74522a92bb
For every IO, memory of PAGE size is allocated for handling NVMe native PRPS. And in addition to that for every IO (chains need per IO * chain buffer size, e.g. 38 * 128byte) amount of memory is allocated for chain buffers. However, at any point of time; the IO request can be for NVMe target device (where PRP's page is used for framing PRP's) or can be for SCSI target device (where chain buffers are used for framing chain SGE's). This patch modifies the driver to reuse same pre-allocated PRP page buffers as a chain buffer for IO's targeted for SCSI target devices. No need to allocate separate buffers for chain SGE's buffers. Suppose if the number of chain buffers need for IO doesn't fit in the PRP Page size then driver maintain's separate buffers for those extra chain buffers that exceeds the PRP page size. For example consider PRP page size as 4K and chain buffer size as 128 bytes, then number of chain buffers that can fit in PRP page is 4096/128 => 32. if the number of chain buffer need per IO exceeds 32; for example consider number of chains need per IO is 36 then for remaining 4 chain buffer's driver allocates them individual. Signed-off-by: Chaitra P B <chaitra.basappa@broadcom.com> Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.