Re: [PATCH v8 02/25] m68k/atari: Move Atari-specific code out of drivers/char/nvram.c

From: LEROY Christophe
Date: Fri Dec 28 2018 - 11:52:00 EST


Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> a ÃcritÂ:

Move the m68k-specific code out of the driver to make the driver generic.

I've used 'SPDX-License-Identifier: GPL-2.0+' for the new file because the
old file is covered by MODULE_LICENSE("GPL").

Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Tested-by: Christian T. Steigies <cts@xxxxxxxxxx>
Acked-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
---
Changed since v7:
- Added SPDX-License-Identifier.
---
arch/m68k/atari/Makefile | 2 +
arch/m68k/atari/nvram.c | 243 +++++++++++++++++++++++++++++++++
drivers/char/nvram.c | 280 +++++----------------------------------
3 files changed, 280 insertions(+), 245 deletions(-)
create mode 100644 arch/m68k/atari/nvram.c

diff --git a/arch/m68k/atari/Makefile b/arch/m68k/atari/Makefile
index 0cac723306f9..0b86bb6cfa87 100644
--- a/arch/m68k/atari/Makefile
+++ b/arch/m68k/atari/Makefile
@@ -6,3 +6,5 @@ obj-y := config.o time.o debug.o ataints.o stdma.o \
atasound.o stram.o

obj-$(CONFIG_ATARI_KBD_CORE) += atakeyb.o
+
+obj-$(CONFIG_NVRAM:m=y) += nvram.o
diff --git a/arch/m68k/atari/nvram.c b/arch/m68k/atari/nvram.c
new file mode 100644
index 000000000000..3e620ee955ba
--- /dev/null
+++ b/arch/m68k/atari/nvram.c
@@ -0,0 +1,243 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * CMOS/NV-RAM driver for Atari. Adapted from drivers/char/nvram.c.
+ * Copyright (C) 1997 Roman Hodek <Roman.Hodek@xxxxxxxxxxxxxxxxxxxxxxxxxx>
+ * idea by and with help from Richard Jelinek <rj@xxxxxxx>
+ * Portions copyright (c) 2001,2002 Sun Microsystems (thockin@xxxxxxx)
+ * Further contributions from Cesar Barros, Erik Gilling, Tim Hockin and
+ * Wim Van Sebroeck.
+ */
+
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/module.h>
+#include <linux/nvram.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <asm/atarihw.h>
+#include <asm/atariints.h>
+
+#define NVRAM_BYTES 50
+
+/* It is worth noting that these functions all access bytes of general
+ * purpose memory in the NVRAM - that is to say, they all add the
+ * NVRAM_FIRST_BYTE offset. Pass them offsets into NVRAM as if you did not
+ * know about the RTC cruft.
+ */
+
+/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
+ * rtc_lock held. Due to the index-port/data-port design of the RTC, we
+ * don't want two different things trying to get to it at once. (e.g. the
+ * periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
+ */
+
+unsigned char __nvram_read_byte(int i)
+{
+ return CMOS_READ(NVRAM_FIRST_BYTE + i);
+}
+
+unsigned char nvram_read_byte(int i)
+{
+ unsigned long flags;
+ unsigned char c;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ c = __nvram_read_byte(i);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return c;
+}
+EXPORT_SYMBOL(nvram_read_byte);
+
+/* This races nicely with trying to read with checksum checking */
+void __nvram_write_byte(unsigned char c, int i)
+{
+ CMOS_WRITE(c, NVRAM_FIRST_BYTE + i);
+}
+
+void nvram_write_byte(unsigned char c, int i)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ __nvram_write_byte(c, i);
+ spin_unlock_irqrestore(&rtc_lock, flags);
+}
+
+/* On Ataris, the checksum is over all bytes except the checksum bytes
+ * themselves; these are at the very end.
+ */
+#define ATARI_CKS_RANGE_START 0
+#define ATARI_CKS_RANGE_END 47
+#define ATARI_CKS_LOC 48
+
+int __nvram_check_checksum(void)
+{
+ int i;
+ unsigned char sum = 0;
+
+ for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
+ (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
+}
+
+int nvram_check_checksum(void)
+{
+ unsigned long flags;
+ int rv;
+
+ spin_lock_irqsave(&rtc_lock, flags);
+ rv = __nvram_check_checksum();
+ spin_unlock_irqrestore(&rtc_lock, flags);
+ return rv;
+}
+EXPORT_SYMBOL(nvram_check_checksum);
+
+static void __nvram_set_checksum(void)
+{
+ int i;
+ unsigned char sum = 0;
+
+ for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ __nvram_write_byte(~sum, ATARI_CKS_LOC);
+ __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
+}
+
+#ifdef CONFIG_PROC_FS
+static struct {
+ unsigned char val;
+ const char *name;
+} boot_prefs[] = {
+ { 0x80, "TOS" },
+ { 0x40, "ASV" },
+ { 0x20, "NetBSD (?)" },
+ { 0x10, "Linux" },
+ { 0x00, "unspecified" },
+};
+
+static const char * const languages[] = {
+ "English (US)",
+ "German",
+ "French",
+ "English (UK)",
+ "Spanish",
+ "Italian",
+ "6 (undefined)",
+ "Swiss (French)",
+ "Swiss (German)",
+};
+
+static const char * const dateformat[] = {
+ "MM%cDD%cYY",
+ "DD%cMM%cYY",
+ "YY%cMM%cDD",
+ "YY%cDD%cMM",
+ "4 (undefined)",
+ "5 (undefined)",
+ "6 (undefined)",
+ "7 (undefined)",
+};
+
+static const char * const colors[] = {
+ "2", "4", "16", "256", "65536", "??", "??", "??"
+};
+
+static void atari_nvram_proc_read(unsigned char *nvram, struct seq_file *seq,
+ void *offset)
+{
+ int checksum;
+ int i;
+ unsigned int vmode;
+
+ spin_lock_irq(&rtc_lock);
+ checksum = __nvram_check_checksum();
+ spin_unlock_irq(&rtc_lock);
+
+ seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not ");
+
+ seq_puts(seq, "Boot preference : ");
+ for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i)
+ if (nvram[1] == boot_prefs[i].val) {
+ seq_printf(seq, "%s\n", boot_prefs[i].name);
+ break;
+ }
+ if (i < 0)
+ seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
+
+ seq_printf(seq, "SCSI arbitration : %s\n",
+ (nvram[16] & 0x80) ? "on" : "off");
+ seq_puts(seq, "SCSI host ID : ");
+ if (nvram[16] & 0x80)
+ seq_printf(seq, "%d\n", nvram[16] & 7);
+ else
+ seq_puts(seq, "n/a\n");
+
+ if (!MACH_IS_FALCON)
+ return;
+
+ seq_puts(seq, "OS language : ");
+ if (nvram[6] < ARRAY_SIZE(languages))
+ seq_printf(seq, "%s\n", languages[nvram[6]]);
+ else
+ seq_printf(seq, "%u (undefined)\n", nvram[6]);
+ seq_puts(seq, "Keyboard language: ");
+ if (nvram[7] < ARRAY_SIZE(languages))
+ seq_printf(seq, "%s\n", languages[nvram[7]]);
+ else
+ seq_printf(seq, "%u (undefined)\n", nvram[7]);
+ seq_puts(seq, "Date format : ");
+ seq_printf(seq, dateformat[nvram[8] & 7],
+ nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
+ seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
+ seq_puts(seq, "Boot delay : ");
+ if (nvram[10] == 0)
+ seq_puts(seq, "default");
+ else
+ seq_printf(seq, "%ds%s\n", nvram[10],
+ nvram[10] < 8 ? ", no memory test" : "");
+
+ vmode = (nvram[14] << 8) | nvram[15];
+ seq_printf(seq,
+ "Video mode : %s colors, %d columns, %s %s monitor\n",
+ colors[vmode & 7], vmode & 8 ? 80 : 40,
+ vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
+ seq_printf(seq,
+ " %soverscan, compat. mode %s%s\n",
+ vmode & 64 ? "" : "no ", vmode & 128 ? "on" : "off",
+ vmode & 256 ?
+ (vmode & 16 ? ", line doubling" : ", half screen") : "");
+}
+
+static int nvram_proc_read(struct seq_file *seq, void *offset)
+{
+ unsigned char contents[NVRAM_BYTES];
+ int i;
+
+ spin_lock_irq(&rtc_lock);
+ for (i = 0; i < NVRAM_BYTES; ++i)
+ contents[i] = __nvram_read_byte(i);
+ spin_unlock_irq(&rtc_lock);
+
+ atari_nvram_proc_read(contents, seq, offset);
+
+ return 0;
+}
+
+static int __init atari_nvram_init(void)
+{
+ if (!(MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK)))
+ return -ENODEV;
+
+ if (!proc_create_single("driver/nvram", 0, NULL, nvram_proc_read)) {
+ pr_err("nvram: can't create /proc/driver/nvram\n");
+ return -ENOMEM;
+ }
+
+ return 0;
+}
+device_initcall(atari_nvram_init);
+#endif /* CONFIG_PROC_FS */
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 25264d65e716..a9d4652f9e90 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -21,13 +21,6 @@
* ioctl(NVRAM_SETCKS) (doesn't change contents, just makes checksum valid
* again; use with care!)
*
- * This file also provides some functions for other parts of the kernel that
- * want to access the NVRAM: nvram_{read,write,check_checksum,set_checksum}.
- * Obviously this can be used only if this driver is always configured into
- * the kernel and is not a module. Since the functions are used by some Atari
- * drivers, this is the case on the Atari.
- *
- *
* 1.1 Cesar Barros: SMP locking fixes
* added changelog
* 1.2 Erik Gilling: Cobalt Networks support
@@ -39,64 +32,6 @@

#include <linux/module.h>
#include <linux/nvram.h>
-
-#define PC 1
-#define ATARI 2
-
-/* select machine configuration */
-#if defined(CONFIG_ATARI)
-# define MACH ATARI
-#elif defined(__i386__) || defined(__x86_64__) || defined(__arm__) /* and ?? */
-# define MACH PC
-#else
-# error Cannot build nvram driver for this machine configuration.
-#endif
-
-#if MACH == PC
-
-/* RTC in a PC */
-#define CHECK_DRIVER_INIT() 1
-
-/* On PCs, the checksum is built only over bytes 2..31 */
-#define PC_CKS_RANGE_START 2
-#define PC_CKS_RANGE_END 31
-#define PC_CKS_LOC 32
-#define NVRAM_BYTES (128-NVRAM_FIRST_BYTE)
-
-#define mach_check_checksum pc_check_checksum
-#define mach_set_checksum pc_set_checksum
-#define mach_proc_infos pc_proc_infos
-
-#endif
-
-#if MACH == ATARI
-
-/* Special parameters for RTC in Atari machines */
-#include <asm/atarihw.h>
-#include <asm/atariints.h>
-#define RTC_PORT(x) (TT_RTC_BAS + 2*(x))
-#define CHECK_DRIVER_INIT() (MACH_IS_ATARI && ATARIHW_PRESENT(TT_CLK))
-
-#define NVRAM_BYTES 50
-
-/* On Ataris, the checksum is over all bytes except the checksum bytes
- * themselves; these are at the very end */
-#define ATARI_CKS_RANGE_START 0
-#define ATARI_CKS_RANGE_END 47
-#define ATARI_CKS_LOC 48
-
-#define mach_check_checksum atari_check_checksum
-#define mach_set_checksum atari_set_checksum
-#define mach_proc_infos atari_proc_infos
-
-#endif
-
-/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
- * rtc_lock held. Due to the index-port/data-port design of the RTC, we
- * don't want two different things trying to get to it at once. (e.g. the
- * periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
- */
-
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/miscdevice.h>
@@ -120,12 +55,9 @@ static int nvram_open_mode; /* special open modes */
#define NVRAM_WRITE 1 /* opened for writing (exclusive) */
#define NVRAM_EXCL 2 /* opened with O_EXCL */

-static int mach_check_checksum(void);
-static void mach_set_checksum(void);
-
#ifdef CONFIG_PROC_FS
-static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
- void *offset);
+static void pc_nvram_proc_read(unsigned char *contents, struct seq_file *seq,
+ void *offset);
#endif

/*
@@ -139,6 +71,14 @@ static void mach_proc_infos(unsigned char *contents, struct seq_file *seq,
* know about the RTC cruft.
*/

+#define NVRAM_BYTES (128 - NVRAM_FIRST_BYTE)
+
+/* Note that *all* calls to CMOS_READ and CMOS_WRITE must be done with
+ * rtc_lock held. Due to the index-port/data-port design of the RTC, we
+ * don't want two different things trying to get to it at once. (e.g. the
+ * periodic 11 min sync from kernel/time/ntp.c vs. this driver.)
+ */
+
unsigned char __nvram_read_byte(int i)
{
return CMOS_READ(NVRAM_FIRST_BYTE + i);
@@ -174,9 +114,22 @@ void nvram_write_byte(unsigned char c, int i)
}
EXPORT_SYMBOL(nvram_write_byte);

+/* On PCs, the checksum is built only over bytes 2..31 */
+#define PC_CKS_RANGE_START 2
+#define PC_CKS_RANGE_END 31
+#define PC_CKS_LOC 32
+
int __nvram_check_checksum(void)
{
- return mach_check_checksum();
+ int i;
+ unsigned short sum = 0;
+ unsigned short expect;
+
+ for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
+ __nvram_read_byte(PC_CKS_LOC+1);
+ return (sum & 0xffff) == expect;
}


I don't understand how this is part of the code move.
Does the pc specific checksum becomes the generic one ?

Christophe

EXPORT_SYMBOL(__nvram_check_checksum);

@@ -194,7 +147,13 @@ EXPORT_SYMBOL(nvram_check_checksum);

static void __nvram_set_checksum(void)
{
- mach_set_checksum();
+ int i;
+ unsigned short sum = 0;
+
+ for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
+ sum += __nvram_read_byte(i);
+ __nvram_write_byte(sum >> 8, PC_CKS_LOC);
+ __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
}

#if 0
@@ -384,7 +343,7 @@ static int nvram_proc_read(struct seq_file *seq, void *offset)
contents[i] = __nvram_read_byte(i);
spin_unlock_irq(&rtc_lock);

- mach_proc_infos(contents, seq, offset);
+ pc_nvram_proc_read(contents, seq, offset);

return 0;
}
@@ -418,10 +377,6 @@ static int __init nvram_init(void)
{
int ret;

- /* First test whether the driver should init at all */
- if (!CHECK_DRIVER_INIT())
- return -ENODEV;
-
ret = misc_register(&nvram_dev);
if (ret) {
printk(KERN_ERR "nvram: can't misc_register on minor=%d\n",
@@ -451,36 +406,6 @@ static void __exit nvram_cleanup_module(void)
module_init(nvram_init);
module_exit(nvram_cleanup_module);

-/*
- * Machine specific functions
- */
-
-#if MACH == PC
-
-static int pc_check_checksum(void)
-{
- int i;
- unsigned short sum = 0;
- unsigned short expect;
-
- for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
- sum += __nvram_read_byte(i);
- expect = __nvram_read_byte(PC_CKS_LOC)<<8 |
- __nvram_read_byte(PC_CKS_LOC+1);
- return (sum & 0xffff) == expect;
-}
-
-static void pc_set_checksum(void)
-{
- int i;
- unsigned short sum = 0;
-
- for (i = PC_CKS_RANGE_START; i <= PC_CKS_RANGE_END; ++i)
- sum += __nvram_read_byte(i);
- __nvram_write_byte(sum >> 8, PC_CKS_LOC);
- __nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
-}
-
#ifdef CONFIG_PROC_FS

static const char * const floppy_types[] = {
@@ -495,8 +420,8 @@ static const char * const gfx_types[] = {
"monochrome",
};

-static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,
- void *offset)
+static void pc_nvram_proc_read(unsigned char *nvram, struct seq_file *seq,
+ void *offset)
{
int checksum;
int type;
@@ -557,143 +482,8 @@ static void pc_proc_infos(unsigned char *nvram, struct seq_file *seq,

return;
}
-#endif
-
-#endif /* MACH == PC */
-
-#if MACH == ATARI
-
-static int atari_check_checksum(void)
-{
- int i;
- unsigned char sum = 0;
-
- for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
- sum += __nvram_read_byte(i);
- return (__nvram_read_byte(ATARI_CKS_LOC) == (~sum & 0xff)) &&
- (__nvram_read_byte(ATARI_CKS_LOC + 1) == (sum & 0xff));
-}
-
-static void atari_set_checksum(void)
-{
- int i;
- unsigned char sum = 0;
-
- for (i = ATARI_CKS_RANGE_START; i <= ATARI_CKS_RANGE_END; ++i)
- sum += __nvram_read_byte(i);
- __nvram_write_byte(~sum, ATARI_CKS_LOC);
- __nvram_write_byte(sum, ATARI_CKS_LOC + 1);
-}
-
-#ifdef CONFIG_PROC_FS
-
-static struct {
- unsigned char val;
- const char *name;
-} boot_prefs[] = {
- { 0x80, "TOS" },
- { 0x40, "ASV" },
- { 0x20, "NetBSD (?)" },
- { 0x10, "Linux" },
- { 0x00, "unspecified" }
-};
-
-static const char * const languages[] = {
- "English (US)",
- "German",
- "French",
- "English (UK)",
- "Spanish",
- "Italian",
- "6 (undefined)",
- "Swiss (French)",
- "Swiss (German)"
-};
-
-static const char * const dateformat[] = {
- "MM%cDD%cYY",
- "DD%cMM%cYY",
- "YY%cMM%cDD",
- "YY%cDD%cMM",
- "4 (undefined)",
- "5 (undefined)",
- "6 (undefined)",
- "7 (undefined)"
-};
-
-static const char * const colors[] = {
- "2", "4", "16", "256", "65536", "??", "??", "??"
-};
-
-static void atari_proc_infos(unsigned char *nvram, struct seq_file *seq,
- void *offset)
-{
- int checksum = nvram_check_checksum();
- int i;
- unsigned vmode;
-
- seq_printf(seq, "Checksum status : %svalid\n", checksum ? "" : "not ");
-
- seq_printf(seq, "Boot preference : ");
- for (i = ARRAY_SIZE(boot_prefs) - 1; i >= 0; --i) {
- if (nvram[1] == boot_prefs[i].val) {
- seq_printf(seq, "%s\n", boot_prefs[i].name);
- break;
- }
- }
- if (i < 0)
- seq_printf(seq, "0x%02x (undefined)\n", nvram[1]);
-
- seq_printf(seq, "SCSI arbitration : %s\n",
- (nvram[16] & 0x80) ? "on" : "off");
- seq_printf(seq, "SCSI host ID : ");
- if (nvram[16] & 0x80)
- seq_printf(seq, "%d\n", nvram[16] & 7);
- else
- seq_printf(seq, "n/a\n");
-
- /* the following entries are defined only for the Falcon */
- if ((atari_mch_cookie >> 16) != ATARI_MCH_FALCON)
- return;
-
- seq_printf(seq, "OS language : ");
- if (nvram[6] < ARRAY_SIZE(languages))
- seq_printf(seq, "%s\n", languages[nvram[6]]);
- else
- seq_printf(seq, "%u (undefined)\n", nvram[6]);
- seq_printf(seq, "Keyboard language: ");
- if (nvram[7] < ARRAY_SIZE(languages))
- seq_printf(seq, "%s\n", languages[nvram[7]]);
- else
- seq_printf(seq, "%u (undefined)\n", nvram[7]);
- seq_printf(seq, "Date format : ");
- seq_printf(seq, dateformat[nvram[8] & 7],
- nvram[9] ? nvram[9] : '/', nvram[9] ? nvram[9] : '/');
- seq_printf(seq, ", %dh clock\n", nvram[8] & 16 ? 24 : 12);
- seq_printf(seq, "Boot delay : ");
- if (nvram[10] == 0)
- seq_printf(seq, "default");
- else
- seq_printf(seq, "%ds%s\n", nvram[10],
- nvram[10] < 8 ? ", no memory test" : "");
-
- vmode = (nvram[14] << 8) | nvram[15];
- seq_printf(seq,
- "Video mode : %s colors, %d columns, %s %s monitor\n",
- colors[vmode & 7],
- vmode & 8 ? 80 : 40,
- vmode & 16 ? "VGA" : "TV", vmode & 32 ? "PAL" : "NTSC");
- seq_printf(seq, " %soverscan, compat. mode %s%s\n",
- vmode & 64 ? "" : "no ",
- vmode & 128 ? "on" : "off",
- vmode & 256 ?
- (vmode & 16 ? ", line doubling" : ", half screen") : "");
-
- return;
-}
-#endif

-#endif /* MACH == ATARI */
+#endif /* CONFIG_PROC_FS */

MODULE_LICENSE("GPL");
MODULE_ALIAS_MISCDEV(NVRAM_MINOR);
--
2.19.2