From: Finn Thain <fthain@telegraphics.com.au>
To: Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-m68k@lists.linux-m68k.org, linuxppc-dev@lists.ozlabs.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v8 07/25] char/nvram: Allow the set_checksum and initialize ioctls to be omitted
Date: Wed, 26 Dec 2018 11:37:59 +1100 [thread overview]
Message-ID: <b8154e56502650a08734355831399406676834e2.1545784679.git.fthain@telegraphics.com.au> (raw)
In-Reply-To: <cover.1545784679.git.fthain@telegraphics.com.au>
The drivers/char/nvram module has previously only supported RTC "CMOS"
NVRAM, for which it provides appropriate checksum ioctls. Make these
ioctls optional so the module can be re-used with other kinds of NVRAM.
The ops struct methods that implement the ioctls now return error
codes so that a multi-platform kernel binary can do the right thing when
running on hardware without suitable NVRAM.
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
---
drivers/char/nvram.c | 70 ++++++++++++++++++++++++-------------------
include/linux/nvram.h | 2 ++
2 files changed, 42 insertions(+), 30 deletions(-)
diff --git a/drivers/char/nvram.c b/drivers/char/nvram.c
index 00897daa0643..33ef3b02d365 100644
--- a/drivers/char/nvram.c
+++ b/drivers/char/nvram.c
@@ -153,16 +153,25 @@ static void __nvram_set_checksum(void)
__nvram_write_byte(sum & 0xff, PC_CKS_LOC + 1);
}
-#if 0
-void nvram_set_checksum(void)
+static long nvram_set_checksum(void)
{
- unsigned long flags;
+ spin_lock_irq(&rtc_lock);
+ __nvram_set_checksum();
+ spin_unlock_irq(&rtc_lock);
+ return 0;
+}
- spin_lock_irqsave(&rtc_lock, flags);
+static long nvram_initialize(void)
+{
+ ssize_t i;
+
+ spin_lock_irq(&rtc_lock);
+ for (i = 0; i < NVRAM_BYTES; ++i)
+ __nvram_write_byte(0, i);
__nvram_set_checksum();
- spin_unlock_irqrestore(&rtc_lock, flags);
+ spin_unlock_irq(&rtc_lock);
+ return 0;
}
-#endif /* 0 */
static ssize_t nvram_get_size(void)
{
@@ -173,6 +182,8 @@ const struct nvram_ops arch_nvram_ops = {
.read_byte = nvram_read_byte,
.write_byte = nvram_write_byte,
.get_size = nvram_get_size,
+ .set_checksum = nvram_set_checksum,
+ .initialize = nvram_initialize,
};
EXPORT_SYMBOL(arch_nvram_ops);
#endif /* CONFIG_X86 */
@@ -258,51 +269,50 @@ static ssize_t nvram_misc_write(struct file *file, const char __user *buf,
static long nvram_misc_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
- int i;
+ long ret = -ENOTTY;
switch (cmd) {
-
case NVRAM_INIT:
/* initialize NVRAM contents and checksum */
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- mutex_lock(&nvram_mutex);
- spin_lock_irq(&rtc_lock);
-
- for (i = 0; i < NVRAM_BYTES; ++i)
- __nvram_write_byte(0, i);
- __nvram_set_checksum();
-
- spin_unlock_irq(&rtc_lock);
- mutex_unlock(&nvram_mutex);
- return 0;
-
+ if (arch_nvram_ops.initialize != NULL) {
+ mutex_lock(&nvram_mutex);
+ ret = arch_nvram_ops.initialize();
+ mutex_unlock(&nvram_mutex);
+ }
+ break;
case NVRAM_SETCKS:
/* just set checksum, contents unchanged (maybe useful after
* checksum garbaged somehow...) */
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
- mutex_lock(&nvram_mutex);
- spin_lock_irq(&rtc_lock);
- __nvram_set_checksum();
- spin_unlock_irq(&rtc_lock);
- mutex_unlock(&nvram_mutex);
- return 0;
-
- default:
- return -ENOTTY;
+ if (arch_nvram_ops.set_checksum != NULL) {
+ mutex_lock(&nvram_mutex);
+ ret = arch_nvram_ops.set_checksum();
+ mutex_unlock(&nvram_mutex);
+ }
+ break;
}
+ return ret;
}
static int nvram_misc_open(struct inode *inode, struct file *file)
{
spin_lock(&nvram_state_lock);
+ /* Prevent multiple readers/writers if desired. */
if ((nvram_open_cnt && (file->f_flags & O_EXCL)) ||
- (nvram_open_mode & NVRAM_EXCL) ||
- ((file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE))) {
+ (nvram_open_mode & NVRAM_EXCL)) {
+ spin_unlock(&nvram_state_lock);
+ return -EBUSY;
+ }
+
+ /* Prevent multiple writers if the set_checksum ioctl is implemented. */
+ if ((arch_nvram_ops.set_checksum != NULL) &&
+ (file->f_mode & FMODE_WRITE) && (nvram_open_mode & NVRAM_WRITE)) {
spin_unlock(&nvram_state_lock);
return -EBUSY;
}
diff --git a/include/linux/nvram.h b/include/linux/nvram.h
index d1bdee50d6a8..b7bfaec60a43 100644
--- a/include/linux/nvram.h
+++ b/include/linux/nvram.h
@@ -18,6 +18,8 @@ struct nvram_ops {
unsigned char (*read_byte)(int);
void (*write_byte)(unsigned char, int);
ssize_t (*get_size)(void);
+ long (*set_checksum)(void);
+ long (*initialize)(void);
};
extern const struct nvram_ops arch_nvram_ops;
--
2.19.2
next prev parent reply other threads:[~2018-12-26 4:13 UTC|newest]
Thread overview: 79+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-26 0:37 [PATCH v8 00/25] Re-use nvram module Finn Thain
2018-12-26 0:37 ` [PATCH v8 24/25] powerpc: Adopt nvram module for PPC64 Finn Thain
2018-12-29 22:36 ` Arnd Bergmann
2018-12-30 3:28 ` Finn Thain
2018-12-31 12:32 ` Arnd Bergmann
2019-01-01 1:38 ` Finn Thain
2019-01-04 8:45 ` Finn Thain
2019-01-06 23:36 ` Michael Ellerman
2019-01-07 4:52 ` Finn Thain
2019-01-08 9:27 ` Michael Ellerman
2019-01-08 22:51 ` Finn Thain
2018-12-26 0:37 ` Finn Thain [this message]
2018-12-26 0:37 ` [PATCH v8 22/25] powerpc: Remove CONFIG_GENERIC_NVRAM and adopt CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2019-01-03 8:05 ` Christoph Hellwig
2019-01-03 22:11 ` Finn Thain
2018-12-26 0:37 ` [PATCH v8 16/25] powerpc: Add missing ppc_md.nvram_size for CHRP and PowerMac Finn Thain
2018-12-26 0:37 ` [PATCH v8 03/25] m68k/atari: Replace nvram_{read,write}_byte with arch_nvram_ops Finn Thain
2018-12-26 0:37 ` [PATCH v8 11/25] m68k/mac: Use macros for RTC accesses not magic numbers Finn Thain
2018-12-26 0:37 ` [PATCH v8 02/25] m68k/atari: Move Atari-specific code out of drivers/char/nvram.c Finn Thain
2018-12-28 16:51 ` LEROY Christophe
2018-12-29 1:16 ` Finn Thain
2019-01-02 22:29 ` Finn Thain
2018-12-26 0:37 ` [PATCH v8 21/25] nvram: Drop nvram_* symbol exports and prototypes Finn Thain
2018-12-26 0:37 ` [PATCH v8 14/25] char/nvram: Add "devname:nvram" module alias Finn Thain
2018-12-26 0:37 ` [PATCH v8 08/25] char/nvram: Implement NVRAM read/write methods Finn Thain
2018-12-26 0:37 ` [PATCH v8 15/25] powerpc: Clean up nvram includes Finn Thain
2018-12-26 0:37 ` [PATCH v8 05/25] char/nvram: Adopt arch_nvram_ops Finn Thain
2019-01-03 8:02 ` Christoph Hellwig
2019-01-03 22:08 ` Finn Thain
2019-01-04 17:56 ` Christoph Hellwig
2019-01-04 22:05 ` Finn Thain
2018-12-26 0:37 ` [PATCH v8 25/25] powerpc: Remove pmac_xpram_{read,write} functions Finn Thain
2018-12-26 0:37 ` [PATCH v8 06/25] x86/thinkpad_acpi: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2018-12-26 0:37 ` [PATCH v8 12/25] m68k/mac: Fix PRAM accessors Finn Thain
2018-12-26 0:37 ` [PATCH v8 18/25] powerpc: Implement nvram sync ioctl Finn Thain
2018-12-29 22:19 ` Arnd Bergmann
2018-12-30 7:25 ` Finn Thain
2018-12-30 23:13 ` Finn Thain
2018-12-31 12:17 ` Arnd Bergmann
2018-12-31 12:16 ` Arnd Bergmann
2019-01-01 1:06 ` Finn Thain
2019-01-02 22:25 ` Finn Thain
2018-12-26 0:37 ` [PATCH v8 23/25] char/generic_nvram: Remove as unused Finn Thain
2018-12-26 0:37 ` [PATCH v8 10/25] m68k/mac: Adopt naming and calling conventions for PRAM routines Finn Thain
2018-12-26 0:37 ` [PATCH v8 17/25] powerpc: Implement arch_nvram_ops.get_size() and remove old nvram_* exports Finn Thain
2018-12-26 0:37 ` [PATCH v8 09/25] m68k/atari: Implement arch_nvram_ops methods and enable CONFIG_HAVE_ARCH_NVRAM_OPS Finn Thain
2018-12-26 0:37 ` [PATCH v8 04/25] char/nvram: Re-order functions to remove forward declarations and #ifdefs Finn Thain
2018-12-26 0:37 ` [PATCH v8 13/25] m68k: Dispatch nvram_ops calls to Atari or Mac functions Finn Thain
2018-12-29 22:27 ` Arnd Bergmann
2018-12-30 7:26 ` Finn Thain
2018-12-30 17:53 ` LEROY Christophe
2018-12-30 22:12 ` Finn Thain
2018-12-31 12:19 ` Arnd Bergmann
2018-12-26 0:37 ` [PATCH v8 19/25] powerpc, fbdev: Use NV_CMODE and NV_VMODE only when CONFIG_PPC32 && CONFIG_PPC_PMAC && CONFIG_NVRAM Finn Thain
2018-12-26 0:37 ` [PATCH v8 20/25] powerpc, fbdev: Use arch_nvram_ops methods instead of nvram_read_byte() and nvram_write_byte() Finn Thain
2018-12-29 17:02 ` LEROY Christophe
2018-12-29 23:43 ` Finn Thain
2018-12-31 12:29 ` Arnd Bergmann
2019-01-01 1:10 ` Finn Thain
2019-01-05 23:06 ` Finn Thain
2018-12-26 0:37 ` [PATCH v8 01/25] scsi/atari_scsi: Don't select CONFIG_NVRAM Finn Thain
2018-12-28 16:38 ` LEROY Christophe
2018-12-29 1:06 ` Finn Thain
2018-12-29 1:33 ` Michael Schmitz
2018-12-29 2:34 ` Finn Thain
2018-12-29 2:50 ` Michael Schmitz
2018-12-29 21:37 ` Arnd Bergmann
2018-12-30 17:50 ` LEROY Christophe
2018-12-30 18:06 ` James Bottomley
2018-12-30 21:44 ` Finn Thain
2018-12-30 22:45 ` Finn Thain
2018-12-29 16:55 ` LEROY Christophe
2018-12-29 18:54 ` Michael Schmitz
2018-12-29 2:54 ` Michael Schmitz
2018-12-29 22:45 ` [PATCH v8 00/25] Re-use nvram module Arnd Bergmann
2018-12-30 0:09 ` Finn Thain
2018-12-30 4:05 ` Finn Thain
2018-12-31 12:22 ` Arnd Bergmann
2018-12-31 22:54 ` Finn Thain
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