cxl/pmem: Add "Passphrase Secure Erase" security command support

Create callback function to support the nvdimm_security_ops() ->erase()
callback. Translate the operation to send "Passphrase Secure Erase"
security command for CXL memory device.

When the mem device is secure erased, cpu_cache_invalidate_memregion() is
called in order to invalidate all CPU caches before attempting to access
the mem device again.

See CXL 3.0 spec section 8.2.9.8.6.6 for reference.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/166983615293.2734609.10358657600295932156.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
index 4f84d39..8747db3 100644 (file)
--- a/drivers/cxl/core/mbox.c
+++ b/drivers/cxl/core/mbox.c
@@ -70,6 +70,7 @@ static struct cxl_mem_command cxl_mem_commands[CXL_MEM_COMMAND_ID_MAX] = {
        CXL_CMD(DISABLE_PASSPHRASE, 0x40, 0, 0),
        CXL_CMD(FREEZE_SECURITY, 0, 0, 0),
        CXL_CMD(UNLOCK, 0x20, 0, 0),
+       CXL_CMD(PASSPHRASE_SECURE_ERASE, 0x40, 0, 0),
 };
 
 /*

diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
index 4e6897e..75baeb0 100644 (file)
--- a/drivers/cxl/cxlmem.h
+++ b/drivers/cxl/cxlmem.h
@@ -278,6 +278,7 @@ enum cxl_opcode {
        CXL_MBOX_OP_DISABLE_PASSPHRASE  = 0x4502,
        CXL_MBOX_OP_UNLOCK              = 0x4503,
        CXL_MBOX_OP_FREEZE_SECURITY     = 0x4504,
+       CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE     = 0x4505,
        CXL_MBOX_OP_MAX                 = 0x10000
 };
 
@@ -400,6 +401,13 @@ struct cxl_disable_pass {
        u8 pass[NVDIMM_PASSPHRASE_LEN];
 } __packed;
 
+/* passphrase secure erase payload */
+struct cxl_pass_erase {
+       u8 type;
+       u8 reserved[31];
+       u8 pass[NVDIMM_PASSPHRASE_LEN];
+} __packed;
+
 enum {
        CXL_PMEM_SEC_PASS_MASTER = 0,
        CXL_PMEM_SEC_PASS_USER,

diff --git a/drivers/cxl/security.c b/drivers/cxl/security.c
index 32b9e27..4a81325 100644 (file)
--- a/drivers/cxl/security.c
+++ b/drivers/cxl/security.c
@@ -120,12 +120,41 @@ static int cxl_pmem_security_unlock(struct nvdimm *nvdimm,
        return 0;
 }
 
+static int cxl_pmem_security_passphrase_erase(struct nvdimm *nvdimm,
+                                             const struct nvdimm_key_data *key,
+                                             enum nvdimm_passphrase_type ptype)
+{
+       struct cxl_nvdimm *cxl_nvd = nvdimm_provider_data(nvdimm);
+       struct cxl_memdev *cxlmd = cxl_nvd->cxlmd;
+       struct cxl_dev_state *cxlds = cxlmd->cxlds;
+       struct cxl_pass_erase erase;
+       int rc;
+
+       if (!cpu_cache_has_invalidate_memregion())
+               return -EINVAL;
+
+       erase.type = ptype == NVDIMM_MASTER ?
+               CXL_PMEM_SEC_PASS_MASTER : CXL_PMEM_SEC_PASS_USER;
+       memcpy(erase.pass, key->data, NVDIMM_PASSPHRASE_LEN);
+       /* Flush all cache before we erase mem device */
+       cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
+       rc = cxl_mbox_send_cmd(cxlds, CXL_MBOX_OP_PASSPHRASE_SECURE_ERASE,
+                              &erase, sizeof(erase), NULL, 0);
+       if (rc < 0)
+               return rc;
+
+       /* mem device erased, invalidate all CPU caches before data is read */
+       cpu_cache_invalidate_memregion(IORES_DESC_PERSISTENT_MEMORY);
+       return 0;
+}
+
 static const struct nvdimm_security_ops __cxl_security_ops = {
        .get_flags = cxl_pmem_get_security_flags,
        .change_key = cxl_pmem_security_change_key,
        .disable = cxl_pmem_security_disable,
        .freeze = cxl_pmem_security_freeze,
        .unlock = cxl_pmem_security_unlock,
+       .erase = cxl_pmem_security_passphrase_erase,
 };
 
 const struct nvdimm_security_ops *cxl_security_ops = &__cxl_security_ops;

diff --git a/include/uapi/linux/cxl_mem.h b/include/uapi/linux/cxl_mem.h
index 95dca8d..82bdad4 100644 (file)
--- a/include/uapi/linux/cxl_mem.h
+++ b/include/uapi/linux/cxl_mem.h
@@ -46,6 +46,7 @@
        ___C(DISABLE_PASSPHRASE, "Disable Passphrase"),                   \
        ___C(FREEZE_SECURITY, "Freeze Security"),                         \
        ___C(UNLOCK, "Unlock"),                                           \
+       ___C(PASSPHRASE_SECURE_ERASE, "Passphrase Secure Erase"),         \
        ___C(MAX, "invalid / last command")
 
 #define ___C(a, b) CXL_MEM_COMMAND_ID_##a