summaryrefslogtreecommitdiff
path: root/arch/i386/kernel/cpu/mtrr/centaur.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/cpu/mtrr/centaur.c
Linux-2.6.12-rc2v2.6.12-rc2
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!
Diffstat (limited to 'arch/i386/kernel/cpu/mtrr/centaur.c')
-rw-r--r--arch/i386/kernel/cpu/mtrr/centaur.c223
1 files changed, 223 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/mtrr/centaur.c b/arch/i386/kernel/cpu/mtrr/centaur.c
new file mode 100644
index 000000000000..33f00ac314ef
--- /dev/null
+++ b/arch/i386/kernel/cpu/mtrr/centaur.c
@@ -0,0 +1,223 @@
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+#include "mtrr.h"
+
+static struct {
+ unsigned long high;
+ unsigned long low;
+} centaur_mcr[8];
+
+static u8 centaur_mcr_reserved;
+static u8 centaur_mcr_type; /* 0 for winchip, 1 for winchip2 */
+
+/*
+ * Report boot time MCR setups
+ */
+
+static int
+centaur_get_free_region(unsigned long base, unsigned long size)
+/* [SUMMARY] Get a free MTRR.
+ <base> The starting (base) address of the region.
+ <size> The size (in bytes) of the region.
+ [RETURNS] The index of the region on success, else -1 on error.
+*/
+{
+ int i, max;
+ mtrr_type ltype;
+ unsigned long lbase;
+ unsigned int lsize;
+
+ max = num_var_ranges;
+ for (i = 0; i < max; ++i) {
+ if (centaur_mcr_reserved & (1 << i))
+ continue;
+ mtrr_if->get(i, &lbase, &lsize, &ltype);
+ if (lsize == 0)
+ return i;
+ }
+ return -ENOSPC;
+}
+
+void
+mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)
+{
+ centaur_mcr[mcr].low = lo;
+ centaur_mcr[mcr].high = hi;
+}
+
+static void
+centaur_get_mcr(unsigned int reg, unsigned long *base,
+ unsigned int *size, mtrr_type * type)
+{
+ *base = centaur_mcr[reg].high >> PAGE_SHIFT;
+ *size = -(centaur_mcr[reg].low & 0xfffff000) >> PAGE_SHIFT;
+ *type = MTRR_TYPE_WRCOMB; /* If it is there, it is write-combining */
+ if (centaur_mcr_type == 1 && ((centaur_mcr[reg].low & 31) & 2))
+ *type = MTRR_TYPE_UNCACHABLE;
+ if (centaur_mcr_type == 1 && (centaur_mcr[reg].low & 31) == 25)
+ *type = MTRR_TYPE_WRBACK;
+ if (centaur_mcr_type == 0 && (centaur_mcr[reg].low & 31) == 31)
+ *type = MTRR_TYPE_WRBACK;
+
+}
+
+static void centaur_set_mcr(unsigned int reg, unsigned long base,
+ unsigned long size, mtrr_type type)
+{
+ unsigned long low, high;
+
+ if (size == 0) {
+ /* Disable */
+ high = low = 0;
+ } else {
+ high = base << PAGE_SHIFT;
+ if (centaur_mcr_type == 0)
+ low = -size << PAGE_SHIFT | 0x1f; /* only support write-combining... */
+ else {
+ if (type == MTRR_TYPE_UNCACHABLE)
+ low = -size << PAGE_SHIFT | 0x02; /* NC */
+ else
+ low = -size << PAGE_SHIFT | 0x09; /* WWO,WC */
+ }
+ }
+ centaur_mcr[reg].high = high;
+ centaur_mcr[reg].low = low;
+ wrmsr(MSR_IDT_MCR0 + reg, low, high);
+}
+
+#if 0
+/*
+ * Initialise the later (saner) Winchip MCR variant. In this version
+ * the BIOS can pass us the registers it has used (but not their values)
+ * and the control register is read/write
+ */
+
+static void __init
+centaur_mcr1_init(void)
+{
+ unsigned i;
+ u32 lo, hi;
+
+ /* Unfortunately, MCR's are read-only, so there is no way to
+ * find out what the bios might have done.
+ */
+
+ rdmsr(MSR_IDT_MCR_CTRL, lo, hi);
+ if (((lo >> 17) & 7) == 1) { /* Type 1 Winchip2 MCR */
+ lo &= ~0x1C0; /* clear key */
+ lo |= 0x040; /* set key to 1 */
+ wrmsr(MSR_IDT_MCR_CTRL, lo, hi); /* unlock MCR */
+ }
+
+ centaur_mcr_type = 1;
+
+ /*
+ * Clear any unconfigured MCR's.
+ */
+
+ for (i = 0; i < 8; ++i) {
+ if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0) {
+ if (!(lo & (1 << (9 + i))))
+ wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+ else
+ /*
+ * If the BIOS set up an MCR we cannot see it
+ * but we don't wish to obliterate it
+ */
+ centaur_mcr_reserved |= (1 << i);
+ }
+ }
+ /*
+ * Throw the main write-combining switch...
+ * However if OOSTORE is enabled then people have already done far
+ * cleverer things and we should behave.
+ */
+
+ lo |= 15; /* Write combine enables */
+ wrmsr(MSR_IDT_MCR_CTRL, lo, hi);
+}
+
+/*
+ * Initialise the original winchip with read only MCR registers
+ * no used bitmask for the BIOS to pass on and write only control
+ */
+
+static void __init
+centaur_mcr0_init(void)
+{
+ unsigned i;
+
+ /* Unfortunately, MCR's are read-only, so there is no way to
+ * find out what the bios might have done.
+ */
+
+ /* Clear any unconfigured MCR's.
+ * This way we are sure that the centaur_mcr array contains the actual
+ * values. The disadvantage is that any BIOS tweaks are thus undone.
+ *
+ */
+ for (i = 0; i < 8; ++i) {
+ if (centaur_mcr[i].high == 0 && centaur_mcr[i].low == 0)
+ wrmsr(MSR_IDT_MCR0 + i, 0, 0);
+ }
+
+ wrmsr(MSR_IDT_MCR_CTRL, 0x01F0001F, 0); /* Write only */
+}
+
+/*
+ * Initialise Winchip series MCR registers
+ */
+
+static void __init
+centaur_mcr_init(void)
+{
+ struct set_mtrr_context ctxt;
+
+ set_mtrr_prepare_save(&ctxt);
+ set_mtrr_cache_disable(&ctxt);
+
+ if (boot_cpu_data.x86_model == 4)
+ centaur_mcr0_init();
+ else if (boot_cpu_data.x86_model == 8 || boot_cpu_data.x86_model == 9)
+ centaur_mcr1_init();
+
+ set_mtrr_done(&ctxt);
+}
+#endif
+
+static int centaur_validate_add_page(unsigned long base,
+ unsigned long size, unsigned int type)
+{
+ /*
+ * FIXME: Winchip2 supports uncached
+ */
+ if (type != MTRR_TYPE_WRCOMB &&
+ (centaur_mcr_type == 0 || type != MTRR_TYPE_UNCACHABLE)) {
+ printk(KERN_WARNING
+ "mtrr: only write-combining%s supported\n",
+ centaur_mcr_type ? " and uncacheable are"
+ : " is");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static struct mtrr_ops centaur_mtrr_ops = {
+ .vendor = X86_VENDOR_CENTAUR,
+// .init = centaur_mcr_init,
+ .set = centaur_set_mcr,
+ .get = centaur_get_mcr,
+ .get_free_region = centaur_get_free_region,
+ .validate_add_page = centaur_validate_add_page,
+ .have_wrcomb = positive_have_wrcomb,
+};
+
+int __init centaur_init_mtrr(void)
+{
+ set_mtrr_ops(&centaur_mtrr_ops);
+ return 0;
+}
+
+//arch_initcall(centaur_init_mtrr);