From a9a72aeefbd3ef8bcbbeeccaf174ee10db2978ac Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= Date: Thu, 24 Aug 2017 10:45:58 +0200 Subject: tpm: Clean up driver registration & lookup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We have a strict separation between enum TpmType and be_drivers[]: * TpmType may have any number of members. It just happens to have one. * tpm_register_driver() uses the first empty slot in be_drivers[]. If you register more than tpm_models[] has space, tpm_register_driver() fails. Its caller silently ignores the failure. If you register more than one with a given TpmType, tpm_display_backend_drivers() will shows all of them, but tpm_driver_find_by_type() and tpm_get_backend_driver() will find only the one one that registered first. Since we only ever register one driver, and be_drivers[] has space for just that one, this contraption even works. Turn be_drivers[] into a straight map from enum TpmType to driver. Much simpler, and has a decent chance to actually work should we ever acquire additional drivers. While there, use qapi_enum_parse() in tpm_get_backend_driver(). Signed-off-by: Marc-André Lureau Message-Id: <20170822132255.23945-8-marcandre.lureau@redhat.com> Reviewed-by: Markus Armbruster [Rebased, superfluous initializer dropped, commit message rewritten] Cc: Stefan Berger Signed-off-by: Markus Armbruster Message-Id: <1503564371-26090-4-git-send-email-armbru@redhat.com> --- tpm.c | 45 +++++++++++++-------------------------------- 1 file changed, 13 insertions(+), 32 deletions(-) (limited to 'tpm.c') diff --git a/tpm.c b/tpm.c index 9a7c7114d3..6f39ec9192 100644 --- a/tpm.c +++ b/tpm.c @@ -14,6 +14,7 @@ #include "qemu/osdep.h" #include "qapi/qmp/qerror.h" +#include "qapi/util.h" #include "sysemu/tpm_backend.h" #include "sysemu/tpm.h" #include "qemu/config-file.h" @@ -25,11 +26,8 @@ static QLIST_HEAD(, TPMBackend) tpm_backends = #define TPM_MAX_MODELS 1 -#define TPM_MAX_DRIVERS 1 -static TPMDriverOps const *be_drivers[TPM_MAX_DRIVERS] = { - NULL, -}; +static TPMDriverOps const *be_drivers[TPM_TYPE__MAX]; static enum TpmModel tpm_models[TPM_MAX_MODELS] = { TPM_MODEL__MAX, @@ -63,31 +61,18 @@ static bool tpm_model_is_registered(enum TpmModel model) const TPMDriverOps *tpm_get_backend_driver(const char *type) { - int i; - - for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) { - if (!strcmp(TpmType_lookup[be_drivers[i]->type], type)) { - return be_drivers[i]; - } - } + int i = qapi_enum_parse(TpmType_lookup, type, -1, NULL); - return NULL; + return i >= 0 ? be_drivers[i] : NULL; } #ifdef CONFIG_TPM -int tpm_register_driver(const TPMDriverOps *tdo) +void tpm_register_driver(const TPMDriverOps *tdo) { - int i; + assert(!be_drivers[tdo->type]); - for (i = 0; i < TPM_MAX_DRIVERS; i++) { - if (!be_drivers[i]) { - be_drivers[i] = tdo; - return 0; - } - } - error_report("Could not register TPM driver"); - return 1; + be_drivers[tdo->type] = tdo; } /* @@ -100,9 +85,12 @@ static void tpm_display_backend_drivers(void) fprintf(stderr, "Supported TPM types (choose only one):\n"); - for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) { + for (i = 0; i < TPM_TYPE__MAX; i++) { + if (be_drivers[i] == NULL) { + continue; + } fprintf(stderr, "%12s %s\n", - TpmType_lookup[be_drivers[i]->type], be_drivers[i]->desc()); + TpmType_lookup[i], be_drivers[i]->desc()); } fprintf(stderr, "\n"); } @@ -239,14 +227,7 @@ int tpm_config_parse(QemuOptsList *opts_list, const char *optarg) static const TPMDriverOps *tpm_driver_find_by_type(enum TpmType type) { - int i; - - for (i = 0; i < TPM_MAX_DRIVERS && be_drivers[i] != NULL; i++) { - if (be_drivers[i]->type == type) { - return be_drivers[i]; - } - } - return NULL; + return be_drivers[type]; } static TPMInfo *qmp_query_tpm_inst(TPMBackend *drv) -- cgit v1.2.1