acpi: Add initial support for CEDT

Add initial CEDT (CXL Early Discovery Table) support based on
CXL spec 2.0 section 9.14.1.

Add functions to create CEDT table (revision 1), and create CEDT
CXL Host Bridge Structure (CHBS) and CXL Fixed Memory Windows
Structure (CFMWS).

TESTED=Create CEDT table on Intel Archer City CRB, dumped the
CEDT table and examined the content.

Signed-off-by: Jonathan Zhang <jonzhang@fb.com>
Change-Id: I4fbce78efc86ad9f2468c37b4827a6dadbdc6802
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64263
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/src/acpi/acpi.c b/src/acpi/acpi.c
index e1d40881c2..8d81284ced 100644
--- a/src/acpi/acpi.c
+++ b/src/acpi/acpi.c
@@ -575,6 +575,90 @@ void acpi_create_srat(acpi_srat_t *srat,
 	header->checksum = acpi_checksum((void *)srat, header->length);
 }
 
+int acpi_create_cedt_chbs(acpi_cedt_chbs_t *chbs, u32 uid, u32 cxl_ver, u64 base)
+{
+	memset((void *)chbs, 0, sizeof(acpi_cedt_chbs_t));
+
+	chbs->type = ACPI_CEDT_STRUCTURE_CHBS;
+	chbs->length = sizeof(acpi_cedt_chbs_t);
+	chbs->uid = uid;
+	chbs->cxl_ver = cxl_ver;
+	chbs->base = base;
+
+	/*
+	 * CXL spec 2.0 section 9.14.1.2 "CXL CHBS"
+	 * CXL 1.1 spec compliant host bridge: 8KB
+	 * CXL 2.0 spec compliant host bridge: 64KB
+	 */
+	if (cxl_ver == ACPI_CEDT_CHBS_CXL_VER_1_1)
+		chbs->len = 8 * KiB;
+	else if (cxl_ver == ACPI_CEDT_CHBS_CXL_VER_2_0)
+		chbs->len = 64 * KiB;
+	else
+		printk(BIOS_ERR, "ACPI(%s:%s): Incorrect CXL version:%d\n", __FILE__, __func__,
+		       cxl_ver);
+
+	return chbs->length;
+}
+
+int acpi_create_cedt_cfmws(acpi_cedt_cfmws_t *cfmws, u64 base_hpa, u64 window_size, u8 eniw,
+			   u32 hbig, u16 restriction, u16 qtg_id, const u32 *interleave_target)
+{
+	memset((void *)cfmws, 0, sizeof(acpi_cedt_cfmws_t));
+
+	cfmws->type = ACPI_CEDT_STRUCTURE_CFMWS;
+
+	u8 niw = 0;
+	if (eniw >= 8)
+		printk(BIOS_ERR, "ACPI(%s:%s): Incorrect eniw::%d\n", __FILE__, __func__, eniw);
+	else
+		/* NIW = 2 ** ENIW */
+		niw = 0x1 << eniw;
+	/* 36 + 4 * NIW */
+	cfmws->length = sizeof(acpi_cedt_cfmws_t) + 4 * niw;
+
+	cfmws->base_hpa = base_hpa;
+	cfmws->window_size = window_size;
+	cfmws->eniw = eniw;
+
+	// 0: Standard Modulo Arithmetic. Other values reserved.
+	cfmws->interleave_arithmetic = 0;
+
+	cfmws->hbig = hbig;
+	cfmws->restriction = restriction;
+	cfmws->qtg_id = qtg_id;
+	memcpy(&cfmws->interleave_target, interleave_target, 4 * niw);
+
+	return cfmws->length;
+}
+
+void acpi_create_cedt(acpi_cedt_t *cedt, unsigned long (*acpi_fill_cedt)(unsigned long current))
+{
+	acpi_header_t *header = &(cedt->header);
+	unsigned long current = (unsigned long)cedt + sizeof(acpi_cedt_t);
+
+	memset((void *)cedt, 0, sizeof(acpi_cedt_t));
+
+	if (!header)
+		return;
+
+	/* Fill out header fields. */
+	memcpy(header->signature, "CEDT", 4);
+	memcpy(header->oem_id, OEM_ID, 6);
+	memcpy(header->oem_table_id, ACPI_TABLE_CREATOR, 8);
+	memcpy(header->asl_compiler_id, ASLC, 4);
+
+	header->asl_compiler_revision = asl_revision;
+	header->length = sizeof(acpi_cedt_t);
+	header->revision = get_acpi_table_revision(CEDT);
+
+	current = acpi_fill_cedt(current);
+
+	/* (Re)calculate length and checksum. */
+	header->length = current - (unsigned long)cedt;
+	header->checksum = acpi_checksum((void *)cedt, header->length);
+}
+
 int acpi_create_hmat_mpda(acpi_hmat_mpda_t *mpda, u32 initiator, u32 memory)
 {
 	memset((void *)mpda, 0, sizeof(acpi_hmat_mpda_t));