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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
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| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /lib/kfifo.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'lib/kfifo.c')
| -rw-r--r-- | lib/kfifo.c | 595 |
1 files changed, 595 insertions, 0 deletions
diff --git a/lib/kfifo.c b/lib/kfifo.c new file mode 100644 index 000000000..2633f9cc3 --- /dev/null +++ b/lib/kfifo.c @@ -0,0 +1,595 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * A generic kernel FIFO implementation + * + * Copyright (C) 2009/2010 Stefani Seibold <stefani@seibold.net> + */ + +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/export.h> +#include <linux/kfifo.h> +#include <linux/log2.h> +#include <linux/scatterlist.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +/* + * internal helper to calculate the unused elements in a fifo + */ +static inline unsigned int kfifo_unused(struct __kfifo *fifo) +{ + return (fifo->mask + 1) - (fifo->in - fifo->out); +} + +int __kfifo_alloc_node(struct __kfifo *fifo, unsigned int size, + size_t esize, gfp_t gfp_mask, int node) +{ + /* + * round up to the next power of 2, since our 'let the indices + * wrap' technique works only in this case. + */ + size = roundup_pow_of_two(size); + + fifo->in = 0; + fifo->out = 0; + fifo->esize = esize; + + if (size < 2) { + fifo->data = NULL; + fifo->mask = 0; + return -EINVAL; + } + + fifo->data = kmalloc_array_node(size, esize, gfp_mask, node); + + if (!fifo->data) { + fifo->mask = 0; + return -ENOMEM; + } + fifo->mask = size - 1; + + return 0; +} +EXPORT_SYMBOL(__kfifo_alloc_node); + +void __kfifo_free(struct __kfifo *fifo) +{ + kfree(fifo->data); + fifo->in = 0; + fifo->out = 0; + fifo->esize = 0; + fifo->data = NULL; + fifo->mask = 0; +} +EXPORT_SYMBOL(__kfifo_free); + +int __kfifo_init(struct __kfifo *fifo, void *buffer, + unsigned int size, size_t esize) +{ + size /= esize; + + if (!is_power_of_2(size)) + size = rounddown_pow_of_two(size); + + fifo->in = 0; + fifo->out = 0; + fifo->esize = esize; + fifo->data = buffer; + + if (size < 2) { + fifo->mask = 0; + return -EINVAL; + } + fifo->mask = size - 1; + + return 0; +} +EXPORT_SYMBOL(__kfifo_init); + +static void kfifo_copy_in(struct __kfifo *fifo, const void *src, + unsigned int len, unsigned int off) +{ + unsigned int size = fifo->mask + 1; + unsigned int esize = fifo->esize; + unsigned int l; + + off &= fifo->mask; + if (esize != 1) { + off *= esize; + size *= esize; + len *= esize; + } + l = min(len, size - off); + + memcpy(fifo->data + off, src, l); + memcpy(fifo->data, src + l, len - l); + /* + * make sure that the data in the fifo is up to date before + * incrementing the fifo->in index counter + */ + smp_wmb(); +} + +unsigned int __kfifo_in(struct __kfifo *fifo, + const void *buf, unsigned int len) +{ + unsigned int l; + + l = kfifo_unused(fifo); + if (len > l) + len = l; + + kfifo_copy_in(fifo, buf, len, fifo->in); + fifo->in += len; + return len; +} +EXPORT_SYMBOL(__kfifo_in); + +static void kfifo_copy_out(struct __kfifo *fifo, void *dst, + unsigned int len, unsigned int off) +{ + unsigned int size = fifo->mask + 1; + unsigned int esize = fifo->esize; + unsigned int l; + + off &= fifo->mask; + if (esize != 1) { + off *= esize; + size *= esize; + len *= esize; + } + l = min(len, size - off); + + memcpy(dst, fifo->data + off, l); + memcpy(dst + l, fifo->data, len - l); + /* + * make sure that the data is copied before + * incrementing the fifo->out index counter + */ + smp_wmb(); +} + +unsigned int __kfifo_out_peek(struct __kfifo *fifo, + void *buf, unsigned int len) +{ + unsigned int l; + + l = fifo->in - fifo->out; + if (len > l) + len = l; + + kfifo_copy_out(fifo, buf, len, fifo->out); + return len; +} +EXPORT_SYMBOL(__kfifo_out_peek); + +unsigned int __kfifo_out_linear(struct __kfifo *fifo, + unsigned int *tail, unsigned int n) +{ + unsigned int size = fifo->mask + 1; + unsigned int off = fifo->out & fifo->mask; + + if (tail) + *tail = off; + + return min3(n, fifo->in - fifo->out, size - off); +} +EXPORT_SYMBOL(__kfifo_out_linear); + +unsigned int __kfifo_out(struct __kfifo *fifo, + void *buf, unsigned int len) +{ + len = __kfifo_out_peek(fifo, buf, len); + fifo->out += len; + return len; +} +EXPORT_SYMBOL(__kfifo_out); + +static unsigned long kfifo_copy_from_user(struct __kfifo *fifo, + const void __user *from, unsigned int len, unsigned int off, + unsigned int *copied) +{ + unsigned int size = fifo->mask + 1; + unsigned int esize = fifo->esize; + unsigned int l; + unsigned long ret; + + off &= fifo->mask; + if (esize != 1) { + off *= esize; + size *= esize; + len *= esize; + } + l = min(len, size - off); + + ret = copy_from_user(fifo->data + off, from, l); + if (unlikely(ret)) + ret = DIV_ROUND_UP(ret + len - l, esize); + else { + ret = copy_from_user(fifo->data, from + l, len - l); + if (unlikely(ret)) + ret = DIV_ROUND_UP(ret, esize); + } + /* + * make sure that the data in the fifo is up to date before + * incrementing the fifo->in index counter + */ + smp_wmb(); + *copied = len - ret * esize; + /* return the number of elements which are not copied */ + return ret; +} + +int __kfifo_from_user(struct __kfifo *fifo, const void __user *from, + unsigned long len, unsigned int *copied) +{ + unsigned int l; + unsigned long ret; + unsigned int esize = fifo->esize; + int err; + + if (esize != 1) + len /= esize; + + l = kfifo_unused(fifo); + if (len > l) + len = l; + + ret = kfifo_copy_from_user(fifo, from, len, fifo->in, copied); + if (unlikely(ret)) { + len -= ret; + err = -EFAULT; + } else + err = 0; + fifo->in += len; + return err; +} +EXPORT_SYMBOL(__kfifo_from_user); + +static unsigned long kfifo_copy_to_user(struct __kfifo *fifo, void __user *to, + unsigned int len, unsigned int off, unsigned int *copied) +{ + unsigned int l; + unsigned long ret; + unsigned int size = fifo->mask + 1; + unsigned int esize = fifo->esize; + + off &= fifo->mask; + if (esize != 1) { + off *= esize; + size *= esize; + len *= esize; + } + l = min(len, size - off); + + ret = copy_to_user(to, fifo->data + off, l); + if (unlikely(ret)) + ret = DIV_ROUND_UP(ret + len - l, esize); + else { + ret = copy_to_user(to + l, fifo->data, len - l); + if (unlikely(ret)) + ret = DIV_ROUND_UP(ret, esize); + } + /* + * make sure that the data is copied before + * incrementing the fifo->out index counter + */ + smp_wmb(); + *copied = len - ret * esize; + /* return the number of elements which are not copied */ + return ret; +} + +int __kfifo_to_user(struct __kfifo *fifo, void __user *to, + unsigned long len, unsigned int *copied) +{ + unsigned int l; + unsigned long ret; + unsigned int esize = fifo->esize; + int err; + + if (esize != 1) + len /= esize; + + l = fifo->in - fifo->out; + if (len > l) + len = l; + ret = kfifo_copy_to_user(fifo, to, len, fifo->out, copied); + if (unlikely(ret)) { + len -= ret; + err = -EFAULT; + } else + err = 0; + fifo->out += len; + return err; +} +EXPORT_SYMBOL(__kfifo_to_user); + +static unsigned int setup_sgl_buf(struct __kfifo *fifo, struct scatterlist *sgl, + unsigned int data_offset, int nents, + unsigned int len, dma_addr_t dma) +{ + const void *buf = fifo->data + data_offset; + + if (!nents || !len) + return 0; + + sg_set_buf(sgl, buf, len); + + if (dma != DMA_MAPPING_ERROR) { + sg_dma_address(sgl) = dma + data_offset; + sg_dma_len(sgl) = len; + } + + return 1; +} + +static unsigned int setup_sgl(struct __kfifo *fifo, struct scatterlist *sgl, + int nents, unsigned int len, unsigned int off, dma_addr_t dma) +{ + unsigned int size = fifo->mask + 1; + unsigned int esize = fifo->esize; + unsigned int len_to_end; + unsigned int n; + + off &= fifo->mask; + if (esize != 1) { + off *= esize; + size *= esize; + len *= esize; + } + len_to_end = min(len, size - off); + + n = setup_sgl_buf(fifo, sgl, off, nents, len_to_end, dma); + n += setup_sgl_buf(fifo, sgl + n, 0, nents - n, len - len_to_end, dma); + + return n; +} + +unsigned int __kfifo_dma_in_prepare(struct __kfifo *fifo, + struct scatterlist *sgl, int nents, unsigned int len, + dma_addr_t dma) +{ + unsigned int l; + + l = kfifo_unused(fifo); + if (len > l) + len = l; + + return setup_sgl(fifo, sgl, nents, len, fifo->in, dma); +} +EXPORT_SYMBOL(__kfifo_dma_in_prepare); + +unsigned int __kfifo_dma_out_prepare(struct __kfifo *fifo, + struct scatterlist *sgl, int nents, unsigned int len, + dma_addr_t dma) +{ + unsigned int l; + + l = fifo->in - fifo->out; + if (len > l) + len = l; + + return setup_sgl(fifo, sgl, nents, len, fifo->out, dma); +} +EXPORT_SYMBOL(__kfifo_dma_out_prepare); + +unsigned int __kfifo_max_r(unsigned int len, size_t recsize) +{ + unsigned int max = (1 << (recsize << 3)) - 1; + + if (len > max) + return max; + return len; +} +EXPORT_SYMBOL(__kfifo_max_r); + +#define __KFIFO_PEEK(data, out, mask) \ + ((data)[(out) & (mask)]) +/* + * __kfifo_peek_n internal helper function for determinate the length of + * the next record in the fifo + */ +static unsigned int __kfifo_peek_n(struct __kfifo *fifo, size_t recsize) +{ + unsigned int l; + unsigned int mask = fifo->mask; + unsigned char *data = fifo->data; + + l = __KFIFO_PEEK(data, fifo->out, mask); + + if (--recsize) + l |= __KFIFO_PEEK(data, fifo->out + 1, mask) << 8; + + return l; +} + +#define __KFIFO_POKE(data, in, mask, val) \ + ( \ + (data)[(in) & (mask)] = (unsigned char)(val) \ + ) + +/* + * __kfifo_poke_n internal helper function for storing the length of + * the record into the fifo + */ +static void __kfifo_poke_n(struct __kfifo *fifo, unsigned int n, size_t recsize) +{ + unsigned int mask = fifo->mask; + unsigned char *data = fifo->data; + + __KFIFO_POKE(data, fifo->in, mask, n); + + if (recsize > 1) + __KFIFO_POKE(data, fifo->in + 1, mask, n >> 8); +} + +unsigned int __kfifo_len_r(struct __kfifo *fifo, size_t recsize) +{ + return __kfifo_peek_n(fifo, recsize); +} +EXPORT_SYMBOL(__kfifo_len_r); + +unsigned int __kfifo_in_r(struct __kfifo *fifo, const void *buf, + unsigned int len, size_t recsize) +{ + if (len + recsize > kfifo_unused(fifo)) + return 0; + + __kfifo_poke_n(fifo, len, recsize); + + kfifo_copy_in(fifo, buf, len, fifo->in + recsize); + fifo->in += len + recsize; + return len; +} +EXPORT_SYMBOL(__kfifo_in_r); + +static unsigned int kfifo_out_copy_r(struct __kfifo *fifo, + void *buf, unsigned int len, size_t recsize, unsigned int *n) +{ + *n = __kfifo_peek_n(fifo, recsize); + + if (len > *n) + len = *n; + + kfifo_copy_out(fifo, buf, len, fifo->out + recsize); + return len; +} + +unsigned int __kfifo_out_peek_r(struct __kfifo *fifo, void *buf, + unsigned int len, size_t recsize) +{ + unsigned int n; + + if (fifo->in == fifo->out) + return 0; + + return kfifo_out_copy_r(fifo, buf, len, recsize, &n); +} +EXPORT_SYMBOL(__kfifo_out_peek_r); + +unsigned int __kfifo_out_linear_r(struct __kfifo *fifo, + unsigned int *tail, unsigned int n, size_t recsize) +{ + if (fifo->in == fifo->out) + return 0; + + if (tail) + *tail = fifo->out + recsize; + + return min(n, __kfifo_peek_n(fifo, recsize)); +} +EXPORT_SYMBOL(__kfifo_out_linear_r); + +unsigned int __kfifo_out_r(struct __kfifo *fifo, void *buf, + unsigned int len, size_t recsize) +{ + unsigned int n; + + if (fifo->in == fifo->out) + return 0; + + len = kfifo_out_copy_r(fifo, buf, len, recsize, &n); + fifo->out += n + recsize; + return len; +} +EXPORT_SYMBOL(__kfifo_out_r); + +void __kfifo_skip_r(struct __kfifo *fifo, size_t recsize) +{ + unsigned int n; + + n = __kfifo_peek_n(fifo, recsize); + fifo->out += n + recsize; +} +EXPORT_SYMBOL(__kfifo_skip_r); + +int __kfifo_from_user_r(struct __kfifo *fifo, const void __user *from, + unsigned long len, unsigned int *copied, size_t recsize) +{ + unsigned long ret; + + len = __kfifo_max_r(len, recsize); + + if (len + recsize > kfifo_unused(fifo)) { + *copied = 0; + return 0; + } + + __kfifo_poke_n(fifo, len, recsize); + + ret = kfifo_copy_from_user(fifo, from, len, fifo->in + recsize, copied); + if (unlikely(ret)) { + *copied = 0; + return -EFAULT; + } + fifo->in += len + recsize; + return 0; +} +EXPORT_SYMBOL(__kfifo_from_user_r); + +int __kfifo_to_user_r(struct __kfifo *fifo, void __user *to, + unsigned long len, unsigned int *copied, size_t recsize) +{ + unsigned long ret; + unsigned int n; + + if (fifo->in == fifo->out) { + *copied = 0; + return 0; + } + + n = __kfifo_peek_n(fifo, recsize); + if (len > n) + len = n; + + ret = kfifo_copy_to_user(fifo, to, len, fifo->out + recsize, copied); + if (unlikely(ret)) { + *copied = 0; + return -EFAULT; + } + fifo->out += n + recsize; + return 0; +} +EXPORT_SYMBOL(__kfifo_to_user_r); + +unsigned int __kfifo_dma_in_prepare_r(struct __kfifo *fifo, + struct scatterlist *sgl, int nents, unsigned int len, size_t recsize, + dma_addr_t dma) +{ + BUG_ON(!nents); + + len = __kfifo_max_r(len, recsize); + + if (len + recsize > kfifo_unused(fifo)) + return 0; + + return setup_sgl(fifo, sgl, nents, len, fifo->in + recsize, dma); +} +EXPORT_SYMBOL(__kfifo_dma_in_prepare_r); + +void __kfifo_dma_in_finish_r(struct __kfifo *fifo, + unsigned int len, size_t recsize) +{ + len = __kfifo_max_r(len, recsize); + __kfifo_poke_n(fifo, len, recsize); + fifo->in += len + recsize; +} +EXPORT_SYMBOL(__kfifo_dma_in_finish_r); + +unsigned int __kfifo_dma_out_prepare_r(struct __kfifo *fifo, + struct scatterlist *sgl, int nents, unsigned int len, size_t recsize, + dma_addr_t dma) +{ + BUG_ON(!nents); + + len = __kfifo_max_r(len, recsize); + + if (len + recsize > fifo->in - fifo->out) + return 0; + + return setup_sgl(fifo, sgl, nents, len, fifo->out + recsize, dma); +} +EXPORT_SYMBOL(__kfifo_dma_out_prepare_r); + |
