On 7/6/20 6:40 PM, Michael Ellerman wrote:
"Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> writes:
Parse storage keys related device tree entry in early_init_devtree
and enable MMU feature MMU_FTR_PKEY if pkeys are supported.
MMU feature is used instead of CPU feature because this enables us
to group MMU_FTR_KUAP and MMU_FTR_PKEY in asm feature fixup code.
Subject should probably be "Add MMU_FTR_PKEY".
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index f4ac25d4df05..72966d3d8f64 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -23,6 +23,7 @@
/* Radix page table supported and enabled */
#define MMU_FTR_TYPE_RADIX ASM_CONST(0x00000040)
+#define MMU_FTR_PKEY ASM_CONST(0x00000080)
It's not a type, so it should be with the individual feature bits below:
We don't have free bit in the other group. For now i will move this to
modified arch/powerpc/include/asm/mmu.h
@@ -23,12 +23,15 @@
/* Radix page table supported and enabled */
#define MMU_FTR_TYPE_RADIX ASM_CONST(0x00000040)
-#define MMU_FTR_PKEY ASM_CONST(0x00000080)
/*
* Individual features below.
*/
+/*
+ * Support for memory protection keys.
+ */
+#define MMU_FTR_PKEY ASM_CONST(0x00001000)
/*
* Support for 68 bit VA space. We added that from ISA 2.05
*/
/*
* Individual features below.
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 6a3bac357e24..6d70797352d8 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -815,6 +815,11 @@ void __init early_init_devtree(void *params)
/* Now try to figure out if we are running on LPAR and so on */
pseries_probe_fw_features();
+ /*
+ * Initialize pkey features and default AMR/IAMR values
+ */
+ pkey_early_init_devtree();
Not your fault, but the fact that we're having to do more and more
initialisation this early, based on the flat device tree, makes me
wonder if we need to rethink how we're doing the CPU/MMU feature setup.
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index 0ff59acdbb84..bbba9c601e14 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -38,38 +39,45 @@ static int execute_only_key = 2;
#define PKEY_REG_BITS (sizeof(u64) * 8)
#define pkeyshift(pkey) (PKEY_REG_BITS - ((pkey+1) * AMR_BITS_PER_PKEY))
+static int __init dt_scan_storage_keys(unsigned long node,
+ const char *uname, int depth,
+ void *data)
+{
+ const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+ const __be32 *prop;
+ int pkeys_total;
+
+ /* We are scanning "cpu" nodes only */
+ if (type == NULL || strcmp(type, "cpu") != 0)
+ return 0;
+
+ prop = of_get_flat_dt_prop(node, "ibm,processor-storage-keys", NULL);
+ if (!prop)
+ return 0;
+ pkeys_total = be32_to_cpu(prop[0]);
+ return pkeys_total;
That's not really the way the return value is meant to be used for these
scanning functions.
The usual return values are 0 to keep scanning and !0 means we've found
the node we're looking for and we should stop scanning.
Doing it this way means if you find 0 pkeys it will keep scanning.
Instead you should pass &pkeys_total as the data pointer and set that.
+}
+
done
modified arch/powerpc/mm/book3s64/pkeys.c
@@ -52,7 +52,7 @@ static int __init dt_scan_storage_keys(unsigned long node,
{
const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
const __be32 *prop;
- int pkeys_total;
+ int *pkeys_total = (int *) data;
/* We are scanning "cpu" nodes only */
if (type == NULL || strcmp(type, "cpu") != 0)
@@ -61,12 +61,13 @@ static int __init dt_scan_storage_keys(unsigned long
node,
prop = of_get_flat_dt_prop(node, "ibm,processor-storage-keys", NULL);
if (!prop)
return 0;
- pkeys_total = be32_to_cpu(prop[0]);
- return pkeys_total;
+ *pkeys_total = be32_to_cpu(prop[0]);
+ return 1;
}
static int scan_pkey_feature(void)
{
+ int ret;
int pkeys_total;
/*
@@ -75,8 +76,8 @@ static int scan_pkey_feature(void)
if (early_radix_enabled())
return 0;
- pkeys_total = of_scan_flat_dt(dt_scan_storage_keys, NULL);
- if (pkeys_total == 0) {
+ ret = of_scan_flat_dt(dt_scan_storage_keys, &pkeys_total);
+ if (ret == 0) {
/*
* Let's assume 32 pkeys on P8/P9 bare metal, if its not defined by
device
@@ -87,7 +88,6 @@ static int scan_pkey_feature(void)
(early_cpu_has_feature(CPU_FTR_ARCH_207S) ||
early_cpu_has_feature(CPU_FTR_ARCH_300)))
pkeys_total = 32;
-
}
/*
static int scan_pkey_feature(void)
{
- u32 vals[2];
- int pkeys_total = 0;
- struct device_node *cpu;
+ int pkeys_total;
/*
* Pkey is not supported with Radix translation.
*/
- if (radix_enabled())
+ if (early_radix_enabled())
return 0;
- cpu = of_find_node_by_type(NULL, "cpu");
- if (!cpu)
- return 0;
+ pkeys_total = of_scan_flat_dt(dt_scan_storage_keys, NULL);
+ if (pkeys_total == 0) {
- if (of_property_read_u32_array(cpu,
- "ibm,processor-storage-keys", vals, 2)
== 0) {
- /*
- * Since any pkey can be used for data or execute, we will
- * just treat all keys as equal and track them as one entity.
- */
- pkeys_total = vals[0];
- /* Should we check for IAMR support FIXME!! */
???
The device tree allows us to have different count for both AMR and IAMR.
The current code skip that. I guess i added a comment in earlier patch
to check that whether we need to handle different AMR and IAMR counts.
The same comment get dropped here.
- } else {
This loses the ability to differentiate between no storage-keys property
at all vs a property that specifies zero keys, which I don't think is a
good change.
/*
* Let's assume 32 pkeys on P8 bare metal, if its not defined
by device
* tree. We make this exception since skiboot forgot to expose
this
* property on power8.
*/
if (!firmware_has_feature(FW_FEATURE_LPAR) &&
- cpu_has_feature(CPU_FTRS_POWER8))
+ early_cpu_has_feature(CPU_FTRS_POWER8))
pkeys_total = 32;
That's not how cpu_has_feature() works, we'll need to fix that.
cheers
I did a separate patch to handle that which switch the above to
/*
* Let's assume 32 pkeys on P8/P9 bare metal, if its not
defined by device
* tree. We make this exception since skiboot forgot to expose
this
* property on power8/9.
*/
if (!firmware_has_feature(FW_FEATURE_LPAR) &&
(early_cpu_has_feature(CPU_FTR_ARCH_207S) ||
early_cpu_has_feature(CPU_FTR_ARCH_300)))
pkeys_total = 32;
