arm: mach-keystone: Fixes issue with return values in inline assembly
PATCH 1/1 arm: mach-keystone: Fixes issue with return values in inline assembly
From: "Srinivas, Madan" <[email protected]>
The inline assembly functions in mon.c assume that the caller will check for the return value in r0 according to regular ARM calling conventions.
However, this assumption breaks down if the compiler inlines the functions. The caller is then under no obligation to use r0 for the result.
To fix this disconnect, we must explicitly move the return value from the smc/bl call to the variable that the function returns.
--- arch/arm/mach-keystone/mon.c | 4 ++++ 1 file changed, 4 insertions(+)
arch/arm/mach-keystone/mon.c +4 -0
@@ -24,6 +24,7 @@ int mon_install(u32 addr, u32 dpsc, u32 freq, u32 bm_addr)"mov r2, %3\n" "mov r3, %4\n" "blx r0\n" +"mov %0, r0\n" "ldmfd r13!, {lr}\n" : "=&r" (result) : "r" (addr), "r" (dpsc), "r" (freq), "r" (bm_addr)
@@ -41,6 +42,7 @@ int mon_power_on(int core_id, void *ep)"mov r2, %2\n" "mov r0, #0\n" "smc #0\n" +"mov %0, r0\n" "ldmfd r13!, {lr}\n" : "=&r" (result) : "r" (core_id), "r" (ep)
@@ -57,6 +59,7 @@ int mon_power_off(int core_id)"mov r1, %1\n" "mov r0, #1\n" "smc #1\n" +"mov %0, r0\n" "ldmfd r13!, {lr}\n" : "=&r" (result) : "r" (core_id)
@@ -90,6 +93,7 @@ static int k2_hs_bm_auth(int cmd, void *arg1)"mov r0, %1\n" "mov r1, %2\n" "smc #2\n" +"mov %0, r0\n" "ldmfd r13!, {r4-r12, lr}\n" : "=&r" (result) : "r" (cmd), "r" (arg1)
Signature · 1 line
2.13.0
PATCH 1/1 arm: mach-keystone: Fixes issue with return values in inline assembly
Quoted 6 lines · Andrew F. Davis
From: "Srinivas, Madan" <[email protected]>
The inline assembly functions in
mon.cassume that the caller will check for the return value in r0 according to regular ARM calling conventions.
Quoted 8 lines
However, this assumption breaks down if the compiler inlines the functions. The caller is then under no obligation to use r0 for the result.
To fix this disconnect, we must explicitly move the return value from the smc/bl call to the variable that the function returns.
Signed-off-by Madan Srinivas <[email protected]>
Signature · 8 lines
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Quoted 10 lines · Andrew F. Davis
From: "Srinivas, Madan" <[email protected]>
The inline assembly functions in
mon.cassume that the caller will check for the return value in r0 according to regular ARM calling conventions.However, this assumption breaks down if the compiler inlines the functions. The caller is then under no obligation to use r0 for the result.
Quoted 5 lines
To fix this disconnect, we must explicitly move the return value from the smc/bl call to the variable that the function returns.
Signed-off-by Madan Srinivas <[email protected]>Reviewed-by Tom Rini <[email protected]>
Applied to u-boot/master, thanks!
Signature · 8 lines
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