[PATCH 4/8] x86, microcode, intel: add error logging to early update driver

Henrique de Moraes Holschuh
2014-09-08T17:48:31Z

Enhance the logging in the Intel early microcode update driver to
be able to report errors.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
---
arch/x86/kernel/cpu/microcode/intel_early.c | 94 +++++++++++++++------------
1 file changed, 54 insertions(+), 40 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/intel_early.c b/arch/x86/kernel/cpu/microcode/intel_early.c
index f73fc0a..8ad50d6 100644
--- a/arch/x86/kernel/cpu/microcode/intel_early.c
+++ b/arch/x86/kernel/cpu/microcode/intel_early.c
@@ -31,6 +31,12 @@
#include <asm/tlbflush.h>
#include <asm/setup.h>

+enum {
+ INTEL_EARLYMCU_NONE = 0, /* did nothing */
+ INTEL_EARLYMCU_UPDATEOK, /* microcode updated */
+ INTEL_EARLYMCU_REJECTED, /* cpu rejected it */
+};
+
static unsigned long mc_saved_in_initrd[MAX_UCODE_COUNT];
static struct mc_saved_data {
unsigned int mc_saved_count;
@@ -576,37 +582,50 @@ scan_microcode(unsigned long start, unsigned long end,

/*
* Print ucode update info.
+ * for status == INTEL_EARLYMCU_UPDATEOK, data should be the mcu date
+ * for status == INTEL_EARLYMCU_REJECTED, data should be mcu revision
*/
-static void
-print_ucode_info(struct ucode_cpu_info *uci, unsigned int date)
+static void print_ucode_info(const unsigned int status,
+ const struct ucode_cpu_info *uci,
+ const unsigned int data)
{
int cpu = smp_processor_id();
-
- pr_info("CPU%d: entire core updated early to revision 0x%x, date %04x-%02x-%02x\n",
- cpu,
- uci->cpu_sig.rev,
- date & 0xffff,
- date >> 24,
- (date >> 16) & 0xff);
+ struct ucode_cpu_info ucil;
+
+ switch (status) {
+ case INTEL_EARLYMCU_NONE:
+ break;
+ case INTEL_EARLYMCU_UPDATEOK:
+ if (!uci) {
+ collect_cpu_info_early(&ucil);
+ uci = &ucil;
+ }
+ pr_info("CPU%d: entire core updated early to revision 0x%x, date %04x-%02x-%02x\n",
+ cpu,
+ uci->cpu_sig.rev,
+ data & 0xffff,
+ data >> 24,
+ (data >> 16) & 0xff);
+ break;
+ case INTEL_EARLYMCU_REJECTED:
+ pr_err("CPU%d: update to revision 0x%x rejected by the processor\n", cpu, data);
+ break;
+ }
}

#ifdef CONFIG_X86_32

-static int delay_ucode_info;
-static int current_mc_date;
+static unsigned int delay_ucode_info;
+static unsigned int delay_ucode_info_data;

/*
* Print early updated ucode info after printk works. This is delayed info dump.
+ * This is only used for the BSP.
*/
void show_ucode_info_early(void)
{
- struct ucode_cpu_info uci;
-
- if (delay_ucode_info) {
- collect_cpu_info_early(&uci);
- print_ucode_info(&uci, current_mc_date);
- delay_ucode_info = 0;
- }
+ print_ucode_info(delay_ucode_info, NULL, delay_ucode_info_data);
+ delay_ucode_info = INTEL_EARLYMCU_NONE;
}

/*
@@ -614,21 +633,18 @@ void show_ucode_info_early(void)
* mc_saved_data.mc_saved and delay printing microcode info in
* show_ucode_info_early() until printk() works.
*/
-static void print_ucode(struct ucode_cpu_info *uci)
+static void print_ucode(const unsigned int status,
+ const struct ucode_cpu_info * const uci,
+ const unsigned int data)
{
- struct microcode_intel *mc_intel;
- int *delay_ucode_info_p;
- int *current_mc_date_p;
-
- mc_intel = uci->mc;
- if (mc_intel == NULL)
- return;
+ unsigned int *delay_ucode_info_p;
+ unsigned int *delay_ucode_info_data_p;

- delay_ucode_info_p = (int *)__pa_nodebug(&delay_ucode_info);
- current_mc_date_p = (int *)__pa_nodebug(&current_mc_date);
+ delay_ucode_info_p = (unsigned int *)__pa_nodebug(&delay_ucode_info);
+ delay_ucode_info_data_p = (unsigned int *)__pa_nodebug(&delay_ucode_info_data);

- *delay_ucode_info_p = 1;
- *current_mc_date_p = mc_intel->hdr.date;
+ *delay_ucode_info_p = status;
+ *delay_ucode_info_data_p = data;
}
#else

@@ -641,15 +657,11 @@ static inline void flush_tlb_early(void)
__native_flush_tlb_global_irq_disabled();
}

-static inline void print_ucode(struct ucode_cpu_info *uci)
+static inline void print_ucode(const unsigned int status,
+ const struct ucode_cpu_info * const uci,
+ const unsigned int data)
{
- struct microcode_intel *mc_intel;
-
- mc_intel = uci->mc;
- if (mc_intel == NULL)
- return;
-
- print_ucode_info(uci, mc_intel->hdr.date);
+ print_ucode_info(status, uci, data);
}
#endif

@@ -674,8 +686,10 @@ static int apply_microcode_early(struct mc_saved_data *mc_saved_data,

/* get the current revision from MSR 0x8B */
native_rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
- if (val[1] != mc_intel->hdr.rev)
+ if (val[1] != mc_intel->hdr.rev) {
+ print_ucode(INTEL_EARLYMCU_REJECTED, uci, mc_intel->hdr.rev);
return -1;
+ }

#ifdef CONFIG_X86_64
/* Flush global tlb. This is precaution. */
@@ -683,7 +697,7 @@ static int apply_microcode_early(struct mc_saved_data *mc_saved_data,
#endif
uci->cpu_sig.rev = val[1];

- print_ucode(uci);
+ print_ucode(INTEL_EARLYMCU_UPDATEOK, uci, mc_intel->hdr.date);

return 0;
}
--
1.7.10.4