x86/sev: Rename snp_init() in boot/compressed/sev.c

The snp_init() function in boot/compressed/sev.c is local to that file, is
not called from outside of the file and is independent of the snp_init()
function in kernel/sev.c. Change the name to better differentiate when
each function is used.

Move the renamed snp_init() and related functions up in the file to avoid
having to add a forward declaration and make the function static.

No functional change.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/afda29585c2724b9698003f24cefa77eb35f4ffb.1713974291.git.thomas.lendacky@amd.com

Author: tlendacky

arch/x86/boot/compressed/sev.c

@@ -413,6 +413,85 @@ void snp_check_features(void)
 	}
 }
 
+/* Search for Confidential Computing blob in the EFI config table. */
+static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
+{
+	unsigned long cfg_table_pa;
+	unsigned int cfg_table_len;
+	int ret;
+
+	ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
+	if (ret)
+		return NULL;
+
+	return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
+								cfg_table_len,
+								EFI_CC_BLOB_GUID);
+}
+
+/*
+ * Initial set up of SNP relies on information provided by the
+ * Confidential Computing blob, which can be passed to the boot kernel
+ * by firmware/bootloader in the following ways:
+ *
+ * - via an entry in the EFI config table
+ * - via a setup_data structure, as defined by the Linux Boot Protocol
+ *
+ * Scan for the blob in that order.
+ */
+static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	cc_info = find_cc_blob_efi(bp);
+	if (cc_info)
+		goto found_cc_info;
+
+	cc_info = find_cc_blob_setup_data(bp);
+	if (!cc_info)
+		return NULL;
+
+found_cc_info:
+	if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
+		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
+
+	return cc_info;
+}
+
+/*
+ * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
+ * will verify the SNP CPUID/MSR bits.
+ */
+static bool early_snp_init(struct boot_params *bp)
+{
+	struct cc_blob_sev_info *cc_info;
+
+	if (!bp)
+		return false;
+
+	cc_info = find_cc_blob(bp);
+	if (!cc_info)
+		return false;
+
+	/*
+	 * If a SNP-specific Confidential Computing blob is present, then
+	 * firmware/bootloader have indicated SNP support. Verifying this
+	 * involves CPUID checks which will be more reliable if the SNP
+	 * CPUID table is used. See comments over snp_setup_cpuid_table() for
+	 * more details.
+	 */
+	setup_cpuid_table(cc_info);
+
+	/*
+	 * Pass run-time kernel a pointer to CC info via boot_params so EFI
+	 * config table doesn't need to be searched again during early startup
+	 * phase.
+	 */
+	bp->cc_blob_address = (u32)(unsigned long)cc_info;
+
+	return true;
+}
+
 /*
  * sev_check_cpu_support - Check for SEV support in the CPU capabilities
  *
@@ -463,7 +542,7 @@ void sev_enable(struct boot_params *bp)
 		bp->cc_blob_address = 0;
 
 	/*
-	 * Do an initial SEV capability check before snp_init() which
+	 * Do an initial SEV capability check before early_snp_init() which
 	 * loads the CPUID page and the same checks afterwards are done
 	 * without the hypervisor and are trustworthy.
 	 *
@@ -478,7 +557,7 @@ void sev_enable(struct boot_params *bp)
 	 * Setup/preliminary detection of SNP. This will be sanity-checked
 	 * against CPUID/MSR values later.
 	 */
-	snp = snp_init(bp);
+	snp = early_snp_init(bp);
 
 	/* Now repeat the checks with the SNP CPUID table. */
 
@@ -535,85 +614,6 @@ u64 sev_get_status(void)
 	return m.q;
 }
 
-/* Search for Confidential Computing blob in the EFI config table. */
-static struct cc_blob_sev_info *find_cc_blob_efi(struct boot_params *bp)
-{
-	unsigned long cfg_table_pa;
-	unsigned int cfg_table_len;
-	int ret;
-
-	ret = efi_get_conf_table(bp, &cfg_table_pa, &cfg_table_len);
-	if (ret)
-		return NULL;
-
-	return (struct cc_blob_sev_info *)efi_find_vendor_table(bp, cfg_table_pa,
-								cfg_table_len,
-								EFI_CC_BLOB_GUID);
-}
-
-/*
- * Initial set up of SNP relies on information provided by the
- * Confidential Computing blob, which can be passed to the boot kernel
- * by firmware/bootloader in the following ways:
- *
- * - via an entry in the EFI config table
- * - via a setup_data structure, as defined by the Linux Boot Protocol
- *
- * Scan for the blob in that order.
- */
-static struct cc_blob_sev_info *find_cc_blob(struct boot_params *bp)
-{
-	struct cc_blob_sev_info *cc_info;
-
-	cc_info = find_cc_blob_efi(bp);
-	if (cc_info)
-		goto found_cc_info;
-
-	cc_info = find_cc_blob_setup_data(bp);
-	if (!cc_info)
-		return NULL;
-
-found_cc_info:
-	if (cc_info->magic != CC_BLOB_SEV_HDR_MAGIC)
-		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SNP_UNSUPPORTED);
-
-	return cc_info;
-}
-
-/*
- * Indicate SNP based on presence of SNP-specific CC blob. Subsequent checks
- * will verify the SNP CPUID/MSR bits.
- */
-bool snp_init(struct boot_params *bp)
-{
-	struct cc_blob_sev_info *cc_info;
-
-	if (!bp)
-		return false;
-
-	cc_info = find_cc_blob(bp);
-	if (!cc_info)
-		return false;
-
-	/*
-	 * If a SNP-specific Confidential Computing blob is present, then
-	 * firmware/bootloader have indicated SNP support. Verifying this
-	 * involves CPUID checks which will be more reliable if the SNP
-	 * CPUID table is used. See comments over snp_setup_cpuid_table() for
-	 * more details.
-	 */
-	setup_cpuid_table(cc_info);
-
-	/*
-	 * Pass run-time kernel a pointer to CC info via boot_params so EFI
-	 * config table doesn't need to be searched again during early startup
-	 * phase.
-	 */
-	bp->cc_blob_address = (u32)(unsigned long)cc_info;
-
-	return true;
-}
-
 void sev_prep_identity_maps(unsigned long top_level_pgt)
 {
 	/*