crypto: ccp: Add external API interface for PSP module initialization

KVM is dependent on the PSP SEV driver and PSP SEV driver needs to be
loaded before KVM module. In case of module loading any dependent
modules are automatically loaded but in case of built-in modules there
is no inherent mechanism available to specify dependencies between
modules and ensure that any dependent modules are loaded implicitly.

Add a new external API interface for PSP module initialization which
allows PSP SEV driver to be loaded explicitly if KVM is built-in.

Signed-off-by: Sean Christopherson <[e-mail]>
Co-developed-by: Ashish Kalra <[e-mail]>
Signed-off-by: Ashish Kalra <[e-mail]>
Reviewed-by: Tom Lendacky <[e-mail]>
Message-ID: <1527[e-mail]>
Signed-off-by: Paolo Bonzini <[e-mail]>

drivers/crypto/ccp/sp-dev.c

···
 #include <linux/types.h>
 #include <linux/ccp.h>
 
+#include "sev-dev.h"
 #include "ccp-dev.h"
 #include "sp-dev.h"
 
···
 static int __init sp_mod_init(void)
 {
 #ifdef CONFIG_X86
+	static bool initialized;
 	int ret;
+
+	if (initialized)
+		return 0;
 
 	ret = sp_pci_init();
 	if (ret)
···
 #ifdef CONFIG_CRYPTO_DEV_SP_PSP
 	psp_pci_init();
 #endif
+
+	initialized = true;
 
 	return 0;
 #endif
···
 
 	return -ENODEV;
 }
+
+#if IS_BUILTIN(CONFIG_KVM_AMD) && IS_ENABLED(CONFIG_KVM_AMD_SEV)
+int __init sev_module_init(void)
+{
+	return sp_mod_init();
+}
+#endif
 
 static void __exit sp_mod_exit(void)
 {

include/linux/psp-sev.h

···
 #ifdef CONFIG_CRYPTO_DEV_SP_PSP
 
 /**
+ * sev_module_init - perform PSP SEV module initialization
+ *
+ * Returns:
+ * 0 if the PSP module is successfully initialized
+ * negative value if the PSP module initialization fails
+ */
+int sev_module_init(void);
+
+/**
  * sev_platform_init - perform SEV INIT command
  *
  * @args: struct sev_platform_init_args to pass in arguments