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x86/resctrl: Use __set_bit()/__clear_bit() instead of open coding

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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>
This commit is contained in:
James Morse 2024-02-13 18:44:23 +00:00 committed by Borislav Petkov (AMD)
parent b30a55df60
commit 5d920b6881
1 changed files with 12 additions and 6 deletions
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18
arch/x86/kernel/cpu/resctrl/rdtgroup.c
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@ -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);
}
/**