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path: root/drivers/staging/memrar/memrar_handler.c
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2011-04-04staging: memrar: remove driver from treeGreg Kroah-Hartman1-1007/+0
It's no longer needed at all. Cc: Ossama Othman <ossama.othman@intel.com> Cc: Eugene Epshteyn <eugene.epshteyn@intel.com> Cc: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann1-0/+1
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-05Staging: Merge staging-next into Linus's treeGreg Kroah-Hartman1-13/+24
Conflicts: drivers/staging/Kconfig drivers/staging/batman-adv/bat_sysfs.c drivers/staging/batman-adv/device.c drivers/staging/batman-adv/hard-interface.c drivers/staging/cx25821/cx25821-audups11.c Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-03rar: Move the RAR driver into the right place as its now cleanAlan Cox1-2/+1
We exit staging rar! rar! rar!... Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-07-22memrar: Address kernel oops during resource cleanupOssama Othman1-9/+19
Some delayed initialization is performed in this driver. Make sure resources that are used during driver clean-up (e.g. during driver's release() function) are fully initialized before first use. This is particularly important for the case when the delayed initialization isn't completed, leaving behind a partially initialized driver. Such a scenario can occur when RAR is not available on the platform, and the driver is release()d. Signed-off-by: Ossama Othman <ossama.othman@intel.com> Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-06-22Staging: memrar: memrar_handler.c: Fixed whitespace and tab warningsMatti Lammi1-4/+5
Fixed several witespace and tab related warnings and errors reported by the chechpatch.pl tool. Signed-off-by: Matti Lammi <mattij.lammi@gmail.com> Acked-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-11Staging: rar and memrar updatesAlan Cox1-205/+264
rar: perform a clean up pass - Move to a registration model where each RAR is claimed/unclaimed - Use that to fix the client stuff (one client per RAR so no need to queue stuff) - Support unregister so drivers can rmmod themselves safely - Fix locking hang on calling rar lock from rar callback - Clean up - Kerneldoc Folded in the memrar update as Greg asked - Fix various unload related bugs - Use the per RAR allocator/deallocator - Add kerneldoc Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-11Staging: memrar: fix printk format warningRandy Dunlap1-1/+1
Fix printk format warning in memrar: drivers/staging/memrar/memrar_handler.c:393: warning: format '%u' expects type 'unsigned int', but argument 4 has type 'size_t' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Ossama Othman <ossama.othman@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-11staging: Intel Restricted Access Region HandlerOssama Othman1-0/+937
The Intel Restricted Access Region Handler provides a buffer allocation mechanism to RAR users. Since the intended usage model is to lock out CPU access to RAR (the CPU will not be able to access RAR memory), this driver does not access RAR memory, and merely keeps track of what areas of RAR memory are in use. It has it's own simple allocator that does not rely on existing kernel allocators (SLAB, etc) since those allocators are too tightly coupled with the paging mechanism, which isn't needed for the intended RAR use cases. An mmap() implementation is provided for debugging purposes to simplify RAR memory access from the user space. However, it will effectively be a no-op when RAR access control is enabled since the CPU will not be able to access RAR. This driver should not be confused with the rar_register driver. That driver exposes an interface to access RAR registers on the Moorestown platform. The RAR handler driver relies on the rar_register driver for low level RAR register reads and writes. This patch was generated and built against the latest linux-2.6 master branch. Signed-off-by: Ossama Othman <ossama.othman@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>