/* SPDX-License-Identifier: GPL-2.0-or-later */ #include #include #include #include #include #include #include #include #include #include "i440bx.h" #include "raminit.h" /* * Macros and definitions */ /* Debugging macros. */ #if CONFIG(DEBUG_RAM_SETUP) #define PRINT_DEBUG(x...) printk(BIOS_DEBUG, x) #define DUMPNORTH() dump_pci_device(NB) #else #define PRINT_DEBUG(x...) #define DUMPNORTH() #endif /* SDRAMC[7:5] - SDRAM Mode Select (SMS). */ #define RAM_COMMAND_NORMAL 0x0 #define RAM_COMMAND_NOP 0x1 #define RAM_COMMAND_PRECHARGE 0x2 #define RAM_COMMAND_MRS 0x3 #define RAM_COMMAND_CBR 0x4 /* Map the JEDEC SPD refresh rates (array index) to 440BX refresh rates as * defined in DRAMC[2:0]. * * [0] == Normal 15.625 us -> 15.6 us * [1] == Reduced(.25X) 3.9 us -> 7.8 ns * [2] == Reduced(.5X) 7.8 us -> 7.8 us * [3] == Extended(2x) 31.3 us -> 31.2 us * [4] == Extended(4x) 62.5 us -> 62.4 us * [5] == Extended(8x) 125 us -> 124.8 us */ static const uint32_t refresh_rate_map[] = { 1, 5, 5, 2, 3, 4 }; /* Table format: register, value. */ static const u8 register_values[] = { /* NBXCFG - NBX Configuration Register * 0x50 - 0x53 * * [31:24] SDRAM Row Without ECC * 0 = ECC components are populated in this row * 1 = ECC components are not populated in this row * [23:19] Reserved * [18:18] Host Bus Fast Data Ready Enable (HBFDRE) * Assertion of DRAM data on host bus occurs... * 0 = ...one clock after sampling snoop results (default) * 1 = ...on the same clock the snoop result is being sampled * (this mode is faster by one clock cycle) * [17:17] ECC - EDO static Drive mode * 0 = Normal mode (default) * 1 = ECC signals are always driven * [16:16] IDSEL_REDIRECT * 0 = IDSEL1 is allocated to this bridge (default) * 1 = IDSEL7 is allocated to this bridge * [15:15] WSC# Handshake Disable * 1 = Uni-processor mode * 0 = Dual-processor mode with external IOAPIC (default) * [14:14] Intel Reserved * [13:12] Host/DRAM Frequency * 00 = 100 MHz * 01 = Reserved * 10 = 66 MHz * 11 = Reserved * [11:11] AGP to PCI Access Enable * 1 = Enable * 0 = Disable * [10:10] PCI Agent to Aperture Access Disable * 1 = Disable * 0 = Enable (default) * [09:09] Aperture Access Global Enable * 1 = Enable * 0 = Disable * [08:07] DRAM Data Integrity Mode (DDIM) * 00 = Non-ECC * 01 = EC-only * 10 = ECC Mode * 11 = ECC Mode with hardware scrubbing enabled * [06:06] ECC Diagnostic Mode Enable (EDME) * 1 = Enable * 0 = Normal operation mode (default) * [05:05] MDA Present (MDAP) * Works in conjunction with the VGA_EN bit. * VGA_EN MDAP * 0 x All VGA cycles are sent to PCI * 1 0 All VGA cycles are sent to AGP * 1 1 All VGA cycles are sent to AGP, except for * cycles in the MDA range. * [04:04] Reserved * [03:03] USWC Write Post During I/O Bridge Access Enable (UWPIO) * 1 = Enable * 0 = Disable * [02:02] In-Order Queue Depth (IOQD) * 1 = In-order queue = maximum * 0 = A7# is sampled asserted (i.e., 0) * [01:00] Reserved */ NBXCFG + 0, 0x0c, #if CONFIG(SMP) NBXCFG + 1, 0x00, #else NBXCFG + 1, 0x80, #endif NBXCFG + 2, 0x00, NBXCFG + 3, 0xff, /* DRAMC - DRAM Control Register * 0x57 * * [7:6] Reserved * [5:5] Module Mode Configuration (MMCONFIG) * The combination of SDRAMPWR and this bit (set by an * external strapping option) determine how CKE works. * SDRAMPWR MMCONFIG * 0 0 = 3 DIMM, CKE[5:0] driven * X 1 = 3 DIMM, CKE0 only * 1 0 = 4 DIMM, GCKE only * [4:3] DRAM Type (DT) * 00 = EDO * 01 = SDRAM * 10 = Registered SDRAM * 11 = Reserved * Note: EDO, SDRAM and Registered SDRAM cannot be mixed. * [2:0] DRAM Refresh Rate (DRR) * 000 = Refresh disabled * 001 = 15.6 us * 010 = 31.2 us * 011 = 62.4 us * 100 = 124.8 us * 101 = 249.6 us * 110 = Reserved * 111 = Reserved */ /* Choose SDRAM (not registered), and disable refresh for now. */ DRAMC, 0x08, /* * PAM[6:0] - Programmable Attribute Map Registers * 0x59 - 0x5f * * 0x59 [3:0] Reserved * 0x59 [5:4] 0xF0000 - 0xFFFFF BIOS area * 0x5a [1:0] 0xC0000 - 0xC3FFF ISA add-on BIOS * 0x5a [5:4] 0xC4000 - 0xC7FFF ISA add-on BIOS * 0x5b [1:0] 0xC8000 - 0xCBFFF ISA add-on BIOS * 0x5b [5:4] 0xCC000 - 0xCFFFF ISA add-on BIOS * 0x5c [1:0] 0xD0000 - 0xD3FFF ISA add-on BIOS * 0x5c [5:4] 0xD4000 - 0xD7FFF ISA add-on BIOS * 0x5d [1:0] 0xD8000 - 0xDBFFF ISA add-on BIOS * 0x5d [5:4] 0xDC000 - 0xDFFFF ISA add-on BIOS * 0x5e [1:0] 0xE0000 - 0xE3FFF BIOS extension * 0x5e [5:4] 0xE4000 - 0xE7FFF BIOS extension * 0x5f [1:0] 0xE8000 - 0xEBFFF BIOS extension * 0x5f [5:4] 0xEC000 - 0xEFFFF BIOS extension * * Bit assignment: * 00 = DRAM Disabled (all access goes 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 = Read/Write (all access goes to DRAM) */ /* * Map all legacy regions to RAM (read/write). This is required if * you want to use the RAM area from 768 KB - 1 MB. If the PAM * registers are not set here appropriately, the RAM in that region * will not be accessible, thus a RAM check of it will also fail. */ PAM0, 0x30, PAM1, 0x33, PAM2, 0x33, PAM3, 0x33, PAM4, 0x33, PAM5, 0x33, PAM6, 0x33, /* DRB[0:7] - DRAM Row Boundary Registers * 0x60 - 0x67 * * An array of 8 byte registers, which hold the ending memory address * assigned to each pair of DIMMs, in 8MB granularity. * * 0x60 DRB0 = Total memory in row0 (in 8 MB) * 0x61 DRB1 = Total memory in row0+1 (in 8 MB) * 0x62 DRB2 = Total memory in row0+1+2 (in 8 MB) * 0x63 DRB3 = Total memory in row0+1+2+3 (in 8 MB) * 0x64 DRB4 = Total memory in row0+1+2+3+4 (in 8 MB) * 0x65 DRB5 = Total memory in row0+1+2+3+4+5 (in 8 MB) * 0x66 DRB6 = Total memory in row0+1+2+3+4+5+6 (in 8 MB) * 0x67 DRB7 = Total memory in row0+1+2+3+4+5+6+7 (in 8 MB) */ /* DRBs will be set later. */ /* FDHC - Fixed DRAM Hole Control Register * 0x68 * * Controls two fixed DRAM holes: 512 KB - 640 KB and 15 MB - 16 MB. * * [7:6] Hole Enable (HEN) * 00 = None * 01 = 512 KB - 640 KB (128 KB) * 10 = 15 MB - 16 MB (1 MB) * 11 = Reserved * [5:0] Reserved */ /* No memory holes. */ FDHC, 0x00, /* RPS - SDRAM Row Page Size Register * 0x74 - 0x75 * * Sets the row page size for SDRAM. For EDO memory, the page * size is fixed at 2 KB. * * Bits[1:0] Page Size * 00 2 KB * 01 4 KB * 10 8 KB * 11 Reserved * * RPS bits Corresponding DRB register * [01:00] DRB[0], row 0 * [03:02] DRB[1], row 1 * [05:04] DRB[2], row 2 * [07:06] DRB[3], row 3 * [09:08] DRB[4], row 4 * [11:10] DRB[5], row 5 * [13:12] DRB[6], row 6 * [15:14] DRB[7], row 7 */ /* Power on defaults to 2KB. Will be set later. */ /* SDRAMC - SDRAM Control Register * 0x76 - 0x77 * * [15:10] Reserved * [09:08] Idle/Pipeline DRAM Leadoff Timing (IPDLT) * 00 = Illegal * 01 = Add a clock delay to the lead-off clock count * 1x = Illegal * [07:05] SDRAM Mode Select (SMS) * 000 = Normal SDRAM Operation (default) * 001 = NOP Command Enable * 010 = All Banks Precharge Enable * 011 = Mode Register Set Enable * 100 = CBR Enable * 101 = Reserved * 110 = Reserved * 111 = Reserved * [04:04] SDRAMPWR * 0 = 3 DIMM configuration * 1 = 4 DIMM configuration * [03:03] Leadoff Command Timing (LCT) * 0 = 4 CS# Clock * 1 = 3 CS# Clock * [02:02] CAS# Latency (CL) * 0 = 3 DCLK CAS# latency * 1 = 2 DCLK CAS# latency * [01:01] SDRAM RAS# to CAS# Delay (SRCD) * 0 = 3 clocks between a row activate and a read or write cmd. * 1 = 2 clocks between a row activate and a read or write cmd. * [00:00] SDRAM RAS# Precharge (SRP) * 0 = 3 clocks of RAS# precharge * 1 = 2 clocks of RAS# precharge */ #if CONFIG(SDRAMPWR_4DIMM) SDRAMC, 0x10, /* The board has 4 DIMM slots. */ #else SDRAMC, 0x00, /* The board has 3 DIMM slots. */ #endif /* PGPOL - Paging Policy Register * 0x78 - 0x79 * * [15:08] Banks per Row (BPR) * Each bit in this field corresponds to one row of the memory * array. Bit 15 corresponds to row 7 while bit 8 corresponds * to row 0. Bits for empty rows are "don't care". * 0 = 2 banks * 1 = 4 banks * [07:05] Reserved * [04:04] Intel Reserved * [03:00] DRAM Idle Timer (DIT) * 0000 = 0 clocks * 0001 = 2 clocks * 0010 = 4 clocks * 0011 = 8 clocks * 0100 = 10 clocks * 0101 = 12 clocks * 0110 = 16 clocks * 0111 = 32 clocks * 1xxx = Infinite (pages are not closed for idle condition) */ /* PGPOL will be set later. */ /* PMCR - Power Management Control Register * 0x7a * * [7] Power Down SDRAM Enable (PDSE) * 1 = Enable * 0 = Disable * [6] ACPI Control Register Enable (SCRE) * 1 = Enable * 0 = Disable (default) * [5] Suspend Refresh Type (SRT) * 1 = Self refresh mode * 0 = CBR fresh mode * [4] Normal Refresh Enable (NREF_EN) * 1 = Enable * 0 = Disable * [3] Quick Start Mode (QSTART) * 1 = Quick start mode for the processor is enabled * [2] Gated Clock Enable (GCLKEN) * 1 = Enable * 0 = Disable * [1] AGP Disable (AGP_DIS) * 1 = AGP disabled (Hardware strap) * [0] CPU reset without PCIRST enable (CRst_En) * 1 = Enable * 0 = Disable */ /* PMCR will be set later. */ /* Enable SCRR.SRRAEN and let BX choose the SRR. */ SCRR + 1, 0x10, }; /*----------------------------------------------------------------------------- SDRAM configuration functions. -----------------------------------------------------------------------------*/ /** * Send the specified RAM command to all DIMMs. * * @param command The RAM command to send to the DIMM(s). */ static void do_ram_command(u32 command) { int i, caslatency; u8 dimm_start, dimm_end; u16 reg16; void *addr; u32 addr_offset; /* Configure the RAM command. */ reg16 = pci_read_config16(NB, SDRAMC); reg16 &= 0xff1f; /* Clear bits 7-5. */ reg16 |= (u16) (command << 5); /* Write command into bits 7-5. */ pci_write_config16(NB, SDRAMC, reg16); /* * RAM_COMMAND_NORMAL affects only the memory controller and * doesn't need to be "sent" to the DIMMs. */ if (command == RAM_COMMAND_NORMAL) return; /* Send the RAM command to each row of memory. */ dimm_start = 0; for (i = 0; i < (DIMM_SOCKETS * 2); i++) { addr_offset = 0; caslatency = 3; /* TODO: Dynamically get CAS latency later. */ if (command == RAM_COMMAND_MRS) { /* * MAA[12:11,9:0] must be inverted when sent to DIMM * 2 or 3 (no inversion if sent to DIMM 0 or 1). */ if ((i >= 0 && i <= 3) && caslatency == 3) addr_offset = 0x1d0; if ((i >= 4 && i <= 7) && caslatency == 3) addr_offset = 0x1e28; if ((i >= 0 && i <= 3) && caslatency == 2) addr_offset = 0x150; if ((i >= 4 && i <= 7) && caslatency == 2) addr_offset = 0x1ea8; } dimm_end = pci_read_config8(NB, DRB + i); addr = (void *)((dimm_start * 8 * 1024 * 1024) + addr_offset); if (dimm_end > dimm_start) { read32(addr); } /* Set the start of the next DIMM. */ dimm_start = dimm_end; } } static void set_dram_buffer_strength(void) { /* * Program MBSC[39:0] and MBFS[23:0]. * * The 440BX datasheet says buffer frequency is independent from bus * frequency and mismatch both ways are possible. * * MBSC[47:40] and MBFS[23] are reserved. */ unsigned int i, reg, drb; uint8_t mbsc0, mbfs0, mbfs1, mbfs2; uint16_t mbsc1, mbsc3; /* * Tally how many rows between rows 0-3 and rows 4-7 are populated. * This determines how to program MBFS and MBSC. */ uint8_t dimm03 = 0; uint8_t dimm47 = 0; for (drb = 0, i = DRB0; i <= DRB7; i++) { reg = pci_read_config8(NB, i); if (drb != reg) { if (i <= DRB3) dimm03++; else dimm47++; drb = reg; } } if (CONFIG(SDRAMPWR_4DIMM)) { /* * For a 4 DIMM board, based on ASUS P2B-LS mainboard. * * There are four main conditions to check when programming * DRAM buffer frequency and strength: * * a: >2 rows populated across DIMM0,1 * b: >2 rows populated across DIMM2,3 * c: >4 rows populated across all DIMM slots * and either one of: * 1: NBXCFG[13] strapped as 100MHz, or * 6: NBXCFG[13] strapped as 66MHz * * CKE0/FENA ----------------------------------------------------------+ * CKE1/GCKE ----------------------[ MBFS ]---------------------+| * DQMA/CASA[764320]# -------------[ 0 = 66MHz ]--------------------+|| * DQMB1/CASB1# (Fixed for 66MHz) -[ 1 = 100MHz ]-------------------+||| * DQMB5/CASB5# (Fixed for 66MHz) ---------------------------------+|||| * DQMA1/CASA1# (Fixed for 66MHz) --------------------------------+||||| * DQMA5/CASA5# (Fixed for 66MHz) -------------------------------+|||||| * CSA[5:0]#,CSB[5:0]# ------------------------------------++++++||||||| * CS[B7,A7,B6,A6]#/CKE[5342] -------------------------++++||||||||||||| * MECC[7:0] #2/#1 ----------------------------------++||||||||||||||||| * MD[63:0] #2/#1 ---------------------------------++||||||||||||||||||| * MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# -+||||||||||||||||||||| * MAA[13:0],WEA#,SRASA#,SCASA# -----------------+|||||||||||||||||||||| * Reserved ------------------------------------+||||||||||||||||||||||| * |||||||||||||||||||||||| * 3 32 21 10 0 * 2 21 10 0 * 9876543210987654321098765432109876543210 * 321098765432109876543210 * 10------------------------1010---------- a -1---------------11----- * 11------------------------1111---------- !a -0---------------00----- * --10--------------------------1010------ b --1----------------11--- * --11--------------------------1111------ !b --0----------------00--- * ----------------------------------1100-- c ----------------------1- * ----------------------------------1011-- !c ----------------------0- * ----1010101000000000000000------------00 1 ---11111111111111----1-0 * ----000000000000000000000010101010----00 6 ---1111111111111100000-0 * | | | | | | | | | | ||||||| | | | | | | * | | | | | | | | | | ||||||| | | | | | +- CKE0/FENA * | | | | | | | | | | ||||||| | | | | +--- CKE1/GCKE * | | | | | | | | | | ||||||| | | | +----- DQMA/CASA[764320]# * | | | | | | | | | | ||||||| | | +------- DQMB1/CASB1# (66MHz: 2x) * | | | | | | | | | | ||||||| | +--------- DQMB5/CASB5# (66MHz: 2x) * | | | | | | | | | | ||||||| +----------- DQMA1/CASA1# (66MHz: 2x) * | | | | | | | | | | ||||||+------------- DQMA5/CASA5# (66MHz: 2x) * | | | | | | | | | | ++++++-------------- CSA0-5#,CSB0-5# (1x) * | | | | | | | | | +--------------------- CSA6#/CKE2 * | | | | | | | | +---[ MBSC ]------ CSB6#/CKE4 * | | | | | | | +-----[ 00 = 1x ]------ CSA7#/CKE3 * | | | | | | +-------[ 01 invalid ]------ CSB7#/CKE5 * | | | | | +---------[ 10 = 2x ]------ MECC[7:0] #1 * | | | | +-----------[ 11 = 3x ]------ MECC[7:0] #2 * | | | +--------------------------------- MD[63:0] #1 * | | +----------------------------------- MD[63:0] #2 * | +------------------ MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# * +------------------------------------- MAA[13:0],WEA#,SRASA#,SCASA# */ unsigned int fsb; mbsc0 = 0xa0; mbsc1 = 0x002a; mbfs1 = 0xff; mbfs2 = 0x1f; if (pci_read_config8(NB, NBXCFG + 1) & 0x30) { fsb = 66; mbsc3 = 0xa000; mbfs0 = 0x80; } else { fsb = 100; mbsc3 = 0xaaa0; mbfs0 = 0x84; } if (dimm03 > 2) { mbfs2 |= 0x40; if (fsb == 100) mbfs0 |= 0x60; } else { mbsc3 |= 0xc000; if (fsb == 100) mbsc1 |= 0x003c; } if (dimm47 > 2) { mbfs2 |= 0x20; if (fsb == 100) mbfs0 |= 0x18; } else { mbsc3 |= 0x3000; if (fsb == 100) { mbsc1 |= 0x0003; mbsc0 |= 0xc0; } } if ((dimm03 + dimm47) > 4) { mbsc0 |= 0x30; mbfs0 |= 0x02; } else { mbsc0 |= 0x2c; } } else { /* * For a 3 DIMM board, based on ASUS P2B mainboard. * * There are two main conditions to check when programming DRAM buffer * frequency and strength: * * a: >2 rows populated across DIMM0,1 * c: >4 rows populated across all DIMM slots * * CKE0 ---------------------------------------------------------------+ * CKE1 ------------------------[ MBFS ]------------------------+| * DQMA/CASA[764320]# ----------[ 0 = 66MHz ]-----------------------+|| * DQMB1/CASB1# ----------------[ 1 = 100MHz ]----------------------+||| * DQMB5/CASB5# ---------------------------------------------------+|||| * DQMA1/CASA1# --------------------------------------------------+||||| * DQMA5/CASA5# -------------------------------------------------+|||||| * CSA0-5#,CSB0-5# ----------------------------------------++++++||||||| * CS[B7,A7,B6,A6]#/CKE[5342] -------------------------++++||||||||||||| * MECC[7:0] #2/#1 (100MHz) -------------------------++||||||||||||||||| * MD[63:0] #2/#1 (100MHz) ------------------------++||||||||||||||||||| * MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# -+||||||||||||||||||||| * MAA[13:0],WEA#,SRASA#,SCASA# -----------------+|||||||||||||||||||||| * Reserved ------------------------------------+||||||||||||||||||||||| * |||||||||||||||||||||||| * 3 32 21 10 0 * 2 21 10 0 * 9876543210987654321098765432109876543210 * 321098765432109876543210 * 10------------------------1111---------- a -1---------------------- * 11------------------------1010---------- !a -0---------------------- * --110000000010101010111111----1010--1010 * --01111000000000000000-0 * ----------------------------------11---- c ----------------------1- * ----------------------------------10---- !c ----------------------0- * | | | | | | | | | | ||||||| | | | | | | * | | | | | | | | | | ||||||| | | | | | +- CKE0 * | | | | | | | | | | ||||||| | | | | +--- CKE1 * | | | | | | | | | | ||||||| | | | +----- DQMA/CASA[764320]# * | | | | | | | | | | ||||||| | | +------- DQMB1/CASB1# * | | | | | | | | | | ||||||| | +--------- DQMB5/CASB5# * | | | | | | | | | | ||||||| +----------- DQMA1/CASA1# * | | | | | | | | | | ||||||+------------- DQMA5/CASA5# * | | | | | | | | | | ++++++-------------- CSA0-5#,CSB0-5# (2x) * | | | | | | | | | +--------------------- CSA6#/CKE2 * | | | | | | | | +---[ MBSC ]------ CSB6#/CKE4 * | | | | | | | +-----[ 00 = 1x ]------ CSA7#/CKE3 * | | | | | | +-------[ 01 invalid ]------ CSB7#/CKE5 * | | | | | +---------[ 10 = 2x ]------ MECC[7:0] #1 (1x) * | | | | +-----------[ 11 = 3x ]------ MECC[7:0] #2 (1x) * | | | +--------------------------------- MD[63:0] #1 (1x) * | | +----------------------------------- MD[63:0] #2 (1x) * | +------------------ MAB[12:11,9:0]#,MAB[13,10],WEB#,SRASB#,SCASB# * +------------------------------------- MAA[13:0],WEA#,SRASA#,SCASA# */ mbsc0 = 0xaa; mbsc1 = 0xafea; mbsc3 = 0xb00a; mbfs0 = 0x00; mbfs1 = 0x00; mbfs2 = 0x1e; if (dimm03 > 2) { mbsc1 |= 0x003c; mbfs2 |= 0x40; } else { mbsc3 |= 0xc000; } if ((dimm03 + dimm47) > 4) { mbsc0 |= 0x30; mbfs0 |= 0x02; } } pci_write_config8(NB, MBSC + 0, mbsc0); pci_write_config16(NB, MBSC + 1, mbsc1); pci_write_config16(NB, MBSC + 3, mbsc3); pci_write_config16(NB, MBFS + 0, mbfs1 << 8 | mbfs0); pci_write_config8(NB, MBFS + 2, mbfs2); } /*----------------------------------------------------------------------------- DIMM-independent configuration functions. -----------------------------------------------------------------------------*/ static void spd_enable_refresh(void) { int i, value; uint8_t reg; reg = pci_read_config8(NB, DRAMC); for (i = 0; i < DIMM_SOCKETS; i++) { value = smbus_read_byte(DIMM0 + i, SPD_REFRESH); if (value < 0) continue; reg = (reg & 0xf8) | refresh_rate_map[(value & 0x7f)]; PRINT_DEBUG(" Enabling refresh (DRAMC = 0x%02x) for DIMM %02x\n", reg, i); } pci_write_config8(NB, DRAMC, reg); } /*----------------------------------------------------------------------------- Public interface. -----------------------------------------------------------------------------*/ static void sdram_set_registers(void) { int i, max; PRINT_DEBUG("Northbridge prior to SDRAM init:\n"); DUMPNORTH(); max = ARRAY_SIZE(register_values); /* Set registers as specified in the register_values[] array. */ for (i = 0; i < max; i += 2) pci_write_config8(NB, register_values[i], register_values[i + 1]); } struct dimm_size { u32 side1; u32 side2; }; static struct dimm_size spd_get_dimm_size(unsigned int device) { struct dimm_size sz; int i, module_density, dimm_banks; sz.side1 = 0; module_density = smbus_read_byte(device, SPD_DENSITY_OF_EACH_ROW_ON_MODULE); dimm_banks = smbus_read_byte(device, SPD_NUM_DIMM_BANKS); /* Find the size of side1. */ /* Find the larger value. The larger value is always side1. */ for (i = 512; i >= 0; i >>= 1) { if ((module_density & i) == i) { sz.side1 = i; break; } } /* Set to 0 in case it's single sided. */ sz.side2 = 0; /* Test if it's a dual-sided DIMM. */ if (dimm_banks > 1) { /* Test if there's a second value. If so it's asymmetrical. */ if (module_density != i) { /* * Find second value, picking up where we left off. * i >>= 1 done initially to make sure we don't get * the same value again. */ for (i >>= 1; i >= 0; i >>= 1) { if (module_density == (sz.side1 | i)) { sz.side2 = i; break; } } /* If not, it's symmetrical. */ } else { sz.side2 = sz.side1; } } /* * SPD byte 31 is the memory size divided by 4 so we * need to multiply by 4 to get the total size. */ sz.side1 *= 4; sz.side2 *= 4; /* * It is possible to partially use larger than supported * modules by setting them to a supported size. */ if (sz.side1 > 128) { PRINT_DEBUG("Side1 was %dMB but only 128MB will be used.\n", sz.side1); sz.side1 = 128; if (sz.side2 > 128) { PRINT_DEBUG("Side2 was %dMB but only 128MB will be used.\n", sz.side2); sz.side2 = 128; } } return sz; } /* * Sets DRAM attributes one DIMM at a time, based on SPD data. * Northbridge settings that are set: NBXCFG[31:24], DRB0-DRB7, RPS, DRAMC. */ static void set_dram_row_attributes(void) { int i, dra, drb, col, width, value, rps; u8 bpr; /* Top 8 bits of PGPOL */ u8 nbxecc = 0; /* NBXCFG[31:24] */ u8 edo, sd, regsd; /* EDO, SDRAM, registered SDRAM */ edo = 0; sd = 0; regsd = 1; rps = 0; drb = 0; bpr = 0; for (i = 0; i < DIMM_SOCKETS; i++) { unsigned int device; device = DIMM0 + i; bpr >>= 2; nbxecc >>= 2; /* First check if a DIMM is actually present. */ value = smbus_read_byte(device, SPD_MEMORY_TYPE); /* This is 440BX! We do EDO too! */ if (value == SPD_MEMORY_TYPE_EDO || value == SPD_MEMORY_TYPE_SDRAM) { if (value == SPD_MEMORY_TYPE_EDO) { edo = 1; } else if (value == SPD_MEMORY_TYPE_SDRAM) { sd = 1; } PRINT_DEBUG("Found DIMM in slot %d\n", i); if (edo && sd) { printk(BIOS_ERR, "Mixing EDO/SDRAM unsupported!\n"); die("HALT\n"); } /* "DRA" is our RPS for the two rows on this DIMM. */ dra = 0; /* Columns */ col = smbus_read_byte(device, SPD_NUM_COLUMNS); /* * Is this an ECC DIMM? Actually will be a 2 if so. * TODO: Other register than NBXCFG also needs this * ECC information. */ value = smbus_read_byte(device, SPD_DIMM_CONFIG_TYPE); /* Data width */ width = smbus_read_byte(device, SPD_MODULE_DATA_WIDTH_LSB); /* Exclude error checking data width from page size calculations */ if (value) { value = smbus_read_byte(device, SPD_ERROR_CHECKING_SDRAM_WIDTH); width -= value; /* ### ECC */ /* Clear top 2 bits to help set up NBXCFG. */ nbxecc &= 0x3f; } else { /* Without ECC, top 2 bits should be 11. */ nbxecc |= 0xc0; } /* If any installed DIMM is *not* registered, this system cannot be * configured for registered SDRAM. * By registered, only the address and control lines need to be, which * we can tell by reading SPD byte 21, bit 1. */ value = smbus_read_byte(device, SPD_MODULE_ATTRIBUTES); PRINT_DEBUG("DIMM is "); if ((value & MODULE_REGISTERED) == 0) { regsd = 0; PRINT_DEBUG("not "); } PRINT_DEBUG("registered\n"); /* Calculate page size in bits. */ value = ((1 << col) * width); /* Convert to KB. */ dra = (value >> 13); /* Number of banks of DIMM (single or double sided). */ value = smbus_read_byte(device, SPD_NUM_DIMM_BANKS); /* Once we have dra, col is done and can be reused. * So it's reused for number of banks. */ col = smbus_read_byte(device, SPD_NUM_BANKS_PER_SDRAM); if (value == 1) { /* * Second bank of 1-bank DIMMs "doesn't have * ECC" - or anything. */ if (dra == 2) { dra = 0x0; /* 2KB */ } else if (dra == 4) { dra = 0x1; /* 4KB */ } else if (dra == 8) { dra = 0x2; /* 8KB */ } else if (dra >= 16) { /* Page sizes larger than supported are * set to 8KB to use module partially. */ PRINT_DEBUG("Page size forced to 8KB.\n"); dra = 0x2; /* 8KB */ } else { dra = -1; } /* * Sets a flag in PGPOL[BPR] if this DIMM has * 4 banks per row. */ if (col == 4) bpr |= 0x40; } else if (value == 2) { if (dra == 2) { dra = 0x0; /* 2KB */ } else if (dra == 4) { dra = 0x05; /* 4KB */ } else if (dra == 8) { dra = 0x0a; /* 8KB */ } else if (dra >= 16) { /* Ditto */ PRINT_DEBUG("Page size forced to 8KB.\n"); dra = 0x0a; /* 8KB */ } else { dra = -1; } /* Ditto */ if (col == 4) bpr |= 0xc0; } else { printk(BIOS_ERR, "# of banks of DIMM unsupported!\n"); die("HALT\n"); } if (dra == -1) { printk(BIOS_ERR, "Page size not supported\n"); die("HALT\n"); } /* * 440BX supports asymmetrical dual-sided DIMMs, * but can't handle DIMMs smaller than 8MB per * side. */ struct dimm_size sz = spd_get_dimm_size(device); if ((sz.side1 < 8)) { printk(BIOS_ERR, "DIMMs smaller than 8MB per side\n" "are not supported on this NB.\n"); die("HALT\n"); } /* Divide size by 8 to set up the DRB registers. */ drb += (sz.side1 / 8); /* * Build the DRB for the next row in MSB so it gets * placed in DRB[n+1] where it belongs when written * as a 16-bit word. */ drb &= 0xff; drb |= (drb + (sz.side2 / 8)) << 8; } else { /* If there's no DIMM in the slot, set dra to 0x00. */ dra = 0x00; /* Still have to propagate DRB over. */ drb &= 0xff; drb |= (drb << 8); } pci_write_config16(NB, DRB + (2 * i), drb); /* Brings the upper DRB back down to be base for * DRB calculations for the next two rows. */ drb >>= 8; rps |= (dra & 0x0f) << (i * 4); } /* Set paging policy register. */ pci_write_config8(NB, PGPOL + 1, bpr); PRINT_DEBUG("PGPOL[BPR] has been set to 0x%02x\n", bpr); /* Set DRAM row page size register. */ pci_write_config16(NB, RPS, rps); PRINT_DEBUG("RPS has been set to 0x%04x\n", rps); /* ### ECC */ pci_write_config8(NB, NBXCFG + 3, nbxecc); PRINT_DEBUG("NBXECC[31:24] has been set to 0x%02x\n", nbxecc); /* Set DRAMC[4:3] to proper memory type (EDO/SDRAM/Registered SDRAM). */ /* i will be used to set DRAMC[4:3]. */ if (regsd && sd) { i = 0x10; // Registered SDRAM } else if (sd) { i = 0x08; // SDRAM } else { i = 0; // EDO } value = pci_read_config8(NB, DRAMC) & 0xe7; value |= i; pci_write_config8(NB, DRAMC, value); PRINT_DEBUG("DRAMC has been set to 0x%02x\n", value); } static void sdram_set_spd_registers(void) { /* Setup DRAM row boundary registers and other attributes. */ set_dram_row_attributes(); /* Setup DRAM buffer strength. */ set_dram_buffer_strength(); } static void sdram_enable(void) { int i; /* 0. Wait until power/voltages and clocks are stable (200us). */ udelay(200); /* 1. Apply NOP. Wait 200 clock cycles (200us should do). */ PRINT_DEBUG("RAM Enable 1: Apply NOP\n"); do_ram_command(RAM_COMMAND_NOP); udelay(200); /* 2. Precharge all. Wait tRP. */ PRINT_DEBUG("RAM Enable 2: Precharge all\n"); do_ram_command(RAM_COMMAND_PRECHARGE); udelay(1); /* 3. Perform 8 refresh cycles. Wait tRC each time. */ PRINT_DEBUG("RAM Enable 3: CBR\n"); for (i = 0; i < 8; i++) { do_ram_command(RAM_COMMAND_CBR); udelay(1); } /* 4. Mode register set. Wait two memory cycles. */ PRINT_DEBUG("RAM Enable 4: Mode register set\n"); do_ram_command(RAM_COMMAND_MRS); udelay(2); /* 5. Normal operation. */ PRINT_DEBUG("RAM Enable 5: Normal operation\n"); do_ram_command(RAM_COMMAND_NORMAL); udelay(1); /* 6. Finally enable refresh. */ PRINT_DEBUG("RAM Enable 6: Enable refresh\n"); pci_write_config8(NB, PMCR, 0x10); spd_enable_refresh(); udelay(1); PRINT_DEBUG("Northbridge following SDRAM init:\n"); DUMPNORTH(); } /* Implemented under mainboard. */ void __weak enable_spd(void) { } void __weak disable_spd(void) { } void sdram_initialize(int s3resume) { timestamp_add_now(TS_INITRAM_START); enable_spd(); dump_spd_registers(); sdram_set_registers(); sdram_set_spd_registers(); sdram_enable(); disable_spd(); timestamp_add_now(TS_INITRAM_END); }