ARMv8: Allow SiP service extensions on top of PSCI code

Allow PSCI layer to handle any SiP service functions added by
platform vendors. PSCI layer will look for SiP service function
in the SiP function table located in '._secure_svc_tbl_entries'
section if the SMC function identifier is not found in the PSCI
standard functions table. Use DECLARE_SECURE_SVC macro to declare
and add platform specific SiP service function.
This new section '._secure_svc_tbl_entries' is located next to
'._secure.text' section. Refer to arch/arm/cpu/armv8/u-boot.lds.

Signed-off-by: Chee Hong Ang <chee.hong.ang@intel.com>

diff --git a/arch/arm/cpu/armv8/psci.S b/arch/arm/cpu/armv8/psci.S
index 358df8fee9c32a1d5956e5a1252e48b8f88fa896..fc42d807b529754bd941505bddbe41f822db6012 100644 (file)
--- a/arch/arm/cpu/armv8/psci.S
+++ b/arch/arm/cpu/armv8/psci.S
@@ -8,6 +8,7 @@
 #include <config.h>
 #include <linux/linkage.h>
 #include <asm/psci.h>
+#include <asm/secure.h>
 
 /* Default PSCI function, return -1, Not Implemented */
 #define PSCI_DEFAULT(__fn) \
@@ -147,18 +148,38 @@ handle_psci:
 3:     mov     x0, #ARM_PSCI_RET_NI
        psci_return
 
-unknown_smc_id:
-       ldr     x0, =0xFFFFFFFF
+/*
+ * Handle SiP service functions defined in SiP service function table.
+ * Use DECLARE_SECURE_SVC(_name, _id, _fn) to add platform specific SiP
+ * service function into the SiP service function table.
+ * SiP service function table is located in '._secure_svc_tbl_entries' section,
+ * which is next to '._secure.text' section.
+ */
+handle_svc:
+       adr     x9, __secure_svc_tbl_start
+       adr     x10, __secure_svc_tbl_end
+       subs    x12, x10, x9    /* Get number of entries in table */
+       b.eq    2f              /* Make sure SiP function table is not empty */
+       psci_enter
+1:     ldr x10, [x9]           /* Load SiP function table */
+       ldr x11, [x9, #8]
+       cmp     w10, w0
+       b.eq    2b              /* SiP service function found */
+       add x9, x9, #SECURE_SVC_TBL_OFFSET      /* Move to next entry */
+       subs    x12, x12, #SECURE_SVC_TBL_OFFSET
+       b.eq    3b              /* If reach the end, bail out */
+       b       1b
+2:     ldr     x0, =0xFFFFFFFF
        eret
 
 handle_smc32:
        /* SMC function ID  0x84000000-0x8400001F: 32 bits PSCI */
        ldr     w9, =0x8400001F
        cmp     w0, w9
-       b.gt    unknown_smc_id
+       b.gt    handle_svc
        ldr     w9, =0x84000000
        cmp     w0, w9
-       b.lt    unknown_smc_id
+       b.lt    handle_svc
 
        adr     x9, _psci_32_table
        b       handle_psci
@@ -171,10 +192,10 @@ handle_smc64:
        /* SMC function ID 0xC4000000-0xC400001F: 64 bits PSCI */
        ldr     x9, =0xC400001F
        cmp     x0, x9
-       b.gt    unknown_smc_id
+       b.gt    handle_svc
        ldr     x9, =0xC4000000
        cmp     x0, x9
-       b.lt    unknown_smc_id
+       b.lt    handle_svc
 
        adr     x9, _psci_64_table
        b       handle_psci

diff --git a/arch/arm/cpu/armv8/u-boot.lds b/arch/arm/cpu/armv8/u-boot.lds
index 53de80f745ecd5e15ba158853ef59b85926d0345..2554980595b14cf9a1f5b13db03f147f73048305 100644 (file)
--- a/arch/arm/cpu/armv8/u-boot.lds
+++ b/arch/arm/cpu/armv8/u-boot.lds
@@ -58,6 +58,10 @@ SECTIONS
                AT(ADDR(.__secure_start) + SIZEOF(.__secure_start))
        {
                *(._secure.text)
+               . = ALIGN(8);
+               __secure_svc_tbl_start = .;
+               KEEP(*(._secure_svc_tbl_entries))
+               __secure_svc_tbl_end = .;
        }
 
        .secure_data : AT(LOADADDR(.secure_text) + SIZEOF(.secure_text))

diff --git a/arch/arm/include/asm/secure.h b/arch/arm/include/asm/secure.h
index d23044a1c368a1d7fd5435db1ba84280f18be5d5..50582c972b7ab2cabe6adbc737a1bbfcdda8b907 100644 (file)
--- a/arch/arm/include/asm/secure.h
+++ b/arch/arm/include/asm/secure.h
@@ -6,6 +6,37 @@
 #define __secure __attribute__ ((section ("._secure.text")))
 #define __secure_data __attribute__ ((section ("._secure.data")))
 
+#ifndef __ASSEMBLY__
+
+typedef struct secure_svc_tbl {
+       u32     id;
+#ifdef CONFIG_ARMV8_PSCI
+       u8      pad[4];
+#endif
+       void    *func;
+} secure_svc_tbl_t;
+
+/*
+ * Macro to declare a SiP function service in '_secure_svc_tbl_entries' section
+ */
+#define DECLARE_SECURE_SVC(_name, _id, _fn) \
+       static const secure_svc_tbl_t __secure_svc_ ## _name \
+               __attribute__((used, section("._secure_svc_tbl_entries"))) \
+                        = { \
+                               .id = _id, \
+                               .func = _fn }
+
+#else
+
+#ifdef CONFIG_ARMV8_PSCI
+#define SECURE_SVC_TBL_OFFSET          16
+#else
+#define SECURE_SVC_TBL_OFFSET          8
+
+#endif
+
+#endif /* __ASSEMBLY__ */
+
 #if defined(CONFIG_ARMV7_SECURE_BASE) || defined(CONFIG_ARMV8_SECURE_BASE)
 /*
  * Warning, horror ahead.