From 8a128bc32aba2a19feadc4973b3590db66440e4f Mon Sep 17 00:00:00 2001
From: Colin Ian King <colin.king@canonical.com>
Date: Thu, 17 Dec 2020 17:24:27 +0000
Subject: [PATCH 01/14] xtensa: fix spelling mistake in Kconfig "wont" ->
 "won't"

There is a spelling mistake in the Kconfig help text. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Message-Id: <20201217172427.58009-1-colin.king@canonical.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 9ad6b7b82707..a99dc39f6964 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -466,7 +466,7 @@ config INITIALIZE_XTENSA_MMU_INSIDE_VMLINUX
 	  then enter your normal kernel breakpoints once the MMU was mapped
 	  to the kernel mappings (0XC0000000).
 
-	  This unfortunately won't work for U-Boot and likely also wont
+	  This unfortunately won't work for U-Boot and likely also won't
 	  work for using KEXEC to have a hot kernel ready for doing a
 	  KDUMP.
 

From 9aa44cd2c24e302df5da49193a7cc233a0f7ddf8 Mon Sep 17 00:00:00 2001
From: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Date: Wed, 10 Mar 2021 15:10:38 +0800
Subject: [PATCH 02/14] xtensa: fix warning comparing pointer to 0

Fix the following coccicheck warning:

./arch/xtensa/kernel/pci.c:79:17-18: WARNING comparing pointer to 0.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Message-Id: <1615360238-22508-1-git-send-email-jiapeng.chong@linux.alibaba.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/kernel/pci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/kernel/pci.c b/arch/xtensa/kernel/pci.c
index 3f32e275997a..62c900e400d6 100644
--- a/arch/xtensa/kernel/pci.c
+++ b/arch/xtensa/kernel/pci.c
@@ -76,7 +76,7 @@ int pci_iobar_pfn(struct pci_dev *pdev, int bar, struct vm_area_struct *vma)
 	struct pci_controller *pci_ctrl = (struct pci_controller*) pdev->sysdata;
 	resource_size_t ioaddr = pci_resource_start(pdev, bar);
 
-	if (pci_ctrl == 0)
+	if (!pci_ctrl)
 		return -EINVAL;		/* should never happen */
 
 	/* Convert to an offset within this PCI controller */

From c425c546c0f149560c778595c1a20a88a444711f Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 13 Mar 2021 21:23:41 +0900
Subject: [PATCH 03/14] xtensa: move CONFIG_CPU_*_ENDIAN defines to Kconfig

Move the definition of CONFIG_CPU_*_ENDIAN to Kconfig, the best place
for CONFIG options.

I slightly simplified the test code. You can use the -P option to suppress
linemarker generation. The grep command is unneeded.

  $ echo __XTENSA_EB__ | xtensa-linux-gcc -E -
  # 1 "<stdin>"
  # 1 "<built-in>"
  # 1 "<command-line>"
  # 1 "<stdin>"
  1

  $ echo __XTENSA_EB__ | xtensa-linux-gcc -E -P -
  1

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210313122342.69995-1-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig                    | 6 ++++++
 arch/xtensa/Makefile                   | 9 +--------
 arch/xtensa/boot/Makefile              | 4 ----
 arch/xtensa/boot/boot-elf/Makefile     | 6 +-----
 arch/xtensa/boot/boot-redboot/Makefile | 6 +-----
 5 files changed, 9 insertions(+), 22 deletions(-)

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index a99dc39f6964..d637b396f81c 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -84,6 +84,12 @@ config KASAN_SHADOW_OFFSET
 	hex
 	default 0x6e400000
 
+config CPU_BIG_ENDIAN
+	def_bool $(success,test "$(shell,echo __XTENSA_EB__ | $(CC) -E -P -)" = 1)
+
+config CPU_LITTLE_ENDIAN
+	def_bool !CPU_BIG_ENDIAN
+
 menu "Processor type and features"
 
 choice
diff --git a/arch/xtensa/Makefile b/arch/xtensa/Makefile
index cf0940708702..ba9fee75e675 100644
--- a/arch/xtensa/Makefile
+++ b/arch/xtensa/Makefile
@@ -52,14 +52,7 @@ ifneq ($(CONFIG_LD_NO_RELAX),)
 KBUILD_LDFLAGS := --no-relax
 endif
 
-ifeq ($(shell echo __XTENSA_EB__ | $(CC) -E - | grep -v "\#"),1)
-CHECKFLAGS += -D__XTENSA_EB__
-KBUILD_CPPFLAGS += -DCONFIG_CPU_BIG_ENDIAN
-endif
-ifeq ($(shell echo __XTENSA_EL__ | $(CC) -E - | grep -v "\#"),1)
-CHECKFLAGS += -D__XTENSA_EL__
-KBUILD_CPPFLAGS += -DCONFIG_CPU_LITTLE_ENDIAN
-endif
+CHECKFLAGS += -D$(if $(CONFIG_CPU_BIG_ENDIAN),__XTENSA_EB__,__XTENSA_EL__)
 
 vardirs := $(patsubst %,arch/xtensa/variants/%/,$(variant-y))
 plfdirs := $(patsubst %,arch/xtensa/platforms/%/,$(platform-y))
diff --git a/arch/xtensa/boot/Makefile b/arch/xtensa/boot/Makefile
index f6bb352f94b4..a65b7a9ebff2 100644
--- a/arch/xtensa/boot/Makefile
+++ b/arch/xtensa/boot/Makefile
@@ -12,10 +12,6 @@
 KBUILD_CFLAGS	+= -fno-builtin -Iarch/$(ARCH)/boot/include
 HOSTFLAGS	+= -Iarch/$(ARCH)/boot/include
 
-BIG_ENDIAN	:= $(shell echo __XTENSA_EB__ | $(CC) -E - | grep -v "\#")
-
-export BIG_ENDIAN
-
 subdir-y	:= lib
 targets		+= vmlinux.bin vmlinux.bin.gz
 targets		+= uImage xipImage
diff --git a/arch/xtensa/boot/boot-elf/Makefile b/arch/xtensa/boot/boot-elf/Makefile
index f7c775d53012..47b9063f2c5d 100644
--- a/arch/xtensa/boot/boot-elf/Makefile
+++ b/arch/xtensa/boot/boot-elf/Makefile
@@ -4,11 +4,7 @@
 # for more details.
 #
 
-ifeq ($(BIG_ENDIAN),1)
-OBJCOPY_ARGS    := -O elf32-xtensa-be
-else
-OBJCOPY_ARGS    := -O elf32-xtensa-le
-endif
+OBJCOPY_ARGS := -O $(if $(CONFIG_CPU_BIG_ENDIAN),elf32-xtensa-be,elf32-xtensa-le)
 
 export OBJCOPY_ARGS
 export CPPFLAGS_boot.lds += -P -C
diff --git a/arch/xtensa/boot/boot-redboot/Makefile b/arch/xtensa/boot/boot-redboot/Makefile
index 07cb24afedc2..1d1d46215b1c 100644
--- a/arch/xtensa/boot/boot-redboot/Makefile
+++ b/arch/xtensa/boot/boot-redboot/Makefile
@@ -4,11 +4,7 @@
 # for more details.
 #
 
-ifeq ($(BIG_ENDIAN),1)
-OBJCOPY_ARGS 	:= -O elf32-xtensa-be
-else
-OBJCOPY_ARGS 	:= -O elf32-xtensa-le
-endif
+OBJCOPY_ARGS := -O $(if $(CONFIG_CPU_BIG_ENDIAN),elf32-xtensa-be,elf32-xtensa-le)
 
 LD_ARGS	= -T $(srctree)/$(obj)/boot.ld
 

From 7b6657843c6a227da08af8a8e94c3519bc0ae582 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 13 Mar 2021 21:23:42 +0900
Subject: [PATCH 04/14] xtensa: remove unneeded export in boot-elf/Makefile

No one uses these as environment variables.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210313122342.69995-2-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/boot/boot-elf/Makefile | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/arch/xtensa/boot/boot-elf/Makefile b/arch/xtensa/boot/boot-elf/Makefile
index 47b9063f2c5d..faec2002923b 100644
--- a/arch/xtensa/boot/boot-elf/Makefile
+++ b/arch/xtensa/boot/boot-elf/Makefile
@@ -6,9 +6,8 @@
 
 OBJCOPY_ARGS := -O $(if $(CONFIG_CPU_BIG_ENDIAN),elf32-xtensa-be,elf32-xtensa-le)
 
-export OBJCOPY_ARGS
-export CPPFLAGS_boot.lds += -P -C
-export KBUILD_AFLAGS += -mtext-section-literals
+CPPFLAGS_boot.lds += -P -C
+KBUILD_AFLAGS += -mtext-section-literals
 
 boot-y		:= bootstrap.o
 targets		+= $(boot-y) boot.lds

From 8d949ae25bd0c18038c51e291cb4053dff5f0297 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 2 Mar 2021 00:36:54 +0900
Subject: [PATCH 05/14] xtensa: stop filling syscall array with sys_ni_syscall

arch/xtensa/kernel/syscalls/syscalltbl.sh fills missing syscall numbers
with sys_ni_syscall.

So, the generated arch/xtensa/include/generated/asm/syscall_table.h
has no hole.

Hence, the line:

  [0 ... __NR_syscalls - 1] = (syscall_t)&sys_ni_syscall,

is meaningless.

The number of generated __SYSCALL() macros is the same as __NR_syscalls
(this is 442 as of v5.11).

Hence, the array size, [__NR_syscalls] is unneeded.

The designated initializer, '[nr] =', is also unneeded.

This file does not need to know __NR_syscalls. Drop the unneeded
<asm/unistd.h> include directive.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210301153656.363839-1-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/kernel/syscall.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 2c415fce6801..26fa09ce4d17 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -17,7 +17,6 @@
  */
 #include <linux/uaccess.h>
 #include <asm/syscall.h>
-#include <asm/unistd.h>
 #include <linux/linkage.h>
 #include <linux/stringify.h>
 #include <linux/errno.h>
@@ -28,10 +27,8 @@
 #include <linux/sched/mm.h>
 #include <linux/shm.h>
 
-syscall_t sys_call_table[__NR_syscalls] /* FIXME __cacheline_aligned */= {
-	[0 ... __NR_syscalls - 1] = (syscall_t)&sys_ni_syscall,
-
-#define __SYSCALL(nr, entry, nargs)[nr] = (syscall_t)entry,
+syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
+#define __SYSCALL(nr, entry, nargs)	(syscall_t)entry,
 #include <asm/syscall_table.h>
 #undef __SYSCALL
 };

From daf2618002356ee1bd2bd0231e251b3a1bffbb8f Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 2 Mar 2021 00:36:55 +0900
Subject: [PATCH 06/14] xtensa: syscalls: switch to generic syscalltbl.sh

Many architectures duplicate similar shell scripts.

This commit converts xtensa to use scripts/syscalltbl.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210301153656.363839-2-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/kernel/syscall.c              |  3 +--
 arch/xtensa/kernel/syscalls/Makefile      |  7 ++---
 arch/xtensa/kernel/syscalls/syscalltbl.sh | 32 -----------------------
 3 files changed, 3 insertions(+), 39 deletions(-)
 delete mode 100644 arch/xtensa/kernel/syscalls/syscalltbl.sh

diff --git a/arch/xtensa/kernel/syscall.c b/arch/xtensa/kernel/syscall.c
index 26fa09ce4d17..201356faa7e6 100644
--- a/arch/xtensa/kernel/syscall.c
+++ b/arch/xtensa/kernel/syscall.c
@@ -28,9 +28,8 @@
 #include <linux/shm.h>
 
 syscall_t sys_call_table[] /* FIXME __cacheline_aligned */= {
-#define __SYSCALL(nr, entry, nargs)	(syscall_t)entry,
+#define __SYSCALL(nr, entry)	(syscall_t)entry,
 #include <asm/syscall_table.h>
-#undef __SYSCALL
 };
 
 #define COLOUR_ALIGN(addr, pgoff) \
diff --git a/arch/xtensa/kernel/syscalls/Makefile b/arch/xtensa/kernel/syscalls/Makefile
index 285aaba832d9..ad2492cb5568 100644
--- a/arch/xtensa/kernel/syscalls/Makefile
+++ b/arch/xtensa/kernel/syscalls/Makefile
@@ -7,7 +7,7 @@ _dummy := $(shell [ -d '$(uapi)' ] || mkdir -p '$(uapi)')	\
 
 syscall := $(src)/syscall.tbl
 syshdr := $(srctree)/$(src)/syscallhdr.sh
-systbl := $(srctree)/$(src)/syscalltbl.sh
+systbl := $(srctree)/scripts/syscalltbl.sh
 
 quiet_cmd_syshdr = SYSHDR  $@
       cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@'	\
@@ -16,10 +16,7 @@ quiet_cmd_syshdr = SYSHDR  $@
 		   '$(syshdr_offset_$(basetarget))'
 
 quiet_cmd_systbl = SYSTBL  $@
-      cmd_systbl = $(CONFIG_SHELL) '$(systbl)' '$<' '$@'	\
-		   '$(systbl_abis_$(basetarget))'		\
-		   '$(systbl_abi_$(basetarget))'		\
-		   '$(systbl_offset_$(basetarget))'
+      cmd_systbl = $(CONFIG_SHELL) $(systbl) $< $@
 
 $(uapi)/unistd_32.h: $(syscall) $(syshdr) FORCE
 	$(call if_changed,syshdr)
diff --git a/arch/xtensa/kernel/syscalls/syscalltbl.sh b/arch/xtensa/kernel/syscalls/syscalltbl.sh
deleted file mode 100644
index 85d78d9309ad..000000000000
--- a/arch/xtensa/kernel/syscalls/syscalltbl.sh
+++ /dev/null
@@ -1,32 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-in="$1"
-out="$2"
-my_abis=`echo "($3)" | tr ',' '|'`
-my_abi="$4"
-offset="$5"
-
-emit() {
-	t_nxt="$1"
-	t_nr="$2"
-	t_entry="$3"
-
-	while [ $t_nxt -lt $t_nr ]; do
-		printf "__SYSCALL(%s, sys_ni_syscall, )\n" "${t_nxt}"
-		t_nxt=$((t_nxt+1))
-	done
-	printf "__SYSCALL(%s, %s, )\n" "${t_nxt}" "${t_entry}"
-}
-
-grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
-	nxt=0
-	if [ -z "$offset" ]; then
-		offset=0
-	fi
-
-	while read nr abi name entry ; do
-		emit $((nxt+offset)) $((nr+offset)) $entry
-		nxt=$((nr+1))
-	done
-) > "$out"

From 2da7559452504f8f8d9950708f293b636e483b21 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 2 Mar 2021 00:36:56 +0900
Subject: [PATCH 07/14] xtensa: syscalls: switch to generic syscallhdr.sh

Many architectures duplicate similar shell scripts.

This commit converts xtensa to use scripts/syscallhdr.sh.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Message-Id: <20210301153656.363839-3-masahiroy@kernel.org>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/kernel/syscalls/Makefile      |  7 ++---
 arch/xtensa/kernel/syscalls/syscallhdr.sh | 36 -----------------------
 2 files changed, 2 insertions(+), 41 deletions(-)
 delete mode 100644 arch/xtensa/kernel/syscalls/syscallhdr.sh

diff --git a/arch/xtensa/kernel/syscalls/Makefile b/arch/xtensa/kernel/syscalls/Makefile
index ad2492cb5568..6713c65a25e1 100644
--- a/arch/xtensa/kernel/syscalls/Makefile
+++ b/arch/xtensa/kernel/syscalls/Makefile
@@ -6,14 +6,11 @@ _dummy := $(shell [ -d '$(uapi)' ] || mkdir -p '$(uapi)')	\
 	  $(shell [ -d '$(kapi)' ] || mkdir -p '$(kapi)')
 
 syscall := $(src)/syscall.tbl
-syshdr := $(srctree)/$(src)/syscallhdr.sh
+syshdr := $(srctree)/scripts/syscallhdr.sh
 systbl := $(srctree)/scripts/syscalltbl.sh
 
 quiet_cmd_syshdr = SYSHDR  $@
-      cmd_syshdr = $(CONFIG_SHELL) '$(syshdr)' '$<' '$@'	\
-		   '$(syshdr_abis_$(basetarget))'		\
-		   '$(syshdr_pfx_$(basetarget))'		\
-		   '$(syshdr_offset_$(basetarget))'
+      cmd_syshdr = $(CONFIG_SHELL) $(syshdr) --emit-nr $< $@
 
 quiet_cmd_systbl = SYSTBL  $@
       cmd_systbl = $(CONFIG_SHELL) $(systbl) $< $@
diff --git a/arch/xtensa/kernel/syscalls/syscallhdr.sh b/arch/xtensa/kernel/syscalls/syscallhdr.sh
deleted file mode 100644
index eebfb8a8ace6..000000000000
--- a/arch/xtensa/kernel/syscalls/syscallhdr.sh
+++ /dev/null
@@ -1,36 +0,0 @@
-#!/bin/sh
-# SPDX-License-Identifier: GPL-2.0
-
-in="$1"
-out="$2"
-my_abis=`echo "($3)" | tr ',' '|'`
-prefix="$4"
-offset="$5"
-
-fileguard=_UAPI_ASM_XTENSA_`basename "$out" | sed \
-	-e 'y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/' \
-	-e 's/[^A-Z0-9_]/_/g' -e 's/__/_/g'`
-grep -E "^[0-9A-Fa-fXx]+[[:space:]]+${my_abis}" "$in" | sort -n | (
-	printf "#ifndef %s\n" "${fileguard}"
-	printf "#define %s\n" "${fileguard}"
-	printf "\n"
-
-	nxt=0
-	while read nr abi name entry ; do
-		if [ -z "$offset" ]; then
-			printf "#define __NR_%s%s\t%s\n" \
-				"${prefix}" "${name}" "${nr}"
-		else
-			printf "#define __NR_%s%s\t(%s + %s)\n" \
-				"${prefix}" "${name}" "${offset}" "${nr}"
-		fi
-		nxt=$((nr+1))
-	done
-
-	printf "\n"
-	printf "#ifdef __KERNEL__\n"
-	printf "#define __NR_syscalls\t%s\n" "${nxt}"
-	printf "#endif\n"
-	printf "\n"
-	printf "#endif /* %s */\n" "${fileguard}"
-) > "$out"

From 4f22ca7e192ee313a83f8093ba5b5b2ca72d10e4 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Tue, 16 Feb 2021 22:39:41 -0800
Subject: [PATCH 08/14] xtensa: simplify coherent_kvaddr logic

Functions coherent_kvaddr, clear_page_alias and copy_page_alias use
physical address 0 as a special value that means 'this page is in the
KSEG mapping and its existing virtual address has the same color as the
virtual address of its future mapping, so don't map it to the
TLBTEMP_BASE area'.

Simplify this logic and drop special handling of low memory pages/pages
with coherent mapping and always use TLBTEMP_BASE area.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/mm/cache.c |  9 ++-------
 arch/xtensa/mm/misc.S  | 36 +++++-------------------------------
 2 files changed, 7 insertions(+), 38 deletions(-)

diff --git a/arch/xtensa/mm/cache.c b/arch/xtensa/mm/cache.c
index 085b8c77b9d9..19e5a478a7e8 100644
--- a/arch/xtensa/mm/cache.c
+++ b/arch/xtensa/mm/cache.c
@@ -81,13 +81,8 @@ static inline void kmap_invalidate_coherent(struct page *page,
 static inline void *coherent_kvaddr(struct page *page, unsigned long base,
 				    unsigned long vaddr, unsigned long *paddr)
 {
-	if (PageHighMem(page) || !DCACHE_ALIAS_EQ(page_to_phys(page), vaddr)) {
-		*paddr = page_to_phys(page);
-		return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
-	} else {
-		*paddr = 0;
-		return page_to_virt(page);
-	}
+	*paddr = page_to_phys(page);
+	return (void *)(base + (vaddr & DCACHE_ALIAS_MASK));
 }
 
 void clear_user_highpage(struct page *page, unsigned long vaddr)
diff --git a/arch/xtensa/mm/misc.S b/arch/xtensa/mm/misc.S
index 25cd67debee6..0527bf6e3211 100644
--- a/arch/xtensa/mm/misc.S
+++ b/arch/xtensa/mm/misc.S
@@ -118,20 +118,13 @@ ENTRY(clear_page_alias)
 
 	abi_entry_default
 
-	/* Skip setting up a temporary DTLB if not aliased low page. */
-
 	movi	a5, PAGE_OFFSET
-	movi	a6, 0
-	beqz	a3, 1f
-
-	/* Setup a temporary DTLB for the addr. */
-
 	addi	a6, a3, (PAGE_KERNEL | _PAGE_HW_WRITE)
 	mov	a4, a2
 	wdtlb	a6, a2
 	dsync
 
-1:	movi	a3, 0
+	movi	a3, 0
 	__loopi	a2, a7, PAGE_SIZE, 32
 	s32i	a3, a2, 0
 	s32i	a3, a2, 4
@@ -143,12 +136,9 @@ ENTRY(clear_page_alias)
 	s32i	a3, a2, 28
 	__endla	a2, a7, 32
 
-	bnez	a6, 1f
-	abi_ret_default
+	/* We need to invalidate the temporary dtlb entry. */
 
-	/* We need to invalidate the temporary idtlb entry, if any. */
-
-1:	idtlb	a4
+	idtlb	a4
 	dsync
 
 	abi_ret_default
@@ -166,22 +156,12 @@ ENTRY(copy_page_alias)
 
 	abi_entry_default
 
-	/* Skip setting up a temporary DTLB for destination if not aliased. */
-
-	movi	a6, 0
-	movi	a7, 0
-	beqz	a4, 1f
-
 	/* Setup a temporary DTLB for destination. */
 
 	addi	a6, a4, (PAGE_KERNEL | _PAGE_HW_WRITE)
 	wdtlb	a6, a2
 	dsync
 
-	/* Skip setting up a temporary DTLB for source if not aliased. */
-
-1:	beqz	a5, 1f
-
 	/* Setup a temporary DTLB for source. */
 
 	addi	a7, a5, PAGE_KERNEL
@@ -219,17 +199,11 @@ ENTRY(copy_page_alias)
 
 	/* We need to invalidate any temporary mapping! */
 
-	bnez	a6, 1f
-	bnez	a7, 2f
-	abi_ret_default
-
-1:	addi	a2, a2, -PAGE_SIZE
+	addi	a2, a2, -PAGE_SIZE
 	idtlb	a2
 	dsync
-	bnez	a7, 2f
-	abi_ret_default
 
-2:	addi	a3, a3, -PAGE_SIZE+1
+	addi	a3, a3, -PAGE_SIZE+1
 	idtlb	a3
 	dsync
 

From d4ff983e323870478f04054c1ba817b481eb1f19 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Wed, 17 Feb 2021 01:36:57 -0800
Subject: [PATCH 09/14] xtensa: fix pgprot_noncached assumptions

pgprot_noncached assumes that cache bypass attribute is represented as
zero. This may not always be true. Fix pgprot_noncached definition by
adding _PAGE_CA_BYPASS to the result.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/include/asm/pgtable.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
index 4dc04e6c01d7..d7fc45c920c2 100644
--- a/arch/xtensa/include/asm/pgtable.h
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -280,7 +280,9 @@ static inline pte_t pte_mkyoung(pte_t pte)
 static inline pte_t pte_mkwrite(pte_t pte)
 	{ pte_val(pte) |= _PAGE_WRITABLE; return pte; }
 
-#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) & ~_PAGE_CA_MASK))
+#define pgprot_noncached(prot) \
+		((__pgprot((pgprot_val(prot) & ~_PAGE_CA_MASK) | \
+			   _PAGE_CA_BYPASS)))
 
 /*
  * Conversion functions: convert a page and protection to a page entry,

From f96c4ad6107ec3652c258864d4a2412aca51c923 Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Sun, 14 Mar 2021 20:33:27 -0700
Subject: [PATCH 10/14] xtensa: drop extraneous register load from
 initialize_mmu

Commit a9f2fc628e3a ("xtensa: cleanup MMU setup and kernel layout macros")
removed the use of a2 in the beginning of the initialize_mmu macro, but
left the register load that is no longer used. Remove it as well.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/include/asm/initialize_mmu.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/include/asm/initialize_mmu.h b/arch/xtensa/include/asm/initialize_mmu.h
index 05cb13dfe6f4..9793b49fc641 100644
--- a/arch/xtensa/include/asm/initialize_mmu.h
+++ b/arch/xtensa/include/asm/initialize_mmu.h
@@ -73,7 +73,7 @@
 	_j	2f
 
 	.align	4
-1:	movi	a2, 0x10000000
+1:
 
 #if CONFIG_KERNEL_LOAD_ADDRESS < 0x40000000ul
 #define TEMP_MAPPING_VADDR 0x40000000

From e1532777cae340517f64d13a83138f6b8ad9f8b9 Mon Sep 17 00:00:00 2001
From: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Date: Thu, 25 Mar 2021 09:38:32 +0530
Subject: [PATCH 11/14] xtensa: Couple of typo fixes

s/contans/contains/
s/desination/destination/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Message-Id: <20210325040832.26018-1-unixbhaskar@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/kernel/head.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/xtensa/kernel/head.S b/arch/xtensa/kernel/head.S
index e0c1fac0910f..b9b81e76beea 100644
--- a/arch/xtensa/kernel/head.S
+++ b/arch/xtensa/kernel/head.S
@@ -212,7 +212,7 @@ ENTRY(_startup)
 	 *
 	 * The linker script used to build the Linux kernel image
 	 * creates a table located at __boot_reloc_table_start
-	 * that contans the information what data needs to be unpacked.
+	 * that contains the information what data needs to be unpacked.
 	 *
 	 * Uses a2-a7.
 	 */
@@ -222,7 +222,7 @@ ENTRY(_startup)
 
 1:	beq	a2, a3, 3f	# no more entries?
 	l32i	a4, a2, 0	# start destination (in RAM)
-	l32i	a5, a2, 4	# end desination (in RAM)
+	l32i	a5, a2, 4	# end destination (in RAM)
 	l32i	a6, a2, 8	# start source (in ROM)
 	addi	a2, a2, 12	# next entry
 	beq	a4, a5, 1b	# skip, empty entry

From 4671076c4d37a377be3863ba88f62083f1fe3281 Mon Sep 17 00:00:00 2001
From: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Date: Fri, 26 Mar 2021 06:57:39 +0530
Subject: [PATCH 12/14] xtensa: simcall.h: Change compitible to compatible

s/compitible/compatible/

Signed-off-by: Bhaskar Chowdhury <unixbhaskar@gmail.com>
Message-Id: <20210326012739.18038-1-unixbhaskar@gmail.com>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/platforms/iss/include/platform/simcall.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/xtensa/platforms/iss/include/platform/simcall.h b/arch/xtensa/platforms/iss/include/platform/simcall.h
index f42870ab551b..5ba2454e6c37 100644
--- a/arch/xtensa/platforms/iss/include/platform/simcall.h
+++ b/arch/xtensa/platforms/iss/include/platform/simcall.h
@@ -46,7 +46,7 @@
 #define SYS_socket      26
 #define SYS_sendto      27
 #define SYS_recvfrom    28
-#define SYS_select_one  29      /* not compitible select, one file descriptor at the time */
+#define SYS_select_one  29      /* not compatible select, one file descriptor at the time */
 #define SYS_bind        30
 #define SYS_ioctl	31
 

From 54467c126b19230f4d722b67ed7ae5807ed8f5ce Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Thu, 18 Feb 2021 09:12:28 -0800
Subject: [PATCH 13/14] xtensa: ISS: split simcall implementation from
 semihosting interface

Disconnect existing ISS simcall implementation from the semihosting
interface to allow for alternative implementations selectable at
configure time.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 .../iss/include/platform/simcall-iss.h        | 73 +++++++++++++++++++
 .../platforms/iss/include/platform/simcall.h  | 70 +-----------------
 2 files changed, 75 insertions(+), 68 deletions(-)
 create mode 100644 arch/xtensa/platforms/iss/include/platform/simcall-iss.h

diff --git a/arch/xtensa/platforms/iss/include/platform/simcall-iss.h b/arch/xtensa/platforms/iss/include/platform/simcall-iss.h
new file mode 100644
index 000000000000..5a1e7a1f182e
--- /dev/null
+++ b/arch/xtensa/platforms/iss/include/platform/simcall-iss.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Cadence Design Systems Inc. */
+
+#ifndef _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H
+#define _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H
+
+/*
+ *  System call like services offered by the simulator host.
+ */
+
+#define SYS_nop		0	/* unused */
+#define SYS_exit	1	/*x*/
+#define SYS_fork	2
+#define SYS_read	3	/*x*/
+#define SYS_write	4	/*x*/
+#define SYS_open	5	/*x*/
+#define SYS_close	6	/*x*/
+#define SYS_rename	7	/*x 38 - waitpid */
+#define SYS_creat	8	/*x*/
+#define SYS_link	9	/*x (not implemented on WIN32) */
+#define SYS_unlink	10	/*x*/
+#define SYS_execv	11	/* n/a - execve */
+#define SYS_execve	12	/* 11 - chdir */
+#define SYS_pipe	13	/* 42 - time */
+#define SYS_stat	14	/* 106 - mknod */
+#define SYS_chmod	15
+#define SYS_chown	16	/* 202 - lchown */
+#define SYS_utime	17	/* 30 - break */
+#define SYS_wait	18	/* n/a - oldstat */
+#define SYS_lseek	19	/*x*/
+#define SYS_getpid	20
+#define SYS_isatty	21	/* n/a - mount */
+#define SYS_fstat	22	/* 108 - oldumount */
+#define SYS_time	23	/* 13 - setuid */
+#define SYS_gettimeofday 24	/*x 78 - getuid (not implemented on WIN32) */
+#define SYS_times	25	/*X 43 - stime (Xtensa-specific implementation) */
+#define SYS_socket      26
+#define SYS_sendto      27
+#define SYS_recvfrom    28
+#define SYS_select_one  29      /* not compatible select, one file descriptor at the time */
+#define SYS_bind        30
+#define SYS_ioctl	31
+
+#define SYS_iss_argc	1000	/* returns value of argc */
+#define SYS_iss_argv_size 1001	/* bytes needed for argv & arg strings */
+#define SYS_iss_set_argv 1002	/* saves argv & arg strings at given addr */
+
+/*
+ * SYS_select_one specifiers
+ */
+
+#define  XTISS_SELECT_ONE_READ    1
+#define  XTISS_SELECT_ONE_WRITE   2
+#define  XTISS_SELECT_ONE_EXCEPT  3
+
+static int errno;
+
+static inline int __simc(int a, int b, int c, int d)
+{
+	register int a1 asm("a2") = a;
+	register int b1 asm("a3") = b;
+	register int c1 asm("a4") = c;
+	register int d1 asm("a5") = d;
+	__asm__ __volatile__ (
+			"simcall\n"
+			: "+r"(a1), "+r"(b1)
+			: "r"(c1), "r"(d1)
+			: "memory");
+	errno = b1;
+	return a1;
+}
+
+#endif /* _XTENSA_PLATFORM_ISS_SIMCALL_ISS_H */
diff --git a/arch/xtensa/platforms/iss/include/platform/simcall.h b/arch/xtensa/platforms/iss/include/platform/simcall.h
index 5ba2454e6c37..612080bf0b3d 100644
--- a/arch/xtensa/platforms/iss/include/platform/simcall.h
+++ b/arch/xtensa/platforms/iss/include/platform/simcall.h
@@ -6,78 +6,13 @@
  * for more details.
  *
  * Copyright (C) 2001 Tensilica Inc.
- * Copyright (C) 2017 Cadence Design Systems Inc.
+ * Copyright (C) 2017 - 2021 Cadence Design Systems Inc.
  */
 
 #ifndef _XTENSA_PLATFORM_ISS_SIMCALL_H
 #define _XTENSA_PLATFORM_ISS_SIMCALL_H
 
-
-/*
- *  System call like services offered by the simulator host.
- */
-
-#define SYS_nop		0	/* unused */
-#define SYS_exit	1	/*x*/
-#define SYS_fork	2
-#define SYS_read	3	/*x*/
-#define SYS_write	4	/*x*/
-#define SYS_open	5	/*x*/
-#define SYS_close	6	/*x*/
-#define SYS_rename	7	/*x 38 - waitpid */
-#define SYS_creat	8	/*x*/
-#define SYS_link	9	/*x (not implemented on WIN32) */
-#define SYS_unlink	10	/*x*/
-#define SYS_execv	11	/* n/a - execve */
-#define SYS_execve	12	/* 11 - chdir */
-#define SYS_pipe	13	/* 42 - time */
-#define SYS_stat	14	/* 106 - mknod */
-#define SYS_chmod	15
-#define SYS_chown	16	/* 202 - lchown */
-#define SYS_utime	17	/* 30 - break */
-#define SYS_wait	18	/* n/a - oldstat */
-#define SYS_lseek	19	/*x*/
-#define SYS_getpid	20
-#define SYS_isatty	21	/* n/a - mount */
-#define SYS_fstat	22	/* 108 - oldumount */
-#define SYS_time	23	/* 13 - setuid */
-#define SYS_gettimeofday 24	/*x 78 - getuid (not implemented on WIN32) */
-#define SYS_times	25	/*X 43 - stime (Xtensa-specific implementation) */
-#define SYS_socket      26
-#define SYS_sendto      27
-#define SYS_recvfrom    28
-#define SYS_select_one  29      /* not compatible select, one file descriptor at the time */
-#define SYS_bind        30
-#define SYS_ioctl	31
-
-#define SYS_iss_argc	1000	/* returns value of argc */
-#define SYS_iss_argv_size 1001	/* bytes needed for argv & arg strings */
-#define SYS_iss_set_argv 1002	/* saves argv & arg strings at given addr */
-
-/*
- * SYS_select_one specifiers
- */
-
-#define  XTISS_SELECT_ONE_READ    1
-#define  XTISS_SELECT_ONE_WRITE   2
-#define  XTISS_SELECT_ONE_EXCEPT  3
-
-static int errno;
-
-static inline int __simc(int a, int b, int c, int d)
-{
-	register int a1 asm("a2") = a;
-	register int b1 asm("a3") = b;
-	register int c1 asm("a4") = c;
-	register int d1 asm("a5") = d;
-	__asm__ __volatile__ (
-			"simcall\n"
-			: "+r"(a1), "+r"(b1)
-			: "r"(c1), "r"(d1)
-			: "memory");
-	errno = b1;
-	return a1;
-}
+#include <platform/simcall-iss.h>
 
 static inline int simc_exit(int exit_code)
 {
@@ -137,4 +72,3 @@ static inline void simc_argv(void *buf)
 }
 
 #endif /* _XTENSA_PLATFORM_ISS_SIMCALL_H */
-

From 6a8eb99e130f3f7658de2776934374fe1c41279e Mon Sep 17 00:00:00 2001
From: Max Filippov <jcmvbkbc@gmail.com>
Date: Thu, 18 Feb 2021 10:18:00 -0800
Subject: [PATCH 14/14] xtensa: ISS: add GDBIO implementation to semihosting
 interface

Add GDBIO implementation for the xtensa semihosting interface. It offers
less functions than the simcall interface, so make some semihosting
functions optional and return error when implementation is not
available.
Add Kconfig menu to select semihosting implementation and add simcall and
GDBIO choices there.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
---
 arch/xtensa/Kconfig                           | 22 ++++++++++++
 .../iss/include/platform/simcall-gdbio.h      | 34 ++++++++++++++++++
 .../platforms/iss/include/platform/simcall.h  | 36 +++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 arch/xtensa/platforms/iss/include/platform/simcall-gdbio.h

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index d637b396f81c..6ad4c1161518 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -393,6 +393,28 @@ config PARSE_BOOTPARAM
 
 	  If unsure, say Y.
 
+choice
+	prompt "Semihosting interface"
+	default XTENSA_SIMCALL_ISS
+	depends on XTENSA_PLATFORM_ISS
+	help
+	  Choose semihosting interface that will be used for serial port,
+	  block device and networking.
+
+config XTENSA_SIMCALL_ISS
+	bool "simcall"
+	help
+	  Use simcall instruction. simcall is only available on simulators,
+	  it does nothing on hardware.
+
+config XTENSA_SIMCALL_GDBIO
+	bool "GDBIO"
+	help
+	  Use break instruction. It is available on real hardware when GDB
+	  is attached to it via JTAG.
+
+endchoice
+
 config BLK_DEV_SIMDISK
 	tristate "Host file-based simulated block device support"
 	default n
diff --git a/arch/xtensa/platforms/iss/include/platform/simcall-gdbio.h b/arch/xtensa/platforms/iss/include/platform/simcall-gdbio.h
new file mode 100644
index 000000000000..e642860e25a8
--- /dev/null
+++ b/arch/xtensa/platforms/iss/include/platform/simcall-gdbio.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2021 Cadence Design Systems Inc. */
+
+#ifndef _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H
+#define _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H
+
+/*
+ *  System call like services offered by the GDBIO host.
+ */
+
+#define SYS_open	-2
+#define SYS_close	-3
+#define SYS_read	-4
+#define SYS_write	-5
+#define SYS_lseek	-6
+
+static int errno;
+
+static inline int __simc(int a, int b, int c, int d)
+{
+	register int a1 asm("a2") = a;
+	register int b1 asm("a6") = b;
+	register int c1 asm("a3") = c;
+	register int d1 asm("a4") = d;
+	__asm__ __volatile__ (
+			"break 1, 14\n"
+			: "+r"(a1), "+r"(c1)
+			: "r"(b1), "r"(d1)
+			: "memory");
+	errno = c1;
+	return a1;
+}
+
+#endif /* _XTENSA_PLATFORM_ISS_SIMCALL_GDBIO_H */
diff --git a/arch/xtensa/platforms/iss/include/platform/simcall.h b/arch/xtensa/platforms/iss/include/platform/simcall.h
index 612080bf0b3d..e1ec50ce39ee 100644
--- a/arch/xtensa/platforms/iss/include/platform/simcall.h
+++ b/arch/xtensa/platforms/iss/include/platform/simcall.h
@@ -12,11 +12,23 @@
 #ifndef _XTENSA_PLATFORM_ISS_SIMCALL_H
 #define _XTENSA_PLATFORM_ISS_SIMCALL_H
 
+#include <linux/bug.h>
+
+#ifdef CONFIG_XTENSA_SIMCALL_ISS
 #include <platform/simcall-iss.h>
+#endif
+#ifdef CONFIG_XTENSA_SIMCALL_GDBIO
+#include <platform/simcall-gdbio.h>
+#endif
 
 static inline int simc_exit(int exit_code)
 {
+#ifdef SYS_exit
 	return __simc(SYS_exit, exit_code, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
 }
 
 static inline int simc_open(const char *file, int flags, int mode)
@@ -31,7 +43,12 @@ static inline int simc_close(int fd)
 
 static inline int simc_ioctl(int fd, int request, void *arg)
 {
+#ifdef SYS_ioctl
 	return __simc(SYS_ioctl, fd, request, (int) arg);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
 }
 
 static inline int simc_read(int fd, void *buf, size_t count)
@@ -46,9 +63,14 @@ static inline int simc_write(int fd, const void *buf, size_t count)
 
 static inline int simc_poll(int fd)
 {
+#ifdef SYS_select_one
 	long timeval[2] = { 0, 0 };
 
 	return __simc(SYS_select_one, fd, XTISS_SELECT_ONE_READ, (int)&timeval);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return -1;
+#endif
 }
 
 static inline int simc_lseek(int fd, uint32_t off, int whence)
@@ -58,17 +80,31 @@ static inline int simc_lseek(int fd, uint32_t off, int whence)
 
 static inline int simc_argc(void)
 {
+#ifdef SYS_iss_argc
 	return __simc(SYS_iss_argc, 0, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return 0;
+#endif
 }
 
 static inline int simc_argv_size(void)
 {
+#ifdef SYS_iss_argv_size
 	return __simc(SYS_iss_argv_size, 0, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+	return 0;
+#endif
 }
 
 static inline void simc_argv(void *buf)
 {
+#ifdef SYS_iss_set_argv
 	__simc(SYS_iss_set_argv, (int)buf, 0, 0);
+#else
+	WARN_ONCE(1, "%s: not implemented\n", __func__);
+#endif
 }
 
 #endif /* _XTENSA_PLATFORM_ISS_SIMCALL_H */