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2010-10-15llseek: automatically add .llseek fopArnd Bergmann
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>
2010-08-04DMAENGINE: add runtime slave control to COH 901 318 v3Linus Walleij
This extends the DMA engine driver for the COH 901 318 used in the U300 platform with the generic runtime slave control command. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-17DMAENGINE: extend the control command to include an argLinus Walleij
This adds an argument to the DMAengine control function, so that we can later provide control commands that need some external data passed in through an argument akin to the ioctl() operation prototype. [dan.j.williams@intel.com: fix up some missed conversions] Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26dmaengine: provide helper for setting txstateDan Williams
Simple conditional struct filler to cut out some duplicated code. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26DMAENGINE: generic channel status v2Linus Walleij
Convert the device_is_tx_complete() operation on the DMA engine to a generic device_tx_status()operation which can return three states, DMA_TX_RUNNING, DMA_TX_COMPLETE, DMA_TX_PAUSED. [dan.j.williams@intel.com: update for timberdale] Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Li Yang <leoli@freescale.com> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: Magnus Damm <damm@opensource.se> Cc: Liam Girdwood <lrg@slimlogic.co.uk> Cc: Joe Perches <joe@perches.com> Cc: Roland Dreier <rdreier@cisco.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-26DMAENGINE: generic slave control v2Linus Walleij
Convert the device_terminate_all() operation on the DMA engine to a generic device_control() operation which can now optionally support also pausing and resuming DMA on a certain channel. Implemented for the COH 901 318 DMAC as an example. [dan.j.williams@intel.com: update for timberdale] Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Maciej Sosnowski <maciej.sosnowski@intel.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Li Yang <leoli@freescale.com> Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Cc: Paul Mundt <lethal@linux-sh.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Haavard Skinnemoen <haavard.skinnemoen@atmel.com> Cc: Magnus Damm <damm@opensource.se> Cc: Liam Girdwood <lrg@slimlogic.co.uk> Cc: Joe Perches <joe@perches.com> Cc: Roland Dreier <rdreier@cisco.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-24DMAENGINE: COH 901 318 fix bytesleftLinus Walleij
This makes the function to get the number of bytes left in the ongoing DMA transaction actually work: the old code did not take neither lli:s nor queued jobs into account. Also fix a missing spinlock while we're at it. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-24DMAENGINE: COH 901 318 rename confusing varsLinus Walleij
This fixes up the code with a lot of comments that make it readable, rename things with opaque names like "data" into something more appropriate, and remove some very confusing BUG() statements. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-02DMAENGINE: COH 901 318 configure channel directionLinus Walleij
This makes the COH 901 318 configure channel direction (to or from device) dynamically, instead of being passed in from the platform data. This was necessary in order to get the MMC/SD-card channel bidirectional (all other channels on the U300 were either RX or TX but this one was both). This also sets memcpy() alignent to even 2^2 (32bit) boundaries, which makes the memcpy() stress tests start working. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-02DMAENGINE: COH 901 318 remove irq countingLinus Walleij
This removes the pointless irq counting for the COH 901 318, as it turns out the hardware will only ever fire one IRQ for a linked list anyway. In the process also a missing spinlock was introduced. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-02DMAENGINE: COH 901 318 descriptor pool refactoringLinus Walleij
This centralize some spread-out initialization of descriptors into one function and cleans up the error paths. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-03-02DMAENGINE: COH 901 318 cleanupsLinus Walleij
This cleans up the some debug code that was not working in the COH 901 318 driver, adds some helpful comments and rearrange the code a bit. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-02-10drivers/dma: Correct NULL testJulia Lawall
cohd_fin has already been verified not to be NULL, so the argument to BUG_ON cannot be true. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ expression *x; expression e; identifier l; @@ if (x == NULL || ...) { ... when forall return ...; } ... when != goto l; when != x = e when != &x *x == NULL // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-22drivers/dma: Correct use after freeJulia Lawall
Move the kfree after the iounmap that refers to the same structure. A simplified version of the semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression x,e; identifier f; iterator I; statement S; @@ *kfree(x); ... when != &x when != x = e when != I(x,...) S *x->f // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-11-19Add COH 901 318 DMA block driver v5Linus Walleij
This patch adds support for the ST-Ericsson COH 901 318 DMA block, found in the U300 series platforms. It registers a DMA slave for device I/O and also a memcpy slave for memcpy. Signed-off-by: Linus Walleij <linus.walleij@stericsson.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>