Commit 0a0c866f authored by Eric Biggers's avatar Eric Biggers Committed by Ulf Hansson
Browse files

mmc: cqhci: add cqhci_host_ops::program_key 



On Snapdragon SoCs, the Linux kernel isn't permitted to directly access
the standard CQHCI 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 cqhci_host_ops'.  This allows overriding the standard CQHCI
crypto key programming / eviction procedure.

This is inspired by the corresponding UFS crypto support, which uses
these same SMC calls.  See commit 1bc726e2 ("scsi: ufs: Add
program_key() variant op").

Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarSatya Tangirala <satyat@google.com>
Reviewed-and-tested-by: default avatarPeng Zhou <peng.zhou@mediatek.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20210126001456.382989-6-ebiggers@kernel.org


Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 1e80709b

drivers/mmc/host/cqhci-crypto.c

+13 −9
Original line number Diff line number Diff line
@@ -30,13 +30,16 @@ cqhci_host_from_ksm(struct blk_keyslot_manager *ksm) 
	return mmc->cqe_private;

}



static void cqhci_crypto_program_key(struct cqhci_host *cq_host,

static int cqhci_crypto_program_key(struct cqhci_host *cq_host,

				    const union cqhci_crypto_cfg_entry *cfg,

				    int slot)

{

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

	int i;



	if (cq_host->ops->program_key)

		return cq_host->ops->program_key(cq_host, cfg, slot);



	/* Clear CFGE */

	cqhci_writel(cq_host, 0, slot_offset + 16 * sizeof(cfg->reg_val[0]));
@@ -51,6 +54,7 @@ static void cqhci_crypto_program_key(struct cqhci_host *cq_host, 
	/* Write dword 16, which includes the new value of CFGE */

	cqhci_writel(cq_host, le32_to_cpu(cfg->reg_val[16]),

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

	return 0;

}



static int cqhci_crypto_keyslot_program(struct blk_keyslot_manager *ksm,
@@ -67,6 +71,7 @@ static int cqhci_crypto_keyslot_program(struct blk_keyslot_manager *ksm, 
	int i;

	int cap_idx = -1;

	union cqhci_crypto_cfg_entry cfg = {};

	int err;



	BUILD_BUG_ON(CQHCI_CRYPTO_KEY_SIZE_INVALID != 0);

	for (i = 0; i < cq_host->crypto_capabilities.num_crypto_cap; i++) {
@@ -93,13 +98,13 @@ static int cqhci_crypto_keyslot_program(struct blk_keyslot_manager *ksm, 
		memcpy(cfg.crypto_key, key->raw, key->size);

	}



	cqhci_crypto_program_key(cq_host, &cfg, slot);

	err = cqhci_crypto_program_key(cq_host, &cfg, slot);



	memzero_explicit(&cfg, sizeof(cfg));

	return 0;

	return err;

}



static void cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)

static int cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot)

{

	/*

	 * Clear the crypto cfg on the device. Clearing CFGE
@@ -107,7 +112,7 @@ static void cqhci_crypto_clear_keyslot(struct cqhci_host *cq_host, int slot) 
	 */

	union cqhci_crypto_cfg_entry cfg = {};



	cqhci_crypto_program_key(cq_host, &cfg, slot);

	return cqhci_crypto_program_key(cq_host, &cfg, slot);

}



static int cqhci_crypto_keyslot_evict(struct blk_keyslot_manager *ksm,
@@ -116,8 +121,7 @@ static int cqhci_crypto_keyslot_evict(struct blk_keyslot_manager *ksm, 
{

	struct cqhci_host *cq_host = cqhci_host_from_ksm(ksm);



	cqhci_crypto_clear_keyslot(cq_host, slot);

	return 0;

	return cqhci_crypto_clear_keyslot(cq_host, slot);

}



/*

drivers/mmc/host/cqhci.h

+4 −0
Original line number Diff line number Diff line
@@ -286,6 +286,10 @@ struct cqhci_host_ops { 
				 u64 *data);

	void (*pre_enable)(struct mmc_host *mmc);

	void (*post_disable)(struct mmc_host *mmc);

#ifdef CONFIG_MMC_CRYPTO

	int (*program_key)(struct cqhci_host *cq_host,

			   const union cqhci_crypto_cfg_entry *cfg, int slot);

#endif

};



static inline void cqhci_writel(struct cqhci_host *host, u32 val, int reg)