From 3710e9972bc9e35e8389bb3b47d443e3c5e01859 Mon Sep 17 00:00:00 2001
From: Subrata Banik <subrata.banik@intel.com>
Date: Thu, 30 Sep 2021 16:59:09 +0530
Subject: [PATCH] soc/intel/common: Helper function to check CSE device `devfn`
 status

This patch creates a helper function in cse common code block to check
the status of any CSE `devfn`. Example: CSE, CSE_2, IDER, KT, CSE_3 and
CSE_4.

Currently cse common code is only able to read the device state of
`PCH_DEVFN_CSE` CSE device alone.

Additionally, print `slot` and 'func' number of CSE devices in case
the device is either disable or hidden.

BUG=b:200644229
TEST=Able to build and boot ADLRVP-P with this patch where the serial
message listed the CSE devices that are disabled in the device tree
as below:

HECI: CSE device 16.01 is disabled
HECI: CSE device 16.04 is disabled
HECI: CSE device 16.05 is disabled

Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Change-Id: I208b07e89e3aa9d682837380809fbff01ea225b0
Reviewed-on: https://review.coreboot.org/c/coreboot/+/58064
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
---
 src/soc/intel/common/block/cse/cse.c           | 18 ++++++++++++------
 .../common/block/include/intelblocks/cse.h     |  6 ++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/soc/intel/common/block/cse/cse.c b/src/soc/intel/common/block/cse/cse.c
index 471bc1b341..e41e337550 100644
--- a/src/soc/intel/common/block/cse/cse.c
+++ b/src/soc/intel/common/block/cse/cse.c
@@ -581,23 +581,29 @@ int heci_reset(void)
 	return 0;
 }
 
-bool is_cse_enabled(void)
+bool is_cse_devfn_visible(unsigned int devfn)
 {
-	const struct device *cse_dev = pcidev_path_on_root(PCH_DEVFN_CSE);
+	int slot = PCI_SLOT(devfn);
+	int func = PCI_FUNC(devfn);
 
-	if (!cse_dev || !cse_dev->enabled) {
-		printk(BIOS_WARNING, "HECI: No CSE device\n");
+	if (!is_devfn_enabled(devfn)) {
+		printk(BIOS_WARNING, "HECI: CSE device %02x.%01x is disabled\n", slot, func);
 		return false;
 	}
 
-	if (pci_read_config16(PCH_DEV_CSE, PCI_VENDOR_ID) == 0xFFFF) {
-		printk(BIOS_WARNING, "HECI: CSE device is hidden\n");
+	if (pci_read_config16(PCI_DEV(0, slot, func), PCI_VENDOR_ID) == 0xFFFF) {
+		printk(BIOS_WARNING, "HECI: CSE device %02x.%01x is hidden\n", slot, func);
 		return false;
 	}
 
 	return true;
 }
 
+bool is_cse_enabled(void)
+{
+	return is_cse_devfn_visible(PCH_DEVFN_CSE);
+}
+
 uint32_t me_read_config32(int offset)
 {
 	return pci_read_config32(PCH_DEV_CSE, offset);
diff --git a/src/soc/intel/common/block/include/intelblocks/cse.h b/src/soc/intel/common/block/include/intelblocks/cse.h
index 076f29465c..f162d485fd 100644
--- a/src/soc/intel/common/block/include/intelblocks/cse.h
+++ b/src/soc/intel/common/block/include/intelblocks/cse.h
@@ -152,6 +152,12 @@ void heci_disable(void);
 /* Reads config value from a specified offset in the CSE PCI Config space. */
 uint32_t me_read_config32(int offset);
 
+/*
+ * Check if the CSE device as per function argument `devfn` is enabled in device tree
+ * and also visible on the PCI bus.
+ */
+bool is_cse_devfn_visible(unsigned int devfn);
+
 /*
  * Check if the CSE device is enabled in device tree. Also check if the device
  * is visible on the PCI bus by reading config space.