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Message-Id: <20180216112640.11554-2-bp@alien8.de>
Date: Fri, 16 Feb 2018 12:26:38 +0100
From: Borislav Petkov <bp@...en8.de>
To: Ashok Raj <ashok.raj@...el.com>
Cc: X86 ML <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/3] x86/microcode: Propagate return value from updating functions
From: Borislav Petkov <bp@...e.de>
... so that callers can know when microcode was updated and act
accordingly.
Signed-off-by: Borislav Petkov <bp@...e.de>
---
arch/x86/include/asm/microcode.h | 9 +++++++--
arch/x86/kernel/cpu/microcode/amd.c | 10 +++++-----
arch/x86/kernel/cpu/microcode/core.c | 33 +++++++++++++++++----------------
arch/x86/kernel/cpu/microcode/intel.c | 10 +++++-----
4 files changed, 34 insertions(+), 28 deletions(-)
diff --git a/arch/x86/include/asm/microcode.h b/arch/x86/include/asm/microcode.h
index 55520cec8b27..7fb1047d61c7 100644
--- a/arch/x86/include/asm/microcode.h
+++ b/arch/x86/include/asm/microcode.h
@@ -37,7 +37,12 @@ struct cpu_signature {
struct device;
-enum ucode_state { UCODE_ERROR, UCODE_OK, UCODE_NFOUND };
+enum ucode_state {
+ UCODE_OK = 0,
+ UCODE_UPDATED,
+ UCODE_NFOUND,
+ UCODE_ERROR,
+};
struct microcode_ops {
enum ucode_state (*request_microcode_user) (int cpu,
@@ -54,7 +59,7 @@ struct microcode_ops {
* are being called.
* See also the "Synchronization" section in microcode_core.c.
*/
- int (*apply_microcode) (int cpu);
+ enum ucode_state (*apply_microcode) (int cpu);
int (*collect_cpu_info) (int cpu, struct cpu_signature *csig);
};
diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c
index 330b8462d426..a998e1a7d46f 100644
--- a/arch/x86/kernel/cpu/microcode/amd.c
+++ b/arch/x86/kernel/cpu/microcode/amd.c
@@ -498,7 +498,7 @@ static unsigned int verify_patch_size(u8 family, u32 patch_size,
return patch_size;
}
-static int apply_microcode_amd(int cpu)
+static enum ucode_state apply_microcode_amd(int cpu)
{
struct cpuinfo_x86 *c = &cpu_data(cpu);
struct microcode_amd *mc_amd;
@@ -512,7 +512,7 @@ static int apply_microcode_amd(int cpu)
p = find_patch(cpu);
if (!p)
- return 0;
+ return UCODE_NFOUND;
mc_amd = p->data;
uci->mc = p->data;
@@ -523,13 +523,13 @@ static int apply_microcode_amd(int cpu)
if (rev >= mc_amd->hdr.patch_id) {
c->microcode = rev;
uci->cpu_sig.rev = rev;
- return 0;
+ return UCODE_OK;
}
if (__apply_microcode_amd(mc_amd)) {
pr_err("CPU%d: update failed for patch_level=0x%08x\n",
cpu, mc_amd->hdr.patch_id);
- return -1;
+ return UCODE_ERROR;
}
pr_info("CPU%d: new patch_level=0x%08x\n", cpu,
mc_amd->hdr.patch_id);
@@ -537,7 +537,7 @@ static int apply_microcode_amd(int cpu)
uci->cpu_sig.rev = mc_amd->hdr.patch_id;
c->microcode = mc_amd->hdr.patch_id;
- return 0;
+ return UCODE_UPDATED;
}
static int install_equiv_cpu_table(const u8 *buf)
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 319dd65f98a2..6fdaf7cf3182 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -374,7 +374,7 @@ static int collect_cpu_info(int cpu)
}
struct apply_microcode_ctx {
- int err;
+ enum ucode_state err;
};
static void apply_microcode_local(void *arg)
@@ -489,31 +489,29 @@ static void __exit microcode_dev_exit(void)
/* fake device for request_firmware */
static struct platform_device *microcode_pdev;
-static int reload_for_cpu(int cpu)
+static enum ucode_state reload_for_cpu(int cpu)
{
struct ucode_cpu_info *uci = ucode_cpu_info + cpu;
enum ucode_state ustate;
- int err = 0;
if (!uci->valid)
- return err;
+ return UCODE_OK;
ustate = microcode_ops->request_microcode_fw(cpu, µcode_pdev->dev, true);
- if (ustate == UCODE_OK)
- apply_microcode_on_target(cpu);
- else
- if (ustate == UCODE_ERROR)
- err = -EINVAL;
- return err;
+ if (ustate != UCODE_OK)
+ return ustate;
+
+ return apply_microcode_on_target(cpu);
}
static ssize_t reload_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
+ enum ucode_state tmp_ret = UCODE_OK;
unsigned long val;
+ ssize_t ret = 0;
int cpu;
- ssize_t ret = 0, tmp_ret;
ret = kstrtoul(buf, 0, &val);
if (ret)
@@ -526,15 +524,18 @@ static ssize_t reload_store(struct device *dev,
mutex_lock(µcode_mutex);
for_each_online_cpu(cpu) {
tmp_ret = reload_for_cpu(cpu);
- if (tmp_ret != 0)
+ if (tmp_ret > UCODE_NFOUND) {
pr_warn("Error reloading microcode on CPU %d\n", cpu);
- /* save retval of the first encountered reload error */
- if (!ret)
- ret = tmp_ret;
+ /* set retval for the first encountered reload error */
+ if (!ret)
+ ret = -EINVAL;
+ }
}
- if (!ret)
+
+ if (!ret && tmp_ret == UCODE_UPDATED)
perf_check_microcode();
+
mutex_unlock(µcode_mutex);
put_online_cpus();
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index f7c55b0e753a..09b95a7b5dff 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -772,7 +772,7 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
return 0;
}
-static int apply_microcode_intel(int cpu)
+static enum ucode_state apply_microcode_intel(int cpu)
{
struct microcode_intel *mc;
struct ucode_cpu_info *uci;
@@ -782,7 +782,7 @@ static int apply_microcode_intel(int cpu)
/* We should bind the task to the CPU */
if (WARN_ON(raw_smp_processor_id() != cpu))
- return -1;
+ return UCODE_ERROR;
uci = ucode_cpu_info + cpu;
mc = uci->mc;
@@ -790,7 +790,7 @@ static int apply_microcode_intel(int cpu)
/* Look for a newer patch in our cache: */
mc = find_patch(uci);
if (!mc)
- return 0;
+ return UCODE_NFOUND;
}
/* write microcode via MSR 0x79 */
@@ -801,7 +801,7 @@ static int apply_microcode_intel(int cpu)
if (rev != mc->hdr.rev) {
pr_err("CPU%d update to revision 0x%x failed\n",
cpu, mc->hdr.rev);
- return -1;
+ return UCODE_ERROR;
}
if (rev != prev_rev) {
@@ -818,7 +818,7 @@ static int apply_microcode_intel(int cpu)
uci->cpu_sig.rev = rev;
c->microcode = rev;
- return 0;
+ return UCODE_UPDATED;
}
static enum ucode_state generic_load_microcode(int cpu, void *data, size_t size,
--
2.13.0
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