[RFC PATCH 21/31] x86/resctrl: Parse ACPI MARC table

[Chen Yu]

The MARC table is used to provide Memory Bandwidth Allocation Register
information. Its register addresses are mapped, and the MARC pointer
is saved in the corresponding domain information entry.

Signed-off-by: Chen Yu <yu.c.chen@xxxxxxxxx>
---
 arch/x86/kernel/cpu/resctrl/erdt.c     | 70 ++++++++++++++++++++++++++
 arch/x86/kernel/cpu/resctrl/internal.h | 10 +++-
 2 files changed, 79 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/erdt.c b/arch/x86/kernel/cpu/resctrl/erdt.c
index d16cd6af6648..c44e1d00b89f 100644
--- a/arch/x86/kernel/cpu/resctrl/erdt.c
+++ b/arch/x86/kernel/cpu/resctrl/erdt.c
@@ -25,8 +25,13 @@ static bool erdt_enabled;
 #define ERDT_VALID_VERSION		1
 #define CMRC_SUPPORTED_INDEX_FN		1
 #define MMRC_SUPPORTED_INDEX_FN		1
+#define MARC_SUPPORTED_INDEX_FN		1
 #define RMDD_FLAG_CPU_L3_DOMAIN		BIT(0)
 
+#define MARC_FLAG_OPT			BIT(0)
+#define MARC_FLAG_MIN			BIT(1)
+#define MARC_FLAG_MAX			BIT(2)
+
 /* Set in a monitoring counter when it holds no valid data to report. */
 #define UNAVAILABLE_COUNTER		BIT_ULL(63)
 #define CMRC_FLAG_UNAVAILABLE_BIT	BIT(0)
@@ -283,6 +288,7 @@ static void cleanup_one_domain(struct erdt_domain_info *d)
 	erdt_iounmap_domain(d);
 	kfree(d->cmrc);
 	kfree(d->mmrc);
+	kfree(d->marc);
 	kfree(d);
 }
 
@@ -396,6 +402,64 @@ static __init int mmrc_init(struct acpi_subtbl_hdr_16 *subtbl,
 	return 0;
 }
 
+static __init int marc_init(struct acpi_subtbl_hdr_16 *subtbl,
+			    struct erdt_domain_info *domain_info)
+{
+	struct acpi_erdt_marc *marc = (struct acpi_erdt_marc *)subtbl;
+
+	if (subtbl->length < sizeof(*marc)) {
+		pr_warn(FW_BUG "Truncated MARC subtable\n");
+		return -EIO;
+	}
+
+	if (marc->index_fn != MARC_SUPPORTED_INDEX_FN) {
+		pr_info("Unsupported MARC index function %d\n", marc->index_fn);
+		return -EIO;
+	}
+
+	if (marc->flags & MARC_FLAG_OPT) {
+		domain_info->base[ERDT_MMIO_MARC_OPT] =
+			erdt_ioremap(marc->reg_base_opt, marc->mba_reg_size, "MARC OPT base");
+		if (!domain_info->base[ERDT_MMIO_MARC_OPT])
+			return -EIO;
+	}
+
+	if (marc->flags & MARC_FLAG_MIN) {
+		domain_info->base[ERDT_MMIO_MARC_MIN] =
+			erdt_ioremap(marc->reg_base_min, marc->mba_reg_size, "MARC MIN base");
+		if (!domain_info->base[ERDT_MMIO_MARC_MIN])
+			goto unmap;
+	}
+
+	if (marc->flags & MARC_FLAG_MAX) {
+		domain_info->base[ERDT_MMIO_MARC_MAX] =
+			erdt_ioremap(marc->reg_base_max, marc->mba_reg_size, "MARC MAX base");
+		if (!domain_info->base[ERDT_MMIO_MARC_MAX])
+			goto unmap;
+	}
+
+	domain_info->marc = kmemdup(marc, subtbl->length, GFP_KERNEL);
+	if (!domain_info->marc)
+		goto unmap;
+
+	return 0;
+
+unmap:
+	if (domain_info->base[ERDT_MMIO_MARC_OPT]) {
+		iounmap(domain_info->base[ERDT_MMIO_MARC_OPT]);
+		domain_info->base[ERDT_MMIO_MARC_OPT] = NULL;
+	}
+	if (domain_info->base[ERDT_MMIO_MARC_MIN]) {
+		iounmap(domain_info->base[ERDT_MMIO_MARC_MIN]);
+		domain_info->base[ERDT_MMIO_MARC_MIN] = NULL;
+	}
+	if (domain_info->base[ERDT_MMIO_MARC_MAX]) {
+		iounmap(domain_info->base[ERDT_MMIO_MARC_MAX]);
+		domain_info->base[ERDT_MMIO_MARC_MAX] = NULL;
+	}
+	return -EIO;
+}
+
 static inline struct acpi_subtbl_hdr_16 *rmdd_subtbl(struct acpi_erdt_rmdd *rmdd)
 {
 	return (void *)rmdd + sizeof(*rmdd);
@@ -478,6 +542,12 @@ static __init bool parse_rmdd_table(struct acpi_subtbl_hdr_16 *rmdd_hdr)
 			    !mmrc_init(subtbl, domain_info))
 				subtbl_mask |= BIT(ACPI_ERDT_TYPE_MMRC);
 
+			break;
+		case ACPI_ERDT_TYPE_MARC:
+			if (!(subtbl_mask & BIT(ACPI_ERDT_TYPE_MARC)) &&
+			    !marc_init(subtbl, domain_info))
+				subtbl_mask |= BIT(ACPI_ERDT_TYPE_MARC);
+
 			break;
 		default:
 			break;
diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
index ca9124e9aea5..6855022bf07e 100644
--- a/arch/x86/kernel/cpu/resctrl/internal.h
+++ b/arch/x86/kernel/cpu/resctrl/internal.h
@@ -26,12 +26,18 @@
  * @ERDT_MMIO_RMDD_CREG: RMDD control register base address
  * @ERDT_MMIO_CMRC_BASE: CMRC monitoring register base address
  * @ERDT_MMIO_MMRC_BASE: MMRC monitoring register base address
+ * @ERDT_MMIO_MARC_OPT:  MARC optimal BW register base address
+ * @ERDT_MMIO_MARC_MIN:  MARC minimum BW register base address
+ * @ERDT_MMIO_MARC_MAX:  MARC maximum BW register base address
  */
 enum erdt_mmio_type {
 	ERDT_MMIO_RMDD_CREG,
 	ERDT_MMIO_CMRC_BASE,
 	ERDT_MMIO_MMRC_BASE,
-	ERDT_MMIO_LAST = ERDT_MMIO_MMRC_BASE
+	ERDT_MMIO_MARC_OPT,
+	ERDT_MMIO_MARC_MIN,
+	ERDT_MMIO_MARC_MAX,
+	ERDT_MMIO_LAST = ERDT_MMIO_MARC_MAX
 };
 
 #define ERDT_MMIO_NUM_TYPES	(ERDT_MMIO_LAST + 1)
@@ -41,6 +47,7 @@ enum erdt_mmio_type {
  * @base:	Array of ioremapped MMIO region base addresses, indexed by ERDT_MMIO_* type
  * @cmrc:	Copy of the ACPI CMRC sub-table for this domain
  * @mmrc:	Copy of the ACPI MMRC sub-table for this domain
+ * @marc:	Copy of the ACPI MARC sub-table for this domain
  * @cpu_mask:	CPUs belonging to this resource management domain
  * @max_rmid:	Maximum RMID supported by this domain
  * @dom_id:	L3 cache ID shared by all CPUs in this domain (-1 if unset)
@@ -50,6 +57,7 @@ struct erdt_domain_info {
 	void __iomem		*base[ERDT_MMIO_NUM_TYPES];
 	struct acpi_erdt_cmrc	*cmrc;
 	struct acpi_erdt_mmrc	*mmrc;
+	struct acpi_erdt_marc	*marc;
 	struct cpumask		cpu_mask;
 	u32			max_rmid;
 	int			dom_id;
-- 
2.43.0