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d2f025b08e
Clean up the code to use the "mmc" directly instead of "host->mmc".
If the code sits in hot code path, this clean up also brings trvial
performance improvement. Take the sdhci_post_req() for example:
before the patch:
...
8d0: a9be7bfd stp x29, x30, [sp, #-32]!
8d4: 910003fd mov x29, sp
8d8: f9000bf3 str x19, [sp, #16]
8dc: f9400833 ldr x19, [x1, #16]
8e0: b9404261 ldr w1, [x19, #64]
8e4: 34000161 cbz w1, 910 <sdhci_post_req+0x50>
8e8: f9424400 ldr x0, [x0, #1160]
8ec: d2800004 mov x4, #0x0 // #0
8f0: b9401a61 ldr w1, [x19, #24]
8f4: b9403262 ldr w2, [x19, #48]
8f8: f9400000 ldr x0, [x0]
8fc: f278003f tst x1, #0x100
900: f9401e61 ldr x1, [x19, #56]
904: 1a9f17e3 cset w3, eq // eq = none
908: 11000463 add w3, w3, #0x1
90c: 94000000 bl 0 <dma_unmap_sg_attrs>
...
After the patch:
...
8d0: a9be7bfd stp x29, x30, [sp, #-32]!
8d4: 910003fd mov x29, sp
8d8: f9000bf3 str x19, [sp, #16]
8dc: f9400833 ldr x19, [x1, #16]
8e0: b9404261 ldr w1, [x19, #64]
8e4: 34000141 cbz w1, 90c <sdhci_post_req+0x4c>
8e8: b9401a61 ldr w1, [x19, #24]
8ec: d2800004 mov x4, #0x0 // #0
8f0: b9403262 ldr w2, [x19, #48]
8f4: f9400000 ldr x0, [x0]
8f8: f278003f tst x1, #0x100
8fc: f9401e61 ldr x1, [x19, #56]
900: 1a9f17e3 cset w3, eq // eq = none
904: 11000463 add w3, w3, #0x1
908: 94000000 bl 0 <dma_unmap_sg_attrs>
...
We saved one ldr instruction: "ldr x0, [x0, #1160]"
Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20210311174046.597d1951@xhacker.debian
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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.
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.