soc/intel/common/block: Add HECI driver
Add common driver that can send/receive HECI messages. This driver is
inspired by Linux kernel mei driver and somewhat based on Skylake's.
Currently it has been only tested on Apollolake.
BUG=b:35586975
BRANCH=reef
TEST=tested on Apollolake to send single messages and receive both
fragmented and non-fragmented versions.
Change-Id: Ie3772700270f4f333292b80d59f79555851780f7
Signed-off-by: Andrey Petrov <andrey.petrov@intel.com>
Reviewed-on: https://review.coreboot.org/18547
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins)
diff --git a/src/soc/intel/common/block/cse/Kconfig b/src/soc/intel/common/block/cse/Kconfig
new file mode 100644
index 0000000..441ff93
--- /dev/null
+++ b/src/soc/intel/common/block/cse/Kconfig
@@ -0,0 +1,7 @@
+config SOC_INTEL_COMMON_BLOCK_CSE
+ bool
+ default n
+ help
+ Driver for communication with Converged Security Engine (CSE)
+ over Host Embedded Controller Interface (HECI)
+
diff --git a/src/soc/intel/common/block/cse/Makefile.inc b/src/soc/intel/common/block/cse/Makefile.inc
new file mode 100644
index 0000000..fe7b13c
--- /dev/null
+++ b/src/soc/intel/common/block/cse/Makefile.inc
@@ -0,0 +1,2 @@
+romstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CSE) += cse.c
+ramstage-$(CONFIG_SOC_INTEL_COMMON_BLOCK_CSE) += cse.c
diff --git a/src/soc/intel/common/block/cse/cse.c b/src/soc/intel/common/block/cse/cse.c
new file mode 100644
index 0000000..77cedb1
--- /dev/null
+++ b/src/soc/intel/common/block/cse/cse.c
@@ -0,0 +1,477 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2017 Intel Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <arch/early_variables.h>
+#include <commonlib/helpers.h>
+#include <console/console.h>
+#include <delay.h>
+#include <device/pci.h>
+#include <device/pci_ids.h>
+#include <device/pci_ops.h>
+#include <intelblocks/cse.h>
+#include <soc/pci_devs.h>
+#include <soc/pci_ids.h>
+#include <string.h>
+#include <timer.h>
+
+/* default window for early boot, must be at least 12 bytes in size */
+#define HECI1_BASE_ADDRESS 0xfed1a000
+
+/* Wait up to 15 sec for HECI to get ready */
+#define HECI_DELAY_READY (15 * 1000)
+/* Wait up to 100 usec between circullar buffer polls */
+#define HECI_DELAY 100
+/* Wait up to 5 sec for CSE to chew something we sent */
+#define HECI_SEND_TIMEOUT (5 * 1000)
+/* Wait up to 5 sec for CSE to blurp a reply */
+#define HECI_READ_TIMEOUT (5 * 1000)
+
+#define SLOT_SIZE sizeof(uint32_t)
+
+#define MMIO_CSE_CB_WW 0x00
+#define MMIO_HOST_CSR 0x04
+#define MMIO_CSE_CB_RW 0x08
+#define MMIO_CSE_CSR 0x0c
+
+#define CSR_IE (1 << 0)
+#define CSR_IS (1 << 1)
+#define CSR_IG (1 << 2)
+#define CSR_READY (1 << 3)
+#define CSR_RESET (1 << 4)
+#define CSR_RP_START 8
+#define CSR_RP (((1 << 8) - 1) << CSR_RP_START)
+#define CSR_WP_START 16
+#define CSR_WP (((1 << 8) - 1) << CSR_WP_START)
+#define CSR_CBD_START 24
+#define CSR_CBD (((1 << 8) - 1) << CSR_CBD_START)
+
+#define MEI_HDR_IS_COMPLETE (1 << 31)
+#define MEI_HDR_LENGTH_START 16
+#define MEI_HDR_LENGTH_SIZE 9
+#define MEI_HDR_LENGTH (((1 << MEI_HDR_LENGTH_SIZE) - 1) \
+ << MEI_HDR_LENGTH_START)
+#define MEI_HDR_HOST_ADDR_START 8
+#define MEI_HDR_HOST_ADDR (((1 << 8) - 1) << MEI_HDR_HOST_ADDR_START)
+#define MEI_HDR_CSE_ADDR_START 0
+#define MEI_HDR_CSE_ADDR (((1 << 8) - 1) << MEI_HDR_CSE_ADDR_START)
+
+
+struct cse_device {
+ uintptr_t sec_bar;
+} g_cse CAR_GLOBAL;
+
+/*
+ * Initialize the device with provided temporary BAR. If BAR is 0 use a
+ * default. This is intended for pre-mem usage only where BARs haven't been
+ * assigned yet and devices are not enabled.
+ */
+void heci_init(uintptr_t tempbar)
+{
+ struct cse_device *cse = car_get_var_ptr(&g_cse);
+ device_t dev = HECI1_DEV;
+ u8 pcireg;
+
+ /* Assume it is already initialized, nothing else to do */
+ if (cse->sec_bar)
+ return;
+
+ /* Use default pre-ram bar */
+ if (!tempbar)
+ tempbar = HECI1_BASE_ADDRESS;
+
+ /* Assign Resources to HECI1 */
+ /* Clear BIT 1-2 of Command Register */
+ pcireg = pci_read_config8(dev, PCI_COMMAND);
+ pcireg &= ~(PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY);
+ pci_write_config8(dev, PCI_COMMAND, pcireg);
+
+ /* Program Temporary BAR for HECI1 */
+ pci_write_config32(dev, PCI_BASE_ADDRESS_0, tempbar);
+ pci_write_config32(dev, PCI_BASE_ADDRESS_1, 0x0);
+
+ /* Enable Bus Master and MMIO Space */
+ pcireg = pci_read_config8(dev, PCI_COMMAND);
+ pcireg |= PCI_COMMAND_MASTER | PCI_COMMAND_MEMORY;
+ pci_write_config8(dev, PCI_COMMAND, pcireg);
+
+ cse->sec_bar = tempbar;
+}
+
+static uint32_t read_bar(uint32_t offset)
+{
+ struct cse_device *cse = car_get_var_ptr(&g_cse);
+ return read32((void *)(cse->sec_bar + offset));
+}
+
+static void write_bar(uint32_t offset, uint32_t val)
+{
+ struct cse_device *cse = car_get_var_ptr(&g_cse);
+ return write32((void *)(cse->sec_bar + offset), val);
+}
+
+static uint32_t read_cse_csr(void)
+{
+ return read_bar(MMIO_CSE_CSR);
+}
+
+static uint32_t read_host_csr(void)
+{
+ return read_bar(MMIO_HOST_CSR);
+}
+
+static void write_host_csr(uint32_t data)
+{
+ write_bar(MMIO_HOST_CSR, data);
+}
+
+static size_t filled_slots(uint32_t data)
+{
+ uint8_t wp, rp;
+ rp = data >> CSR_RP_START;
+ wp = data >> CSR_WP_START;
+ return (uint8_t) (wp - rp);
+}
+
+static size_t cse_filled_slots(void)
+{
+ return filled_slots(read_cse_csr());
+}
+
+static size_t host_empty_slots(void)
+{
+ uint32_t csr;
+ csr = read_host_csr();
+
+ return ((csr & CSR_CBD) >> CSR_CBD_START) - filled_slots(csr);
+}
+
+static void clear_int(void)
+{
+ uint32_t csr;
+ csr = read_host_csr();
+ csr |= CSR_IS;
+ write_host_csr(csr);
+}
+
+static uint32_t read_slot(void)
+{
+ return read_bar(MMIO_CSE_CB_RW);
+}
+
+static void write_slot(uint32_t val)
+{
+ write_bar(MMIO_CSE_CB_WW, val);
+}
+
+static int wait_write_slots(size_t cnt)
+{
+ struct stopwatch sw;
+
+ stopwatch_init_msecs_expire(&sw, HECI_SEND_TIMEOUT);
+ while (host_empty_slots() < cnt) {
+ udelay(HECI_DELAY);
+ if (stopwatch_expired(&sw)) {
+ printk(BIOS_ERR, "HECI: timeout, buffer not drained\n");
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int wait_read_slots(size_t cnt)
+{
+ struct stopwatch sw;
+
+ stopwatch_init_msecs_expire(&sw, HECI_READ_TIMEOUT);
+ while (cse_filled_slots() < cnt) {
+ udelay(HECI_DELAY);
+ if (stopwatch_expired(&sw)) {
+ printk(BIOS_ERR, "HECI: timed out reading answer!\n");
+ return 0;
+ }
+ }
+ return 1;
+}
+
+/* get number of full 4-byte slots */
+static size_t bytes_to_slots(size_t bytes)
+{
+ return ALIGN_UP(bytes, SLOT_SIZE) / SLOT_SIZE;
+}
+
+static int cse_ready(void)
+{
+ uint32_t csr;
+ csr = read_cse_csr();
+ return csr & CSR_READY;
+}
+
+static int wait_heci_ready(void)
+{
+ struct stopwatch sw;
+
+ stopwatch_init_msecs_expire(&sw, HECI_DELAY_READY);
+ while (!cse_ready()) {
+ udelay(HECI_DELAY);
+ if (stopwatch_expired(&sw))
+ return 0;
+ }
+
+ return 1;
+}
+
+static void host_gen_interrupt(void)
+{
+ uint32_t csr;
+ csr = read_host_csr();
+ csr |= CSR_IG;
+ write_host_csr(csr);
+}
+
+static size_t hdr_get_length(uint32_t hdr)
+{
+ return (hdr & MEI_HDR_LENGTH) >> MEI_HDR_LENGTH_START;
+}
+
+static int
+send_one_message(uint32_t hdr, const void *buff)
+{
+ size_t pend_len, pend_slots, remainder, i;
+ uint32_t tmp;
+ const uint32_t *p = buff;
+
+ /* Get space for the header */
+ if (!wait_write_slots(1))
+ return 0;
+
+ /* First, write header */
+ write_slot(hdr);
+
+ pend_len = hdr_get_length(hdr);
+ pend_slots = bytes_to_slots(pend_len);
+
+ if (!wait_write_slots(pend_slots))
+ return 0;
+
+ /* Write the body in whole slots */
+ i = 0;
+ while (i < ALIGN_DOWN(pend_len, SLOT_SIZE)) {
+ write_slot(*p++);
+ i += SLOT_SIZE;
+ }
+
+ remainder = pend_len % SLOT_SIZE;
+ /* Pad to 4 bytes not touching caller's buffer */
+ if (remainder) {
+ memcpy(&tmp, p, remainder);
+ write_slot(tmp);
+ }
+
+ host_gen_interrupt();
+
+ /* Make sure nothing bad happened during transmission */
+ if (!cse_ready())
+ return 0;
+
+ return pend_len;
+}
+
+int
+heci_send(const void *msg, size_t len, uint8_t host_addr, uint8_t client_addr)
+{
+ uint32_t csr, hdr;
+ size_t sent = 0, remaining, cb_size, max_length;
+ uint8_t *p = (uint8_t *) msg;
+
+ if (!msg || !len)
+ return 0;
+
+ clear_int();
+
+ if (!wait_heci_ready()) {
+ printk(BIOS_ERR, "HECI: not ready\n");
+ return 0;
+ }
+
+ csr = read_cse_csr();
+ cb_size = ((csr & CSR_CBD) >> CSR_CBD_START) * SLOT_SIZE;
+ /*
+ * Reserve one slot for the header. Limit max message length by 9
+ * bits that are available in the header.
+ */
+ max_length = MIN(cb_size, (1 << MEI_HDR_LENGTH_SIZE) - 1) - SLOT_SIZE;
+ remaining = len;
+
+ /*
+ * Fragment the message into smaller messages not exceeding useful
+ * circullar buffer length. Mark last message complete.
+ */
+ do {
+ hdr = MIN(max_length, remaining) << MEI_HDR_LENGTH_START;
+ hdr |= client_addr << MEI_HDR_CSE_ADDR_START;
+ hdr |= host_addr << MEI_HDR_HOST_ADDR_START;
+ hdr |= (MIN(max_length, remaining) == remaining) ?
+ MEI_HDR_IS_COMPLETE: 0;
+ sent = send_one_message(hdr, p);
+ p += sent;
+ remaining -= sent;
+ } while (remaining > 0 && sent != 0);
+
+ return remaining == 0;
+}
+
+static size_t
+recv_one_message(uint32_t *hdr, void *buff, size_t maxlen)
+{
+ uint32_t reg, *p = buff;
+ size_t recv_slots, recv_len, remainder, i;
+
+ /* first get the header */
+ if (!wait_read_slots(1))
+ return 0;
+
+ *hdr = read_slot();
+ recv_len = hdr_get_length(*hdr);
+
+ if (!recv_len)
+ printk(BIOS_WARNING, "HECI: message is zero-sized\n");
+
+ recv_slots = bytes_to_slots(recv_len);
+
+ i = 0;
+ if (recv_len > maxlen) {
+ printk(BIOS_ERR, "HECI: response is too big\n");
+ return 0;
+ }
+
+ /* wait for the rest of messages to arrive */
+ wait_read_slots(recv_slots);
+
+ /* fetch whole slots first */
+ while (i < ALIGN_DOWN(recv_len, SLOT_SIZE)) {
+ *p++ = read_slot();
+ i += SLOT_SIZE;
+ }
+
+ remainder = recv_len % SLOT_SIZE;
+
+ if (remainder) {
+ reg = read_slot();
+ memcpy(p, ®, remainder);
+ }
+
+ return recv_len;
+}
+
+int heci_receive(void *buff, size_t *maxlen)
+{
+ size_t left, received;
+ uint32_t hdr = 0;
+ uint8_t *p = buff;
+
+ if (!buff || !maxlen || !*maxlen)
+ return 0;
+
+ left = *maxlen;
+
+ clear_int();
+
+ if (!wait_heci_ready()) {
+ printk(BIOS_ERR, "HECI: not ready\n");
+ return 0;
+ }
+
+ /*
+ * Receive multiple packets until we meet one marked complete or we run
+ * out of space in caller-provided buffer.
+ */
+ do {
+ received = recv_one_message(&hdr, p, left);
+ left -= received;
+ p += received;
+ /* If we read out everything ping to send more */
+ if (!(hdr & MEI_HDR_IS_COMPLETE) && !cse_filled_slots())
+ host_gen_interrupt();
+ } while (received && !(hdr & MEI_HDR_IS_COMPLETE) && left > 0);
+
+ *maxlen = p - (uint8_t *) buff;
+
+ /* If ME is not ready, something went wrong and we received junk */
+ if (!cse_ready())
+ return 0;
+
+ return !!((hdr & MEI_HDR_IS_COMPLETE) && received);
+}
+
+/*
+ * Attempt to reset the device. This is useful when host and ME are out
+ * of sync during transmission or ME didn't understand the message.
+ */
+int heci_reset(void)
+{
+ uint32_t csr;
+
+ /* Send reset request */
+ csr = read_host_csr();
+ csr |= CSR_RESET;
+ csr |= CSR_IG;
+ write_host_csr(csr);
+
+ if (wait_heci_ready()) {
+ /* Device is back on its imaginary feet, clear reset */
+ csr = read_host_csr();
+ csr &= ~CSR_RESET;
+ csr |= CSR_IG;
+ csr |= CSR_READY;
+ write_host_csr(csr);
+ return 1;
+ }
+
+ printk(BIOS_CRIT, "HECI: reset failed\n");
+
+ return 0;
+}
+
+#if ENV_RAMSTAGE
+
+static void update_sec_bar(struct device *dev)
+{
+ g_cse.sec_bar = find_resource(dev, PCI_BASE_ADDRESS_0)->base;
+}
+
+static void cse_set_resources(struct device *dev)
+{
+ if (dev->path.pci.devfn == HECI1_DEVFN)
+ update_sec_bar(dev);
+
+ pci_dev_set_resources(dev);
+}
+
+static struct device_operations cse_ops = {
+ .set_resources = cse_set_resources,
+ .read_resources = pci_dev_read_resources,
+ .enable_resources = pci_dev_enable_resources,
+ .init = pci_dev_init,
+ .enable_resources = pci_dev_enable_resources
+};
+
+static const struct pci_driver cse_driver __pci_driver = {
+ .ops = &cse_ops,
+ .vendor = PCI_VENDOR_ID_INTEL,
+ /* SoC/chipset needs to provide PCI device ID */
+ .device = PCI_DEVICE_ID_HECI1
+};
+
+#endif