1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
440 lines
11 KiB
C
440 lines
11 KiB
C
#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/delay.h>
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#include <linux/pci.h>
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#include <asm/dma.h>
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#include <asm/io.h>
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#include <asm/processor.h>
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#include <asm/timer.h>
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#include "cpu.h"
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/*
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* Read NSC/Cyrix DEVID registers (DIR) to get more detailed info. about the CPU
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*/
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static void __init do_cyrix_devid(unsigned char *dir0, unsigned char *dir1)
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{
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unsigned char ccr2, ccr3;
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unsigned long flags;
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/* we test for DEVID by checking whether CCR3 is writable */
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local_irq_save(flags);
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, ccr3 ^ 0x80);
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getCx86(0xc0); /* dummy to change bus */
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if (getCx86(CX86_CCR3) == ccr3) { /* no DEVID regs. */
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ccr2 = getCx86(CX86_CCR2);
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setCx86(CX86_CCR2, ccr2 ^ 0x04);
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getCx86(0xc0); /* dummy */
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if (getCx86(CX86_CCR2) == ccr2) /* old Cx486SLC/DLC */
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*dir0 = 0xfd;
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else { /* Cx486S A step */
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setCx86(CX86_CCR2, ccr2);
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*dir0 = 0xfe;
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}
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}
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else {
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setCx86(CX86_CCR3, ccr3); /* restore CCR3 */
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/* read DIR0 and DIR1 CPU registers */
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*dir0 = getCx86(CX86_DIR0);
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*dir1 = getCx86(CX86_DIR1);
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}
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local_irq_restore(flags);
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}
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/*
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* Cx86_dir0_msb is a HACK needed by check_cx686_cpuid/slop in bugs.h in
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* order to identify the Cyrix CPU model after we're out of setup.c
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*
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* Actually since bugs.h doesn't even reference this perhaps someone should
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* fix the documentation ???
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*/
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static unsigned char Cx86_dir0_msb __initdata = 0;
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static char Cx86_model[][9] __initdata = {
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"Cx486", "Cx486", "5x86 ", "6x86", "MediaGX ", "6x86MX ",
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"M II ", "Unknown"
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};
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static char Cx486_name[][5] __initdata = {
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"SLC", "DLC", "SLC2", "DLC2", "SRx", "DRx",
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"SRx2", "DRx2"
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};
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static char Cx486S_name[][4] __initdata = {
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"S", "S2", "Se", "S2e"
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};
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static char Cx486D_name[][4] __initdata = {
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"DX", "DX2", "?", "?", "?", "DX4"
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};
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static char Cx86_cb[] __initdata = "?.5x Core/Bus Clock";
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static char cyrix_model_mult1[] __initdata = "12??43";
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static char cyrix_model_mult2[] __initdata = "12233445";
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/*
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* Reset the slow-loop (SLOP) bit on the 686(L) which is set by some old
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* BIOSes for compatibility with DOS games. This makes the udelay loop
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* work correctly, and improves performance.
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*
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* FIXME: our newer udelay uses the tsc. We don't need to frob with SLOP
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*/
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extern void calibrate_delay(void) __init;
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static void __init check_cx686_slop(struct cpuinfo_x86 *c)
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{
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unsigned long flags;
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if (Cx86_dir0_msb == 3) {
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unsigned char ccr3, ccr5;
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local_irq_save(flags);
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */
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ccr5 = getCx86(CX86_CCR5);
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if (ccr5 & 2)
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setCx86(CX86_CCR5, ccr5 & 0xfd); /* reset SLOP */
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setCx86(CX86_CCR3, ccr3); /* disable MAPEN */
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local_irq_restore(flags);
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if (ccr5 & 2) { /* possible wrong calibration done */
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printk(KERN_INFO "Recalibrating delay loop with SLOP bit reset\n");
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calibrate_delay();
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c->loops_per_jiffy = loops_per_jiffy;
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}
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}
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}
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static void __init set_cx86_reorder(void)
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{
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u8 ccr3;
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printk(KERN_INFO "Enable Memory access reorder on Cyrix/NSC processor.\n");
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN<45> */
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/* Load/Store Serialize to mem access disable (=reorder it)<29> */
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setCx86(CX86_PCR0, getCx86(CX86_PCR0) & ~0x80);
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/* set load/store serialize from 1GB to 4GB */
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ccr3 |= 0xe0;
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setCx86(CX86_CCR3, ccr3);
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}
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static void __init set_cx86_memwb(void)
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{
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u32 cr0;
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printk(KERN_INFO "Enable Memory-Write-back mode on Cyrix/NSC processor.\n");
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/* CCR2 bit 2: unlock NW bit */
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setCx86(CX86_CCR2, getCx86(CX86_CCR2) & ~0x04);
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/* set 'Not Write-through' */
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cr0 = 0x20000000;
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__asm__("movl %%cr0,%%eax\n\t"
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"orl %0,%%eax\n\t"
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"movl %%eax,%%cr0\n"
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: : "r" (cr0)
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:"ax");
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/* CCR2 bit 2: lock NW bit and set WT1 */
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setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x14 );
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}
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static void __init set_cx86_inc(void)
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{
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unsigned char ccr3;
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printk(KERN_INFO "Enable Incrementor on Cyrix/NSC processor.\n");
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN<45> */
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/* PCR1 -- Performance Control */
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/* Incrementor on, whatever that is */
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setCx86(CX86_PCR1, getCx86(CX86_PCR1) | 0x02);
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/* PCR0 -- Performance Control */
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/* Incrementor Margin 10 */
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setCx86(CX86_PCR0, getCx86(CX86_PCR0) | 0x04);
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setCx86(CX86_CCR3, ccr3); /* disable MAPEN */
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}
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/*
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* Configure later MediaGX and/or Geode processor.
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*/
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static void __init geode_configure(void)
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{
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unsigned long flags;
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u8 ccr3, ccr4;
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local_irq_save(flags);
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/* Suspend on halt power saving and enable #SUSP pin */
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setCx86(CX86_CCR2, getCx86(CX86_CCR2) | 0x88);
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* Enable */
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ccr4 = getCx86(CX86_CCR4);
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ccr4 |= 0x38; /* FPU fast, DTE cache, Mem bypass */
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setCx86(CX86_CCR3, ccr3);
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set_cx86_memwb();
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set_cx86_reorder();
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set_cx86_inc();
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local_irq_restore(flags);
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}
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#ifdef CONFIG_PCI
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static struct pci_device_id cyrix_55x0[] = {
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{ PCI_DEVICE(PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5510) },
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{ PCI_DEVICE(PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5520) },
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{ },
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};
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#endif
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static void __init init_cyrix(struct cpuinfo_x86 *c)
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{
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unsigned char dir0, dir0_msn, dir0_lsn, dir1 = 0;
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char *buf = c->x86_model_id;
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const char *p = NULL;
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/* Bit 31 in normal CPUID used for nonstandard 3DNow ID;
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3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */
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clear_bit(0*32+31, c->x86_capability);
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/* Cyrix used bit 24 in extended (AMD) CPUID for Cyrix MMX extensions */
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if ( test_bit(1*32+24, c->x86_capability) ) {
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clear_bit(1*32+24, c->x86_capability);
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set_bit(X86_FEATURE_CXMMX, c->x86_capability);
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}
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do_cyrix_devid(&dir0, &dir1);
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check_cx686_slop(c);
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Cx86_dir0_msb = dir0_msn = dir0 >> 4; /* identifies CPU "family" */
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dir0_lsn = dir0 & 0xf; /* model or clock multiplier */
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/* common case step number/rev -- exceptions handled below */
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c->x86_model = (dir1 >> 4) + 1;
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c->x86_mask = dir1 & 0xf;
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/* Now cook; the original recipe is by Channing Corn, from Cyrix.
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* We do the same thing for each generation: we work out
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* the model, multiplier and stepping. Black magic included,
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* to make the silicon step/rev numbers match the printed ones.
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*/
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switch (dir0_msn) {
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unsigned char tmp;
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case 0: /* Cx486SLC/DLC/SRx/DRx */
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p = Cx486_name[dir0_lsn & 7];
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break;
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case 1: /* Cx486S/DX/DX2/DX4 */
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p = (dir0_lsn & 8) ? Cx486D_name[dir0_lsn & 5]
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: Cx486S_name[dir0_lsn & 3];
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break;
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case 2: /* 5x86 */
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Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5];
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p = Cx86_cb+2;
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break;
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case 3: /* 6x86/6x86L */
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Cx86_cb[1] = ' ';
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Cx86_cb[2] = cyrix_model_mult1[dir0_lsn & 5];
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if (dir1 > 0x21) { /* 686L */
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Cx86_cb[0] = 'L';
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p = Cx86_cb;
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(c->x86_model)++;
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} else /* 686 */
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p = Cx86_cb+1;
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/* Emulate MTRRs using Cyrix's ARRs. */
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set_bit(X86_FEATURE_CYRIX_ARR, c->x86_capability);
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/* 6x86's contain this bug */
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c->coma_bug = 1;
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break;
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case 4: /* MediaGX/GXm or Geode GXM/GXLV/GX1 */
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#ifdef CONFIG_PCI
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/* It isn't really a PCI quirk directly, but the cure is the
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same. The MediaGX has deep magic SMM stuff that handles the
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SB emulation. It thows away the fifo on disable_dma() which
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is wrong and ruins the audio.
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Bug2: VSA1 has a wrap bug so that using maximum sized DMA
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causes bad things. According to NatSemi VSA2 has another
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bug to do with 'hlt'. I've not seen any boards using VSA2
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and X doesn't seem to support it either so who cares 8).
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VSA1 we work around however.
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*/
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printk(KERN_INFO "Working around Cyrix MediaGX virtual DMA bugs.\n");
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isa_dma_bridge_buggy = 2;
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#endif
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c->x86_cache_size=16; /* Yep 16K integrated cache thats it */
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/*
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* The 5510/5520 companion chips have a funky PIT.
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*/
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if (pci_dev_present(cyrix_55x0))
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pit_latch_buggy = 1;
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/* GXm supports extended cpuid levels 'ala' AMD */
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if (c->cpuid_level == 2) {
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/* Enable cxMMX extensions (GX1 Datasheet 54) */
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setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1);
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/* GXlv/GXm/GX1 */
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if((dir1 >= 0x50 && dir1 <= 0x54) || dir1 >= 0x63)
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geode_configure();
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get_model_name(c); /* get CPU marketing name */
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return;
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}
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else { /* MediaGX */
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Cx86_cb[2] = (dir0_lsn & 1) ? '3' : '4';
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p = Cx86_cb+2;
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c->x86_model = (dir1 & 0x20) ? 1 : 2;
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}
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break;
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case 5: /* 6x86MX/M II */
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if (dir1 > 7)
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{
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dir0_msn++; /* M II */
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/* Enable MMX extensions (App note 108) */
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setCx86(CX86_CCR7, getCx86(CX86_CCR7)|1);
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}
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else
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{
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c->coma_bug = 1; /* 6x86MX, it has the bug. */
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}
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tmp = (!(dir0_lsn & 7) || dir0_lsn & 1) ? 2 : 0;
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Cx86_cb[tmp] = cyrix_model_mult2[dir0_lsn & 7];
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p = Cx86_cb+tmp;
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if (((dir1 & 0x0f) > 4) || ((dir1 & 0xf0) == 0x20))
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(c->x86_model)++;
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/* Emulate MTRRs using Cyrix's ARRs. */
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set_bit(X86_FEATURE_CYRIX_ARR, c->x86_capability);
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break;
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case 0xf: /* Cyrix 486 without DEVID registers */
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switch (dir0_lsn) {
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case 0xd: /* either a 486SLC or DLC w/o DEVID */
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dir0_msn = 0;
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p = Cx486_name[(c->hard_math) ? 1 : 0];
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break;
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case 0xe: /* a 486S A step */
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dir0_msn = 0;
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p = Cx486S_name[0];
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break;
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}
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break;
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default: /* unknown (shouldn't happen, we know everyone ;-) */
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dir0_msn = 7;
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break;
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}
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strcpy(buf, Cx86_model[dir0_msn & 7]);
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if (p) strcat(buf, p);
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return;
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}
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/*
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* Cyrix CPUs without cpuid or with cpuid not yet enabled can be detected
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* by the fact that they preserve the flags across the division of 5/2.
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* PII and PPro exhibit this behavior too, but they have cpuid available.
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*/
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/*
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* Perform the Cyrix 5/2 test. A Cyrix won't change
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* the flags, while other 486 chips will.
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*/
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static inline int test_cyrix_52div(void)
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{
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unsigned int test;
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__asm__ __volatile__(
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"sahf\n\t" /* clear flags (%eax = 0x0005) */
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"div %b2\n\t" /* divide 5 by 2 */
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"lahf" /* store flags into %ah */
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: "=a" (test)
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: "0" (5), "q" (2)
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: "cc");
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/* AH is 0x02 on Cyrix after the divide.. */
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return (unsigned char) (test >> 8) == 0x02;
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}
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static void cyrix_identify(struct cpuinfo_x86 * c)
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{
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/* Detect Cyrix with disabled CPUID */
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if ( c->x86 == 4 && test_cyrix_52div() ) {
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unsigned char dir0, dir1;
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strcpy(c->x86_vendor_id, "CyrixInstead");
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c->x86_vendor = X86_VENDOR_CYRIX;
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/* Actually enable cpuid on the older cyrix */
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/* Retrieve CPU revisions */
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do_cyrix_devid(&dir0, &dir1);
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dir0>>=4;
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/* Check it is an affected model */
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if (dir0 == 5 || dir0 == 3)
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{
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unsigned char ccr3, ccr4;
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unsigned long flags;
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printk(KERN_INFO "Enabling CPUID on Cyrix processor.\n");
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local_irq_save(flags);
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ccr3 = getCx86(CX86_CCR3);
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setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */
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ccr4 = getCx86(CX86_CCR4);
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setCx86(CX86_CCR4, ccr4 | 0x80); /* enable cpuid */
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setCx86(CX86_CCR3, ccr3); /* disable MAPEN */
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local_irq_restore(flags);
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}
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}
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generic_identify(c);
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}
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static struct cpu_dev cyrix_cpu_dev __initdata = {
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.c_vendor = "Cyrix",
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.c_ident = { "CyrixInstead" },
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.c_init = init_cyrix,
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.c_identify = cyrix_identify,
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};
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int __init cyrix_init_cpu(void)
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{
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cpu_devs[X86_VENDOR_CYRIX] = &cyrix_cpu_dev;
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return 0;
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}
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//early_arch_initcall(cyrix_init_cpu);
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static struct cpu_dev nsc_cpu_dev __initdata = {
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.c_vendor = "NSC",
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.c_ident = { "Geode by NSC" },
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.c_init = init_cyrix,
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.c_identify = generic_identify,
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};
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int __init nsc_init_cpu(void)
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{
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cpu_devs[X86_VENDOR_NSC] = &nsc_cpu_dev;
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return 0;
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}
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//early_arch_initcall(nsc_init_cpu);
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