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| author | James Morse <james.morse@arm.com> | 2024-02-13 18:44:23 +0000 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2024-02-16 19:18:31 +0100 |
| commit | 5d920b6881f2249be3a028ce0a7f31c5cc61b1ee (patch) | |
| tree | 45aa379268c18aa0d05af6a66c621f7f3787fe19 | |
| parent | b30a55df60c35df09b9ef08dfb0a0cbb543abe81 (diff) | |
| download | linux-5d920b6881f2249be3a028ce0a7f31c5cc61b1ee.tar.gz linux-5d920b6881f2249be3a028ce0a7f31c5cc61b1ee.tar.bz2 linux-5d920b6881f2249be3a028ce0a7f31c5cc61b1ee.zip | |
x86/resctrl: Use __set_bit()/__clear_bit() instead of open coding
The resctrl CLOSID allocator uses a single 32bit word to track which
CLOSID are free. The setting and clearing of bits is open coded.
Convert the existing open coded bit manipulations of closid_free_map
to use __set_bit() and friends. These don't need to be atomic as this
list is protected by the mutex.
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Babu Moger <babu.moger@amd.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
Link: https://lore.kernel.org/r/20240213184438.16675-10-james.morse@arm.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
| -rw-r--r-- | arch/x86/kernel/cpu/resctrl/rdtgroup.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index dcffd1c4a476..bc6e0f83c847 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -111,7 +111,7 @@ void rdt_staged_configs_clear(void) * - Our choices on how to configure each resource become progressively more * limited as the number of resources grows. */ -static int closid_free_map; +static unsigned long closid_free_map; static int closid_free_map_len; int closids_supported(void) @@ -130,8 +130,8 @@ static void closid_init(void) closid_free_map = BIT_MASK(rdt_min_closid) - 1; - /* CLOSID 0 is always reserved for the default group */ - closid_free_map &= ~1; + /* RESCTRL_RESERVED_CLOSID is always reserved for the default group */ + __clear_bit(RESCTRL_RESERVED_CLOSID, &closid_free_map); closid_free_map_len = rdt_min_closid; } @@ -139,17 +139,21 @@ static int closid_alloc(void) { u32 closid = ffs(closid_free_map); + lockdep_assert_held(&rdtgroup_mutex); + if (closid == 0) return -ENOSPC; closid--; - closid_free_map &= ~(1 << closid); + __clear_bit(closid, &closid_free_map); return closid; } void closid_free(int closid) { - closid_free_map |= 1 << closid; + lockdep_assert_held(&rdtgroup_mutex); + + __set_bit(closid, &closid_free_map); } /** @@ -161,7 +165,9 @@ void closid_free(int closid) */ static bool closid_allocated(unsigned int closid) { - return (closid_free_map & (1 << closid)) == 0; + lockdep_assert_held(&rdtgroup_mutex); + + return !test_bit(closid, &closid_free_map); } /** |