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gpu: nvgpu: add Doxygen documentation for bitops

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Add Doxygen documentation details for bitops unit.

Jira NVGPU-2596

Change-Id: I5eb268fd24466c35cbddee1547f8b7205c9421c1
Signed-off-by: ajesh <akv@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/2201232
Reviewed-by: Automatic_Commit_Validation_User
GVS: Gerrit_Virtual_Submit
Reviewed-by: Philip Elcan <pelcan@nvidia.com>
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>
This commit is contained in:
ajesh
2019-09-19 10:46:27 +05:30
committed by Alex Waterman
parent b31038728f
commit cb97705055
1 changed files with 227 additions and 2 deletions
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229
drivers/gpu/nvgpu/include/nvgpu/posix/bitops.h
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@@ -28,16 +28,45 @@
/*
* Assume an 8 bit byte, of course.
*/
/**
* Number of bits in a byte.
*/
#define BITS_PER_BYTE 8UL
/**
* Number of bits in data type long.
*/
#define BITS_PER_LONG ((unsigned long)__SIZEOF_LONG__ * BITS_PER_BYTE)
/**
* @brief Convert number of bits into long.
*
* @param bits [in] Number of bits to convert.
*
* Converts the input param \a bits into equivalent number of long.
*/
#define BITS_TO_LONGS(bits) \
(nvgpu_safe_add_u64(bits, BITS_PER_LONG - 1UL) / BITS_PER_LONG)
/*
/**
* @brief Set the bit value.
*
* @param i [in] Bit position to set.
*
* Invokes #BIT64 to set the value at bit position indicated by \a i.
* Deprecated; use the explicit BITxx() macros instead.
*/
#define BIT(i) BIT64(i)
/**
* @brief Create a bit mask.
*
* @param hi [in] MSB position of the bit mask.
* @param lo [in] LSB position of the bit mask.
*
* Creates a bit mask starting at bit position lo and ending at hi.
*/
#define GENMASK(hi, lo) \
(((~0UL) - (1UL << (lo)) + 1UL) & \
(~0UL >> (BITS_PER_LONG - 1UL - (unsigned long)(hi))))
@@ -46,49 +75,245 @@
* Can't use BITS_TO_LONGS to declare arrays where we can't use BUG(), so if the
* range is invalid, use -1 for the size which will generate a compiler error.
*/
/**
* @brief Create an array of unsigned long to represent a bitmap.
*
* @param bmap [in] Bitmap to create.
* @param bits [in] Number of bits.
*
* Creates an array of data type unsigned long by name \a bmap. The size of the
* array is taken as \a bits value converted into an equivalent rounded up long
* value if the rounded up value is less than or equal to #LONG_MAX. Otherwise
* the array declaration will generate a compiler error.
*/
#define DECLARE_BITMAP(bmap, bits) \
unsigned long bmap[(((LONG_MAX - (bits)) < (BITS_PER_LONG - 1UL)) ? \
-1 : \
(long int)(((bits) + BITS_PER_LONG - 1UL) / \
BITS_PER_LONG))]
/**
* @brief Loop for each set bit.
*
* @param bit [in] Each set bit, this is the loop index.
* @param addr [in] Starting of the bitmap.
* @param size [in] Size of the bitmap.
*/
#define for_each_set_bit(bit, addr, size) \
for ((bit) = find_first_bit((addr), (size)); \
(bit) < (size); \
(bit) = find_next_bit((addr), (size), (bit) + 1U))
/**
* @brief Find first set bit.
*
* @param word [in] Input of datatype long.
*
* Function returns the position of the first set bit in \a word.
*
* @return Returns one plus the index of the least significant 1-bit of input
* param \a word. Returns 0 if input param is 0.
*/
unsigned long nvgpu_posix_ffs(unsigned long word);
/**
* @brief Find last set bit.
*
* @param word [in] Input of datatype long.
*
* Function returns the position of the last set bit in \a word.
*
* @return Returns one plus the index of the most significant 1-bit of input
* param word. If input param is 0, returns 0.
*/
unsigned long nvgpu_posix_fls(unsigned long word);
/**
* Wrapper define for #nvgpu_posix_ffs.
*/
#define nvgpu_ffs(word) nvgpu_posix_ffs(word)
/**
* Wrapper define for #nvgpu_posix_fls.
*/
#define nvgpu_fls(word) nvgpu_posix_fls(word)
/**
* @brief Find first zero bit.
*
* @param word [in] Input value to search for the bit.
*
* Macro to find the position of first zero bit in input data \a word.
*
* @return Returns the bit position of first zero bit in the input data.
*/
#define ffz(word) (nvgpu_ffs(~(word)) - 1UL)
/**
* @brief Find the first set bit.
*
* @param addr [in] Input value to search for set bit.
* @param size [in] Size of the input value in bits.
*
* Finds the first set bit position in the input data \a addr.
*
* @return Returns the position of first set bit.
*/
unsigned long find_first_bit(const unsigned long *addr, unsigned long size);
/**
* @brief Finds the next set bit.
*
* @param addr [in] Input value to search for next set bit.
* @param size [in] Size of the input value in bits.
* @param offset [in] Offset to start from the input data.
*
* Finds the next set bit position in the input data \a addr.
*
* @return Returns the position of next set bit.
*/
unsigned long find_next_bit(const unsigned long *addr, unsigned long size,
unsigned long offset);
/**
* @brief Finds the first zero bit.
*
* @param addr [in] Input value to search.
* @param size [in] Size of the input value in bits.
*
* Finds the first zero bit position in the input data \a addr.
*
* @return Returns the position of first zero bit.
*/
unsigned long find_first_zero_bit(const unsigned long *addr,
unsigned long size);
/**
* @brief Test the bit value at given position.
*
* @param nr [in] Bit position to check.
* @param addr [in] Input data stream.
*
* Checks if the bit at position mentioned by \a nr in \a addr is set or not.
*
* @return Returns true if bit position \a nr is set, else returns false.
*/
bool nvgpu_test_bit(unsigned int nr, const volatile unsigned long *addr);
/**
* @brief Test and set the bit at given position.
*
* @param nr [in] Bit position to test and set.
* @param addr [in] Input data stream.
*
* Tests and sets the bit at position \a nr in \a addr.
*
* @return Returns true if the bit position was already set, else returns false.
*/
bool nvgpu_test_and_set_bit(unsigned int nr, volatile unsigned long *addr);
/**
* @brief Test and clear the bit at given position.
*
* @param nr [in] Bit position to test and clear.
* @param addr [in] Input data stream.
*
* Tests and clears the bit at position \a nr in \a addr.
*
* @return Returns true if the bit position was already set, else returns false.
*/
bool nvgpu_test_and_clear_bit(unsigned int nr, volatile unsigned long *addr);
/*
* These two are atomic.
*/
/**
* @brief Sets the bit at given position.
*
* @param nr [in] Bit position to set.
* @param addr [in] Input data stream.
*
* Sets the bit atomically at bit position \a nr in \a addr.
*/
void nvgpu_set_bit(unsigned int nr, volatile unsigned long *addr);
/**
* @brief Clears the bit at given position.
*
* @param nr [in] Bit position to clear.
* @param addr [in] Input data stream.
*
* Clears the bit atomically at bit position \a nr in \a addr.
*/
void nvgpu_clear_bit(unsigned int nr, volatile unsigned long *addr);
/**
* @brief Sets a bitmap.
*
* @param map [in,out] Input data to set bitmap.
* @param start [in] Start position of the bitmap.
* @param len [in] Length of the bitmap.
*
* Sets a bitmap of length \a len starting from bit position \a start in
* \a map.
*/
void nvgpu_bitmap_set(unsigned long *map, unsigned int start, unsigned int len);
void nvgpu_bitmap_clear(unsigned long *map, unsigned int start, unsigned int len);
/**
* @brief Clears a bitmap.
*
* @param map [in,out] Input data to clear bitmap.
* @param start [in] Start position of the bitmap.
* @param len [in] Length of the bitmap.
*
* Clears a bitmap of length \a len starting from bit position \a start in
* \a map.
*/
void nvgpu_bitmap_clear(unsigned long *map, unsigned int start,
unsigned int len);
/**
* @brief Find first bitmap space from an offset.
*
* @param map [in] Input data stream.
* @param size [in] Size of the input data.
* @param start [in] Start position in input.
* @param nr [in] Number of bits in bitmap.
* @param align_mask [in] Align mask for start.
* @param align_offset [in] Align offset from Input data.
*
* Finds the first space of contiguous zeros in input data stream which can
* accommodate a bitmap of length \a nr starting from position \a start.
*
* @return Returns the position at which the bitmap starts if enough free space
* is present in the input stream to accommodate the bitmap; otherwise, return
* the size of the input data.
*/
unsigned long bitmap_find_next_zero_area_off(unsigned long *map,
unsigned long size,
unsigned long start,
unsigned int nr,
unsigned long align_mask,
unsigned long align_offset);
/**
* @brief Find first bitmap space.
*
* @param map [in] Input data stream.
* @param size [in] Size of the input data.
* @param start [in] Start position in input.
* @param nr [in] Number of bits in bitmap.
* @param align_mask [in] Align mask for start.
*
* Searches a bitmap for the first space of contiguous zeros that is large
* enough to accommodate the requested number of bits.
*
* @return Returns the position at which the bitmap starts if enough free space
* is present in the input stream to accommodate the bitmap; otherwise, return
* the size of the input data.
*/
unsigned long bitmap_find_next_zero_area(unsigned long *map,
unsigned long size,
unsigned long start,