microblaze_mmu_v2: TLB low level code

Signed-off-by: Michal Simek <monstr@monstr.eu>

1 files changed, 120 insertions, 0 deletions

diff --git a/arch/microblaze/kernel/misc.S b/arch/microblaze/kernel/misc.S
new file mode 100644
index 000000000000..d623efc9083c
--- /dev/null
+++ b/arch/microblaze/kernel/misc.S
@@ -0,0 +1,120 @@
+/*
+ * Miscellaneous low-level MMU functions.
+ *
+ * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
+ * Copyright (C) 2008-2009 PetaLogix
+ * Copyright (C) 2007 Xilinx, Inc.  All rights reserved.
+ *
+ * Derived from arch/ppc/kernel/misc.S
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file COPYING in the main directory of this
+ * archive for more details.
+ */
+
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <linux/errno.h>
+#include <asm/mmu.h>
+#include <asm/page.h>
+
+        .text
+/*
+ * Flush MMU TLB
+ *
+ * We avoid flushing the pinned 0, 1 and possibly 2 entries.
+ */
+.globl _tlbia;
+.align 4;
+_tlbia:
+        addik   r12, r0, 63 /* flush all entries (63 - 3) */
+        /* isync */
+_tlbia_1:
+        mts     rtlbx, r12
+        nop
+        mts     rtlbhi, r0 /* flush: ensure V is clear */
+        nop
+        addik   r11, r12, -2
+        bneid   r11, _tlbia_1 /* loop for all entries */
+        addik   r12, r12, -1
+        /* sync */
+        rtsd    r15, 8
+        nop
+
+/*
+ * Flush MMU TLB for a particular address (in r5)
+ */
+.globl _tlbie;
+.align 4;
+_tlbie:
+        mts     rtlbsx, r5 /* look up the address in TLB */
+        nop
+        mfs     r12, rtlbx /* Retrieve index */
+        nop
+        blti    r12, _tlbie_1 /* Check if found */
+        mts     rtlbhi, r0 /* flush: ensure V is clear */
+        nop
+_tlbie_1:
+        rtsd    r15, 8
+        nop
+
+/*
+ * Allocate TLB entry for early console
+ */
+.globl early_console_reg_tlb_alloc;
+.align 4;
+early_console_reg_tlb_alloc:
+        /*
+         * Load a TLB entry for the UART, so that microblaze_progress() can use
+         * the UARTs nice and early.  We use a 4k real==virtual mapping.
+         */
+        ori     r4, r0, 2
+        mts     rtlbx, r4 /* TLB slot 2 */
+
+        or      r4,r5,r0
+        andi    r4,r4,0xfffff000
+        ori     r4,r4,(TLB_WR|TLB_I|TLB_M|TLB_G)
+
+        andi    r5,r5,0xfffff000
+        ori     r5,r5,(TLB_VALID | TLB_PAGESZ(PAGESZ_4K))
+
+        mts     rtlblo,r4 /* Load the data portion of the entry */
+        nop
+        mts     rtlbhi,r5 /* Load the tag portion of the entry */
+        nop
+        rtsd    r15, 8
+        nop
+
+/*
+ * Copy a whole page (4096 bytes).
+ */
+#define COPY_16_BYTES           \
+        lwi     r7, r6, 0;      \
+        lwi     r8, r6, 4;      \
+        lwi     r9, r6, 8;      \
+        lwi     r10, r6, 12;    \
+        swi     r7, r5, 0;      \
+        swi     r8, r5, 4;      \
+        swi     r9, r5, 8;      \
+        swi     r10, r5, 12
+
+
+/* FIXME DCACHE_LINE_BYTES (CONFIG_XILINX_MICROBLAZE0_DCACHE_LINE_LEN * 4)*/
+#define DCACHE_LINE_BYTES (4 * 4)
+
+.globl copy_page;
+.align 4;
+copy_page:
+        ori     r11, r0, (PAGE_SIZE/DCACHE_LINE_BYTES) - 1
+_copy_page_loop:
+        COPY_16_BYTES
+#if DCACHE_LINE_BYTES >= 32
+        COPY_16_BYTES
+#endif
+        addik   r6, r6, DCACHE_LINE_BYTES
+        addik   r5, r5, DCACHE_LINE_BYTES
+        bneid   r11, _copy_page_loop
+        addik   r11, r11, -1
+        rtsd    r15, 8
+        nop