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hw/arm/highbank: Drop unused secondary boot stub code
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The highbank and midway board code includes boot-stub code for
handling secondary CPU boot which keeps the secondaries in a pen
until the primary writes to a known location with the address they
should jump to.

This code is never used, because the boards enable QEMU's PSCI
emulation, so secondary CPUs are kept powered off until the PSCI call
which turns them on, and then start execution from the address given
by the guest in that PSCI call.  Delete the unreachable code.

(The code was wrong for midway in any case -- on the Cortex-A15 the
GIC CPU interface registers are at a different offset from PERIPHBASE
compared to the Cortex-A9, and the code baked-in the offsets for
highbank's A9.)

Note that this commit implicitly depends on the preceding "Don't
write secondary boot stub if using PSCI" commit -- the default
secondary-boot stub code overlaps with one of the highbank-specific
bootcode rom blobs, so we must suppress the secondary-boot
stub code entirely, not merely replace the highbank-specific
version with the default.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20220127154639.2090164-15-peter.maydell@linaro.org
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pm215 committed Feb 8, 2022
1 parent d4a29ed commit 45dd668
Showing 1 changed file with 0 additions and 56 deletions.
56 changes: 0 additions & 56 deletions hw/arm/highbank.c
Expand Up @@ -48,60 +48,6 @@

/* Board init. */

static void hb_write_secondary(ARMCPU *cpu, const struct arm_boot_info *info)
{
int n;
uint32_t smpboot[] = {
0xee100fb0, /* mrc p15, 0, r0, c0, c0, 5 - read current core id */
0xe210000f, /* ands r0, r0, #0x0f */
0xe3a03040, /* mov r3, #0x40 - jump address is 0x40 + 0x10 * core id */
0xe0830200, /* add r0, r3, r0, lsl #4 */
0xe59f2024, /* ldr r2, privbase */
0xe3a01001, /* mov r1, #1 */
0xe5821100, /* str r1, [r2, #256] - set GICC_CTLR.Enable */
0xe3a010ff, /* mov r1, #0xff */
0xe5821104, /* str r1, [r2, #260] - set GICC_PMR.Priority to 0xff */
0xf57ff04f, /* dsb */
0xe320f003, /* wfi */
0xe5901000, /* ldr r1, [r0] */
0xe1110001, /* tst r1, r1 */
0x0afffffb, /* beq <wfi> */
0xe12fff11, /* bx r1 */
MPCORE_PERIPHBASE /* privbase: MPCore peripheral base address. */
};
for (n = 0; n < ARRAY_SIZE(smpboot); n++) {
smpboot[n] = tswap32(smpboot[n]);
}
rom_add_blob_fixed_as("smpboot", smpboot, sizeof(smpboot), SMP_BOOT_ADDR,
arm_boot_address_space(cpu, info));
}

static void hb_reset_secondary(ARMCPU *cpu, const struct arm_boot_info *info)
{
CPUARMState *env = &cpu->env;

switch (info->nb_cpus) {
case 4:
address_space_stl_notdirty(&address_space_memory,
SMP_BOOT_REG + 0x30, 0,
MEMTXATTRS_UNSPECIFIED, NULL);
/* fallthrough */
case 3:
address_space_stl_notdirty(&address_space_memory,
SMP_BOOT_REG + 0x20, 0,
MEMTXATTRS_UNSPECIFIED, NULL);
/* fallthrough */
case 2:
address_space_stl_notdirty(&address_space_memory,
SMP_BOOT_REG + 0x10, 0,
MEMTXATTRS_UNSPECIFIED, NULL);
env->regs[15] = SMP_BOOT_ADDR;
break;
default:
break;
}
}

#define NUM_REGS 0x200
static void hb_regs_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
Expand Down Expand Up @@ -380,8 +326,6 @@ static void calxeda_init(MachineState *machine, enum cxmachines machine_id)
highbank_binfo.board_id = -1;
highbank_binfo.nb_cpus = smp_cpus;
highbank_binfo.loader_start = 0;
highbank_binfo.write_secondary_boot = hb_write_secondary;
highbank_binfo.secondary_cpu_reset_hook = hb_reset_secondary;
highbank_binfo.board_setup_addr = BOARD_SETUP_ADDR;
highbank_binfo.psci_conduit = QEMU_PSCI_CONDUIT_SMC;

Expand Down

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