cbfs: Simplify load/map API names, remove type arguments

This patch renames cbfs_boot_map_with_leak() and cbfs_boot_load_file()
to cbfs_map() and cbfs_load() respectively. This is supposed to be the
start of a new, better organized CBFS API where the most common
operations have the most simple and straight-forward names. Less
commonly used variants of these operations (e.g. cbfs_ro_load() or
cbfs_region_load()) can be introduced later. It seems unnecessary to
keep carrying around "boot" in the names of most CBFS APIs if the vast
majority of accesses go to the boot CBFS (instead, more unusual
operations should have longer names that describe how they diverge from
the common ones).

cbfs_map() is paired with a new cbfs_unmap() to allow callers to cleanly
reap mappings when desired. A few new cbfs_unmap() calls are added to
generic code where it makes sense, but it seems unnecessary to introduce
this everywhere in platform or architecture specific code where the boot
medium is known to be memory-mapped anyway. In fact, even for
non-memory-mapped platforms, sometimes leaking a mapping to the CBFS
cache is a much cleaner solution than jumping through hoops to provide
some other storage for some long-lived file object, and it shouldn't be
outright forbidden when it makes sense.

Additionally, remove the type arguments from these function signatures.
The goal is to eventually remove type arguments for lookup from the
whole CBFS API. Filenames already uniquely identify CBFS files. The type
field is just informational, and there should be APIs to allow callers
to check it when desired, but it's not clear what we gain from forcing
this as a parameter into every single CBFS access when the vast majority
of the time it provides no additional value and is just clutter.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Ib24325400815a9c3d25f66c61829a24a239bb88e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39304
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-by: Mariusz Szafrański <mariuszx.szafranski@intel.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

3 files changed, 8 insertions, 10 deletions

diff --git a/src/security/intel/stm/StmPlatformSmm.c b/src/security/intel/stm/StmPlatformSmm.c
index eb9a0bb22f..abd7667355 100644
--- a/src/security/intel/stm/StmPlatformSmm.c
+++ b/src/security/intel/stm/StmPlatformSmm.c
@@ -35,8 +35,7 @@ int load_stm_image(uintptr_t mseg)
 
 	memset((void *)mseg_base, 0, CONFIG_MSEG_SIZE); // clear the mseg
 
-	stm_image_size = cbfs_boot_load_file("stm.bin", mseg_base,
-					     stm_buffer_size, CBFS_TYPE_RAW);
+	stm_image_size = cbfs_load("stm.bin", mseg_base, stm_buffer_size);
 	printk(BIOS_DEBUG, "STM:loaded into mseg: 0x%p size: %u\n", mseg_base,
 	       stm_image_size);
 	/* status is number of bytes loaded */
diff --git a/src/security/intel/txt/ramstage.c b/src/security/intel/txt/ramstage.c
index 76eeaaffef..81d2dd1083 100644
--- a/src/security/intel/txt/ramstage.c
+++ b/src/security/intel/txt/ramstage.c
@@ -221,10 +221,9 @@ static void txt_initialize_heap(void)
 	data.bdr.no_logical_procs = dev_count_cpu();
 
 	void *sinit_base = (void *)(uintptr_t)read64((void *)TXT_SINIT_BASE);
-	data.bdr.bios_sinit_size = cbfs_boot_load_file(CONFIG_INTEL_TXT_CBFS_SINIT_ACM,
-						       sinit_base,
-						       read64((void *)TXT_SINIT_SIZE),
-						       CBFS_TYPE_RAW);
+	data.bdr.bios_sinit_size = cbfs_load(CONFIG_INTEL_TXT_CBFS_SINIT_ACM,
+					     sinit_base,
+					     read64((void *)TXT_SINIT_SIZE));
 
 	if (data.bdr.bios_sinit_size) {
 		printk(BIOS_INFO, "TEE-TXT: Placing SINIT ACM in memory.\n");
@@ -277,9 +276,7 @@ static void txt_initialize_heap(void)
 		data.heap_acm.num_acms = 1;
 	}
 	data.heap_acm.acm_addrs[0] =
-		(uintptr_t)cbfs_boot_map_with_leak(CONFIG_INTEL_TXT_CBFS_BIOS_ACM,
-						   CBFS_TYPE_RAW,
-						   NULL);
+		(uintptr_t)cbfs_map(CONFIG_INTEL_TXT_CBFS_BIOS_ACM, NULL);
 	/* Extended elements - End marker */
 	data.end.type = HEAP_EXTDATA_TYPE_END;
 	data.end.size = sizeof(data.end);
diff --git a/src/security/vboot/ec_sync.c b/src/security/vboot/ec_sync.c
index 1fd7e7590b..7e3d29a4ab 100644
--- a/src/security/vboot/ec_sync.c
+++ b/src/security/vboot/ec_sync.c
@@ -385,7 +385,9 @@ static vb2_error_t ec_get_expected_hash(enum vb2_firmware_selection select,
 {
 	size_t size;
 	const char *filename = EC_HASH_FILENAME(select);
-	const uint8_t *file = cbfs_boot_map_with_leak(filename, CBFS_TYPE_RAW, &size);
+
+	/* vboot has no API to return this memory, so must permanently leak a mapping here. */
+	const uint8_t *file = cbfs_map(filename, &size);
 
 	if (file == NULL)
 		return VB2_ERROR_UNKNOWN;