x86: ivybridge: Implement SDRAM init

Implement SDRAM init using the Memory Reference Code (mrc.bin) provided in
the board directory and the SDRAM SPD information in the device tree. This
also needs the Intel Management Engine (me.bin) to work. Binary blobs
everywhere: so far we have MRC, ME and microcode.

SDRAM init works by setting up various parameters and calling the MRC. This
in turn does some sort of magic to work out how much memory there is and
the timing parameters to use. It also sets up the DRAM controllers. When
the MRC returns, we use the information it provides to map out the
available memory in U-Boot.

U-Boot normally moves itself to the top of RAM. On x86 the RAM is not
generally contiguous, and anyway some RAM may be above 4GB which doesn't
work in 32-bit mode. So we relocate to the top of the largest block of
RAM we can find below 4GB. Memory above 4GB is accessible with special
functions (see physmem).

It would be possible to build U-Boot in 64-bit mode but this wouldn't
necessarily provide any more memory, since the largest block is often below
4GB. Anyway U-Boot doesn't need huge amounts of memory - even a very large
ramdisk seldom exceeds 100-200MB. U-Boot has support for booting 64-bit
kernels directly so this does not pose a limitation in that area. Also there
are probably parts of U-Boot that will not work correctly in 64-bit mode.
The MRC is one.

There is some work remaining in this area. Since memory init is very slow
(over 500ms) it is possible to save the parameters in SPI flash to speed it
up next time. Suspend/resume support is not fully implemented, or at least
it is not efficient.

With this patch, link boots to a prompt.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 191 insertions, 0 deletions

diff --git a/arch/x86/cpu/ivybridge/early_me.c b/arch/x86/cpu/ivybridge/early_me.c
new file mode 100644
index 0000000000..b24dea10b1
--- /dev/null
+++ b/arch/x86/cpu/ivybridge/early_me.c
@@ -0,0 +1,191 @@
+/*
+ * From Coreboot src/southbridge/intel/bd82x6x/early_me.c
+ *
+ * Copyright (C) 2011 The Chromium OS Authors. All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0
+ */
+
+#include <common.h>
+#include <errno.h>
+#include <asm/pci.h>
+#include <asm/processor.h>
+#include <asm/arch/me.h>
+#include <asm/arch/pch.h>
+#include <asm/io.h>
+
+static const char *const me_ack_values[] = {
+	[ME_HFS_ACK_NO_DID]	= "No DID Ack received",
+	[ME_HFS_ACK_RESET]	= "Non-power cycle reset",
+	[ME_HFS_ACK_PWR_CYCLE]	= "Power cycle reset",
+	[ME_HFS_ACK_S3]		= "Go to S3",
+	[ME_HFS_ACK_S4]		= "Go to S4",
+	[ME_HFS_ACK_S5]		= "Go to S5",
+	[ME_HFS_ACK_GBL_RESET]	= "Global Reset",
+	[ME_HFS_ACK_CONTINUE]	= "Continue to boot"
+};
+
+static inline void pci_read_dword_ptr(void *ptr, int offset)
+{
+	u32 dword;
+
+	dword = pci_read_config32(PCH_ME_DEV, offset);
+	memcpy(ptr, &dword, sizeof(dword));
+}
+
+static inline void pci_write_dword_ptr(void *ptr, int offset)
+{
+	u32 dword = 0;
+	memcpy(&dword, ptr, sizeof(dword));
+	pci_write_config32(PCH_ME_DEV, offset, dword);
+}
+
+void intel_early_me_status(void)
+{
+	struct me_hfs hfs;
+	struct me_gmes gmes;
+
+	pci_read_dword_ptr(&hfs, PCI_ME_HFS);
+	pci_read_dword_ptr(&gmes, PCI_ME_GMES);
+
+	intel_me_status(&hfs, &gmes);
+}
+
+int intel_early_me_init(void)
+{
+	int count;
+	struct me_uma uma;
+	struct me_hfs hfs;
+
+	debug("Intel ME early init\n");
+
+	/* Wait for ME UMA SIZE VALID bit to be set */
+	for (count = ME_RETRY; count > 0; --count) {
+		pci_read_dword_ptr(&uma, PCI_ME_UMA);
+		if (uma.valid)
+			break;
+		udelay(ME_DELAY);
+	}
+	if (!count) {
+		printf("ERROR: ME is not ready!\n");
+		return -EBUSY;
+	}
+
+	/* Check for valid firmware */
+	pci_read_dword_ptr(&hfs, PCI_ME_HFS);
+	if (hfs.fpt_bad) {
+		printf("WARNING: ME has bad firmware\n");
+		return -EBADF;
+	}
+
+	debug("Intel ME firmware is ready\n");
+
+	return 0;
+}
+
+int intel_early_me_uma_size(void)
+{
+	struct me_uma uma;
+
+	pci_read_dword_ptr(&uma, PCI_ME_UMA);
+	if (uma.valid) {
+		debug("ME: Requested %uMB UMA\n", uma.size);
+		return uma.size;
+	}
+
+	debug("ME: Invalid UMA size\n");
+	return -EINVAL;
+}
+
+static inline void set_global_reset(int enable)
+{
+	u32 etr3;
+
+	etr3 = pci_read_config32(PCH_LPC_DEV, ETR3);
+
+	/* Clear CF9 Without Resume Well Reset Enable */
+	etr3 &= ~ETR3_CWORWRE;
+
+	/* CF9GR indicates a Global Reset */
+	if (enable)
+		etr3 |= ETR3_CF9GR;
+	else
+		etr3 &= ~ETR3_CF9GR;
+
+	pci_write_config32(PCH_LPC_DEV, ETR3, etr3);
+}
+
+int intel_early_me_init_done(u8 status)
+{
+	u8 reset;
+	int count;
+	u32 mebase_l, mebase_h;
+	struct me_hfs hfs;
+	struct me_did did = {
+		.init_done = ME_INIT_DONE,
+		.status = status
+	};
+
+	/* MEBASE from MESEG_BASE[35:20] */
+	mebase_l = pci_read_config32(PCH_DEV, PCI_CPU_MEBASE_L);
+	mebase_h = pci_read_config32(PCH_DEV, PCI_CPU_MEBASE_H);
+	mebase_h &= 0xf;
+	did.uma_base = (mebase_l >> 20) | (mebase_h << 12);
+
+	/* Send message to ME */
+	debug("ME: Sending Init Done with status: %d, UMA base: 0x%04x\n",
+	      status, did.uma_base);
+
+	pci_write_dword_ptr(&did, PCI_ME_H_GS);
+
+	/* Must wait for ME acknowledgement */
+	for (count = ME_RETRY; count > 0; --count) {
+		pci_read_dword_ptr(&hfs, PCI_ME_HFS);
+		if (hfs.bios_msg_ack)
+			break;
+		udelay(ME_DELAY);
+	}
+	if (!count) {
+		printf("ERROR: ME failed to respond\n");
+		return -1;
+	}
+
+	/* Return the requested BIOS action */
+	debug("ME: Requested BIOS Action: %s\n", me_ack_values[hfs.ack_data]);
+
+	/* Check status after acknowledgement */
+	intel_early_me_status();
+
+	reset = 0;
+	switch (hfs.ack_data) {
+	case ME_HFS_ACK_CONTINUE:
+		/* Continue to boot */
+		return 0;
+	case ME_HFS_ACK_RESET:
+		/* Non-power cycle reset */
+		set_global_reset(0);
+		reset = 0x06;
+		break;
+	case ME_HFS_ACK_PWR_CYCLE:
+		/* Power cycle reset */
+		set_global_reset(0);
+		reset = 0x0e;
+		break;
+	case ME_HFS_ACK_GBL_RESET:
+		/* Global reset */
+		set_global_reset(1);
+		reset = 0x0e;
+		break;
+	case ME_HFS_ACK_S3:
+	case ME_HFS_ACK_S4:
+	case ME_HFS_ACK_S5:
+		break;
+	}
+
+	/* Perform the requested reset */
+	if (reset) {
+		outb(reset, 0xcf9);
+		cpu_hlt();
+	}
+	return -1;
+}