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-rw-r--r--src/drivers/crb/tpm.c46
-rw-r--r--src/drivers/crb/tpm.h1
2 files changed, 47 insertions, 0 deletions
diff --git a/src/drivers/crb/tpm.c b/src/drivers/crb/tpm.c
index 1bdca0039f..858aeb728c 100644
--- a/src/drivers/crb/tpm.c
+++ b/src/drivers/crb/tpm.c
@@ -48,6 +48,22 @@ static void crb_readControlArea(void)
control_area.response_size = read32(CRB_REG(cur_loc, CRB_REG_RESP_SIZE));
control_area.response_bfr =
(void *)(uintptr_t)read64(CRB_REG(cur_loc, CRB_REG_RESP_ADDR));
+
+ /*
+ * Intel PTT has to write the command/response address and size
+ * register before each command submission otherwise the control area
+ * is all zeroed. This has been observed on Alder Lake S CPU and may be
+ * applicable to other new microarchitectures. Update the local control
+ * area data to make tpm2_process_command not fail on buffer checks.
+ * PTT command/response buffer is fixed to be at offset 0x80 and spans
+ * up to the end of 4KB region for the current locality.
+ */
+ if (CONFIG(HAVE_INTEL_PTT)) {
+ control_area.command_size = 0x1000 - CRB_REG_DATA_BUFF;
+ control_area.response_size = control_area.command_size;
+ control_area.command_bfr = CRB_REG(cur_loc, CRB_REG_DATA_BUFF);
+ control_area.response_bfr = CRB_REG(cur_loc, CRB_REG_DATA_BUFF);
+ }
}
/* Wait for Reg to be expected Value */
@@ -115,6 +131,7 @@ static uint8_t crb_activate_locality(void)
int rc = crb_wait_for_reg32(CRB_REG(locality, CRB_REG_LOC_STATE), 750,
LOC_STATE_LOC_ASSIGN, LOC_STATE_LOC_ASSIGN);
+
if (!rc && (locality == 0))
return locality;
@@ -181,12 +198,33 @@ int tpm2_init(void)
/* Read back control area structure */
crb_readControlArea();
+ /*
+ * PTT may have no assigned locality before startup. Request locality here to save
+ * some precious milliseconds which would be wasted in crb_activate_locality polling
+ * for LOC_STATE_LOC_ASSIGN bit for the first time.
+ */
+ if (CONFIG(HAVE_INTEL_PTT)) {
+ uint8_t locality = (read8(CRB_REG(0, CRB_REG_LOC_STATE)) >> 2) & 0x07;
+ write8(CRB_REG(locality, CRB_REG_LOC_CTRL), LOC_CTRL_REQ_ACCESS);
+ }
+
/* Good to go. */
printk(BIOS_SPEW, "TPM: CRB TPM initialized successfully\n");
return 0;
}
+static void set_ptt_cmd_resp_buffers(void)
+{
+ write32(CRB_REG(cur_loc, CRB_REG_CMD_ADDR + 4), 0);
+ write32(CRB_REG(cur_loc, CRB_REG_CMD_ADDR),
+ (uintptr_t)CRB_REG(cur_loc, CRB_REG_DATA_BUFF));
+ write32(CRB_REG(cur_loc, CRB_REG_CMD_SIZE), control_area.command_size);
+ write64(CRB_REG(cur_loc, CRB_REG_RESP_ADDR),
+ (uintptr_t)CRB_REG(cur_loc, CRB_REG_DATA_BUFF));
+ write32(CRB_REG(cur_loc, CRB_REG_RESP_SIZE), control_area.response_size);
+}
+
/*
* tpm2_process_command
*/
@@ -220,6 +258,14 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size, void
// Write to Command Buffer
memcpy(control_area.command_bfr, tpm2_command, command_size);
+ /*
+ * Initialize CRB addresses and sizes for PTT. It seems to be possible
+ * only after CRB is switched to ready and before writing start bit.
+ * This is also what EDK2 TPM CRB drivers do.
+ */
+ if (CONFIG(HAVE_INTEL_PTT))
+ set_ptt_cmd_resp_buffers();
+
// Write Start Bit
write8(CRB_REG(cur_loc, CRB_REG_START), 0x1);
diff --git a/src/drivers/crb/tpm.h b/src/drivers/crb/tpm.h
index c43beb6843..be26be2d24 100644
--- a/src/drivers/crb/tpm.h
+++ b/src/drivers/crb/tpm.h
@@ -33,6 +33,7 @@
#define CRB_REG_CMD_ADDR 0x5C
#define CRB_REG_RESP_SIZE 0x64
#define CRB_REG_RESP_ADDR 0x68
+#define CRB_REG_DATA_BUFF 0x80
/* CRB INTF BIT MASK */
#define CRB_INTF_REG_CAP_CRB (1<<14)