[PATCH v13 08/25] x86/resctrl: Update special case for Intel Haswell enumeration

[Tony Luck]

Certain Intel Haswell CPUs support resctrl L3 cache allocation but do not
enumerate the feature. A quirk probes for support and provides hard-coded
parameters. The quirk sets both the global rdt_alloc_capable and the resource
specific rdt_resource::alloc_capable, only the global is used to signal that
normal enumeration can be skipped.

The global rdt_alloc_capable is redundant since rdt_resource::alloc_capable
already carries the same information.

Stop setting rdt_alloc_capable in the quirk and rely on the resource specific
flag to prepare for removal of this global variable.

No functional change intended.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
---
v13:
	Replaced commit comment with Reinette's improved version.
---
 arch/x86/kernel/cpu/resctrl/core.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c
index f0cfb37482d3..f2bf160d01c1 100644
--- a/arch/x86/kernel/cpu/resctrl/core.c
+++ b/arch/x86/kernel/cpu/resctrl/core.c
@@ -177,8 +177,6 @@ static inline void cache_alloc_hsw_probe(void)
 	r->cache.min_cbm_bits = 2;
 	r->cache.arch_has_sparse_bitmasks = false;
 	r->alloc_capable = true;
-
-	rdt_alloc_capable = true;
 }
 
 /*
@@ -930,7 +928,11 @@ static __init bool get_rdt_alloc_resources(void)
 	struct rdt_resource *r;
 	bool ret = false;
 
-	if (rdt_alloc_capable)
+	/*
+	 * On Haswell systems cache_alloc_hsw_probe() already marked
+	 * RDT_RESOURCE_L3 as alloc_capable. No further enumeration is needed.
+	 */
+	if (resctrl_alloc_capable())
 		return true;
 
 	if (!boot_cpu_has(X86_FEATURE_RDT_A))
-- 
2.55.0