diff options
| -rw-r--r-- | drivers/virt/coco/arm-cca-guest/arm-cca-guest.c | 97 |
1 files changed, 36 insertions, 61 deletions
diff --git a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c index 32cd038cb79b..dbbb2cc0e124 100644 --- a/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c +++ b/drivers/virt/coco/arm-cca-guest/arm-cca-guest.c @@ -16,54 +16,38 @@ /** * struct arm_cca_token_info - a descriptor for the token buffer. - * @challenge: Pointer to the challenge data - * @challenge_size: Size of the challenge data * @granule: PA of the granule to which the token will be written * @offset: Offset within granule to start of buffer in bytes - * @result: result of rsi_attestation_token_continue operation */ struct arm_cca_token_info { - void *challenge; - unsigned long challenge_size; phys_addr_t granule; unsigned long offset; - unsigned long result; }; -static void arm_cca_attestation_init(void *param) -{ - struct arm_cca_token_info *info; - - info = (struct arm_cca_token_info *)param; - - info->result = rsi_attestation_token_init(info->challenge, - info->challenge_size); -} - /** * arm_cca_attestation_continue - Retrieve the attestation token data. * - * @param: pointer to the arm_cca_token_info + * @info: pointer to the arm_cca_token_info * * Attestation token generation is a long running operation and therefore * the token data may not be retrieved in a single call. Moreover, the * token retrieval operation must be requested on the same CPU on which the * attestation token generation was initialised. - * This helper function is therefore scheduled on the same CPU multiple + * This helper function must therefore be executed on the same CPU multiple * times until the entire token data is retrieved. */ -static void arm_cca_attestation_continue(void *param) +static unsigned long +arm_cca_attestation_continue(struct arm_cca_token_info *info) { + unsigned long ret; unsigned long len; unsigned long size; - struct arm_cca_token_info *info; - - info = (struct arm_cca_token_info *)param; size = RSI_GRANULE_SIZE - info->offset; - info->result = rsi_attestation_token_continue(info->granule, - info->offset, size, &len); + ret = rsi_attestation_token_continue(info->granule, info->offset, size, + &len); info->offset += len; + return ret; } /** @@ -74,8 +58,8 @@ static void arm_cca_attestation_continue(void *param) * * Initialise the attestation token generation using the challenge data * passed in the TSM descriptor. Allocate memory for the attestation token - * and schedule calls to retrieve the attestation token on the same CPU - * on which the attestation token generation was initialised. + * and retrieve the attestation token on the same CPU on which the + * attestation token generation was initialised. * * The challenge data must be at least 32 bytes and no more than 64 bytes. If * less than 64 bytes are provided it will be zero padded to 64 bytes. @@ -85,12 +69,11 @@ static void arm_cca_attestation_continue(void *param) * * %-EINVAL - A parameter was not valid. * * %-ENOMEM - Out of memory. * * %-EFAULT - Failed to get IPA for memory page(s). - * * A negative status code as returned by smp_call_function_single(). */ static int arm_cca_report_new(struct tsm_report *report, void *data) { - int ret; - int cpu; + int ret = 0; + unsigned long rsi_result; long max_size; unsigned long token_size = 0; struct arm_cca_token_info info; @@ -103,37 +86,33 @@ static int arm_cca_report_new(struct tsm_report *report, void *data) /* * The attestation token 'init' and 'continue' calls must be - * performed on the same CPU. smp_call_function_single() is used - * instead of simply calling get_cpu() because of the need to - * allocate outblob based on the returned value from the 'init' - * call and that cannot be done in an atomic context. + * performed on the same CPU, so disable CPU migration around + * those operations. */ - cpu = smp_processor_id(); + migrate_disable(); - info.challenge = desc->inblob; - info.challenge_size = desc->inblob_len; - - ret = smp_call_function_single(cpu, arm_cca_attestation_init, - &info, true); - if (ret) - return ret; - max_size = info.result; - - if (max_size <= 0) - return -EINVAL; + max_size = rsi_attestation_token_init(desc->inblob, desc->inblob_len); + if (max_size <= 0) { + ret = -EINVAL; + goto exit_migrate_enable; + } /* Allocate outblob */ token = kvzalloc(max_size, GFP_KERNEL); - if (!token) - return -ENOMEM; + if (!token) { + ret = -ENOMEM; + goto exit_migrate_enable; + } /* * Since the outblob may not be physically contiguous, use a page * to bounce the buffer from RMM. */ buf = alloc_pages_exact(RSI_GRANULE_SIZE, GFP_KERNEL); - if (!buf) - return -ENOMEM; + if (!buf) { + ret = -ENOMEM; + goto exit_migrate_enable; + } /* Get the PA of the memory page(s) that were allocated */ info.granule = (unsigned long)virt_to_phys(buf); @@ -144,21 +123,15 @@ static int arm_cca_report_new(struct tsm_report *report, void *data) info.offset = 0; do { /* - * Schedule a call to retrieve a sub-granule chunk - * of data per loop iteration. + * Retrieve a sub-granule chunk of data per loop + * iteration. */ - ret = smp_call_function_single(cpu, - arm_cca_attestation_continue, - (void *)&info, true); - if (ret != 0) { - token_size = 0; - goto exit_free_granule_page; - } - } while (info.result == RSI_INCOMPLETE && + rsi_result = arm_cca_attestation_continue(&info); + } while (rsi_result == RSI_INCOMPLETE && info.offset < RSI_GRANULE_SIZE); /* Break out in case of failure */ - if (info.result != RSI_SUCCESS && info.result != RSI_INCOMPLETE) { + if (rsi_result != RSI_SUCCESS && rsi_result != RSI_INCOMPLETE) { ret = -ENXIO; token_size = 0; goto exit_free_granule_page; @@ -173,12 +146,14 @@ static int arm_cca_report_new(struct tsm_report *report, void *data) break; memcpy(&token[token_size], buf, info.offset); token_size += info.offset; - } while (info.result == RSI_INCOMPLETE); + } while (rsi_result == RSI_INCOMPLETE); report->outblob = no_free_ptr(token); exit_free_granule_page: report->outblob_len = token_size; free_pages_exact(buf, RSI_GRANULE_SIZE); +exit_migrate_enable: + migrate_enable(); return ret; } |