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Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/cyrix.c')
-rw-r--r--arch/x86/kernel/cpu/mtrr/cyrix.c284
1 files changed, 284 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/cyrix.c b/arch/x86/kernel/cpu/mtrr/cyrix.c
new file mode 100644
index 000000000..ca670919b
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/cyrix.c
@@ -0,0 +1,284 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/mm.h>
+
+#include <asm/processor-cyrix.h>
+#include <asm/processor-flags.h>
+#include <asm/mtrr.h>
+#include <asm/msr.h>
+
+#include "mtrr.h"
+
+static void
+cyrix_get_arr(unsigned int reg, unsigned long *base,
+ unsigned long *size, mtrr_type * type)
+{
+ unsigned char arr, ccr3, rcr, shift;
+ unsigned long flags;
+
+ arr = CX86_ARR_BASE + (reg << 1) + reg; /* avoid multiplication by 3 */
+
+ local_irq_save(flags);
+
+ ccr3 = getCx86(CX86_CCR3);
+ setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10); /* enable MAPEN */
+ ((unsigned char *)base)[3] = getCx86(arr);
+ ((unsigned char *)base)[2] = getCx86(arr + 1);
+ ((unsigned char *)base)[1] = getCx86(arr + 2);
+ rcr = getCx86(CX86_RCR_BASE + reg);
+ setCx86(CX86_CCR3, ccr3); /* disable MAPEN */
+
+ local_irq_restore(flags);
+
+ shift = ((unsigned char *) base)[1] & 0x0f;
+ *base >>= PAGE_SHIFT;
+
+ /*
+ * Power of two, at least 4K on ARR0-ARR6, 256K on ARR7
+ * Note: shift==0xf means 4G, this is unsupported.
+ */
+ if (shift)
+ *size = (reg < 7 ? 0x1UL : 0x40UL) << (shift - 1);
+ else
+ *size = 0;
+
+ /* Bit 0 is Cache Enable on ARR7, Cache Disable on ARR0-ARR6 */
+ if (reg < 7) {
+ switch (rcr) {
+ case 1:
+ *type = MTRR_TYPE_UNCACHABLE;
+ break;
+ case 8:
+ *type = MTRR_TYPE_WRBACK;
+ break;
+ case 9:
+ *type = MTRR_TYPE_WRCOMB;
+ break;
+ case 24:
+ default:
+ *type = MTRR_TYPE_WRTHROUGH;
+ break;
+ }
+ } else {
+ switch (rcr) {
+ case 0:
+ *type = MTRR_TYPE_UNCACHABLE;
+ break;
+ case 8:
+ *type = MTRR_TYPE_WRCOMB;
+ break;
+ case 9:
+ *type = MTRR_TYPE_WRBACK;
+ break;
+ case 25:
+ default:
+ *type = MTRR_TYPE_WRTHROUGH;
+ break;
+ }
+ }
+}
+
+/*
+ * cyrix_get_free_region - get a free ARR.
+ *
+ * @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.
+*/
+static int
+cyrix_get_free_region(unsigned long base, unsigned long size, int replace_reg)
+{
+ unsigned long lbase, lsize;
+ mtrr_type ltype;
+ int i;
+
+ switch (replace_reg) {
+ case 7:
+ if (size < 0x40)
+ break;
+ fallthrough;
+ case 6:
+ case 5:
+ case 4:
+ return replace_reg;
+ case 3:
+ case 2:
+ case 1:
+ case 0:
+ return replace_reg;
+ }
+ /* If we are to set up a region >32M then look at ARR7 immediately */
+ if (size > 0x2000) {
+ cyrix_get_arr(7, &lbase, &lsize, &ltype);
+ if (lsize == 0)
+ return 7;
+ /* Else try ARR0-ARR6 first */
+ } else {
+ for (i = 0; i < 7; i++) {
+ cyrix_get_arr(i, &lbase, &lsize, &ltype);
+ if (lsize == 0)
+ return i;
+ }
+ /*
+ * ARR0-ARR6 isn't free
+ * try ARR7 but its size must be at least 256K
+ */
+ cyrix_get_arr(i, &lbase, &lsize, &ltype);
+ if ((lsize == 0) && (size >= 0x40))
+ return i;
+ }
+ return -ENOSPC;
+}
+
+static u32 cr4, ccr3;
+
+static void prepare_set(void)
+{
+ u32 cr0;
+
+ /* Save value of CR4 and clear Page Global Enable (bit 7) */
+ if (boot_cpu_has(X86_FEATURE_PGE)) {
+ cr4 = __read_cr4();
+ __write_cr4(cr4 & ~X86_CR4_PGE);
+ }
+
+ /*
+ * Disable and flush caches.
+ * Note that wbinvd flushes the TLBs as a side-effect
+ */
+ cr0 = read_cr0() | X86_CR0_CD;
+ wbinvd();
+ write_cr0(cr0);
+ wbinvd();
+
+ /* Cyrix ARRs - everything else was excluded at the top */
+ ccr3 = getCx86(CX86_CCR3);
+
+ /* Cyrix ARRs - everything else was excluded at the top */
+ setCx86(CX86_CCR3, (ccr3 & 0x0f) | 0x10);
+}
+
+static void post_set(void)
+{
+ /* Flush caches and TLBs */
+ wbinvd();
+
+ /* Cyrix ARRs - everything else was excluded at the top */
+ setCx86(CX86_CCR3, ccr3);
+
+ /* Enable caches */
+ write_cr0(read_cr0() & ~X86_CR0_CD);
+
+ /* Restore value of CR4 */
+ if (boot_cpu_has(X86_FEATURE_PGE))
+ __write_cr4(cr4);
+}
+
+static void cyrix_set_arr(unsigned int reg, unsigned long base,
+ unsigned long size, mtrr_type type)
+{
+ unsigned char arr, arr_type, arr_size;
+
+ arr = CX86_ARR_BASE + (reg << 1) + reg; /* avoid multiplication by 3 */
+
+ /* count down from 32M (ARR0-ARR6) or from 2G (ARR7) */
+ if (reg >= 7)
+ size >>= 6;
+
+ size &= 0x7fff; /* make sure arr_size <= 14 */
+ for (arr_size = 0; size; arr_size++, size >>= 1)
+ ;
+
+ if (reg < 7) {
+ switch (type) {
+ case MTRR_TYPE_UNCACHABLE:
+ arr_type = 1;
+ break;
+ case MTRR_TYPE_WRCOMB:
+ arr_type = 9;
+ break;
+ case MTRR_TYPE_WRTHROUGH:
+ arr_type = 24;
+ break;
+ default:
+ arr_type = 8;
+ break;
+ }
+ } else {
+ switch (type) {
+ case MTRR_TYPE_UNCACHABLE:
+ arr_type = 0;
+ break;
+ case MTRR_TYPE_WRCOMB:
+ arr_type = 8;
+ break;
+ case MTRR_TYPE_WRTHROUGH:
+ arr_type = 25;
+ break;
+ default:
+ arr_type = 9;
+ break;
+ }
+ }
+
+ prepare_set();
+
+ base <<= PAGE_SHIFT;
+ setCx86(arr + 0, ((unsigned char *)&base)[3]);
+ setCx86(arr + 1, ((unsigned char *)&base)[2]);
+ setCx86(arr + 2, (((unsigned char *)&base)[1]) | arr_size);
+ setCx86(CX86_RCR_BASE + reg, arr_type);
+
+ post_set();
+}
+
+typedef struct {
+ unsigned long base;
+ unsigned long size;
+ mtrr_type type;
+} arr_state_t;
+
+static arr_state_t arr_state[8] = {
+ {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL},
+ {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}, {0UL, 0UL, 0UL}
+};
+
+static unsigned char ccr_state[7] = { 0, 0, 0, 0, 0, 0, 0 };
+
+static void cyrix_set_all(void)
+{
+ int i;
+
+ prepare_set();
+
+ /* the CCRs are not contiguous */
+ for (i = 0; i < 4; i++)
+ setCx86(CX86_CCR0 + i, ccr_state[i]);
+ for (; i < 7; i++)
+ setCx86(CX86_CCR4 + i, ccr_state[i]);
+
+ for (i = 0; i < 8; i++) {
+ cyrix_set_arr(i, arr_state[i].base,
+ arr_state[i].size, arr_state[i].type);
+ }
+
+ post_set();
+}
+
+static const struct mtrr_ops cyrix_mtrr_ops = {
+ .vendor = X86_VENDOR_CYRIX,
+ .set_all = cyrix_set_all,
+ .set = cyrix_set_arr,
+ .get = cyrix_get_arr,
+ .get_free_region = cyrix_get_free_region,
+ .validate_add_page = generic_validate_add_page,
+ .have_wrcomb = positive_have_wrcomb,
+};
+
+int __init cyrix_init_mtrr(void)
+{
+ set_mtrr_ops(&cyrix_mtrr_ops);
+ return 0;
+}