Received-SPF: pass (google.com: domain of linux-kernel+bounces-119939-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Feedback-ID: ifd894703:Fastmail
From: Jiaxun Yang <jiaxun.yang@flygoat.com>
Date: Tue, 26 Mar 2024 20:35:40 +0000
Subject: [PATCH v2 8/9] MIPS: zboot: Convert to use debug_ll facilities
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset="utf-8"
Content-Transfer-Encoding: 7bit
Message-Id: <20240326-mips_debug_ll-v2-8-b64abc76f2a1@flygoat.com>
References: <20240326-mips_debug_ll-v2-0-b64abc76f2a1@flygoat.com>
In-Reply-To: <20240326-mips_debug_ll-v2-0-b64abc76f2a1@flygoat.com>
To: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: linux-mips@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Jiaxun Yang <jiaxun.yang@flygoat.com>

Since now debug_ll facilities can cover all platforms supported
by zboot debug print, and it provides extra capability on debugging
exceptions, switch zboot to use those facilities.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/Kconfig                        | 12 ++------
 arch/mips/Kconfig.debug                  | 46 +++++++++++++-----------------
 arch/mips/boot/compressed/Makefile       |  9 ++----
 arch/mips/boot/compressed/dbg.c          | 39 -------------------------
 arch/mips/boot/compressed/debug-vec.S    |  3 ++
 arch/mips/boot/compressed/debug.S        |  3 ++
 arch/mips/boot/compressed/decompress.h   |  8 +++---
 arch/mips/boot/compressed/head.S         |  6 ++++
 arch/mips/boot/compressed/uart-16550.c   | 49 --------------------------------
 arch/mips/boot/compressed/uart-alchemy.c |  9 ------
 arch/mips/boot/compressed/uart-ath79.c   |  2 --
 arch/mips/boot/compressed/uart-prom.c    |  9 ------
 12 files changed, 39 insertions(+), 156 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 06ef440d16ce..6729bf1d158d 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -240,7 +240,7 @@ config ATH79
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_MIPS16
-	select SYS_SUPPORTS_ZBOOT_UART_PROM
+	select SYS_SUPPORTS_ZBOOT
 	select USE_OF
 	select USB_EHCI_ROOT_HUB_TT if USB_EHCI_HCD_PLATFORM
 	help
@@ -422,7 +422,7 @@ config MACH_INGENIC_SOC
 	select MIPS_GENERIC
 	select MACH_INGENIC
 	select MACH_GENERIC_CORE
-	select SYS_SUPPORTS_ZBOOT_UART16550
+	select SYS_SUPPORTS_ZBOOT
 	select CPU_SUPPORTS_CPUFREQ
 	select MIPS_EXTERNAL_TIMER
 
@@ -1792,14 +1792,6 @@ config SYS_SUPPORTS_ZBOOT
 	select HAVE_KERNEL_XZ
 	select HAVE_KERNEL_ZSTD
 
-config SYS_SUPPORTS_ZBOOT_UART16550
-	bool
-	select SYS_SUPPORTS_ZBOOT
-
-config SYS_SUPPORTS_ZBOOT_UART_PROM
-	bool
-	select SYS_SUPPORTS_ZBOOT
-
 config CPU_LOONGSON2EF
 	bool
 	select CPU_SUPPORTS_32BIT_KERNEL
diff --git a/arch/mips/Kconfig.debug b/arch/mips/Kconfig.debug
index a6687c503c34..0ce6d24d05b3 100644
--- a/arch/mips/Kconfig.debug
+++ b/arch/mips/Kconfig.debug
@@ -79,33 +79,6 @@ config SB1XXX_CORELIS
 	  Select compile flags that produce code that can be processed by the
 	  Corelis mksym utility and UDB Emulator.
 
-config DEBUG_ZBOOT
-	bool "Enable compressed kernel support debugging"
-	depends on DEBUG_KERNEL && SYS_SUPPORTS_ZBOOT
-	default n
-	help
-	  If you want to add compressed kernel support to a new board, and the
-	  board supports uart16550 compatible serial port, please select
-	  SYS_SUPPORTS_ZBOOT_UART16550 for your board and enable this option to
-	  debug it.
-
-	  If your board doesn't support uart16550 compatible serial port, you
-	  can try to select SYS_SUPPORTS_ZBOOT and use the other methods to
-	  debug it. for example, add a new serial port support just as
-	  arch/mips/boot/compressed/uart-16550.c does.
-
-	  After the compressed kernel support works, please disable this option
-	  to reduce the kernel image size and speed up the booting procedure a
-	  little.
-
-config ZBOOT_INGENIC_UART
-	int "UART to use for compressed kernel debugging"
-	depends on DEBUG_ZBOOT && MACH_INGENIC_SOC
-	default 0
-	range 0 4
-	help
-	  Specify the UART that should be used for compressed kernel debugging.
-
 config SPINLOCK_TEST
 	bool "Enable spinlock timing tests in debugfs"
 	depends on DEBUG_FS
@@ -328,3 +301,22 @@ config DEBUG_UART_8250_WIDTH
 	int "Register width for the 8250 debug UART"
 	depends on DEBUG_LL_UART_8250 || DEBUG_UART_8250
 	default 1
+
+config DEBUG_ZBOOT
+	bool "Enable compressed kernel debugging via DEBUG_LL output"
+	depends on DEBUG_LL && SYS_SUPPORTS_ZBOOT
+	help
+	  Say Y here if you want to enable debugging of a compressed kernel
+	  via the DEBUG_LL output.  This is useful if you are debugging
+	  decompressor issues.
+
+	  If unsure, say N.
+
+config DEBUG_ZBOOT_EXCEPT
+	bool "Enable compressed kernel debugging of exceptions"
+	depends on DEBUG_ZBOOT
+	help
+	  Say Y here if you want to enable debugging of exceptions happen
+	  during decompression of a compressed kernel via the DEBUG_LL output.
+
+	  If unsure, say N.
diff --git a/arch/mips/boot/compressed/Makefile b/arch/mips/boot/compressed/Makefile
index 6cc28173bee8..78c65db8dd04 100644
--- a/arch/mips/boot/compressed/Makefile
+++ b/arch/mips/boot/compressed/Makefile
@@ -43,13 +43,8 @@ KCSAN_SANITIZE			:= n
 # decompressor objects (linked with vmlinuz)
 vmlinuzobjs-y := $(obj)/head.o $(obj)/decompress.o $(obj)/string.o $(obj)/bswapsi.o
 
-ifdef CONFIG_DEBUG_ZBOOT
-vmlinuzobjs-$(CONFIG_DEBUG_ZBOOT)		   += $(obj)/dbg.o
-vmlinuzobjs-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART16550) += $(obj)/uart-16550.o
-vmlinuzobjs-$(CONFIG_SYS_SUPPORTS_ZBOOT_UART_PROM) += $(obj)/uart-prom.o
-vmlinuzobjs-$(CONFIG_MIPS_ALCHEMY)		   += $(obj)/uart-alchemy.o
-vmlinuzobjs-$(CONFIG_ATH79)			   += $(obj)/uart-ath79.o
-endif
+vmlinuzobjs-$(CONFIG_DEBUG_ZBOOT)		+= $(obj)/debug.o
+vmlinuzobjs-$(CONFIG_DEBUG_ZBOOT_EXCEPT)	+= $(obj)/debug-vec.o
 
 vmlinuzobjs-$(CONFIG_KERNEL_XZ) += $(obj)/ashldi3.o
 
diff --git a/arch/mips/boot/compressed/dbg.c b/arch/mips/boot/compressed/dbg.c
deleted file mode 100644
index 95405292accd..000000000000
--- a/arch/mips/boot/compressed/dbg.c
+++ /dev/null
@@ -1,39 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * MIPS-specific debug support for pre-boot environment
- *
- * NOTE: putc() is board specific, if your board have a 16550 compatible uart,
- * please select SYS_SUPPORTS_ZBOOT_UART16550 for your machine. otherwise, you
- * need to implement your own putc().
- */
-#include <linux/compiler.h>
-#include <linux/types.h>
-
-#include "decompress.h"
-
-void __weak putc(char c)
-{
-}
-
-void puts(const char *s)
-{
-	char c;
-	while ((c = *s++) != '\0') {
-		putc(c);
-		if (c == '\n')
-			putc('\r');
-	}
-}
-
-void puthex(unsigned long long val)
-{
-
-	unsigned char buf[10];
-	int i;
-	for (i = 7; i >= 0; i--) {
-		buf[i] = "0123456789ABCDEF"[val & 0x0F];
-		val >>= 4;
-	}
-	buf[8] = '\0';
-	puts(buf);
-}
diff --git a/arch/mips/boot/compressed/debug-vec.S b/arch/mips/boot/compressed/debug-vec.S
new file mode 100644
index 000000000000..e7bedb183da8
--- /dev/null
+++ b/arch/mips/boot/compressed/debug-vec.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "../../kernel/debug-vec.S"
diff --git a/arch/mips/boot/compressed/debug.S b/arch/mips/boot/compressed/debug.S
new file mode 100644
index 000000000000..0cf3da958f7e
--- /dev/null
+++ b/arch/mips/boot/compressed/debug.S
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#include "../../kernel/debug.S"
diff --git a/arch/mips/boot/compressed/decompress.h b/arch/mips/boot/compressed/decompress.h
index 073b64593b3d..e375d50c71a0 100644
--- a/arch/mips/boot/compressed/decompress.h
+++ b/arch/mips/boot/compressed/decompress.h
@@ -7,11 +7,11 @@ extern unsigned char __image_begin[], __image_end[];
 
 /* debug interfaces  */
 #ifdef CONFIG_DEBUG_ZBOOT
-extern void putc(char c);
-extern void puts(const char *s);
-extern void puthex(unsigned long long val);
+extern void printascii(const char *s);
+extern void printhexl(unsigned long val);
+#define puts(s) printascii(s)
+#define puthex(val) printhexl(val)
 #else
-#define putc(s) do {} while (0)
 #define puts(s) do {} while (0)
 #define puthex(val) do {} while (0)
 #endif
diff --git a/arch/mips/boot/compressed/head.S b/arch/mips/boot/compressed/head.S
index d237a834b85e..b05e9591d3af 100644
--- a/arch/mips/boot/compressed/head.S
+++ b/arch/mips/boot/compressed/head.S
@@ -22,6 +22,12 @@
 	move	s2, a2
 	move	s3, a3
 
+#ifdef CONFIG_DEBUG_ZBOOT_EXCEP
+	/* Set up the exception vector */
+	PTR_LA	t9, setup_debug_ll_exception
+	jalr	t9
+#endif
+
 	/* Clear BSS */
 	PTR_LA	a0, _edata
 	PTR_LA	a2, _end
diff --git a/arch/mips/boot/compressed/uart-16550.c b/arch/mips/boot/compressed/uart-16550.c
deleted file mode 100644
index db618e72a0c4..000000000000
--- a/arch/mips/boot/compressed/uart-16550.c
+++ /dev/null
@@ -1,49 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * 16550 compatible uart based serial debug support for zboot
- */
-
-#include <linux/types.h>
-#include <linux/serial_reg.h>
-
-#include <asm/addrspace.h>
-
-#include "decompress.h"
-
-#if defined(CONFIG_MACH_LOONGSON64) || defined(CONFIG_MIPS_MALTA)
-#define UART_BASE 0x1fd003f8
-#define PORT(offset) (CKSEG1ADDR(UART_BASE) + (offset))
-#endif
-
-#ifdef CONFIG_MACH_INGENIC
-#define INGENIC_UART_BASE_ADDR	(0x10030000 + 0x1000 * CONFIG_ZBOOT_INGENIC_UART)
-#define PORT(offset) (CKSEG1ADDR(INGENIC_UART_BASE_ADDR) + (4 * offset))
-#endif
-
-#ifndef IOTYPE
-#define IOTYPE char
-#endif
-
-#ifndef PORT
-#error please define the serial port address for your own machine
-#endif
-
-static inline unsigned int serial_in(int offset)
-{
-	return *((volatile IOTYPE *)PORT(offset)) & 0xFF;
-}
-
-static inline void serial_out(int offset, int value)
-{
-	*((volatile IOTYPE *)PORT(offset)) = value & 0xFF;
-}
-
-void putc(char c)
-{
-	int timeout = 1000000;
-
-	while (((serial_in(UART_LSR) & UART_LSR_THRE) == 0) && (timeout-- > 0))
-		;
-
-	serial_out(UART_TX, c);
-}
diff --git a/arch/mips/boot/compressed/uart-alchemy.c b/arch/mips/boot/compressed/uart-alchemy.c
deleted file mode 100644
index 003967c084b3..000000000000
--- a/arch/mips/boot/compressed/uart-alchemy.c
+++ /dev/null
@@ -1,9 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <asm/mach-au1x00/au1000.h>
-
-#include "decompress.h"
-
-void putc(char c)
-{
-	alchemy_uart_putchar(AU1000_UART0_PHYS_ADDR, c);
-}
diff --git a/arch/mips/boot/compressed/uart-ath79.c b/arch/mips/boot/compressed/uart-ath79.c
deleted file mode 100644
index d686820921be..000000000000
--- a/arch/mips/boot/compressed/uart-ath79.c
+++ /dev/null
@@ -1,2 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-#include "../../ath79/early_printk.c"
diff --git a/arch/mips/boot/compressed/uart-prom.c b/arch/mips/boot/compressed/uart-prom.c
deleted file mode 100644
index 5fa3b9945333..000000000000
--- a/arch/mips/boot/compressed/uart-prom.c
+++ /dev/null
@@ -1,9 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-#include <asm/setup.h>
-
-#include "decompress.h"
-
-void putc(char c)
-{
-	prom_putchar(c);
-}

-- 
2.34.1