crypto: caam/qi2 - add a CRYPTO_DEV_FSL_CAAM dependency

My previous bugfix was incomplete, we still have a broken kernel
with CRYPTO_DEV_FSL_CAAM=m and CRYPTO_DEV_FSL_DPAA2_CAAM=y:

drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
caamalg_desc.c:(.text+0x14): undefined reference to `caam_little_end'
drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
caamalg_desc.c:(.text+0x310): undefined reference to `caam_imx'
caamalg_desc.c:(.text+0x4a8): undefined reference to `caam_little_end'
drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
caamalg_desc.c:(.text+0x664): undefined reference to `caam_imx'

Everything is fine for the other combinations: if both are loadable
modules, or both are built-in, the flags work as expected, also if
only one of the two is enabled.

Add a dependency to enforce using one of the working configurations.
Overall, I'm still not happy with that dependency, but for now
it documents what the code requires.

Fixes: 52813ab24959 ("crypto: caam/qi2 - avoid double export")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

---
 drivers/crypto/caam/Kconfig | 1 +
 1 file changed, 1 insertion(+)

-- 
2.20.0

On 12/20/2018 5:28 PM, Arnd Bergmann wrote:
> My previous bugfix was incomplete, we still have a broken kernel
> with CRYPTO_DEV_FSL_CAAM=m and CRYPTO_DEV_FSL_DPAA2_CAAM=y:
> 
> drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
> caamalg_desc.c:(.text+0x14): undefined reference to `caam_little_end'
> drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
> caamalg_desc.c:(.text+0x310): undefined reference to `caam_imx'
> caamalg_desc.c:(.text+0x4a8): undefined reference to `caam_little_end'
> drivers/crypto/caam/caamalg_desc.o: In function `cnstr_shdsc_aead_null_encap':
> caamalg_desc.c:(.text+0x664): undefined reference to `caam_imx'
> 
> Everything is fine for the other combinations: if both are loadable
> modules, or both are built-in, the flags work as expected, also if
> only one of the two is enabled.
> 
> Add a dependency to enforce using one of the working configurations.
> Overall, I'm still not happy with that dependency, but for now
> it documents what the code requires.
> 
Thanks Arnd.
This indeed solves the issue, but as you mentioned won't allow for
CRYPTO_DEV_FSL_DPAA2_CAAM=y when CRYPTO_DEV_FSL_CAAM=m.

I think a better solution is the following:

-- >8 --
Subject: [PATCH] crypto: caam - move shared symbols in a common location

There are several issues with symbols shared b/w:
-caam/jr and caam/qi drivers on one hand
-caam/qi2 driver on the other hand

Commit 52813ab24959 ("crypto: caam/qi2 - avoid double export") fixed
some of them, however compilation still fails for CRYPTO_DEV_FSL_CAAM=m
and CRYPTO_DEV_FSL_DPAA2_CAAM=y.

Another issue is related to dependency cycles reported by depmod when
CRYPTO_DEV_FSL_CAAM=n and CRYPTO_DEV_FSL_DPAA2_CAAM=m, as mentioned in
82c7b351be3f ("Revert "arm64: defconfig: Enable FSL_MC_BUS and FSL_MC_DPIO"")

To fix all these, move the symbols shared by these drivers in a common
location. The only existing possibility is error.c file (note that naming
doesn't help and should eventually change).

Fixes: 52813ab24959 ("crypto: caam/qi2 - avoid double export")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
---
 drivers/crypto/caam/caamalg_qi2.c | 7 -------
 drivers/crypto/caam/ctrl.c        | 4 ----
 drivers/crypto/caam/error.c       | 6 ++++++
 3 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 425d5d974613..cc59814afd29 100644
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -25,13 +25,6 @@
 #define CAAM_MAX_KEY_SIZE	(AES_MAX_KEY_SIZE + CTR_RFC3686_NONCE_SIZE + \
 				 SHA512_DIGEST_SIZE * 2)

-#if !IS_ENABLED(CONFIG_CRYPTO_DEV_FSL_CAAM)
-bool caam_little_end;
-EXPORT_SYMBOL(caam_little_end);
-bool caam_imx;
-EXPORT_SYMBOL(caam_imx);
-#endif
-
 /*
  * This is a a cache of buffers, from which the users of CAAM QI driver
  * can allocate short buffers. It's speedier than doing kmalloc on the hotpath.
diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 16bbc72f041a..14fb09223156 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -18,12 +18,8 @@
 #include "desc_constr.h"
 #include "ctrl.h"

-bool caam_little_end;
-EXPORT_SYMBOL(caam_little_end);
 bool caam_dpaa2;
 EXPORT_SYMBOL(caam_dpaa2);
-bool caam_imx;
-EXPORT_SYMBOL(caam_imx);

 #ifdef CONFIG_CAAM_QI
 #include "qi.h"
diff --git a/drivers/crypto/caam/error.c b/drivers/crypto/caam/error.c
index 7e8d690f2827..21a70fd32f5d 100644
--- a/drivers/crypto/caam/error.c
+++ b/drivers/crypto/caam/error.c
@@ -50,6 +50,12 @@ void caam_dump_sg(const char *level, const char *prefix_str,
int prefix_type,
 #endif /* DEBUG */
 EXPORT_SYMBOL(caam_dump_sg);

+bool caam_little_end;
+EXPORT_SYMBOL(caam_little_end);
+
+bool caam_imx;
+EXPORT_SYMBOL(caam_imx);
+
 static const struct {
 	u8 value;
 	const char *error_text;