Commit 1bc726e2 authored by Eric Biggers's avatar Eric Biggers Committed by Martin K. Petersen
Browse files

scsi: ufs: Add program_key() variant op 

On Snapdragon SoCs, the Linux kernel isn't permitted to directly access the
standard UFS crypto configuration registers.  Instead, programming and
evicting keys must be done through vendor-specific SMC calls.

To support this hardware, add a ->program_key() method to 'struct
ufs_hba_variant_ops'.  This allows overriding the UFS standard key
programming / eviction procedure.

Link: https://lore.kernel.org/r/20200710072013.177481-5-ebiggers@kernel.org


Reviewed-by: default avatarAvri Altman <avri.altman@wdc.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent 083dd788

drivers/scsi/ufs/ufshcd-crypto.c

+17 −10
Original line number Diff line number Diff line
@@ -17,14 +17,20 @@ static const struct ufs_crypto_alg_entry { 
	},

};



static void ufshcd_program_key(struct ufs_hba *hba,

			       const union ufs_crypto_cfg_entry *cfg,

			       int slot)

static int ufshcd_program_key(struct ufs_hba *hba,

			      const union ufs_crypto_cfg_entry *cfg, int slot)

{

	int i;

	u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);

	int err = 0;



	ufshcd_hold(hba, false);



	if (hba->vops && hba->vops->program_key) {

		err = hba->vops->program_key(hba, cfg, slot);

		goto out;

	}



	/* Ensure that CFGE is cleared before programming the key */

	ufshcd_writel(hba, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));

	for (i = 0; i < 16; i++) {
@@ -37,7 +43,9 @@ static void ufshcd_program_key(struct ufs_hba *hba, 
	/* Dword 16 must be written last */

	ufshcd_writel(hba, le32_to_cpu(cfg->reg_val[16]),

		      slot_offset + 16 * sizeof(cfg->reg_val[0]));

out:

	ufshcd_release(hba);

	return err;

}



static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
@@ -52,6 +60,7 @@ static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm, 
	int i;

	int cap_idx = -1;

	union ufs_crypto_cfg_entry cfg = { 0 };

	int err;



	BUILD_BUG_ON(UFS_CRYPTO_KEY_SIZE_INVALID != 0);

	for (i = 0; i < hba->crypto_capabilities.num_crypto_cap; i++) {
@@ -79,13 +88,13 @@ static int ufshcd_crypto_keyslot_program(struct blk_keyslot_manager *ksm, 
		memcpy(cfg.crypto_key, key->raw, key->size);

	}



	ufshcd_program_key(hba, &cfg, slot);

	err = ufshcd_program_key(hba, &cfg, slot);



	memzero_explicit(&cfg, sizeof(cfg));

	return 0;

	return err;

}



static void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)

static int ufshcd_clear_keyslot(struct ufs_hba *hba, int slot)

{

	/*

	 * Clear the crypto cfg on the device. Clearing CFGE
@@ -93,7 +102,7 @@ static void ufshcd_clear_keyslot(struct ufs_hba *hba, int slot) 
	 */

	union ufs_crypto_cfg_entry cfg = { 0 };



	ufshcd_program_key(hba, &cfg, slot);

	return ufshcd_program_key(hba, &cfg, slot);

}



static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
@@ -102,9 +111,7 @@ static int ufshcd_crypto_keyslot_evict(struct blk_keyslot_manager *ksm, 
{

	struct ufs_hba *hba = container_of(ksm, struct ufs_hba, ksm);



	ufshcd_clear_keyslot(hba, slot);



	return 0;

	return ufshcd_clear_keyslot(hba, slot);

}



bool ufshcd_crypto_enable(struct ufs_hba *hba)

drivers/scsi/ufs/ufshcd.h

+3 −0
Original line number Diff line number Diff line
@@ -281,6 +281,7 @@ struct ufs_pwr_mode_info { 
 * @dbg_register_dump: used to dump controller debug information

 * @phy_initialization: used to initialize phys

 * @device_reset: called to issue a reset pulse on the UFS device

 * @program_key: program or evict an inline encryption key

 */

struct ufs_hba_variant_ops {

	const char *name;
@@ -314,6 +315,8 @@ struct ufs_hba_variant_ops { 
	void	(*config_scaling_param)(struct ufs_hba *hba,

					struct devfreq_dev_profile *profile,

					void *data);

	int	(*program_key)(struct ufs_hba *hba,

			       const union ufs_crypto_cfg_entry *cfg, int slot);

};



/* clock gating state  */