Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 211 insertions, 0 deletions

diff --git a/arch/mips/kernel/watch.c b/arch/mips/kernel/watch.c
new file mode 100644
index 000000000..c9263b95c
--- /dev/null
+++ b/arch/mips/kernel/watch.c
@@ -0,0 +1,211 @@
+/*
+ * 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.
+ *
+ * Copyright (C) 2008 David Daney
+ */
+
+#include <linux/sched.h>
+
+#include <asm/processor.h>
+#include <asm/watch.h>
+
+/*
+ * Install the watch registers for the current thread.	A maximum of
+ * four registers are installed although the machine may have more.
+ */
+void mips_install_watch_registers(struct task_struct *t)
+{
+	struct mips3264_watch_reg_state *watches = &t->thread.watch.mips3264;
+	unsigned int watchhi = MIPS_WATCHHI_G |		/* Trap all ASIDs */
+			       MIPS_WATCHHI_IRW;	/* Clear result bits */
+
+	switch (current_cpu_data.watch_reg_use_cnt) {
+	default:
+		BUG();
+	case 4:
+		write_c0_watchlo3(watches->watchlo[3]);
+		write_c0_watchhi3(watchhi | watches->watchhi[3]);
+		fallthrough;
+	case 3:
+		write_c0_watchlo2(watches->watchlo[2]);
+		write_c0_watchhi2(watchhi | watches->watchhi[2]);
+		fallthrough;
+	case 2:
+		write_c0_watchlo1(watches->watchlo[1]);
+		write_c0_watchhi1(watchhi | watches->watchhi[1]);
+		fallthrough;
+	case 1:
+		write_c0_watchlo0(watches->watchlo[0]);
+		write_c0_watchhi0(watchhi | watches->watchhi[0]);
+	}
+}
+
+/*
+ * Read back the watchhi registers so the user space debugger has
+ * access to the I, R, and W bits.  A maximum of four registers are
+ * read although the machine may have more.
+ */
+void mips_read_watch_registers(void)
+{
+	struct mips3264_watch_reg_state *watches =
+		&current->thread.watch.mips3264;
+	unsigned int watchhi_mask = MIPS_WATCHHI_MASK | MIPS_WATCHHI_IRW;
+
+	switch (current_cpu_data.watch_reg_use_cnt) {
+	default:
+		BUG();
+	case 4:
+		watches->watchhi[3] = (read_c0_watchhi3() & watchhi_mask);
+		fallthrough;
+	case 3:
+		watches->watchhi[2] = (read_c0_watchhi2() & watchhi_mask);
+		fallthrough;
+	case 2:
+		watches->watchhi[1] = (read_c0_watchhi1() & watchhi_mask);
+		fallthrough;
+	case 1:
+		watches->watchhi[0] = (read_c0_watchhi0() & watchhi_mask);
+	}
+	if (current_cpu_data.watch_reg_use_cnt == 1 &&
+	    (watches->watchhi[0] & MIPS_WATCHHI_IRW) == 0) {
+		/* Pathological case of release 1 architecture that
+		 * doesn't set the condition bits.  We assume that
+		 * since we got here, the watch condition was met and
+		 * signal that the conditions requested in watchlo
+		 * were met.  */
+		watches->watchhi[0] |= (watches->watchlo[0] & MIPS_WATCHHI_IRW);
+	}
+ }
+
+/*
+ * Disable all watch registers.	 Although only four registers are
+ * installed, all are cleared to eliminate the possibility of endless
+ * looping in the watch handler.
+ */
+void mips_clear_watch_registers(void)
+{
+	switch (current_cpu_data.watch_reg_count) {
+	default:
+		BUG();
+	case 8:
+		write_c0_watchlo7(0);
+		fallthrough;
+	case 7:
+		write_c0_watchlo6(0);
+		fallthrough;
+	case 6:
+		write_c0_watchlo5(0);
+		fallthrough;
+	case 5:
+		write_c0_watchlo4(0);
+		fallthrough;
+	case 4:
+		write_c0_watchlo3(0);
+		fallthrough;
+	case 3:
+		write_c0_watchlo2(0);
+		fallthrough;
+	case 2:
+		write_c0_watchlo1(0);
+		fallthrough;
+	case 1:
+		write_c0_watchlo0(0);
+	}
+}
+
+void mips_probe_watch_registers(struct cpuinfo_mips *c)
+{
+	unsigned int t;
+
+	if ((c->options & MIPS_CPU_WATCH) == 0)
+		return;
+	/*
+	 * Check which of the I,R and W bits are supported, then
+	 * disable the register.
+	 */
+	write_c0_watchlo0(MIPS_WATCHLO_IRW);
+	back_to_back_c0_hazard();
+	t = read_c0_watchlo0();
+	write_c0_watchlo0(0);
+	c->watch_reg_masks[0] = t & MIPS_WATCHLO_IRW;
+
+	/* Write the mask bits and read them back to determine which
+	 * can be used. */
+	c->watch_reg_count = 1;
+	c->watch_reg_use_cnt = 1;
+	t = read_c0_watchhi0();
+	write_c0_watchhi0(t | MIPS_WATCHHI_MASK);
+	back_to_back_c0_hazard();
+	t = read_c0_watchhi0();
+	c->watch_reg_masks[0] |= (t & MIPS_WATCHHI_MASK);
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	write_c0_watchlo1(MIPS_WATCHLO_IRW);
+	back_to_back_c0_hazard();
+	t = read_c0_watchlo1();
+	write_c0_watchlo1(0);
+	c->watch_reg_masks[1] = t & MIPS_WATCHLO_IRW;
+
+	c->watch_reg_count = 2;
+	c->watch_reg_use_cnt = 2;
+	t = read_c0_watchhi1();
+	write_c0_watchhi1(t | MIPS_WATCHHI_MASK);
+	back_to_back_c0_hazard();
+	t = read_c0_watchhi1();
+	c->watch_reg_masks[1] |= (t & MIPS_WATCHHI_MASK);
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	write_c0_watchlo2(MIPS_WATCHLO_IRW);
+	back_to_back_c0_hazard();
+	t = read_c0_watchlo2();
+	write_c0_watchlo2(0);
+	c->watch_reg_masks[2] = t & MIPS_WATCHLO_IRW;
+
+	c->watch_reg_count = 3;
+	c->watch_reg_use_cnt = 3;
+	t = read_c0_watchhi2();
+	write_c0_watchhi2(t | MIPS_WATCHHI_MASK);
+	back_to_back_c0_hazard();
+	t = read_c0_watchhi2();
+	c->watch_reg_masks[2] |= (t & MIPS_WATCHHI_MASK);
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	write_c0_watchlo3(MIPS_WATCHLO_IRW);
+	back_to_back_c0_hazard();
+	t = read_c0_watchlo3();
+	write_c0_watchlo3(0);
+	c->watch_reg_masks[3] = t & MIPS_WATCHLO_IRW;
+
+	c->watch_reg_count = 4;
+	c->watch_reg_use_cnt = 4;
+	t = read_c0_watchhi3();
+	write_c0_watchhi3(t | MIPS_WATCHHI_MASK);
+	back_to_back_c0_hazard();
+	t = read_c0_watchhi3();
+	c->watch_reg_masks[3] |= (t & MIPS_WATCHHI_MASK);
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	/* We use at most 4, but probe and report up to 8. */
+	c->watch_reg_count = 5;
+	t = read_c0_watchhi4();
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	c->watch_reg_count = 6;
+	t = read_c0_watchhi5();
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	c->watch_reg_count = 7;
+	t = read_c0_watchhi6();
+	if ((t & MIPS_WATCHHI_M) == 0)
+		return;
+
+	c->watch_reg_count = 8;
+}