[PATCH v5 18/32] x86, mpparse: Use memremap to map the mpf and mpc data

Tom Lendacky
2017-04-18T21:19:59Z

The SMP MP-table is built by UEFI and placed in memory in a decrypted
state. These tables are accessed using a mix of early_memremap(),
early_memunmap(), phys_to_virt() and virt_to_phys(). Change all accesses
to use early_memremap()/early_memunmap(). This allows for proper setting
of the encryption mask so that the data can be successfully accessed when
SME is active.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
arch/x86/kernel/mpparse.c | 102 +++++++++++++++++++++++++++++++--------------
1 file changed, 71 insertions(+), 31 deletions(-)

diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index fd37f39..afbda41d 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -429,7 +429,21 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type)
}
}

-static struct mpf_intel *mpf_found;
+static unsigned long mpf_base;
+
+static void __init unmap_mpf(struct mpf_intel *mpf)
+{
+ early_memunmap(mpf, sizeof(*mpf));
+}
+
+static struct mpf_intel * __init map_mpf(unsigned long paddr)
+{
+ struct mpf_intel *mpf;
+
+ mpf = early_memremap(paddr, sizeof(*mpf));
+
+ return mpf;
+}

static unsigned long __init get_mpc_size(unsigned long physptr)
{
@@ -444,13 +458,21 @@ static unsigned long __init get_mpc_size(unsigned long physptr)
return size;
}

+static void __init unmap_mpc(struct mpc_table *mpc)
+{
+ early_memunmap(mpc, mpc->length);
+}
+
+static struct mpc_table * __init map_mpc(unsigned long paddr)
+{
+ return early_memremap(paddr, get_mpc_size(paddr));
+}
+
static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
{
struct mpc_table *mpc;
- unsigned long size;

- size = get_mpc_size(mpf->physptr);
- mpc = early_memremap(mpf->physptr, size);
+ mpc = map_mpc(mpf->physptr);
/*
* Read the physical hardware table. Anything here will
* override the defaults.
@@ -461,10 +483,10 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
#endif
pr_err("BIOS bug, MP table errors detected!...\n");
pr_cont("... disabling SMP support. (tell your hw vendor)\n");
- early_memunmap(mpc, size);
+ unmap_mpc(mpc);
return -1;
}
- early_memunmap(mpc, size);
+ unmap_mpc(mpc);

if (early)
return -1;
@@ -497,12 +519,12 @@ static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
*/
void __init default_get_smp_config(unsigned int early)
{
- struct mpf_intel *mpf = mpf_found;
+ struct mpf_intel *mpf;

if (!smp_found_config)
return;

- if (!mpf)
+ if (!mpf_base)
return;

if (acpi_lapic && early)
@@ -515,6 +537,8 @@ void __init default_get_smp_config(unsigned int early)
if (acpi_lapic && acpi_ioapic)
return;

+ mpf = map_mpf(mpf_base);
+
pr_info("Intel MultiProcessor Specification v1.%d\n",
mpf->specification);
#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
@@ -542,8 +566,10 @@ void __init default_get_smp_config(unsigned int early)
construct_default_ISA_mptable(mpf->feature1);

} else if (mpf->physptr) {
- if (check_physptr(mpf, early))
+ if (check_physptr(mpf, early)) {
+ unmap_mpf(mpf);
return;
+ }
} else
BUG();

@@ -552,6 +578,8 @@ void __init default_get_smp_config(unsigned int early)
/*
* Only use the first configuration found.
*/
+
+ unmap_mpf(mpf);
}

static void __init smp_reserve_memory(struct mpf_intel *mpf)
@@ -561,15 +589,16 @@ static void __init smp_reserve_memory(struct mpf_intel *mpf)

static int __init smp_scan_config(unsigned long base, unsigned long length)
{
- unsigned int *bp = phys_to_virt(base);
+ unsigned int *bp;
struct mpf_intel *mpf;
- unsigned long mem;
+ int ret = 0;

apic_printk(APIC_VERBOSE, "Scan for SMP in [mem %#010lx-%#010lx]\n",
base, base + length - 1);
BUILD_BUG_ON(sizeof(*mpf) != 16);

while (length > 0) {
+ bp = early_memremap(base, length);
mpf = (struct mpf_intel *)bp;
if ((*bp == SMP_MAGIC_IDENT) &&
(mpf->length == 1) &&
@@ -579,24 +608,26 @@ static int __init smp_scan_config(unsigned long base, unsigned long length)
#ifdef CONFIG_X86_LOCAL_APIC
smp_found_config = 1;
#endif
- mpf_found = mpf;
+ mpf_base = base;

- pr_info("found SMP MP-table at [mem %#010llx-%#010llx] mapped at [%p]\n",
- (unsigned long long) virt_to_phys(mpf),
- (unsigned long long) virt_to_phys(mpf) +
- sizeof(*mpf) - 1, mpf);
+ pr_info("found SMP MP-table at [mem %#010lx-%#010lx] mapped at [%p]\n",
+ base, base + sizeof(*mpf) - 1, mpf);

- mem = virt_to_phys(mpf);
- memblock_reserve(mem, sizeof(*mpf));
+ memblock_reserve(base, sizeof(*mpf));
if (mpf->physptr)
smp_reserve_memory(mpf);

- return 1;
+ ret = 1;
}
- bp += 4;
+ early_memunmap(bp, length);
+
+ if (ret)
+ break;
+
+ base += 16;
length -= 16;
}
- return 0;
+ return ret;
}

void __init default_find_smp_config(void)
@@ -842,25 +873,26 @@ static int __init update_mp_table(void)
if (!enable_update_mptable)
return 0;

- mpf = mpf_found;
- if (!mpf)
+ if (!mpf_base)
return 0;

+ mpf = map_mpf(mpf_base);
+
/*
* Now see if we need to go further.
*/
if (mpf->feature1 != 0)
- return 0;
+ goto do_unmap_mpf;

if (!mpf->physptr)
- return 0;
+ goto do_unmap_mpf;

- mpc = phys_to_virt(mpf->physptr);
+ mpc = map_mpc(mpf->physptr);

if (!smp_check_mpc(mpc, oem, str))
- return 0;
+ goto do_unmap_mpc;

- pr_info("mpf: %llx\n", (u64)virt_to_phys(mpf));
+ pr_info("mpf: %llx\n", (u64)mpf_base);
pr_info("physptr: %x\n", mpf->physptr);

if (mpc_new_phys && mpc->length > mpc_new_length) {
@@ -878,21 +910,23 @@ static int __init update_mp_table(void)
new = mpf_checksum((unsigned char *)mpc, mpc->length);
if (old == new) {
pr_info("mpc is readonly, please try alloc_mptable instead\n");
- return 0;
+ goto do_unmap_mpc;
}
pr_info("use in-position replacing\n");
} else {
mpf->physptr = mpc_new_phys;
- mpc_new = phys_to_virt(mpc_new_phys);
+ mpc_new = map_mpc(mpc_new_phys);
memcpy(mpc_new, mpc, mpc->length);
+ unmap_mpc(mpc);
mpc = mpc_new;
/* check if we can modify that */
if (mpc_new_phys - mpf->physptr) {
struct mpf_intel *mpf_new;
/* steal 16 bytes from [0, 1k) */
pr_info("mpf new: %x\n", 0x400 - 16);
- mpf_new = phys_to_virt(0x400 - 16);
+ mpf_new = map_mpf(0x400 - 16);
memcpy(mpf_new, mpf, 16);
+ unmap_mpf(mpf);
mpf = mpf_new;
mpf->physptr = mpc_new_phys;
}
@@ -909,6 +943,12 @@ static int __init update_mp_table(void)
*/
replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);

+do_unmap_mpc:
+ unmap_mpc(mpc);
+
+do_unmap_mpf:
+ unmap_mpf(mpf);
+
return 0;
}