The ibm,configure-kernel-dump RTAS call sites in rtas_fadump_register(), rtas_fadump_unregister(), and rtas_fadump_invalidate() polled indefinitely while firmware returned a busy status. A misbehaving or hung firmware could stall these paths forever, blocking fadump registration at boot or preventing clean teardown.
Introduce rtas_fadump_call(), a helper that wraps the common busy-wait pattern shared by all three sites. The helper accumulates the total delay and returns -ETIMEDOUT if firmware keeps returning a busy status beyond RTAS_FADUMP_MAX_WAIT_MS (60 seconds). A pr_debug() message is emitted on each busy iteration to aid diagnosis when the timeout is hit. Signed-off-by: Adriano Vero <[email protected]> --- arch/powerpc/platforms/pseries/rtas-fadump.c | 80 ++++++++++++-------- arch/powerpc/platforms/pseries/rtas-fadump.h | 6 ++ 2 files changed, 53 insertions(+), 33 deletions(-) diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c index eceb32893..3bb4ac2ab 100644 --- a/arch/powerpc/platforms/pseries/rtas-fadump.c +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c @@ -179,9 +179,42 @@ static u64 rtas_fadump_get_bootmem_min(void) return RTAS_FADUMP_MIN_BOOT_MEM; } +/* + * Helper to make an ibm,configure-kernel-dump RTAS call with a bounded + * busy-wait loop. Returns the RTAS return code on completion, or + * -ETIMEDOUT if firmware keeps returning a busy status beyond + * RTAS_FADUMP_MAX_WAIT_MS milliseconds. + */ +static int rtas_fadump_call(struct fw_dump *fadump_conf, int operation, + void *fdm_ptr, unsigned int fdm_size, + const char *op_name) +{ + unsigned int wait_time, total_wait = 0; + int rc; + + do { + rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1, + NULL, operation, fdm_ptr, fdm_size); + wait_time = rtas_busy_delay_time(rc); + if (wait_time) { + pr_debug("Firmware busy during fadump %s, waiting %ums (total %ums)\n", + op_name, wait_time, total_wait); + if (total_wait >= RTAS_FADUMP_MAX_WAIT_MS) { + pr_err("Timed out waiting for firmware to complete fadump %s\n", + op_name); + return -ETIMEDOUT; + } + total_wait += wait_time; + mdelay(wait_time); + } + } while (wait_time); + + return rc; +} + static int rtas_fadump_register(struct fw_dump *fadump_conf) { - unsigned int wait_time, fdm_size; + unsigned int fdm_size; int rc, err = -EIO; /* @@ -192,16 +225,10 @@ static int rtas_fadump_register(struct fw_dump *fadump_conf) fdm_size = sizeof(struct rtas_fadump_section_header); fdm_size += be16_to_cpu(fdm.header.dump_num_sections) * sizeof(struct rtas_fadump_section); - /* TODO: Add upper time limit for the delay */ - do { - rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1, - NULL, FADUMP_REGISTER, &fdm, fdm_size); - - wait_time = rtas_busy_delay_time(rc); - if (wait_time) - mdelay(wait_time); - - } while (wait_time); + rc = rtas_fadump_call(fadump_conf, FADUMP_REGISTER, &fdm, fdm_size, + "register"); + if (rc == -ETIMEDOUT) + return -ETIMEDOUT; switch (rc) { case 0: @@ -234,19 +261,12 @@ static int rtas_fadump_register(struct fw_dump *fadump_conf) static int rtas_fadump_unregister(struct fw_dump *fadump_conf) { - unsigned int wait_time; int rc; - /* TODO: Add upper time limit for the delay */ - do { - rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1, - NULL, FADUMP_UNREGISTER, &fdm, - sizeof(struct rtas_fadump_mem_struct)); - - wait_time = rtas_busy_delay_time(rc); - if (wait_time) - mdelay(wait_time); - } while (wait_time); + rc = rtas_fadump_call(fadump_conf, FADUMP_UNREGISTER, &fdm, + sizeof(struct rtas_fadump_mem_struct), "unregister"); + if (rc == -ETIMEDOUT) + return -ETIMEDOUT; if (rc) { pr_err("Failed to un-register - unexpected error(%d).\n", rc); @@ -259,19 +279,13 @@ static int rtas_fadump_unregister(struct fw_dump *fadump_conf) static int rtas_fadump_invalidate(struct fw_dump *fadump_conf) { - unsigned int wait_time; int rc; - /* TODO: Add upper time limit for the delay */ - do { - rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1, - NULL, FADUMP_INVALIDATE, fdm_active, - sizeof(struct rtas_fadump_mem_struct)); - - wait_time = rtas_busy_delay_time(rc); - if (wait_time) - mdelay(wait_time); - } while (wait_time); + rc = rtas_fadump_call(fadump_conf, FADUMP_INVALIDATE, + (void *)fdm_active, + sizeof(struct rtas_fadump_mem_struct), "invalidate"); + if (rc == -ETIMEDOUT) + return -ETIMEDOUT; if (rc) { pr_err("Failed to invalidate - unexpected error (%d).\n", rc); diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.h b/arch/powerpc/platforms/pseries/rtas-fadump.h index c109abf6b..65fdab7b5 100644 --- a/arch/powerpc/platforms/pseries/rtas-fadump.h +++ b/arch/powerpc/platforms/pseries/rtas-fadump.h @@ -41,6 +41,12 @@ #define MAX_SECTIONS 10 #define RTAS_FADUMP_MAX_BOOT_MEM_REGS 7 +/* + * Maximum time to wait for firmware to respond to an + * ibm,configure-kernel-dump RTAS call before giving up. + */ +#define RTAS_FADUMP_MAX_WAIT_MS 60000U + /* Kernel Dump section info */ struct rtas_fadump_section { __be32 request_flag; -- 2.53.0
