From b15975bf5a4a1b9ed4d83e2c8caf622d71a7e4d5 Mon Sep 17 00:00:00 2001 From: Stefan Reinauer Date: Fri, 21 Oct 2011 12:57:59 -0700 Subject: copy e7501 component to e7505 Change-Id: Ie69a6b6a040a8b0e7693083b3a2d13c327a165b3 Signed-off-by: Stefan Reinauer Reviewed-on: http://review.coreboot.org/310 Tested-by: build bot (Jenkins) Reviewed-by: Patrick Georgi --- src/northbridge/intel/e7505/raminit.c | 2007 +++++++++++++++++++++++++++++++++ 1 file changed, 2007 insertions(+) create mode 100644 src/northbridge/intel/e7505/raminit.c (limited to 'src/northbridge/intel/e7505/raminit.c') diff --git a/src/northbridge/intel/e7505/raminit.c b/src/northbridge/intel/e7505/raminit.c new file mode 100644 index 0000000000..f42bef2db0 --- /dev/null +++ b/src/northbridge/intel/e7505/raminit.c @@ -0,0 +1,2007 @@ +/* This was originally for the e7500, modified for e7501 + * The primary differences are that 7501 apparently can + * support single channel RAM (i haven't tested), + * CAS1.5 is no longer supported, The ECC scrubber + * now supports a mode to zero RAM and init ECC in one step + * and the undocumented registers at 0x80 require new + * (undocumented) values determined by guesswork and + * comparison w/ OEM BIOS values. + * Steven James 02/06/2003 + */ + +/* converted to C 6/2004 yhlu */ + +#include +#include +#include +#include +#include "e7501.h" + +/*----------------------------------------------------------------------------- +Definitions: +-----------------------------------------------------------------------------*/ + +// Uncomment this to enable run-time checking of DIMM parameters +// for dual-channel operation +// Unfortunately the code seems to chew up several K of space. +//#define VALIDATE_DIMM_COMPATIBILITY + +#if CONFIG_DEBUG_RAM_SETUP +#define RAM_DEBUG_MESSAGE(x) print_debug(x) +#define RAM_DEBUG_HEX32(x) print_debug_hex32(x) +#define RAM_DEBUG_HEX8(x) print_debug_hex8(x) +#define DUMPNORTH() dump_pci_device(PCI_DEV(0, 0, 0)) +#else +#define RAM_DEBUG_MESSAGE(x) +#define RAM_DEBUG_HEX32(x) +#define RAM_DEBUG_HEX8(x) +#define DUMPNORTH() +#endif + +#define E7501_SDRAM_MODE (SDRAM_BURST_INTERLEAVED | SDRAM_BURST_4) +#define SPD_ERROR "Error reading SPD info\n" + +// NOTE: This used to be 0x100000. +// That doesn't work on systems where A20M# is asserted, because +// attempts to access 0x1000NN end up accessing 0x0000NN. +#define RCOMP_MMIO 0x200000 + +struct dimm_size { + unsigned long side1; + unsigned long side2; +}; + +static const uint32_t refresh_frequency[] = { + /* Relative frequency (array value) of each E7501 Refresh Mode Select + * (RMS) value (array index) + * 0 == least frequent refresh (longest interval between refreshes) + * [0] disabled -> 0 + * [1] 15.6 usec -> 2 + * [2] 7.8 usec -> 3 + * [3] 64 usec -> 1 + * [4] reserved -> 0 + * [5] reserved -> 0 + * [6] reserved -> 0 + * [7] 64 clocks -> 4 + */ + 0, 2, 3, 1, 0, 0, 0, 4 +}; + +static const uint32_t refresh_rate_map[] = { + /* Map the JEDEC spd refresh rates (array index) to E7501 Refresh Mode + * Select values (array value) + * These are all the rates defined by JESD21-C Appendix D, Rev. 1.0 + * The E7501 supports only 15.6 us (1), 7.8 us (2), 64 us (3), and + * 64 clock (481 ns) (7) refresh. + * [0] == 15.625 us -> 15.6 us + * [1] == 3.9 us -> 481 ns + * [2] == 7.8 us -> 7.8 us + * [3] == 31.3 us -> 15.6 us + * [4] == 62.5 us -> 15.6 us + * [5] == 125 us -> 64 us + */ + 1, 7, 2, 1, 1, 3 +}; + +#define MAX_SPD_REFRESH_RATE ((sizeof(refresh_rate_map) / sizeof(uint32_t)) - 1) + +// SPD parameters that must match for dual-channel operation +static const uint8_t dual_channel_parameters[] = { + SPD_MEMORY_TYPE, + SPD_MODULE_VOLTAGE, + SPD_NUM_COLUMNS, + SPD_NUM_ROWS, + SPD_NUM_DIMM_BANKS, + SPD_PRIMARY_SDRAM_WIDTH, + SPD_NUM_BANKS_PER_SDRAM +}; + + /* + * Table: constant_register_values + */ +static const long constant_register_values[] = { + /* SVID - Subsystem Vendor Identification Register + * 0x2c - 0x2d + * [15:00] Subsytem Vendor ID (Indicates system board vendor) + */ + /* SID - Subsystem Identification Register + * 0x2e - 0x2f + * [15:00] Subsystem ID + */ + // Not everyone wants to be Super Micro Computer, Inc. + // The mainboard should set this if desired. + // 0x2c, 0, (0x15d9 << 0) | (0x3580 << 16), + + /* Undocumented + * (DRAM Read Timing Control, if similar to 855PM?) + * 0x80 - 0x81 + * This register has something to do with CAS latencies, + * possibily this is the real chipset control. + * At 0x00 CAS latency 1.5 works. + * At 0x06 CAS latency 2.5 works. + * At 0x01 CAS latency 2.0 works. + */ + /* This is still undocumented in e7501, but with different values + * CAS 2.0 values taken from Intel BIOS settings, others are a guess + * and may be terribly wrong. Old values preserved as comments until I + * figure this out for sure. + * e7501 docs claim that CAS1.5 is unsupported, so it may or may not + * work at all. + * Steven James 02/06/2003 + */ + /* NOTE: values now configured in configure_e7501_cas_latency() based + * on SPD info and total number of DIMMs (per Intel) + */ + + /* FDHC - Fixed DRAM Hole Control + * 0x58 + * [7:7] Hole_Enable + * 0 == No memory Hole + * 1 == Memory Hole from 15MB to 16MB + * [6:0] Reserved + * + * PAM - Programmable Attribute Map + * 0x59 [1:0] Reserved + * 0x59 [5:4] 0xF0000 - 0xFFFFF + * 0x5A [1:0] 0xC0000 - 0xC3FFF + * 0x5A [5:4] 0xC4000 - 0xC7FFF + * 0x5B [1:0] 0xC8000 - 0xCBFFF + * 0x5B [5:4] 0xCC000 - 0xCFFFF + * 0x5C [1:0] 0xD0000 - 0xD3FFF + * 0x5C [5:4] 0xD4000 - 0xD7FFF + * 0x5D [1:0] 0xD8000 - 0xDBFFF + * 0x5D [5:4] 0xDC000 - 0xDFFFF + * 0x5E [1:0] 0xE0000 - 0xE3FFF + * 0x5E [5:4] 0xE4000 - 0xE7FFF + * 0x5F [1:0] 0xE8000 - 0xEBFFF + * 0x5F [5:4] 0xEC000 - 0xEFFFF + * 00 == DRAM Disabled (All Access go to memory mapped I/O space) + * 01 == Read Only (Reads to DRAM, Writes to memory mapped I/O space) + * 10 == Write Only (Writes to DRAM, Reads to memory mapped I/O space) + * 11 == Normal (All Access go to DRAM) + */ + + // Map all legacy ranges to DRAM + 0x58, 0xcccccf7f, (0x00 << 0) | (0x30 << 8) | (0x33 << 16) | (0x33 << 24), + 0x5C, 0xcccccccc, (0x33 << 0) | (0x33 << 8) | (0x33 << 16) | (0x33 << 24), + + /* DRB - DRAM Row Boundary Registers + * 0x60 - 0x6F + * An array of 8 byte registers, which hold the ending + * memory address assigned to each pair of DIMMS, in 64MB + * granularity. + */ + // Conservatively say each row has 64MB of ram, we will fix this up later + // NOTE: These defaults allow us to prime all of the DIMMs on the board + // without jumping through 36-bit adddressing hoops, even if the + // total memory is > 4 GB. Changing these values may break do_ram_command()! + 0x60, 0x00000000, (0x01 << 0) | (0x02 << 8) | (0x03 << 16) | (0x04 << 24), + 0x64, 0x00000000, (0x05 << 0) | (0x06 << 8) | (0x07 << 16) | (0x08 << 24), + + /* DRA - DRAM Row Attribute Register + * 0x70 Row 0,1 + * 0x71 Row 2,3 + * 0x72 Row 4,5 + * 0x73 Row 6,7 + * [7:7] Device width for Odd numbered rows + * 0 == 8 bits wide x8 + * 1 == 4 bits wide x4 + * [6:4] Row Attributes for Odd numbered rows + * 010 == 8KB (for dual-channel) + * 011 == 16KB (for dual-channel) + * 100 == 32KB (for dual-channel) + * 101 == 64KB (for dual-channel) + * Others == Reserved + * [3:3] Device width for Even numbered rows + * 0 == 8 bits wide x8 + * 1 == 4 bits wide x4 + * [2:0] Row Attributes for Even numbered rows + * 010 == 8KB (for dual-channel) + * 011 == 16KB (for dual-channel) + * 100 == 32KB (for dual-channel) + * 101 == 64KB (This page size appears broken) + * Others == Reserved + */ + // NOTE: overridden by configure_e7501_row_attributes(), later + 0x70, 0x00000000, 0, + + /* DRT - DRAM Timing Register + * 0x78 + * [31:30] Reserved + * [29:29] Back to Back Write-Read Turn Around + * 0 == 3 clocks between WR-RD commands + * 1 == 2 clocks between WR-RD commands + * [28:28] Back to Back Read-Write Turn Around + * 0 == 5 clocks between RD-WR commands + * 1 == 4 clocks between RD-WR commands + * [27:27] Back to Back Read Turn Around + * 0 == 4 clocks between RD commands + * 1 == 3 clocks between RD commands + * [26:24] Read Delay (tRD) + * 000 == 7 clocks + * 001 == 6 clocks + * 010 == 5 clocks + * Others == Reserved + * [23:19] Reserved + * [18:16] DRAM idle timer + * 000 == infinite + * 011 == 16 dram clocks + * 001 == 0 clocks + * [15:11] Reserved + * [10:09] Active to Precharge (tRAS) + * 00 == 7 clocks + * 01 == 6 clocks + * 10 == 5 clocks + * 11 == Reserved + * [08:06] Reserved + * [05:04] Cas Latency (tCL) + * 00 == 2.5 Clocks + * 01 == 2.0 Clocks + * 10 == Reserved (was 1.5 Clocks for E7500) + * 11 == Reserved + * [03:03] Write Ras# to Cas# Delay (tRCD) + * 0 == 3 DRAM Clocks + * 1 == 2 DRAM Clocks + * [02:01] Read RAS# to CAS# Delay (tRCD) + * 00 == reserved + * 01 == reserved + * 10 == 3 DRAM Clocks + * 11 == 2 DRAM Clocks + * [00:00] DRAM RAS# to Precharge (tRP) + * 0 == 3 DRAM Clocks + * 1 == 2 DRAM Clocks + */ + + // Some earlier settings: + /* Most aggressive settings possible */ +// 0x78, 0xc0fff8c4, (1<<29)|(1<<28)|(1<<27)|(2<<24)|(2<<9)|CAS_LATENCY|(1<<3)|(1<<1)|(1<<0), +// 0x78, 0xc0f8f8c0, (1<<29)|(1<<28)|(1<<27)|(1<<24)|(1<<16)|(2<<9)|CAS_LATENCY|(1<<3)|(3<<1)|(1<<0), +// 0x78, 0xc0f8f9c0, (1<<29)|(1<<28)|(1<<27)|(1<<24)|(1<<16)|(2<<9)|CAS_LATENCY|(1<<3)|(3<<1)|(1<<0), + + // The only things we need to set here are DRAM idle timer, Back-to-Back Read Turnaround, and + // Back-to-Back Write-Read Turnaround. All others are configured based on SPD. + 0x78, 0xD7F8FFFF, (1 << 29) | (1 << 27) | (1 << 16), + + /* FIXME why was I attempting to set a reserved bit? */ + /* 0x0100040f */ + + /* DRC - DRAM Contoller Mode Register + * 0x7c + * [31:30] Reserved + * [29:29] Initialization Complete + * 0 == Not Complete + * 1 == Complete + * [28:23] Reserved + * [22:22] Channels + * 0 == Single channel + * 1 == Dual Channel + * [21:20] DRAM Data Integrity Mode + * 00 == Disabled, no ECC + * 01 == Reserved + * 10 == Error checking, using chip-kill, with correction + * 11 == Reserved + * [19:18] DRB Granularity (Read-Only) + * 00 == 32 MB quantities (single channel mode) + * 01 == 64 MB quantities (dual-channel mode) + * 10 == Reserved + * 11 == Reserved + * [17:17] (Intel Undocumented) should always be set to 1 (SJM: comment inconsistent with current setting, below) + * [16:16] Command Per Clock - Address/Control Assertion Rule (CPC) + * 0 == 2n Rule + * 1 == 1n rule + * [15:11] Reserved + * [10:08] Refresh mode select + * 000 == Refresh disabled + * 001 == Refresh interval 15.6 usec + * 010 == Refresh interval 7.8 usec + * 011 == Refresh interval 64 usec + * 111 == Refresh every 64 clocks (fast refresh) + * [07:07] Reserved + * [06:04] Mode Select (SMS) + * 000 == Reserved (was Self Refresh Mode in E7500) + * 001 == NOP Command + * 010 == All Banks Precharge + * 011 == Mode Register Set + * 100 == Extended Mode Register Set + * 101 == Reserved + * 110 == CBR Refresh + * 111 == Normal Operation + * [03:00] Reserved + */ +// .long 0x7c, 0xffcefcff, (1<<22)|(2 << 20)|(1 << 16)| (0 << 8), +// .long 0x7c, 0xff8cfcff, (1<<22)|(2 << 20)|(1 << 17)|(1 << 16)| (0 << 8), +// .long 0x7c, 0xff80fcff, (1<<22)|(2 << 20)|(1 << 18)|(1 << 17)|(1 << 16)| (0 << 8), + + // Default to dual-channel mode, ECC, 1-clock address/cmd hold + // NOTE: configure_e7501_dram_controller_mode() configures further + 0x7c, 0xff8ef8ff, (1 << 22) | (2 << 20) | (1 << 16) | (0 << 8), + + /* Another Intel undocumented register + * 0x88 - 0x8B + * [31:31] Purpose unknown + * [26:26] Master DLL Reset? + * 0 == Normal operation? + * 1 == Reset? + * [07:07] Periodic memory recalibration? + * 0 == Disabled? + * 1 == Enabled? + * [04:04] Receive FIFO RE-Sync? + * 0 == Normal operation? + * 1 == Reset? + */ + // NOTE: Some factory BIOSs don't do this. + // Doesn't seem to matter either way. + 0x88, 0xffffff00, 0x80, + + /* CLOCK_DIS - CK/CK# Disable Register + * 0x8C + * [7:7] DDR Frequency + * 0 == 100 MHz (200 MHz data rate) + * 1 == 133 MHz (266 MHz data rate) + * [6:4] Reserved + * [3:3] CK3 + * 0 == Enable + * 1 == Disable + * [2:2] CK2 + * 0 == Enable + * 1 == Disable + * [1:1] CK1 + * 0 == Enable + * 1 == Disable + * [0:0] CK0 + * 0 == Enable + * 1 == Disable + */ + // NOTE: Disable all clocks initially; turn ones we need back on + // in enable_e7501_clocks() + 0x8C, 0xfffffff0, 0xf, + + /* TOLM - Top of Low Memory Register + * 0xC4 - 0xC5 + * [15:11] Top of low memory (TOLM) + * The address below 4GB that should be treated as RAM, + * on a 128MB granularity. + * [10:00] Reserved + */ + /* REMAPBASE - Remap Base Address Regsiter + * 0xC6 - 0xC7 + * [15:10] Reserved + * [09:00] Remap Base Address [35:26] 64M aligned + * Bits [25:0] are assumed to be 0. + */ + + // NOTE: TOLM overridden by configure_e7501_ram_addresses() + 0xc4, 0xfc0007ff, (0x2000 << 0) | (0x3ff << 16), + + /* REMAPLIMIT - Remap Limit Address Register + * 0xC8 - 0xC9 + * [15:10] Reserved + * [09:00] Remap Limit Address [35:26] 64M aligned + * When remaplimit < remapbase the remap window is disabled. + */ + 0xc8, 0xfffffc00, 0, + + /* DVNP - Device Not Present Register + * 0xE0 - 0xE1 + * [15:05] Reserved + * [04:04] Device 4 Function 1 Present + * 0 == Present + * 1 == Absent + * [03:03] Device 3 Function 1 Present + * 0 == Present + * 1 == Absent + * [02:02] Device 2 Function 1 Present + * 0 == Present + * 1 == Absent + * [01:01] Reserved + * [00:00] Device 0 Function 1 Present + * 0 == Present + * 1 == Absent + */ + + // Enable D0:D1, disable D2:F1, D3:F1, D4:F1 + 0xe0, 0xffffffe2, (1 << 4) | (1 << 3) | (1 << 2) | (0 << 0), + + // Undocumented + 0xd8, 0xffff9fff, 0x00000000, + + // Undocumented - this is pure conjecture based on similarity to 855PM + /* MCHTST - MCH Test Register + * 0xF4 - 0xF7 + * [31:31] Purpose unknown + * [30:30] Purpose unknown + * [29:23] Unknown - not used? + * [22:22] System Memory MMR Enable + * 0 == Disable: mem space and BAR at 0x14 are not accessible + * 1 == Enable: mem space and BAR at 0x14 are accessible + * [21:20] Purpose unknown + * [19:02] Unknown - not used? + * [01:01] D6EN (Device #6 enable) + * 0 == Disable + * 1 == Enable + * [00:00] Unknown - not used? + */ + + 0xf4, 0x3f8ffffd, 0x40300002, + +#ifdef SUSPICIOUS_LOOKING_CODE + // SJM: Undocumented. + // This will access D2:F0:0x50, is this correct?? + 0x1050, 0xffffffcf, 0x00000030, +#endif +}; + + /* DDR RECOMP tables */ + +// Slew table for 1x drive? +static const uint32_t maybe_1x_slew_table[] = { + 0x44332211, 0xc9776655, 0xffffffff, 0xffffffff, + 0x22111111, 0x55444332, 0xfffca876, 0xffffffff, +}; + +// Slew table for 2x drive? +static const uint32_t maybe_2x_slew_table[] = { + 0x00000000, 0x76543210, 0xffffeca8, 0xffffffff, + 0x21000000, 0xa8765432, 0xffffffec, 0xffffffff, +}; + +// Pull Up / Pull Down offset table, if analogous to IXP2800? +static const uint32_t maybe_pull_updown_offset_table[] = { + 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff, + 0x88888888, 0x88888888, 0x88888888, 0x88888888, +}; + +/*----------------------------------------------------------------------------- +Delay functions: +-----------------------------------------------------------------------------*/ + +#define SLOW_DOWN_IO inb(0x80) +//#define SLOW_DOWN_IO udelay(40); + + /* Estimate that SLOW_DOWN_IO takes about 50&76us */ + /* delay for 200us */ + +#if 1 +static void do_delay(void) +{ + int i; + for (i = 0; i < 16; i++) { + SLOW_DOWN_IO; + } +} + +#define DO_DELAY do_delay() +#else +#define DO_DELAY \ + udelay(200) +#endif + +#define EXTRA_DELAY DO_DELAY + +static void die_on_spd_error(int spd_return_value) +{ + if (spd_return_value < 0) + die("Error reading SPD info\n"); +} + +/*----------------------------------------------------------------------------- +Serial presence detect (SPD) functions: +-----------------------------------------------------------------------------*/ + +/** + * Calculate the page size for each physical bank of the DIMM: + * log2(page size) = (# columns) + log2(data width) + * + * NOTE: Page size is the total number of data bits in a row. + * + * @param dimm_socket_address SMBus address of DIMM socket to interrogate. + * @return log2(page size) for each side of the DIMM. + */ +static struct dimm_size sdram_spd_get_page_size(uint16_t dimm_socket_address) +{ + uint16_t module_data_width; + int value; + struct dimm_size pgsz; + + pgsz.side1 = 0; + pgsz.side2 = 0; + + // Side 1 + value = spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS); + if (value < 0) + goto hw_err; + pgsz.side1 = value & 0xf; // # columns in bank 1 + + /* Get the module data width and convert it to a power of two */ + value = + spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_MSB); + if (value < 0) + goto hw_err; + module_data_width = (value & 0xff) << 8; + + value = + spd_read_byte(dimm_socket_address, SPD_MODULE_DATA_WIDTH_LSB); + if (value < 0) + goto hw_err; + module_data_width |= (value & 0xff); + + pgsz.side1 += log2(module_data_width); + + /* side two */ + value = spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS); + if (value < 0) + goto hw_err; + if (value > 2) + die("Bad SPD value\n"); + if (value == 2) { + + pgsz.side2 = pgsz.side1; // Assume symmetric banks until we know differently + value = + spd_read_byte(dimm_socket_address, SPD_NUM_COLUMNS); + if (value < 0) + goto hw_err; + if ((value & 0xf0) != 0) { + // Asymmetric banks + pgsz.side2 -= value & 0xf; /* Subtract out columns on side 1 */ + pgsz.side2 += (value >> 4) & 0xf; /* Add in columns on side 2 */ + } + } + + return pgsz; + + hw_err: + die(SPD_ERROR); + return pgsz; // Never reached +} + +/** + * Read the width in bits of each DIMM side's DRAMs via SPD (i.e. 4, 8, 16). + * + * @param dimm_socket_address SMBus address of DIMM socket to interrogate. + * @return Width in bits of each DIMM side's DRAMs. + */ +static struct dimm_size sdram_spd_get_width(uint16_t dimm_socket_address) +{ + int value; + struct dimm_size width; + + width.side1 = 0; + width.side2 = 0; + + value = + spd_read_byte(dimm_socket_address, SPD_PRIMARY_SDRAM_WIDTH); + die_on_spd_error(value); + + width.side1 = value & 0x7f; // Mask off bank 2 flag + + if (value & 0x80) { + width.side2 = width.side1 << 1; // Bank 2 exists and is double-width + } else { + // If bank 2 exists, it's the same width as bank 1 + value = + spd_read_byte(dimm_socket_address, SPD_NUM_DIMM_BANKS); + die_on_spd_error(value); + +#ifdef ROMCC_IF_BUG_FIXED + if (value == 2) + width.side2 = width.side1; +#else + switch (value) { + case 2: + width.side2 = width.side1; + break; + + default: + break; + } +#endif + } + + return width; +} + +/** + * Calculate the log base 2 size in bits of both DIMM sides. + * + * log2(# bits) = (# columns) + log2(data width) + + * (# rows) + log2(banks per SDRAM) + * + * Note that it might be easier to use SPD byte 31 here, it has the DIMM size + * as a multiple of 4MB. The way we do it now we can size both sides of an + * asymmetric DIMM. + * + * @param dimm_socket_address SMBus address of DIMM socket to interrogate. + * @return log2(number of bits) for each side of the DIMM. + */ +static struct dimm_size spd_get_dimm_size(unsigned dimm_socket_address) +{ + int value; + + // Start with log2(page size) + struct dimm_size sz = sdram_spd_get_page_size(dimm_socket_address); + + if (sz.side1 > 0) { + + value = spd_read_byte(dimm_socket_address, SPD_NUM_ROWS); + die_on_spd_error(value); + + sz.side1 += value & 0xf; + + if (sz.side2 > 0) { + + // Double-sided DIMM + if (value & 0xF0) + sz.side2 += value >> 4; // Asymmetric + else + sz.side2 += value; // Symmetric + } + + value = + spd_read_byte(dimm_socket_address, + SPD_NUM_BANKS_PER_SDRAM); + die_on_spd_error(value); + + value = log2(value); + sz.side1 += value; + if (sz.side2 > 0) + sz.side2 += value; + } + + return sz; +} + +#ifdef VALIDATE_DIMM_COMPATIBILITY + +/** + * Determine whether two DIMMs have the same value for an SPD parameter. + * + * @param spd_byte_number The SPD byte number to compare in both DIMMs. + * @param dimm0_address SMBus address of the 1st DIMM socket to interrogate. + * @param dimm1_address SMBus address of the 2nd DIMM socket to interrogate. + * @return 1 if both DIMM sockets report the same value for the specified + * SPD parameter, 0 if the values differed or an error occurred. + */ +static uint8_t are_spd_values_equal(uint8_t spd_byte_number, + uint16_t dimm0_address, + uint16_t dimm1_address) +{ + uint8_t bEqual = 0; + int dimm0_value = spd_read_byte(dimm0_address, spd_byte_number); + int dimm1_value = spd_read_byte(dimm1_address, spd_byte_number); + + if ((dimm0_value >= 0) && (dimm1_value >= 0) + && (dimm0_value == dimm1_value)) + bEqual = 1; + + return bEqual; +} +#endif + +/** + * Scan for compatible DIMMs. + * + * The code in this module only supports dual-channel operation, so we test + * that compatible DIMMs are paired. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @return A bitmask indicating which of the possible sockets for each channel + * was found to contain a compatible DIMM. + * Bit 0 corresponds to the closest socket for channel 0 + * Bit 1 to the next socket for channel 0 + * ... + * Bit MAX_DIMM_SOCKETS_PER_CHANNEL-1 to the last socket for channel 0 + * Bit MAX_DIMM_SOCKETS_PER_CHANNEL is the closest socket for channel 1 + * ... + * Bit 2*MAX_DIMM_SOCKETS_PER_CHANNEL-1 is the last socket for channel 1 + */ +static uint8_t spd_get_supported_dimms(const struct mem_controller *ctrl) +{ + int i; + uint8_t dimm_mask = 0; + + // Have to increase size of dimm_mask if this assertion is violated + ASSERT(MAX_DIMM_SOCKETS_PER_CHANNEL <= 4); + + // Find DIMMs we can support on channel 0. + // Then see if the corresponding channel 1 DIMM has the same parameters, + // since we only support dual-channel. + + for (i = 0; i < MAX_DIMM_SOCKETS_PER_CHANNEL; i++) { + + uint16_t channel0_dimm = ctrl->channel0[i]; + uint16_t channel1_dimm = ctrl->channel1[i]; + uint8_t bDualChannel = 1; +#ifdef VALIDATE_DIMM_COMPATIBILITY + struct dimm_size page_size; + struct dimm_size sdram_width; +#endif + int spd_value; + + if (channel0_dimm == 0) + continue; // No such socket on this mainboard + + if (spd_read_byte(channel0_dimm, SPD_MEMORY_TYPE) != + SPD_MEMORY_TYPE_SDRAM_DDR) + continue; + +#ifdef VALIDATE_DIMM_COMPATIBILITY + if (spd_read_byte(channel0_dimm, SPD_MODULE_VOLTAGE) != + SPD_VOLTAGE_SSTL2) + continue; // Unsupported voltage + + // E7501 does not support unregistered DIMMs + spd_value = + spd_read_byte(channel0_dimm, SPD_MODULE_ATTRIBUTES); + if (!(spd_value & MODULE_REGISTERED) || (spd_value < 0)) + continue; + + // Must support burst = 4 for dual-channel operation on E7501 + // NOTE: for single-channel, burst = 8 is required + spd_value = + spd_read_byte(channel0_dimm, + SPD_SUPPORTED_BURST_LENGTHS); + if (!(spd_value & SPD_BURST_LENGTH_4) || (spd_value < 0)) + continue; + + page_size = sdram_spd_get_page_size(channel0_dimm); + sdram_width = sdram_spd_get_width(channel0_dimm); + + // Validate DIMM page size + // The E7501 only supports page sizes of 4, 8, 16, or 32 KB per channel + // NOTE: 4 KB = 32 Kb = 2^15 + // 32 KB = 262 Kb = 2^18 + + if ((page_size.side1 < 15) || (page_size.side1 > 18)) + continue; + + // If DIMM is double-sided, verify side2 page size + if (page_size.side2 != 0) { + if ((page_size.side2 < 15) + || (page_size.side2 > 18)) + continue; + } + // Validate SDRAM width + // The E7501 only supports x4 and x8 devices + + if ((sdram_width.side1 != 4) && (sdram_width.side1 != 8)) + continue; + + // If DIMM is double-sided, verify side2 width + if (sdram_width.side2 != 0) { + if ((sdram_width.side2 != 4) + && (sdram_width.side2 != 8)) + continue; + } +#endif + // Channel 0 DIMM looks compatible. + // Now see if it is paired with the proper DIMM on channel 1. + + ASSERT(channel1_dimm != 0); // No such socket on this mainboard?? + + // NOTE: unpopulated DIMMs cause read to fail + spd_value = + spd_read_byte(channel1_dimm, SPD_MODULE_ATTRIBUTES); + if (!(spd_value & MODULE_REGISTERED) || (spd_value < 0)) { + + print_debug("Skipping un-matched DIMMs - only dual-channel operation supported\n"); + continue; + } +#ifdef VALIDATE_DIMM_COMPATIBILITY + spd_value = + spd_read_byte(channel1_dimm, + SPD_SUPPORTED_BURST_LENGTHS); + if (!(spd_value & SPD_BURST_LENGTH_4) || (spd_value < 0)) + continue; + + int j; + for (j = 0; j < sizeof(dual_channel_parameters); ++j) { + if (!are_spd_values_equal + (dual_channel_parameters[j], channel0_dimm, + channel1_dimm)) { + + bDualChannel = 0; + break; + } + } +#endif + + // Code around ROMCC bug in optimization of "if" statements +#ifdef ROMCC_IF_BUG_FIXED + if (bDualChannel) { + // Made it through all the checks, this DIMM pair is usable + dimm_mask |= ((1 << i) | (1 << (MAX_DIMM_SOCKETS_PER_CHANNEL + i))); + } else + print_debug("Skipping un-matched DIMMs - only dual-channel operation supported\n"); +#else + switch (bDualChannel) { + case 0: + print_debug("Skipping un-matched DIMMs - only dual-channel operation supported\n"); + break; + + default: + // Made it through all the checks, this DIMM pair is usable + dimm_mask |= (1 << i) | (1 << (MAX_DIMM_SOCKETS_PER_CHANNEL + i)); + break; + } +#endif + } + + return dimm_mask; +} + +/*----------------------------------------------------------------------------- +SDRAM configuration functions: +-----------------------------------------------------------------------------*/ + +/** + * Send the specified command to all DIMMs. + * + * @param command Specifies the command to be sent to the DIMMs. + * @param jedec_mode_bits For the MRS & EMRS commands, bits 0-12 contain the + * register value in JEDEC format. + */ +static void do_ram_command(uint8_t command, uint16_t jedec_mode_bits) +{ + int i; + uint32_t dram_controller_mode; + uint8_t dimm_start_64M_multiple = 0; + uint16_t e7501_mode_bits = jedec_mode_bits; + + // Configure the RAM command + dram_controller_mode = pci_read_config32(PCI_DEV(0, 0, 0), DRC); + dram_controller_mode &= 0xFFFFFF8F; + dram_controller_mode |= command; + pci_write_config32(PCI_DEV(0, 0, 0), DRC, dram_controller_mode); + + // RAM_COMMAND_NORMAL is an exception. + // It affects only the memory controller and does not need to be "sent" to the DIMMs. + + if (command != RAM_COMMAND_NORMAL) { + + // Send the command to all DIMMs by accessing a memory location within each + // NOTE: for mode select commands, some of the location address bits + // are part of the command + + // Map JEDEC mode bits to E7501 + if (command == RAM_COMMAND_MRS) { + // Host address lines [15:5] map to DIMM address lines [12:11, 9:1] + // The E7501 hard-sets DIMM address lines 10 & 0 to zero + + ASSERT(!(jedec_mode_bits & 0x0401)); + + e7501_mode_bits = ((jedec_mode_bits & 0x1800) << (15 - 12)) | // JEDEC bits 11-12 move to bits 14-15 + ((jedec_mode_bits & 0x03FE) << (13 - 9)); // JEDEC bits 1-9 move to bits 5-13 + + } else if (command == RAM_COMMAND_EMRS) { + // Host address lines [15:3] map to DIMM address lines [12:0] + e7501_mode_bits = jedec_mode_bits <<= 3; + } else + ASSERT(jedec_mode_bits == 0); + + dimm_start_64M_multiple = 0; + + for (i = 0; i < (MAX_NUM_CHANNELS * MAX_DIMM_SOCKETS_PER_CHANNEL); ++i) { + + uint8_t dimm_end_64M_multiple = + pci_read_config8(PCI_DEV(0, 0, 0), DRB_ROW_0 + i); + if (dimm_end_64M_multiple > dimm_start_64M_multiple) { + + // This code assumes DRAM row boundaries are all set below 4 GB + // NOTE: 0x40 * 64 MB == 4 GB + ASSERT(dimm_start_64M_multiple < 0x40); + + // NOTE: 2^26 == 64 MB + + uint32_t dimm_start_address = + dimm_start_64M_multiple << 26; + + RAM_DEBUG_MESSAGE(" Sending RAM command to 0x"); + RAM_DEBUG_HEX32(dimm_start_address + e7501_mode_bits); + RAM_DEBUG_MESSAGE("\n"); + + read32(dimm_start_address + e7501_mode_bits); + + // Set the start of the next DIMM + dimm_start_64M_multiple = + dimm_end_64M_multiple; + } + } + } +} + +/** + * Set the mode register of all DIMMs. + * + * The proper CAS# latency setting is added to the mode bits specified + * by the caller. + * + * @param jedec_mode_bits For the MRS & EMRS commands, bits 0-12 contain the + * register value in JEDEC format. + */ +static void set_ram_mode(uint16_t jedec_mode_bits) +{ + ASSERT(!(jedec_mode_bits & SDRAM_CAS_MASK)); + + uint32_t dram_cas_latency = + pci_read_config32(PCI_DEV(0, 0, 0), DRT) & DRT_CAS_MASK; + + switch (dram_cas_latency) { + case DRT_CAS_2_5: + jedec_mode_bits |= SDRAM_CAS_2_5; + break; + + case DRT_CAS_2_0: + jedec_mode_bits |= SDRAM_CAS_2_0; + break; + + default: + BUG(); + break; + } + + do_ram_command(RAM_COMMAND_MRS, jedec_mode_bits); +} + +/*----------------------------------------------------------------------------- +DIMM-independant configuration functions: +-----------------------------------------------------------------------------*/ + +/** + * Configure the E7501's DRAM Row Boundary (DRB) registers for the memory + * present in the specified DIMM. + * + * @param dimm_log2_num_bits Specifies log2(number of bits) for each side of + * the DIMM. + * @param total_dram_64M_multiple Total DRAM in the system (as a multiple of + * 64 MB) for DIMMs < dimm_index. + * @param dimm_index Which DIMM pair is being processed + * (0..MAX_DIMM_SOCKETS_PER_CHANNEL). + * @return New multiple of 64 MB total DRAM in the system. + */ +static uint8_t configure_dimm_row_boundaries(struct dimm_size dimm_log2_num_bits, uint8_t total_dram_64M_multiple, unsigned dimm_index) +{ + int i; + + ASSERT(dimm_index < MAX_DIMM_SOCKETS_PER_CHANNEL); + + // DIMM sides must be at least 32 MB + ASSERT(dimm_log2_num_bits.side1 >= 28); + ASSERT((dimm_log2_num_bits.side2 == 0) + || (dimm_log2_num_bits.side2 >= 28)); + + // In dual-channel mode, we are called only once for each pair of DIMMs. + // Each time we process twice the capacity of a single DIMM. + + // Convert single DIMM capacity to paired DIMM capacity + // (multiply by two ==> add 1 to log2) + dimm_log2_num_bits.side1++; + if (dimm_log2_num_bits.side2 > 0) + dimm_log2_num_bits.side2++; + + // Add the capacity of side 1 this DIMM pair (as a multiple of 64 MB) + // to the total capacity of the system + // NOTE: 64 MB == 512 Mb, and log2(512 Mb) == 29 + + total_dram_64M_multiple += (1 << (dimm_log2_num_bits.side1 - 29)); + + // Configure the boundary address for the row on side 1 + pci_write_config8(PCI_DEV(0, 0, 0), DRB_ROW_0 + (dimm_index << 1), + total_dram_64M_multiple); + + // If the DIMMs are double-sided, add the capacity of side 2 this DIMM pair + // (as a multiple of 64 MB) to the total capacity of the system + if (dimm_log2_num_bits.side2 >= 29) + total_dram_64M_multiple += + (1 << (dimm_log2_num_bits.side2 - 29)); + + // Configure the boundary address for the row (if any) on side 2 + pci_write_config8(PCI_DEV(0, 0, 0), DRB_ROW_1 + (dimm_index << 1), + total_dram_64M_multiple); + + // Update boundaries for rows subsequent to these. + // These settings will be overridden by a subsequent call if a populated physical slot exists + + for (i = dimm_index + 1; i < MAX_DIMM_SOCKETS_PER_CHANNEL; i++) { + pci_write_config8(PCI_DEV(0, 0, 0), DRB_ROW_0 + (i << 1), + total_dram_64M_multiple); + pci_write_config8(PCI_DEV(0, 0, 0), DRB_ROW_1 + (i << 1), + total_dram_64M_multiple); + } + + return total_dram_64M_multiple; +} + +/** + * Set the E7501's DRAM row boundary addresses & its Top Of Low Memory (TOLM). + * + * If necessary, set up a remap window so we don't waste DRAM that ordinarily + * would lie behind addresses reserved for memory-mapped I/O. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @param dimm_mask Bitmask of populated DIMMs, see spd_get_supported_dimms(). + */ +static void configure_e7501_ram_addresses(const struct mem_controller + *ctrl, uint8_t dimm_mask) +{ + int i; + uint8_t total_dram_64M_multiple = 0; + + // Configure the E7501's DRAM row boundaries + // Start by zeroing out the temporary initial configuration + pci_write_config32(PCI_DEV(0, 0, 0), DRB_ROW_0, 0); + pci_write_config32(PCI_DEV(0, 0, 0), DRB_ROW_4, 0); + + for (i = 0; i < MAX_DIMM_SOCKETS_PER_CHANNEL; i++) { + + uint16_t dimm_socket_address = ctrl->channel0[i]; + struct dimm_size sz; + + if (!(dimm_mask & (1 << i))) + continue; // This DIMM not present + + sz = spd_get_dimm_size(dimm_socket_address); + + RAM_DEBUG_MESSAGE("dimm size ="); + RAM_DEBUG_HEX32((u32)sz.side1); + RAM_DEBUG_MESSAGE(" "); + RAM_DEBUG_HEX32((u32)sz.side2); + RAM_DEBUG_MESSAGE("\n"); + + if (sz.side1 == 0) + die("Bad SPD value\n"); + + total_dram_64M_multiple = + configure_dimm_row_boundaries(sz, total_dram_64M_multiple, i); + } + + // Configure the Top Of Low Memory (TOLM) in the E7501 + // This address must be a multiple of 128 MB that is less than 4 GB. + // NOTE: 16-bit wide TOLM register stores only the highest 5 bits of a 32-bit address + // in the highest 5 bits. + + // We set TOLM to the smaller of 0xC0000000 (3 GB) or the total DRAM in the system. + // This reserves addresses from 0xC0000000 - 0xFFFFFFFF for non-DRAM purposes + // such as flash and memory-mapped I/O. + + // If there is more than 3 GB of DRAM, we define a remap window which + // makes the DRAM "behind" the reserved region available above the top of physical + // memory. + + // NOTE: 0xC0000000 / (64 MB) == 0x30 + + if (total_dram_64M_multiple <= 0x30) { + + // <= 3 GB total RAM + + /* I should really adjust all of this in C after I have resources + * to all of the pci devices. + */ + + // Round up to 128MB granularity + // SJM: Is "missing" 64 MB of memory a potential issue? Should this round down? + + uint8_t total_dram_128M_multiple = + (total_dram_64M_multiple + 1) >> 1; + + // Convert to high 16 bits of address + uint16_t top_of_low_memory = + total_dram_128M_multiple << 11; + + pci_write_config16(PCI_DEV(0, 0, 0), TOLM, + top_of_low_memory); + + } else { + + // > 3 GB total RAM + + // Set defaults for > 4 GB DRAM, i.e. remap a 1 GB (= 0x10 * 64 MB) range of memory + uint16_t remap_base = total_dram_64M_multiple; // A[25:0] == 0 + uint16_t remap_limit = total_dram_64M_multiple + 0x10 - 1; // A[25:0] == 0xF + + // Put TOLM at 3 GB + + pci_write_config16(PCI_DEV(0, 0, 0), TOLM, 0xc000); + + // Define a remap window to make the RAM that would appear from 3 GB - 4 GB + // visible just beyond 4 GB or the end of physical memory, whichever is larger + // NOTE: 16-bit wide REMAP registers store only the highest 10 bits of a 36-bit address, + // (i.e. a multiple of 64 MB) in the lowest 10 bits. + // NOTE: 0x100000000 / (64 MB) == 0x40 + + if (total_dram_64M_multiple < 0x40) { + remap_base = 0x40; // 0x100000000 + remap_limit = + 0x40 + (total_dram_64M_multiple - 0x30) - 1; + } + + pci_write_config16(PCI_DEV(0, 0, 0), REMAPBASE, + remap_base); + pci_write_config16(PCI_DEV(0, 0, 0), REMAPLIMIT, + remap_limit); + } +} + +/** + * If we're configured to use ECC, initialize the SDRAM and clear the E7501's + * ECC error flags. + */ +static void initialize_ecc(void) +{ + uint32_t dram_controller_mode; + + /* Test to see if ECC support is enabled */ + dram_controller_mode = pci_read_config32(PCI_DEV(0, 0, 0), DRC); + dram_controller_mode >>= 20; + dram_controller_mode &= 3; + if (dram_controller_mode == 2) { + + uint8_t byte; + + RAM_DEBUG_MESSAGE("Initializing ECC state...\n"); + /* Initialize ECC bits , use ECC zero mode (new to 7501) */ + pci_write_config8(PCI_DEV(0, 0, 0), MCHCFGNS, 0x06); + pci_write_config8(PCI_DEV(0, 0, 0), MCHCFGNS, 0x07); + + // Wait for scrub cycle to complete + do { + byte = + pci_read_config8(PCI_DEV(0, 0, 0), MCHCFGNS); + } while ((byte & 0x08) == 0); + + pci_write_config8(PCI_DEV(0, 0, 0), MCHCFGNS, byte & 0xfc); + RAM_DEBUG_MESSAGE("ECC state initialized.\n"); + + /* Clear the ECC error bits */ + pci_write_config8(PCI_DEV(0, 0, 1), DRAM_FERR, 0x03); + pci_write_config8(PCI_DEV(0, 0, 1), DRAM_NERR, 0x03); + + // Clear DRAM Interface error bits (write-one-clear) + pci_write_config32(PCI_DEV(0, 0, 1), FERR_GLOBAL, 1 << 18); + pci_write_config32(PCI_DEV(0, 0, 1), NERR_GLOBAL, 1 << 18); + + // Start normal ECC scrub + pci_write_config8(PCI_DEV(0, 0, 0), MCHCFGNS, 5); + } + +} + +/** + * Program the DRAM Timing register (DRT) of the E7501 (except for CAS# + * latency, which is assumed to have been programmed already), based on the + * parameters of the various installed DIMMs. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @param dimm_mask Bitmask of populated DIMMs, see spd_get_supported_dimms(). + */ +static void configure_e7501_dram_timing(const struct mem_controller *ctrl, + uint8_t dimm_mask) +{ + int i; + uint32_t dram_timing; + int value; + uint8_t slowest_row_precharge = 0; + uint8_t slowest_ras_cas_delay = 0; + uint8_t slowest_active_to_precharge_delay = 0; + uint32_t current_cas_latency = + pci_read_config32(PCI_DEV(0, 0, 0), DRT) & DRT_CAS_MASK; + + // CAS# latency must be programmed beforehand + ASSERT((current_cas_latency == DRT_CAS_2_0) + || (current_cas_latency == DRT_CAS_2_5)); + + // Each timing parameter is determined by the slowest DIMM + + for (i = 0; i < MAX_DIMM_SOCKETS; i++) { + uint16_t dimm_socket_address; + + if (!(dimm_mask & (1 << i))) + continue; // This DIMM not present + + if (i < MAX_DIMM_SOCKETS_PER_CHANNEL) + dimm_socket_address = ctrl->channel0[i]; + else + dimm_socket_address = + ctrl->channel1[i - MAX_DIMM_SOCKETS_PER_CHANNEL]; + + value = + spd_read_byte(dimm_socket_address, + SPD_MIN_ROW_PRECHARGE_TIME); + if (value < 0) + goto hw_err; + if (value > slowest_row_precharge) + slowest_row_precharge = value; + + value = + spd_read_byte(dimm_socket_address, + SPD_MIN_RAS_TO_CAS_DELAY); + if (value < 0) + goto hw_err; + if (value > slowest_ras_cas_delay) + slowest_ras_cas_delay = value; + + value = + spd_read_byte(dimm_socket_address, + SPD_MIN_ACTIVE_TO_PRECHARGE_DELAY); + if (value < 0) + goto hw_err; + if (value > slowest_active_to_precharge_delay) + slowest_active_to_precharge_delay = value; + } + + // NOTE for timing parameters: + // At 133 MHz, 1 clock == 7.52 ns + + /* Read the initial state */ + dram_timing = pci_read_config32(PCI_DEV(0, 0, 0), DRT); + + /* Trp */ + + // E7501 supports only 2 or 3 clocks for tRP + if (slowest_row_precharge > ((22 << 2) | (2 << 0))) + die("unsupported DIMM tRP"); // > 22.5 ns: 4 or more clocks + else if (slowest_row_precharge > (15 << 2)) + dram_timing &= ~(1 << 0); // > 15.0 ns: 3 clocks + else + dram_timing |= (1 << 0); // <= 15.0 ns: 2 clocks + + /* Trcd */ + + // E7501 supports only 2 or 3 clocks for tRCD + // Use the same value for both read & write + dram_timing &= ~((1 << 3) | (3 << 1)); + if (slowest_ras_cas_delay > ((22 << 2) | (2 << 0))) + die("unsupported DIMM tRCD"); // > 22.5 ns: 4 or more clocks + else if (slowest_ras_cas_delay > (15 << 2)) + dram_timing |= (2 << 1); // > 15.0 ns: 3 clocks + else + dram_timing |= ((1 << 3) | (3 << 1)); // <= 15.0 ns: 2 clocks + + /* Tras */ + + // E7501 supports only 5, 6, or 7 clocks for tRAS + // 5 clocks ~= 37.6 ns, 6 clocks ~= 45.1 ns, 7 clocks ~= 52.6 ns + dram_timing &= ~(3 << 9); + + if (slowest_active_to_precharge_delay > 52) + die("unsupported DIMM tRAS"); // > 52 ns: 8 or more clocks + else if (slowest_active_to_precharge_delay > 45) + dram_timing |= (0 << 9); // 46-52 ns: 7 clocks + else if (slowest_active_to_precharge_delay > 37) + dram_timing |= (1 << 9); // 38-45 ns: 6 clocks + else + dram_timing |= (2 << 9); // < 38 ns: 5 clocks + + /* Trd */ + + /* Set to a 7 clock read delay. This is for 133Mhz + * with a CAS latency of 2.5 if 2.0 a 6 clock + * delay is good */ + + dram_timing &= ~(7 << 24); // 7 clocks + if (current_cas_latency == DRT_CAS_2_0) + dram_timing |= (1 << 24); // 6 clocks + + /* + * Back to Back Read-Write Turn Around + */ + /* Set to a 5 clock back to back read to write turn around. + * 4 is a good delay if the CAS latency is 2.0 */ + + dram_timing &= ~(1 << 28); // 5 clocks + if (current_cas_latency == DRT_CAS_2_0) + dram_timing |= (1 << 28); // 4 clocks + + pci_write_config32(PCI_DEV(0, 0, 0), DRT, dram_timing); + + return; + + hw_err: + die(SPD_ERROR); +} + +/** + * Determine the shortest CAS# latency that the E7501 and all DIMMs have in + * common, and program the E7501 to use it. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @param dimm_mask Bitmask of populated DIMMs, spd_get_supported_dimms(). + */ +static void configure_e7501_cas_latency(const struct mem_controller *ctrl, + uint8_t dimm_mask) +{ + int i; + int value; + uint32_t dram_timing; + uint16_t maybe_dram_read_timing; + uint32_t dword; + + // CAS# latency bitmasks in SPD_ACCEPTABLE_CAS_LATENCIES format + // NOTE: E7501 supports only 2.0 and 2.5 + uint32_t system_compatible_cas_latencies = + SPD_CAS_LATENCY_2_0 | SPD_CAS_LATENCY_2_5; + uint32_t current_cas_latency; + uint32_t dimm_compatible_cas_latencies; + + for (i = 0; i < MAX_DIMM_SOCKETS; i++) { + + uint16_t dimm_socket_address; + + if (!(dimm_mask & (1 << i))) + continue; // This DIMM not usable + + if (i < MAX_DIMM_SOCKETS_PER_CHANNEL) + dimm_socket_address = ctrl->channel0[i]; + else + dimm_socket_address = + ctrl->channel1[i - MAX_DIMM_SOCKETS_PER_CHANNEL]; + + value = + spd_read_byte(dimm_socket_address, + SPD_ACCEPTABLE_CAS_LATENCIES); + if (value < 0) + goto hw_err; + + dimm_compatible_cas_latencies = value & 0x7f; // Start with all supported by DIMM + current_cas_latency = 1 << log2(dimm_compatible_cas_latencies); // Max supported by DIMM + + // Can we support the highest CAS# latency? + + value = + spd_read_byte(dimm_socket_address, + SPD_MIN_CYCLE_TIME_AT_CAS_MAX); + if (value < 0) + goto hw_err; + + // NOTE: At 133 MHz, 1 clock == 7.52 ns + if (value > 0x75) { + // Our bus is too fast for this CAS# latency + // Remove it from the bitmask of those supported by the DIMM that are compatible + dimm_compatible_cas_latencies &= ~current_cas_latency; + } + // Can we support the next-highest CAS# latency (max - 0.5)? + + current_cas_latency >>= 1; + if (current_cas_latency != 0) { + value = + spd_read_byte(dimm_socket_address, + SPD_SDRAM_CYCLE_TIME_2ND); + if (value < 0) + goto hw_err; + if (value > 0x75) + dimm_compatible_cas_latencies &= + ~current_cas_latency; + } + // Can we support the next-highest CAS# latency (max - 1.0)? + current_cas_latency >>= 1; + if (current_cas_latency != 0) { + value = + spd_read_byte(dimm_socket_address, + SPD_SDRAM_CYCLE_TIME_3RD); + if (value < 0) + goto hw_err; + if (value > 0x75) + dimm_compatible_cas_latencies &= + ~current_cas_latency; + } + // Restrict the system to CAS# latencies compatible with this DIMM + system_compatible_cas_latencies &= + dimm_compatible_cas_latencies; + + /* go to the next DIMM */ + } + + /* After all of the arduous calculation setup with the fastest + * cas latency I can use. + */ + + dram_timing = pci_read_config32(PCI_DEV(0, 0, 0), DRT); + dram_timing &= ~(DRT_CAS_MASK); + + maybe_dram_read_timing = + pci_read_config16(PCI_DEV(0, 0, 0), MAYBE_DRDCTL); + maybe_dram_read_timing &= 0xF00C; + + if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_0) { + dram_timing |= DRT_CAS_2_0; + maybe_dram_read_timing |= 0xBB1; + } else if (system_compatible_cas_latencies & SPD_CAS_LATENCY_2_5) { + + uint32_t dram_row_attributes = + pci_read_config32(PCI_DEV(0, 0, 0), DRA); + + dram_timing |= DRT_CAS_2_5; + + // At CAS# 2.5, DRAM Read Timing (if that's what it its) appears to need a slightly + // different value if all DIMM slots are populated + + if ((dram_row_attributes & 0xff) + && (dram_row_attributes & 0xff00) + && (dram_row_attributes & 0xff0000) + && (dram_row_attributes & 0xff000000)) { + + // All slots populated + maybe_dram_read_timing |= 0x0882; + } else { + // Some unpopulated slots + maybe_dram_read_timing |= 0x0662; + } + } else + die("No CAS# latencies compatible with all DIMMs!!\n"); + + pci_write_config32(PCI_DEV(0, 0, 0), DRT, dram_timing); + + /* set master DLL reset */ + dword = pci_read_config32(PCI_DEV(0, 0, 0), 0x88); + dword |= (1 << 26); + pci_write_config32(PCI_DEV(0, 0, 0), 0x88, dword); + + dword &= 0x0c0007ff; /* patch try register 88 is undocumented tnz */ + dword |= 0xd2109800; + + pci_write_config32(PCI_DEV(0, 0, 0), 0x88, dword); + + pci_write_config16(PCI_DEV(0, 0, 0), MAYBE_DRDCTL, + maybe_dram_read_timing); + + dword = pci_read_config32(PCI_DEV(0, 0, 0), 0x88); /* reset master DLL reset */ + dword &= ~(1 << 26); + pci_write_config32(PCI_DEV(0, 0, 0), 0x88, dword); + + return; + + hw_err: + die(SPD_ERROR); +} + +/** + * Configure the refresh interval so that we refresh no more often than + * required by the "most needy" DIMM. Also disable ECC if any of the DIMMs + * don't support it. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @param dimm_mask Bitmask of populated DIMMs, spd_get_supported_dimms(). + */ +static void configure_e7501_dram_controller_mode(const struct + mem_controller *ctrl, + uint8_t dimm_mask) +{ + int i; + + // Initial settings + uint32_t controller_mode = + pci_read_config32(PCI_DEV(0, 0, 0), DRC); + uint32_t system_refresh_mode = (controller_mode >> 8) & 7; + + // Code below assumes that most aggressive settings are in + // force when we are called, either via E7501 reset defaults + // or by sdram_set_registers(): + // - ECC enabled + // - No refresh + + ASSERT((controller_mode & (3 << 20)) == (2 << 20)); // ECC + ASSERT(!(controller_mode & (7 << 8))); // Refresh + + /* Walk through _all_ dimms and find the least-common denominator for: + * - ECC support + * - refresh rates + */ + + for (i = 0; i < MAX_DIMM_SOCKETS; i++) { + + uint32_t dimm_refresh_mode; + int value; + uint16_t dimm_socket_address; + + if (!(dimm_mask & (1 << i))) { + continue; // This DIMM not usable + } + + if (i < MAX_DIMM_SOCKETS_PER_CHANNEL) + dimm_socket_address = ctrl->channel0[i]; + else + dimm_socket_address = + ctrl->channel1[i - + MAX_DIMM_SOCKETS_PER_CHANNEL]; + + // Disable ECC mode if any one of the DIMMs does not support ECC + // SJM: Should we just die here? E7501 datasheet says non-ECC DIMMs aren't supported. + + value = + spd_read_byte(dimm_socket_address, + SPD_DIMM_CONFIG_TYPE); + die_on_spd_error(value); + if (value != ERROR_SCHEME_ECC) { + controller_mode &= ~(3 << 20); + } + + value = spd_read_byte(dimm_socket_address, SPD_REFRESH); + die_on_spd_error(value); + value &= 0x7f; // Mask off self-refresh bit + if (value > MAX_SPD_REFRESH_RATE) { + print_err("unsupported refresh rate\n"); + continue; + } + // Get the appropriate E7501 refresh mode for this DIMM + dimm_refresh_mode = refresh_rate_map[value]; + if (dimm_refresh_mode > 7) { + print_err("unsupported refresh rate\n"); + continue; + } + // If this DIMM requires more frequent refresh than others, + // update the system setting + if (refresh_frequency[dimm_refresh_mode] > + refresh_frequency[system_refresh_mode]) + system_refresh_mode = dimm_refresh_mode; + +#ifdef SUSPICIOUS_LOOKING_CODE +// SJM NOTE: This code doesn't look right. SPD values are an order of magnitude smaller +// than the clock period of the memory controller. Also, no other northbridge +// looks at SPD_CMD_SIGNAL_INPUT_HOLD_TIME. + + // Switch to 2 clocks for address/command if required by any one of the DIMMs + // NOTE: At 133 MHz, 1 clock == 7.52 ns + value = + spd_read_byte(dimm_socket_address, + SPD_CMD_SIGNAL_INPUT_HOLD_TIME); + die_on_spd_error(value); + if (value >= 0xa0) { /* At 133MHz this constant should be 0x75 */ + controller_mode &= ~(1 << 16); /* Use two clock cyles instead of one */ + } +#endif + + /* go to the next DIMM */ + } + + controller_mode |= (system_refresh_mode << 8); + + // Configure the E7501 + pci_write_config32(PCI_DEV(0, 0, 0), DRC, controller_mode); +} + +/** + * Configure the E7501's DRAM Row Attributes (DRA) registers based on DIMM + * parameters read via SPD. This tells the controller the width of the SDRAM + * chips on each DIMM side (x4 or x8) and the page size of each DIMM side + * (4, 8, 16, or 32 KB). + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + * @param dimm_mask Bitmask of populated DIMMs, spd_get_supported_dimms(). + */ +static void configure_e7501_row_attributes(const struct mem_controller + *ctrl, uint8_t dimm_mask) +{ + int i; + uint32_t row_attributes = 0; + + for (i = 0; i < MAX_DIMM_SOCKETS_PER_CHANNEL; i++) { + + uint16_t dimm_socket_address = ctrl->channel0[i]; + struct dimm_size page_size; + struct dimm_size sdram_width; + + if (!(dimm_mask & (1 << i))) + continue; // This DIMM not usable + + // Get the relevant parameters via SPD + page_size = sdram_spd_get_page_size(dimm_socket_address); + sdram_width = sdram_spd_get_width(dimm_socket_address); + + // Update the DRAM Row Attributes. + // Page size is encoded as log2(page size in bits) - log2(8 Kb) + // NOTE: 8 Kb = 2^13 + row_attributes |= (page_size.side1 - 13) << (i << 3); // Side 1 of each DIMM is an EVEN row + + if (sdram_width.side2 > 0) + row_attributes |= (page_size.side2 - 13) << ((i << 3) + 4); // Side 2 is ODD + + // Set x4 flags if appropriate + if (sdram_width.side1 == 4) { + row_attributes |= 0x08 << (i << 3); + } + + if (sdram_width.side2 == 4) { + row_attributes |= 0x08 << ((i << 3) + 4); + } + + /* go to the next DIMM */ + } + + /* Write the new row attributes register */ + pci_write_config32(PCI_DEV(0, 0, 0), DRA, row_attributes); +} + +/* + * Enable clock signals for populated DIMM sockets and disable them for + * unpopulated sockets (to reduce EMI). + * + * @param dimm_mask Bitmask of populated DIMMs, see spd_get_supported_dimms(). + */ +static void enable_e7501_clocks(uint8_t dimm_mask) +{ + int i; + uint8_t clock_disable = pci_read_config8(PCI_DEV(0, 0, 0), CKDIS); + + for (i = 0; i < MAX_DIMM_SOCKETS_PER_CHANNEL; i++) { + + uint8_t socket_mask = 1 << i; + + if (dimm_mask & socket_mask) + clock_disable &= ~socket_mask; // DIMM present, enable clock + else + clock_disable |= socket_mask; // DIMM absent, disable clock + } + + pci_write_config8(PCI_DEV(0, 0, 0), CKDIS, clock_disable); +} + +/* DIMM-dedependent configuration functions */ + +/** + * DDR Receive FIFO RE-Sync (?) + */ +static void RAM_RESET_DDR_PTR(void) +{ + uint8_t byte; + byte = pci_read_config8(PCI_DEV(0, 0, 0), 0x88); + byte |= (1 << 4); + pci_write_config8(PCI_DEV(0, 0, 0), 0x88, byte); + + byte = pci_read_config8(PCI_DEV(0, 0, 0), 0x88); + byte &= ~(1 << 4); + pci_write_config8(PCI_DEV(0, 0, 0), 0x88, byte); +} + +/** + * Set E7501 registers that are either independent of DIMM specifics, or + * establish default settings that will be overridden when we learn the + * specifics. + * + * This sets PCI configuration registers to known good values based on the + * table 'constant_register_values', which are a triple of configuration + * register offset, mask, and bits to set. + */ +static void ram_set_d0f0_regs(void) +{ + int i; + int num_values = ARRAY_SIZE(constant_register_values); + + ASSERT((num_values % 3) == 0); // Bad table? + + for (i = 0; i < num_values; i += 3) { + + uint32_t register_offset = constant_register_values[i]; + uint32_t bits_to_mask = constant_register_values[i + 1]; + uint32_t bits_to_set = constant_register_values[i + 2]; + uint32_t register_value; + + // It's theoretically possible to set values for something other than D0:F0, + // but it's not typically done here + ASSERT(!(register_offset & 0xFFFFFF00)); + + // bits_to_mask and bits_to_set should not reference the same bits + // Again, not strictly an error, but flagged as a potential bug + ASSERT((bits_to_mask & bits_to_set) == 0); + + register_value = + pci_read_config32(PCI_DEV(0, 0, 0), register_offset); + register_value &= bits_to_mask; + register_value |= bits_to_set; + + pci_write_config32(PCI_DEV(0, 0, 0), register_offset, + register_value); + } +} + +/** + * Copy 64 bytes from one location to another. + * + * @param src_addr TODO + * @param dst_addr TODO + */ +static void write_8dwords(const uint32_t *src_addr, uint32_t dst_addr) +{ + int i; + for (i = 0; i < 8; i++) { + write32(dst_addr, *src_addr); + src_addr++; + dst_addr += sizeof(uint32_t); + } +} + +/** + * Set the E7501's (undocumented) RCOMP registers. + * + * Per the 855PM datasheet and IXP2800 HW Initialization Reference Manual, + * RCOMP registers appear to affect drive strength, pullup/pulldown offset, + * and slew rate of various signal groups. + * + * Comments below are conjecture based on apparent similarity between the + * E7501 and these two chips. + */ +static void ram_set_rcomp_regs(void) +{ + uint32_t dword; + uint8_t maybe_strength_control; + + RAM_DEBUG_MESSAGE("Setting RCOMP registers.\n"); + + /*enable access to the rcomp bar */ + dword = pci_read_config32(PCI_DEV(0, 0, 0), MAYBE_MCHTST); + dword |= (1 << 22); + pci_write_config32(PCI_DEV(0, 0, 0), MAYBE_MCHTST, dword); + + // Set the RCOMP MMIO base address + pci_write_config32(PCI_DEV(0, 0, 0), MAYBE_SMRBASE, RCOMP_MMIO); + + // Block RCOMP updates while we configure the registers + dword = read32(RCOMP_MMIO + MAYBE_SMRCTL); + dword |= (1 << 9); + write32(RCOMP_MMIO + MAYBE_SMRCTL, dword); + + /* Begin to write the RCOMP registers */ + + // Set CMD and DQ/DQS strength to 2x (?) + maybe_strength_control = read8(RCOMP_MMIO + MAYBE_DQCMDSTR) & 0x88; + maybe_strength_control |= 0x44; + write8(RCOMP_MMIO + MAYBE_DQCMDSTR, maybe_strength_control); + + write_8dwords(maybe_2x_slew_table, RCOMP_MMIO + 0x80); + write16(RCOMP_MMIO + 0x42, 0); + + write_8dwords(maybe_1x_slew_table, RCOMP_MMIO + 0x60); + + // NOTE: some factory BIOS set 0x9088 here. Seems to work either way. + write16(RCOMP_MMIO + 0x40, 0); + + // Set RCVEnOut# strength to 2x (?) + maybe_strength_control = read8(RCOMP_MMIO + MAYBE_RCVENSTR) & 0xF8; + maybe_strength_control |= 4; + write8(RCOMP_MMIO + MAYBE_RCVENSTR, maybe_strength_control); + + write_8dwords(maybe_2x_slew_table, RCOMP_MMIO + 0x1c0); + write16(RCOMP_MMIO + 0x50, 0); + + // Set CS# strength for x4 SDRAM to 2x (?) + maybe_strength_control = read8(RCOMP_MMIO + MAYBE_CSBSTR) & 0xF8; + maybe_strength_control |= 4; + write8(RCOMP_MMIO + MAYBE_CSBSTR, maybe_strength_control); + + write_8dwords(maybe_2x_slew_table, RCOMP_MMIO + 0x140); + write16(RCOMP_MMIO + 0x48, 0); + + // Set CKE strength for x4 SDRAM to 2x (?) + maybe_strength_control = read8(RCOMP_MMIO + MAYBE_CKESTR) & 0xF8; + maybe_strength_control |= 4; + write8(RCOMP_MMIO + MAYBE_CKESTR, maybe_strength_control); + + write_8dwords(maybe_2x_slew_table, RCOMP_MMIO + 0xa0); + write16(RCOMP_MMIO + 0x44, 0); + + // Set CK strength for x4 SDRAM to 1x (?) + maybe_strength_control = read8(RCOMP_MMIO + MAYBE_CKSTR) & 0xF8; + maybe_strength_control |= 1; + write8(RCOMP_MMIO + MAYBE_CKSTR, maybe_strength_control); + + write_8dwords(maybe_pull_updown_offset_table, RCOMP_MMIO + 0x180); + write16(RCOMP_MMIO + 0x4c, 0); + + write8(RCOMP_MMIO + 0x2c, 0xff); + + // Set the digital filter length to 8 (?) + dword = read32(RCOMP_MMIO + MAYBE_SMRCTL); + + // NOTE: Some factory BIOS don't do this. + // Doesn't seem to matter either way. + dword &= ~2; + + dword |= 1; + write32(RCOMP_MMIO + MAYBE_SMRCTL, dword); + + /* Wait 40 usec */ + SLOW_DOWN_IO; + + /* unblock updates */ + dword = read32(RCOMP_MMIO + MAYBE_SMRCTL); + dword &= ~(1 << 9); + write32(RCOMP_MMIO + MAYBE_SMRCTL, dword); + + // Force a RCOMP measurement cycle? + dword |= (1 << 8); + write32(RCOMP_MMIO + MAYBE_SMRCTL, dword); + dword &= ~(1 << 8); + write32(RCOMP_MMIO + MAYBE_SMRCTL, dword); + + /* Wait 40 usec */ + SLOW_DOWN_IO; + + /*disable access to the rcomp bar */ + dword = pci_read_config32(PCI_DEV(0, 0, 0), MAYBE_MCHTST); + dword &= ~(1 << 22); + pci_write_config32(PCI_DEV(0, 0, 0), MAYBE_MCHTST, dword); + +} + +/*----------------------------------------------------------------------------- +Public interface: +-----------------------------------------------------------------------------*/ + +/** + * Go through the JEDEC initialization sequence for all DIMMs, then enable + * refresh and initialize ECC and memory to zero. Upon exit, SDRAM is up + * and running. + * + * @param controllers Not used. + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + */ +static void sdram_enable(int controllers, + const struct mem_controller *ctrl) +{ + uint8_t dimm_mask = pci_read_config16(PCI_DEV(0, 0, 0), SKPD); + uint32_t dram_controller_mode; + + if (dimm_mask == 0) + return; + + /* 1 & 2 Power up and start clocks */ + RAM_DEBUG_MESSAGE("Ram Enable 1\n"); + RAM_DEBUG_MESSAGE("Ram Enable 2\n"); + + /* A 200us delay is needed */ + DO_DELAY; EXTRA_DELAY; + + /* 3. Apply NOP */ + RAM_DEBUG_MESSAGE("Ram Enable 3\n"); + do_ram_command(RAM_COMMAND_NOP, 0); + EXTRA_DELAY; + + /* 4 Precharge all */ + RAM_DEBUG_MESSAGE("Ram Enable 4\n"); + do_ram_command(RAM_COMMAND_PRECHARGE, 0); + EXTRA_DELAY; + /* wait until the all banks idle state... */ + + /* 5. Issue EMRS to enable DLL */ + RAM_DEBUG_MESSAGE("Ram Enable 5\n"); + do_ram_command(RAM_COMMAND_EMRS, + SDRAM_EXTMODE_DLL_ENABLE | + SDRAM_EXTMODE_DRIVE_NORMAL); + EXTRA_DELAY; + + /* 6. Reset DLL */ + RAM_DEBUG_MESSAGE("Ram Enable 6\n"); + set_ram_mode(E7501_SDRAM_MODE | SDRAM_MODE_DLL_RESET); + EXTRA_DELAY; + /* Ensure a 200us delay between the DLL reset in step 6 and the final + * mode register set in step 9. + * Infineon needs this before any other command is sent to the ram. + */ + DO_DELAY; EXTRA_DELAY; + + /* 7 Precharge all */ + RAM_DEBUG_MESSAGE("Ram Enable 7\n"); + do_ram_command(RAM_COMMAND_PRECHARGE, 0); + EXTRA_DELAY; + + /* 8 Now we need 2 AUTO REFRESH / CBR cycles to be performed */ + RAM_DEBUG_MESSAGE("Ram Enable 8\n"); + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + + /* And for good luck 6 more CBRs */ + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + do_ram_command(RAM_COMMAND_CBR, 0); + EXTRA_DELAY; + + /* 9 mode register set */ + RAM_DEBUG_MESSAGE("Ram Enable 9\n"); + set_ram_mode(E7501_SDRAM_MODE | SDRAM_MODE_NORMAL); + EXTRA_DELAY; + + /* 10 DDR Receive FIFO RE-Sync */ + RAM_DEBUG_MESSAGE("Ram Enable 10\n"); + RAM_RESET_DDR_PTR(); + EXTRA_DELAY; + + /* 11 normal operation */ + RAM_DEBUG_MESSAGE("Ram Enable 11\n"); + do_ram_command(RAM_COMMAND_NORMAL, 0); + EXTRA_DELAY; + + // Reconfigure the row boundaries and Top of Low Memory + // to match the true size of the DIMMs + configure_e7501_ram_addresses(ctrl, dimm_mask); + + /* Finally enable refresh */ + dram_controller_mode = pci_read_config32(PCI_DEV(0, 0, 0), DRC); + dram_controller_mode |= (1 << 29); + pci_write_config32(PCI_DEV(0, 0, 0), DRC, dram_controller_mode); + EXTRA_DELAY; + initialize_ecc(); + + dram_controller_mode = pci_read_config32(PCI_DEV(0, 0, 0), DRC); /* FCS_EN */ + dram_controller_mode |= (1 << 17); // NOTE: undocumented reserved bit + pci_write_config32(PCI_DEV(0, 0, 0), DRC, dram_controller_mode); + + RAM_DEBUG_MESSAGE("Northbridge following SDRAM init:\n"); + DUMPNORTH(); +} + +/** + * Configure SDRAM controller parameters that depend on characteristics of the + * DIMMs installed in the system. These characteristics are read from the + * DIMMs via the standard Serial Presence Detect (SPD) interface. + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + */ +static void sdram_set_spd_registers(const struct mem_controller *ctrl) +{ + uint8_t dimm_mask; + + RAM_DEBUG_MESSAGE("Reading SPD data...\n"); + + dimm_mask = spd_get_supported_dimms(ctrl); + + if (dimm_mask == 0) { + print_debug("No usable memory for this controller\n"); + } else { + enable_e7501_clocks(dimm_mask); + + RAM_DEBUG_MESSAGE("setting based on SPD data...\n"); + + configure_e7501_row_attributes(ctrl, dimm_mask); + configure_e7501_dram_controller_mode(ctrl, dimm_mask); + configure_e7501_cas_latency(ctrl, dimm_mask); + RAM_RESET_DDR_PTR(); + + configure_e7501_dram_timing(ctrl, dimm_mask); + DO_DELAY; + RAM_DEBUG_MESSAGE("done\n"); + } + + /* NOTE: configure_e7501_ram_addresses() is NOT called here. + * We want to keep the default 64 MB/row mapping until sdram_enable() is called, + * even though the default mapping is almost certainly incorrect. + * The default mapping makes it easy to initialize all of the DIMMs + * even if the total system memory is > 4 GB. + * + * Save the dimm_mask for when sdram_enable is called, so it can call + * configure_e7501_ram_addresses() without having to regenerate the bitmask + * of usable DIMMs. + */ + pci_write_config16(PCI_DEV(0, 0, 0), SKPD, dimm_mask); +} + +/** + * Do basic RAM setup that does NOT depend on serial presence detect + * information (i.e. independent of DIMM specifics). + * + * @param ctrl PCI addresses of memory controller functions, and SMBus + * addresses of DIMM slots on the mainboard. + */ +static void sdram_set_registers(const struct mem_controller *ctrl) +{ + RAM_DEBUG_MESSAGE("Northbridge prior to SDRAM init:\n"); + DUMPNORTH(); + + ram_set_rcomp_regs(); + ram_set_d0f0_regs(); +} -- cgit v1.2.3