Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 178 insertions, 0 deletions

diff --git a/arch/arm64/kernel/hibernate-asm.S b/arch/arm64/kernel/hibernate-asm.S
new file mode 100644
index 000000000..dd14ab8c9
--- /dev/null
+++ b/arch/arm64/kernel/hibernate-asm.S
@@ -0,0 +1,178 @@
+/*
+ * Hibernate low-level support
+ *
+ * Copyright (C) 2016 ARM Ltd.
+ * Author:	James Morse <james.morse@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <linux/linkage.h>
+#include <linux/errno.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/assembler.h>
+#include <asm/cputype.h>
+#include <asm/memory.h>
+#include <asm/page.h>
+#include <asm/virt.h>
+
+/*
+ * To prevent the possibility of old and new partial table walks being visible
+ * in the tlb, switch the ttbr to a zero page when we invalidate the old
+ * records. D4.7.1 'General TLB maintenance requirements' in ARM DDI 0487A.i
+ * Even switching to our copied tables will cause a changed output address at
+ * each stage of the walk.
+ */
+.macro break_before_make_ttbr_switch zero_page, page_table, tmp
+	phys_to_ttbr \tmp, \zero_page
+	msr	ttbr1_el1, \tmp
+	isb
+	tlbi	vmalle1
+	dsb	nsh
+	phys_to_ttbr \tmp, \page_table
+	msr	ttbr1_el1, \tmp
+	isb
+.endm
+
+
+/*
+ * Resume from hibernate
+ *
+ * Loads temporary page tables then restores the memory image.
+ * Finally branches to cpu_resume() to restore the state saved by
+ * swsusp_arch_suspend().
+ *
+ * Because this code has to be copied to a 'safe' page, it can't call out to
+ * other functions by PC-relative address. Also remember that it may be
+ * mid-way through over-writing other functions. For this reason it contains
+ * code from flush_icache_range() and uses the copy_page() macro.
+ *
+ * This 'safe' page is mapped via ttbr0, and executed from there. This function
+ * switches to a copy of the linear map in ttbr1, performs the restore, then
+ * switches ttbr1 to the original kernel's swapper_pg_dir.
+ *
+ * All of memory gets written to, including code. We need to clean the kernel
+ * text to the Point of Coherence (PoC) before secondary cores can be booted.
+ * Because the kernel modules and executable pages mapped to user space are
+ * also written as data, we clean all pages we touch to the Point of
+ * Unification (PoU).
+ *
+ * x0: physical address of temporary page tables
+ * x1: physical address of swapper page tables
+ * x2: address of cpu_resume
+ * x3: linear map address of restore_pblist in the current kernel
+ * x4: physical address of __hyp_stub_vectors, or 0
+ * x5: physical address of a  zero page that remains zero after resume
+ */
+.pushsection    ".hibernate_exit.text", "ax"
+ENTRY(swsusp_arch_suspend_exit)
+	/*
+	 * We execute from ttbr0, change ttbr1 to our copied linear map tables
+	 * with a break-before-make via the zero page
+	 */
+	break_before_make_ttbr_switch	x5, x0, x6
+
+	mov	x21, x1
+	mov	x30, x2
+	mov	x24, x4
+	mov	x25, x5
+
+	/* walk the restore_pblist and use copy_page() to over-write memory */
+	mov	x19, x3
+
+1:	ldr	x10, [x19, #HIBERN_PBE_ORIG]
+	mov	x0, x10
+	ldr	x1, [x19, #HIBERN_PBE_ADDR]
+
+	copy_page	x0, x1, x2, x3, x4, x5, x6, x7, x8, x9
+
+	add	x1, x10, #PAGE_SIZE
+	/* Clean the copied page to PoU - based on flush_icache_range() */
+	raw_dcache_line_size x2, x3
+	sub	x3, x2, #1
+	bic	x4, x10, x3
+2:	dc	cvau, x4	/* clean D line / unified line */
+	add	x4, x4, x2
+	cmp	x4, x1
+	b.lo	2b
+
+	ldr	x19, [x19, #HIBERN_PBE_NEXT]
+	cbnz	x19, 1b
+	dsb	ish		/* wait for PoU cleaning to finish */
+
+	/* switch to the restored kernels page tables */
+	break_before_make_ttbr_switch	x25, x21, x6
+
+	ic	ialluis
+	dsb	ish
+	isb
+
+	cbz	x24, 3f		/* Do we need to re-initialise EL2? */
+	hvc	#0
+3:	ret
+
+	.ltorg
+ENDPROC(swsusp_arch_suspend_exit)
+
+/*
+ * Restore the hyp stub.
+ * This must be done before the hibernate page is unmapped by _cpu_resume(),
+ * but happens before any of the hyp-stub's code is cleaned to PoC.
+ *
+ * x24: The physical address of __hyp_stub_vectors
+ */
+el1_sync:
+	msr	vbar_el2, x24
+	eret
+ENDPROC(el1_sync)
+
+.macro invalid_vector	label
+\label:
+	b \label
+ENDPROC(\label)
+.endm
+
+	invalid_vector	el2_sync_invalid
+	invalid_vector	el2_irq_invalid
+	invalid_vector	el2_fiq_invalid
+	invalid_vector	el2_error_invalid
+	invalid_vector	el1_sync_invalid
+	invalid_vector	el1_irq_invalid
+	invalid_vector	el1_fiq_invalid
+	invalid_vector	el1_error_invalid
+
+/* el2 vectors - switch el2 here while we restore the memory image. */
+	.align 11
+ENTRY(hibernate_el2_vectors)
+	ventry	el2_sync_invalid		// Synchronous EL2t
+	ventry	el2_irq_invalid			// IRQ EL2t
+	ventry	el2_fiq_invalid			// FIQ EL2t
+	ventry	el2_error_invalid		// Error EL2t
+
+	ventry	el2_sync_invalid		// Synchronous EL2h
+	ventry	el2_irq_invalid			// IRQ EL2h
+	ventry	el2_fiq_invalid			// FIQ EL2h
+	ventry	el2_error_invalid		// Error EL2h
+
+	ventry	el1_sync			// Synchronous 64-bit EL1
+	ventry	el1_irq_invalid			// IRQ 64-bit EL1
+	ventry	el1_fiq_invalid			// FIQ 64-bit EL1
+	ventry	el1_error_invalid		// Error 64-bit EL1
+
+	ventry	el1_sync_invalid		// Synchronous 32-bit EL1
+	ventry	el1_irq_invalid			// IRQ 32-bit EL1
+	ventry	el1_fiq_invalid			// FIQ 32-bit EL1
+	ventry	el1_error_invalid		// Error 32-bit EL1
+END(hibernate_el2_vectors)
+
+.popsection