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authorSubrata Banik <subratabanik@google.com>2022-08-23 02:27:58 +0530
committerSubrata Banik <subratabanik@google.com>2022-08-26 04:13:10 +0000
commit6f7875fb565f87ca6f9e423af60e2d5516f20ea6 (patch)
tree620b0be9905d464648e9f0e0825cd287ea6e439c /src/soc/intel/common
parent199b10fc21ee094af88abb2b5856502565c40ae7 (diff)
soc/intel/p2sb: Refactor `p2sb_execute_sideband_access` function
This patch refactors p2sb_execute_sideband_access() to be able to handle SBI operations in both SMM and non-SMM scenarios. Prior to FSP-S operation being done, the IOE P2SB device will be visible on the PCI bus hence, performing the SBI operation using IOE P2SB doesn't involve unhide/hide operation. Post FSP-S, the IOE P2SB device is hidden. Additionally, SBI operations can't be performed as is. The only possible way to send SBI is inside SMM mode and to do that, coreboot needs to unhide the P2SB device prior to sending the SBI and hide it post sending SBI. As a result, the p2sb_execute_sideband_access() function has been refactored to manage these cases seamlessly without users of the p2sb_execute_sideband_access() actually being bothered about the calling mode. BUG=b:239806774 TEST=Able to perform p2sb_execute_sideband_access() function call in both SMM and non-SMM mode without any hang/die. Signed-off-by: Subrata Banik <subratabanik@google.com> Change-Id: Iafebd5190deb50fd95382f17bf0248fcbfb23cb8 Reviewed-on: https://review.coreboot.org/c/coreboot/+/66950 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Diffstat (limited to 'src/soc/intel/common')
-rw-r--r--src/soc/intel/common/block/p2sb/p2sblib.c31
1 files changed, 27 insertions, 4 deletions
diff --git a/src/soc/intel/common/block/p2sb/p2sblib.c b/src/soc/intel/common/block/p2sb/p2sblib.c
index e1a5bc2ef8..537f388cb2 100644
--- a/src/soc/intel/common/block/p2sb/p2sblib.c
+++ b/src/soc/intel/common/block/p2sb/p2sblib.c
@@ -63,7 +63,7 @@ void p2sb_dev_hide(pci_devfn_t dev)
"Unable to hide the P2SB device!\n");
}
-static void p2sb_execute_sideband_access(pci_devfn_t dev, uint8_t cmd, uint8_t pid,
+static void p2sb_send_sideband_msg(pci_devfn_t dev, uint8_t cmd, uint8_t pid,
uint16_t reg, uint32_t *data)
{
struct pcr_sbi_msg msg = {
@@ -78,17 +78,40 @@ static void p2sb_execute_sideband_access(pci_devfn_t dev, uint8_t cmd, uint8_t p
uint8_t response;
int status;
- /* Unhide the P2SB device */
- p2sb_dev_unhide(dev);
-
status = pcr_execute_sideband_msg(dev, &msg, data, &response);
if (status || response)
printk(BIOS_ERR, "Fail to execute p2sb sideband access\n");
+}
+
+static void p2sb_execute_sbi_in_smm(pci_devfn_t dev, uint8_t cmd, uint8_t pid,
+ uint16_t reg, uint32_t *data)
+{
+ /* Unhide the P2SB device */
+ p2sb_dev_unhide(dev);
+
+ p2sb_send_sideband_msg(dev, cmd, pid, reg, data);
/* Hide the P2SB device */
p2sb_dev_hide(dev);
}
+static void p2sb_execute_sideband_access(pci_devfn_t dev, uint8_t cmd, uint8_t pid,
+ uint16_t reg, uint32_t *data)
+{
+ if (ENV_SMM)
+ /*
+ * FSP-S will hide the P2SB device. With the device hidden, we will not be
+ * able to send the sideband interface message. Therefore, we need to unhide
+ * the P2SB device which can only be done in SMM requiring that this
+ * function is called from SMM.
+ */
+ p2sb_execute_sbi_in_smm(dev, cmd, pid, reg, data);
+ else if (!p2sb_dev_is_hidden(dev))
+ p2sb_send_sideband_msg(dev, cmd, pid, reg, data);
+ else
+ printk(BIOS_WARNING, "Error: P2SB must be hidden, try calling from SMM!\n");
+}
+
uint32_t p2sb_dev_sbi_read(pci_devfn_t dev, uint8_t pid, uint16_t reg)
{
uint32_t val = 0;