Adding upstream version 6.1.76.upstream/6.1.76

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

1 files changed, 143 insertions, 0 deletions

diff --git a/arch/arm/include/asm/tls.h b/arch/arm/include/asm/tls.h
new file mode 100644
index 000000000..3dcd0f71a
--- /dev/null
+++ b/arch/arm/include/asm/tls.h
@@ -0,0 +1,143 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASMARM_TLS_H
+#define __ASMARM_TLS_H
+
+#include <linux/compiler.h>
+#include <asm/thread_info.h>
+
+#ifdef __ASSEMBLY__
+#include <asm/asm-offsets.h>
+	.macro switch_tls_none, base, tp, tpuser, tmp1, tmp2
+	.endm
+
+	.macro switch_tls_v6k, base, tp, tpuser, tmp1, tmp2
+	mrc	p15, 0, \tmp2, c13, c0, 2	@ get the user r/w register
+	@ TLS register update is deferred until return to user space
+	mcr	p15, 0, \tpuser, c13, c0, 2	@ set the user r/w register
+	str	\tmp2, [\base, #TI_TP_VALUE + 4] @ save it
+	.endm
+
+	.macro switch_tls_v6, base, tp, tpuser, tmp1, tmp2
+#ifdef CONFIG_SMP
+ALT_SMP(nop)
+ALT_UP_B(.L0_\@)
+	.subsection 1
+#endif
+.L0_\@:
+	ldr_va	\tmp1, elf_hwcap
+	mov	\tmp2, #0xffff0fff
+	tst	\tmp1, #HWCAP_TLS		@ hardware TLS available?
+	streq	\tp, [\tmp2, #-15]		@ set TLS value at 0xffff0ff0
+	beq	.L2_\@
+	mcr	p15, 0, \tp, c13, c0, 3		@ yes, set TLS register
+#ifdef CONFIG_SMP
+	b	.L1_\@
+	.previous
+#endif
+.L1_\@: switch_tls_v6k \base, \tp, \tpuser, \tmp1, \tmp2
+.L2_\@:
+	.endm
+
+	.macro switch_tls_software, base, tp, tpuser, tmp1, tmp2
+	mov	\tmp1, #0xffff0fff
+	str	\tp, [\tmp1, #-15]		@ set TLS value at 0xffff0ff0
+	.endm
+#else
+#include <asm/smp_plat.h>
+#endif
+
+#ifdef CONFIG_TLS_REG_EMUL
+#define tls_emu		1
+#define has_tls_reg		1
+#define defer_tls_reg_update	0
+#define switch_tls	switch_tls_none
+#elif defined(CONFIG_CPU_V6)
+#define tls_emu		0
+#define has_tls_reg		(elf_hwcap & HWCAP_TLS)
+#define defer_tls_reg_update	is_smp()
+#define switch_tls	switch_tls_v6
+#elif defined(CONFIG_CPU_32v6K)
+#define tls_emu		0
+#define has_tls_reg		1
+#define defer_tls_reg_update	1
+#define switch_tls	switch_tls_v6k
+#else
+#define tls_emu		0
+#define has_tls_reg		0
+#define defer_tls_reg_update	0
+#define switch_tls	switch_tls_software
+#endif
+
+#ifndef __ASSEMBLY__
+
+static inline void set_tls(unsigned long val)
+{
+	struct thread_info *thread;
+
+	thread = current_thread_info();
+
+	thread->tp_value[0] = val;
+
+	/*
+	 * This code runs with preemption enabled and therefore must
+	 * be reentrant with respect to switch_tls.
+	 *
+	 * We need to ensure ordering between the shadow state and the
+	 * hardware state, so that we don't corrupt the hardware state
+	 * with a stale shadow state during context switch.
+	 *
+	 * If we're preempted here, switch_tls will load TPIDRURO from
+	 * thread_info upon resuming execution and the following mcr
+	 * is merely redundant.
+	 */
+	barrier();
+
+	if (!tls_emu) {
+		if (has_tls_reg && !defer_tls_reg_update) {
+			asm("mcr p15, 0, %0, c13, c0, 3"
+			    : : "r" (val));
+		} else if (!has_tls_reg) {
+#ifdef CONFIG_KUSER_HELPERS
+			/*
+			 * User space must never try to access this
+			 * directly.  Expect your app to break
+			 * eventually if you do so.  The user helper
+			 * at 0xffff0fe0 must be used instead.  (see
+			 * entry-armv.S for details)
+			 */
+			*((unsigned int *)0xffff0ff0) = val;
+#endif
+		}
+
+	}
+}
+
+static inline unsigned long get_tpuser(void)
+{
+	unsigned long reg = 0;
+
+	if (has_tls_reg && !tls_emu)
+		__asm__("mrc p15, 0, %0, c13, c0, 2" : "=r" (reg));
+
+	return reg;
+}
+
+static inline void set_tpuser(unsigned long val)
+{
+	/* Since TPIDRURW is fully context-switched (unlike TPIDRURO),
+	 * we need not update thread_info.
+	 */
+	if (has_tls_reg && !tls_emu) {
+		asm("mcr p15, 0, %0, c13, c0, 2"
+		    : : "r" (val));
+	}
+}
+
+static inline void flush_tls(void)
+{
+	set_tls(0);
+	set_tpuser(0);
+}
+
+#endif
+#endif	/* __ASMARM_TLS_H */