arm: kernel: Add SMC structure parameter

This patch adds a quirk parameter to the arm_smccc_(smc/hvc) calls.
The quirk structure allows for specialized SMC operations due to SoC
specific requirements.  The current arm_smccc_(smc/hvc) is renamed and
macros are used instead to specify the standard arm_smccc_(smc/hvc) or
the arm_smccc_(smc/hvc)_quirk function.

This patch and partial implementation was suggested by Will Deacon.

Signed-off-by: Andy Gross <andy.gross@linaro.org>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 7e45f69a0ddc9d0ef3b04c145195cf1b4ad7d84b..8e8d20cdbce736b251c93f3822f741893dd9824c 100644 (file)
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -178,6 +178,6 @@ EXPORT_SYMBOL(__pv_offset);
 #endif
 
 #ifdef CONFIG_HAVE_ARM_SMCCC
-EXPORT_SYMBOL(arm_smccc_smc);
-EXPORT_SYMBOL(arm_smccc_hvc);
+EXPORT_SYMBOL(__arm_smccc_smc);
+EXPORT_SYMBOL(__arm_smccc_hvc);
 #endif

diff --git a/arch/arm/kernel/smccc-call.S b/arch/arm/kernel/smccc-call.S
index 2e48b674aab190563d321902be9919167d8f80cd..e5d43066b88948b8e079e14f1ffd33ad884db067 100644 (file)
--- a/arch/arm/kernel/smccc-call.S
+++ b/arch/arm/kernel/smccc-call.S
@@ -46,17 +46,19 @@ UNWIND(     .fnend)
 /*
  * void smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
  *               unsigned long a3, unsigned long a4, unsigned long a5,
- *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
+ *               struct arm_smccc_quirk *quirk)
  */
-ENTRY(arm_smccc_smc)
+ENTRY(__arm_smccc_smc)
        SMCCC SMCCC_SMC
-ENDPROC(arm_smccc_smc)
+ENDPROC(__arm_smccc_smc)
 
 /*
  * void smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
  *               unsigned long a3, unsigned long a4, unsigned long a5,
- *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
+ *               struct arm_smccc_quirk *quirk)
  */
-ENTRY(arm_smccc_hvc)
+ENTRY(__arm_smccc_hvc)
        SMCCC SMCCC_HVC
-ENDPROC(arm_smccc_hvc)
+ENDPROC(__arm_smccc_hvc)

diff --git a/arch/arm64/kernel/arm64ksyms.c b/arch/arm64/kernel/arm64ksyms.c
index 78f368039c79a76d45d7256ed64dd7535f198ed6..e9c4dc9e0ada63c25be8d5dd3064739a4b797523 100644 (file)
--- a/arch/arm64/kernel/arm64ksyms.c
+++ b/arch/arm64/kernel/arm64ksyms.c
@@ -73,5 +73,5 @@ NOKPROBE_SYMBOL(_mcount);
 #endif
 
        /* arm-smccc */
-EXPORT_SYMBOL(arm_smccc_smc);
-EXPORT_SYMBOL(arm_smccc_hvc);
+EXPORT_SYMBOL(__arm_smccc_smc);
+EXPORT_SYMBOL(__arm_smccc_hvc);

diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index bc049afc73a782c73f97fe48a42dbcb88ccd9126..b3bb7ef97bc85c2c50580d10179f3fbbbb33e8ef 100644 (file)
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -143,8 +143,11 @@ int main(void)
   DEFINE(SLEEP_STACK_DATA_SYSTEM_REGS, offsetof(struct sleep_stack_data, system_regs));
   DEFINE(SLEEP_STACK_DATA_CALLEE_REGS, offsetof(struct sleep_stack_data, callee_saved_regs));
 #endif
-  DEFINE(ARM_SMCCC_RES_X0_OFFS,        offsetof(struct arm_smccc_res, a0));
-  DEFINE(ARM_SMCCC_RES_X2_OFFS,        offsetof(struct arm_smccc_res, a2));
+  DEFINE(ARM_SMCCC_RES_X0_OFFS,                offsetof(struct arm_smccc_res, a0));
+  DEFINE(ARM_SMCCC_RES_X2_OFFS,                offsetof(struct arm_smccc_res, a2));
+  DEFINE(ARM_SMCCC_QUIRK_ID_OFFS,      offsetof(struct arm_smccc_quirk, id));
+  DEFINE(ARM_SMCCC_QUIRK_STATE_OFFS,   offsetof(struct arm_smccc_quirk, state));
+
   BLANK();
   DEFINE(HIBERN_PBE_ORIG,      offsetof(struct pbe, orig_address));
   DEFINE(HIBERN_PBE_ADDR,      offsetof(struct pbe, address));

diff --git a/arch/arm64/kernel/smccc-call.S b/arch/arm64/kernel/smccc-call.S
index ae0496fa423555a768b1d382a4e159001ecabe6b..ba60a8cb07d2609a70847e0976cc1de5d6773542 100644 (file)
--- a/arch/arm64/kernel/smccc-call.S
+++ b/arch/arm64/kernel/smccc-call.S
@@ -27,17 +27,19 @@
 /*
  * void arm_smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2,
  *               unsigned long a3, unsigned long a4, unsigned long a5,
- *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
+ *               struct arm_smccc_quirk *quirk)
  */
-ENTRY(arm_smccc_smc)
+ENTRY(__arm_smccc_smc)
        SMCCC   smc
-ENDPROC(arm_smccc_smc)
+ENDPROC(__arm_smccc_smc)
 
 /*
  * void arm_smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a2,
  *               unsigned long a3, unsigned long a4, unsigned long a5,
- *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res)
+ *               unsigned long a6, unsigned long a7, struct arm_smccc_res *res,
+ *               struct arm_smccc_quirk *quirk)
  */
-ENTRY(arm_smccc_hvc)
+ENTRY(__arm_smccc_hvc)
        SMCCC   hvc
-ENDPROC(arm_smccc_hvc)
+ENDPROC(__arm_smccc_hvc)

diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index b5abfda80465a10bf14caed699f57bd7abec8567..c66f8ae94b5a51bedf233df768db3fad9ad3fa83 100644 (file)
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -72,33 +72,57 @@ struct arm_smccc_res {
 };
 
 /**
- * arm_smccc_smc() - make SMC calls
+ * struct arm_smccc_quirk - Contains quirk information
+ * @id: quirk identification
+ * @state: quirk specific information
+ * @a6: Qualcomm quirk entry for returning post-smc call contents of a6
+ */
+struct arm_smccc_quirk {
+       int     id;
+       union {
+               unsigned long a6;
+       } state;
+};
+
+/**
+ * __arm_smccc_smc() - make SMC calls
  * @a0-a7: arguments passed in registers 0 to 7
  * @res: result values from registers 0 to 3
+ * @quirk: points to an arm_smccc_quirk, or NULL when no quirks are required.
  *
  * This function is used to make SMC calls following SMC Calling Convention.
  * The content of the supplied param are copied to registers 0 to 7 prior
  * to the SMC instruction. The return values are updated with the content
- * from register 0 to 3 on return from the SMC instruction.
+ * from register 0 to 3 on return from the SMC instruction.  An optional
+ * quirk structure provides vendor specific behavior.
  */
-asmlinkage void arm_smccc_smc(unsigned long a0, unsigned long a1,
+asmlinkage void __arm_smccc_smc(unsigned long a0, unsigned long a1,
                        unsigned long a2, unsigned long a3, unsigned long a4,
                        unsigned long a5, unsigned long a6, unsigned long a7,
-                       struct arm_smccc_res *res);
+                       struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
 
 /**
- * arm_smccc_hvc() - make HVC calls
+ * __arm_smccc_hvc() - make HVC calls
  * @a0-a7: arguments passed in registers 0 to 7
  * @res: result values from registers 0 to 3
  *
  * This function is used to make HVC calls following SMC Calling
  * Convention.  The content of the supplied param are copied to registers 0
  * to 7 prior to the HVC instruction. The return values are updated with
- * the content from register 0 to 3 on return from the HVC instruction.
+ * the content from register 0 to 3 on return from the HVC instruction.  An
+ * optional quirk structure provides vendor specific behavior.
  */
-asmlinkage void arm_smccc_hvc(unsigned long a0, unsigned long a1,
+asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
                        unsigned long a2, unsigned long a3, unsigned long a4,
                        unsigned long a5, unsigned long a6, unsigned long a7,
-                       struct arm_smccc_res *res);
+                       struct arm_smccc_res *res, struct arm_smccc_quirk *quirk);
+
+#define arm_smccc_smc(...) __arm_smccc_smc(__VA_ARGS__, NULL)
+
+#define arm_smccc_smc_quirk(...) __arm_smccc_smc(__VA_ARGS__)
+
+#define arm_smccc_hvc(...) __arm_smccc_hvc(__VA_ARGS__, NULL)
+
+#define arm_smccc_hvc_quirk(...) __arm_smccc_hvc(__VA_ARGS__)
 
 #endif /*__LINUX_ARM_SMCCC_H*/