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staging: gasket: page_table: simplify gasket_components_to_dev_address 

Refactor gasket_components_to_dev_address to be faster and easier to
understand. The old implementation was unnecessarily complex and masked
the page_index for simple addresses but not extended ones. It makes the
most sense for this function to perform no such masking.

Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Nick Ewalt 2018-10-14 21:59:24 -07:00 committed by Greg Kroah-Hartman
parent bae54fb812
commit 4a966fa24a
1 changed files with 2 additions and 19 deletions
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21
drivers/staging/gasket/gasket_page_table.c
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@ -699,26 +699,9 @@ static ulong gasket_components_to_dev_address(struct gasket_page_table *pg_tbl,
int is_simple, uint page_index,
uint offset)
{
ulong lvl0_index, lvl1_index;
ulong dev_addr = (page_index << GASKET_SIMPLE_PAGE_SHIFT) | offset;
if (is_simple) {
/* Return simple addresses directly. */
lvl0_index = page_index & (pg_tbl->config.total_entries - 1);
return (lvl0_index << GASKET_SIMPLE_PAGE_SHIFT) | offset;
}
/*
* This could be compressed into fewer statements, but
* A) the compiler should optimize it
* B) this is not slow
* C) this is an uncommon operation
* D) this is actually readable this way.
*/
lvl0_index = page_index / GASKET_PAGES_PER_SUBTABLE;
lvl1_index = page_index & (GASKET_PAGES_PER_SUBTABLE - 1);
return (pg_tbl)->extended_flag |
(lvl0_index << GASKET_EXTENDED_LVL0_SHIFT) |
(lvl1_index << GASKET_EXTENDED_LVL1_SHIFT) | offset;
return is_simple ? dev_addr : (pg_tbl->extended_flag | dev_addr);
}
/*