[PATCH v2 04/14] x86/microcode/intel: Expose find_matching_signature() for IFS

Jithu Joseph
2022-11-07T22:55:16Z

IFS uses 'scan test images' provided by Intel that can be regarded as
firmware. IFS test image carries microcode header with extended signature
table.

Expose find_matching_signature() for verifying if the test image
header or the extended signature table indicate whether an IFS test image
is fit to run on a system. Move the function to cpu/intel.c and
add intel_ prefix to the function name.

No functional change

Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
---
arch/x86/include/asm/cpu.h | 1 +
arch/x86/kernel/cpu/intel.c | 29 ++++++++++++++++++
arch/x86/kernel/cpu/microcode/intel.c | 44 +++++----------------------
3 files changed, 38 insertions(+), 36 deletions(-)

diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h
index b472ef76826a..e853440b5c65 100644
--- a/arch/x86/include/asm/cpu.h
+++ b/arch/x86/include/asm/cpu.h
@@ -95,5 +95,6 @@ static inline bool intel_cpu_signatures_match(unsigned int s1, unsigned int p1,
}

extern u64 x86_read_arch_cap_msr(void);
+int intel_find_matching_signature(void *mc, unsigned int csig, int cpf);

#endif /* _ASM_X86_CPU_H */
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 2d7ea5480ec3..b6f9210fb31a 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -216,6 +216,35 @@ int intel_cpu_collect_info(struct ucode_cpu_info *uci)
}
EXPORT_SYMBOL_GPL(intel_cpu_collect_info);

+/*
+ * Returns 1 if update has been found, 0 otherwise.
+ */
+int intel_find_matching_signature(void *mc, unsigned int csig, int cpf)
+{
+ struct microcode_header_intel *mc_hdr = mc;
+ struct extended_sigtable *ext_hdr;
+ struct extended_signature *ext_sig;
+ int i;
+
+ if (intel_cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
+ return 1;
+
+ /* Look for ext. headers: */
+ if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
+ return 0;
+
+ ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
+ ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
+
+ for (i = 0; i < ext_hdr->count; i++) {
+ if (intel_cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
+ return 1;
+ ext_sig++;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(intel_find_matching_signature);
+
static void early_init_intel(struct cpuinfo_x86 *c)
{
u64 misc_enable;
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 1fcbd671f1df..4e611a708718 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -45,34 +45,6 @@ static struct microcode_intel *intel_ucode_patch;
/* last level cache size per core */
static int llc_size_per_core;

-/*
- * Returns 1 if update has been found, 0 otherwise.
- */
-static int find_matching_signature(void *mc, unsigned int csig, int cpf)
-{
- struct microcode_header_intel *mc_hdr = mc;
- struct extended_sigtable *ext_hdr;
- struct extended_signature *ext_sig;
- int i;
-
- if (intel_cpu_signatures_match(csig, cpf, mc_hdr->sig, mc_hdr->pf))
- return 1;
-
- /* Look for ext. headers: */
- if (get_totalsize(mc_hdr) <= get_datasize(mc_hdr) + MC_HEADER_SIZE)
- return 0;
-
- ext_hdr = mc + get_datasize(mc_hdr) + MC_HEADER_SIZE;
- ext_sig = (void *)ext_hdr + EXT_HEADER_SIZE;
-
- for (i = 0; i < ext_hdr->count; i++) {
- if (intel_cpu_signatures_match(csig, cpf, ext_sig->sig, ext_sig->pf))
- return 1;
- ext_sig++;
- }
- return 0;
-}
-
/*
* Returns 1 if update has been found, 0 otherwise.
*/
@@ -83,7 +55,7 @@ static int has_newer_microcode(void *mc, unsigned int csig, int cpf, int new_rev
if (mc_hdr->rev <= new_rev)
return 0;

- return find_matching_signature(mc, csig, cpf);
+ return intel_find_matching_signature(mc, csig, cpf);
}

static struct ucode_patch *memdup_patch(void *data, unsigned int size)
@@ -117,7 +89,7 @@ static void save_microcode_patch(struct ucode_cpu_info *uci, void *data, unsigne
sig = mc_saved_hdr->sig;
pf = mc_saved_hdr->pf;

- if (find_matching_signature(data, sig, pf)) {
+ if (intel_find_matching_signature(data, sig, pf)) {
prev_found = true;

if (mc_hdr->rev <= mc_saved_hdr->rev)
@@ -149,7 +121,7 @@ static void save_microcode_patch(struct ucode_cpu_info *uci, void *data, unsigne
if (!p)
return;

- if (!find_matching_signature(p->data, uci->cpu_sig.sig, uci->cpu_sig.pf))
+ if (!intel_find_matching_signature(p->data, uci->cpu_sig.sig, uci->cpu_sig.pf))
return;

/*
@@ -286,8 +258,8 @@ scan_microcode(void *data, size_t size, struct ucode_cpu_info *uci, bool save)

size -= mc_size;

- if (!find_matching_signature(data, uci->cpu_sig.sig,
- uci->cpu_sig.pf)) {
+ if (!intel_find_matching_signature(data, uci->cpu_sig.sig,
+ uci->cpu_sig.pf)) {
data += mc_size;
continue;
}
@@ -652,9 +624,9 @@ static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
if (phdr->rev <= uci->cpu_sig.rev)
continue;

- if (!find_matching_signature(phdr,
- uci->cpu_sig.sig,
- uci->cpu_sig.pf))
+ if (!intel_find_matching_signature(phdr,
+ uci->cpu_sig.sig,
+ uci->cpu_sig.pf))
continue;

return iter->data;
--
2.25.1