From: Todd Poynor <toddpoynor@gmail.com>
To: Rob Springer <rspringer@google.com>,
Ben Chan <benchan@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org,
Nick Ewalt <nicholasewalt@google.com>,
Todd Poynor <toddpoynor@google.com>
Subject: [PATCH 08/11] staging: gasket: page_table: simplify gasket_components_to_dev_address
Date: Sun, 14 Oct 2018 21:59:24 -0700 [thread overview]
Message-ID: <20181015045927.156790-9-toddpoynor@gmail.com> (raw)
In-Reply-To: <20181015045927.156790-1-toddpoynor@gmail.com>
From: Nick Ewalt <nicholasewalt@google.com>
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>
---
drivers/staging/gasket/gasket_page_table.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)
diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index ec9359576ea7c..c2fbab74194f8 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -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);
}
/*
--
2.19.0.605.g01d371f741-goog
next prev parent reply other threads:[~2018-10-15 5:00 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-15 4:59 [PATCH 00/11] staging: gasket: fixes Todd Poynor
2018-10-15 4:59 ` [PATCH 01/11] staging: gasket: core: debug log updates Todd Poynor
2018-10-15 7:34 ` Greg Kroah-Hartman
2018-10-15 20:33 ` Todd Poynor
2018-10-15 4:59 ` [PATCH 02/11] staging: gasket: page table: return valid error code on map fail Todd Poynor
2018-10-15 4:59 ` [PATCH 03/11] staging: gasket: page table: remove dead code in coherent mem alloc Todd Poynor
2018-10-15 4:59 ` [PATCH 04/11] staging: gasket: page_table: remove unnecessary PTE status set to free Todd Poynor
2018-10-15 4:59 ` [PATCH 05/11] staging: gasket: page_table: rearrange gasket_page_table_entry Todd Poynor
2018-10-15 7:37 ` Greg Kroah-Hartman
2018-10-15 4:59 ` [PATCH 06/11] staging: gasket: page table: fixup error path allocating coherent mem Todd Poynor
2018-10-15 4:59 ` [PATCH 07/11] staging: gasket: page_table: fix comment in components_to_dev_address Todd Poynor
2018-10-15 4:59 ` Todd Poynor [this message]
2018-10-15 4:59 ` [PATCH 09/11] staging: gasket: apex: fix sysfs_show Todd Poynor
2018-10-15 4:59 ` [PATCH 10/11] staging: gasket: sysfs: fix attribute release comment Todd Poynor
2018-10-15 4:59 ` [PATCH 11/11] staging: gasket: Update device virtual address comment Todd Poynor
2018-10-15 7:33 ` [PATCH 00/11] staging: gasket: fixes Greg Kroah-Hartman
2018-10-15 10:19 ` Todd Poynor
2018-10-15 10:29 ` Christoph Hellwig
2018-10-15 10:35 ` Greg Kroah-Hartman
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