
+ * Strip out 4 least significant bits.
+ */
+ id_mask = id & ~0xf;
+ printk(BIOS_INFO, "Override DT after FSP-S, PCH is ");
+ if (id_mask == (PCI_DEVICE_ID_INTEL_SPT_LP_PCIE_RP1 & ~0xf)) {
+ printk(BIOS_INFO, "KBL/SKL PCH-LP SKU\n");
+ pcie_update_device_tree(&pcie_table_skl_pch_lp[0],
+ ARRAY_SIZE(pcie_table_skl_pch_lp));
+ } else if (id_mask == (PCI_DEVICE_ID_INTEL_KBP_H_PCIE_RP1 & ~0xf)) {
+ printk(BIOS_INFO, "KBL PCH-H SKU\n");
+ pcie_update_device_tree(&pcie_table_kbl_pch_h[0],
+ ARRAY_SIZE(pcie_table_kbl_pch_h));
+ } else if (id_mask == (PCI_DEVICE_ID_INTEL_SPT_H_PCIE_RP1 & ~0xf)) {
+ printk(BIOS_INFO, "SKL PCH-H SKU\n");
+ pcie_update_device_tree(&pcie_table_skl_pch_h[0],
+ ARRAY_SIZE(pcie_table_skl_pch_h));
+ } else {
+ printk(BIOS_ERR, "[BUG] PCIE Root Port id 0x%x"
+ " is not found\n", id);
+ return;
+ }
+}
+
void soc_init_pre_device(void *chip_info)
{
/* Perform silicon specific init. */
fsp_silicon_init(romstage_handoff_is_resume());
+ /* swap enabled PCI ports in device tree if needed */
+ pcie_override_devicetree_after_silicon_init();
}
void soc_fsp_load(void)