ARM: omap3: Thumb-2 compatibility for sleep34xx.S

 * Build unconditionally as ARM for correct interoperation with
   OMAP firmware.

 * Fix an out-of-range ADR when building for ARM.

 * Remove deprecated PC-relative stores.

 * Add the required ENDPROC() directive for each ENTRY().

 * .align before data words.

 * Handle non-interworking return from v7_flush_dcache_all.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Kevin Hilman <khilman@ti.com>

1 files changed, 43 insertions, 5 deletions

diff --git a/arch/arm/mach-omap2/sleep34xx.S b/arch/arm/mach-omap2/sleep34xx.S
index a05c348885ac..0c1b33511fed 100644
--- a/arch/arm/mach-omap2/sleep34xx.S
+++ b/arch/arm/mach-omap2/sleep34xx.S
@@ -64,6 +64,11 @@
 #define SDRC_DLLA_STATUS_V      OMAP34XX_SDRC_REGADDR(SDRC_DLLA_STATUS)
 #define SDRC_DLLA_CTRL_V        OMAP34XX_SDRC_REGADDR(SDRC_DLLA_CTRL)
 
+/*
+ * This file needs be built unconditionally as ARM to interoperate correctly
+ * with non-Thumb-2-capable firmware.
+ */
+        .arm
 
 /*
  * API functions
@@ -82,6 +87,8 @@ ENTRY(get_restore_pointer)
         stmfd   sp!, {lr}       @ save registers on stack
         adr     r0, restore
         ldmfd   sp!, {pc}       @ restore regs and return
+ENDPROC(get_restore_pointer)
+        .align
 ENTRY(get_restore_pointer_sz)
         .word   . - get_restore_pointer
 
@@ -91,6 +98,8 @@ ENTRY(get_omap3630_restore_pointer)
         stmfd   sp!, {lr}       @ save registers on stack
         adr     r0, restore_3630
         ldmfd   sp!, {pc}       @ restore regs and return
+ENDPROC(get_omap3630_restore_pointer)
+        .align
 ENTRY(get_omap3630_restore_pointer_sz)
         .word   . - get_omap3630_restore_pointer
 
@@ -100,6 +109,8 @@ ENTRY(get_es3_restore_pointer)
         stmfd   sp!, {lr}       @ save registers on stack
         adr     r0, restore_es3
         ldmfd   sp!, {pc}       @ restore regs and return
+ENDPROC(get_es3_restore_pointer)
+        .align
 ENTRY(get_es3_restore_pointer_sz)
         .word   . - get_es3_restore_pointer
 
@@ -113,8 +124,10 @@ ENTRY(enable_omap3630_toggle_l2_on_restore)
         stmfd   sp!, {lr}       @ save registers on stack
         /* Setup so that we will disable and enable l2 */
         mov     r1, #0x1
-        str     r1, l2dis_3630
+        adrl    r2, l2dis_3630  @ may be too distant for plain adr
+        str     r1, [r2]
         ldmfd   sp!, {pc}       @ restore regs and return
+ENDPROC(enable_omap3630_toggle_l2_on_restore)
 
         .text
 /* Function to call rom code to save secure ram context */
@@ -139,12 +152,14 @@ ENTRY(save_secure_ram_context)
         nop
         nop
         ldmfd   sp!, {r1-r12, pc}
+        .align
 sram_phy_addr_mask:
         .word   SRAM_BASE_P
 high_mask:
         .word   0xffff
 api_params:
         .word   0x4, 0x0, 0x0, 0x1, 0x1
+ENDPROC(save_secure_ram_context)
 ENTRY(save_secure_ram_context_sz)
         .word   . - save_secure_ram_context
 
@@ -279,8 +294,18 @@ clean_l2:
          *  - 'might' have to copy address, load and jump to it
          */
         ldr     r1, kernel_flush
-        mov     lr, pc
-        bx      r1
+        blx     r1
+        /*
+         * The kernel doesn't interwork: v7_flush_dcache_all in particluar will
+         * always return in Thumb state when CONFIG_THUMB2_KERNEL is enabled.
+         * This sequence switches back to ARM.  Note that .align may insert a
+         * nop: bx pc needs to be word-aligned in order to work.
+         */
+ THUMB( .thumb          )
+ THUMB( .align          )
+ THUMB( bx      pc      )
+ THUMB( nop             )
+        .arm
 
 omap3_do_wfi:
         ldr     r4, sdrc_power          @ read the SDRC_POWER register
@@ -438,6 +463,7 @@ skipl2dis:
 #endif
         b       logic_l1_restore
 
+        .align
 l2_inv_api_params:
         .word   0x1, 0x00
 l2_inv_gp:
@@ -607,6 +633,7 @@ usettbr0:
 
 /* This function implements the erratum ID i443 WA, applies to 34xx >= ES3.0 */
         .text
+        .align  3
 ENTRY(es3_sdrc_fix)
         ldr     r4, sdrc_syscfg         @ get config addr
         ldr     r5, [r4]                @ get value
@@ -634,6 +661,7 @@ ENTRY(es3_sdrc_fix)
         str     r5, [r4]                @ kick off refreshes
         bx      lr
 
+        .align
 sdrc_syscfg:
         .word   SDRC_SYSCONFIG_P
 sdrc_mr_0:
@@ -648,6 +676,7 @@ sdrc_emr2_1:
         .word   SDRC_EMR2_1_P
 sdrc_manual_1:
         .word   SDRC_MANUAL_1_P
+ENDPROC(es3_sdrc_fix)
 ENTRY(es3_sdrc_fix_sz)
         .word   . - es3_sdrc_fix
 
@@ -682,6 +711,12 @@ wait_sdrc_ready:
         bic     r5, r5, #0x40
         str     r5, [r4]
 
+/*
+ * PC-relative stores lead to undefined behaviour in Thumb-2: use a r7 as a
+ * base instead.
+ * Be careful not to clobber r7 when maintaing this code.
+ */
+
 is_dll_in_lock_mode:
         /* Is dll in lock mode? */
         ldr     r4, sdrc_dlla_ctrl
@@ -689,10 +724,11 @@ is_dll_in_lock_mode:
         tst     r5, #0x4
         bxne    lr                      @ Return if locked
         /* wait till dll locks */
+        adr     r7, kick_counter
 wait_dll_lock_timed:
         ldr     r4, wait_dll_lock_counter
         add     r4, r4, #1
-        str     r4, wait_dll_lock_counter
+        str     r4, [r7, #wait_dll_lock_counter - kick_counter]
         ldr     r4, sdrc_dlla_status
         /* Wait 20uS for lock */
         mov     r6, #8
@@ -718,9 +754,10 @@ kick_dll:
         dsb
         ldr     r4, kick_counter
         add     r4, r4, #1
-        str     r4, kick_counter
+        str     r4, [r7]                @ kick_counter
         b       wait_dll_lock_timed
 
+        .align
 cm_idlest1_core:
         .word   CM_IDLEST1_CORE_V
 cm_idlest_ckgen:
@@ -763,6 +800,7 @@ kick_counter:
         .word   0
 wait_dll_lock_counter:
         .word   0
+ENDPROC(omap34xx_cpu_suspend)
 
 ENTRY(omap34xx_cpu_suspend_sz)
         .word   . - omap34xx_cpu_suspend