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[3/6] hw/arm/exynos4210: Remove tswap32() calls and constify smpboot[]

Message ID 20221222215549.86872-4-philmd@linaro.org
State New
Headers show
Series hw/arm: Fix smpboot[] on big-endian hosts and remove tswap32() | expand

Commit Message

Philippe Mathieu-Daudé Dec. 22, 2022, 9:55 p.m. UTC
ARM CPUs fetch instructions in little-endian.

smpboot[] encoded instructions are written in little-endian.

We call tswap32() on the array. tswap32 function swap a 32-bit
value if the target endianness doesn't match the host one.
Otherwise it is a NOP.

* On a little-endian host, the array is stored as it. tswap32()
  is a NOP, and the vCPU fetches the instructions as it, in
  little-endian.

* On a big-endian host, the array is stored as it. tswap32()
  swap the instructions to little-endian, and the vCPU fetches
  the instructions as it, in little-endian.

Using tswap() on system emulation is a bit odd: while the target
particularities might change the system emulation, the host ones
(such its endianness) shouldn't interfere.

We can simplify by using const_le32() to always store the
instructions in the array in little-endian, removing the need
for the dubious tswap().

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 hw/arm/exynos4210.c | 48 ++++++++++++++++++++-------------------------
 1 file changed, 21 insertions(+), 27 deletions(-)
diff mbox series

Patch

diff --git a/hw/arm/exynos4210.c b/hw/arm/exynos4210.c
index 8dafa2215b..89ee83456d 100644
--- a/hw/arm/exynos4210.c
+++ b/hw/arm/exynos4210.c
@@ -468,35 +468,29 @@  static const MemoryRegionOps exynos4210_chipid_and_omr_ops = {
     }
 };
 
-void exynos4210_write_secondary(ARMCPU *cpu,
-        const struct arm_boot_info *info)
+void exynos4210_write_secondary(ARMCPU *cpu, const struct arm_boot_info *info)
 {
-    int n;
-    uint32_t smpboot[] = {
-        0xe59f3034, /* ldr r3, External gic_cpu_if */
-        0xe59f2034, /* ldr r2, Internal gic_cpu_if */
-        0xe59f0034, /* ldr r0, startaddr */
-        0xe3a01001, /* mov r1, #1 */
-        0xe5821000, /* str r1, [r2] */
-        0xe5831000, /* str r1, [r3] */
-        0xe3a010ff, /* mov r1, #0xff */
-        0xe5821004, /* str r1, [r2, #4] */
-        0xe5831004, /* str r1, [r3, #4] */
-        0xf57ff04f, /* dsb */
-        0xe320f003, /* wfi */
-        0xe5901000, /* ldr     r1, [r0] */
-        0xe1110001, /* tst     r1, r1 */
-        0x0afffffb, /* beq     <wfi> */
-        0xe12fff11, /* bx      r1 */
-        EXYNOS4210_EXT_GIC_CPU_BASE_ADDR,
-        0,          /* gic_cpu_if: base address of Internal GIC CPU interface */
-        0           /* bootreg: Boot register address is held here */
+    const uint32_t smpboot[] = {
+        const_le32(0xe59f3034),     /* ldr r3, External gic_cpu_if */
+        const_le32(0xe59f2034),     /* ldr r2, Internal gic_cpu_if */
+        const_le32(0xe59f0034),     /* ldr r0, startaddr */
+        const_le32(0xe3a01001),     /* mov r1, #1 */
+        const_le32(0xe5821000),     /* str r1, [r2] */
+        const_le32(0xe5831000),     /* str r1, [r3] */
+        const_le32(0xe3a010ff),     /* mov r1, #0xff */
+        const_le32(0xe5821004),     /* str r1, [r2, #4] */
+        const_le32(0xe5831004),     /* str r1, [r3, #4] */
+        const_le32(0xf57ff04f),     /* dsb */
+        const_le32(0xe320f003),     /* wfi */
+        const_le32(0xe5901000),     /* ldr     r1, [r0] */
+        const_le32(0xe1110001),     /* tst     r1, r1 */
+        const_le32(0x0afffffb),     /* beq     <wfi> */
+        const_le32(0xe12fff11),     /* bx      r1 */
+        const_le32(EXYNOS4210_EXT_GIC_CPU_BASE_ADDR),
+        cpu_to_le32(info->gic_cpu_if_addr), /* base address of Internal GIC CPU interface */
+        cpu_to_le32(info->smp_bootreg_addr) /* Boot register address is held here */
     };
-    smpboot[ARRAY_SIZE(smpboot) - 1] = info->smp_bootreg_addr;
-    smpboot[ARRAY_SIZE(smpboot) - 2] = info->gic_cpu_if_addr;
-    for (n = 0; n < ARRAY_SIZE(smpboot); n++) {
-        smpboot[n] = tswap32(smpboot[n]);
-    }
+
     rom_add_blob_fixed("smpboot", smpboot, sizeof(smpboot),
                        info->smp_loader_start);
 }