[PATCH v6 13/23] powerpc/book3s64/pkeys: Add MMU_FTR_PKEY
Aneesh Kumar K.V
aneesh.kumar at linux.ibm.com
Thu Jul 9 13:29:36 AEST 2020
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.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
arch/powerpc/include/asm/book3s/64/mmu.h | 6 +++
arch/powerpc/include/asm/mmu.h | 9 ++++
arch/powerpc/kernel/prom.c | 5 +++
arch/powerpc/mm/book3s64/pkeys.c | 52 ++++++++++++++----------
4 files changed, 50 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h
index 5393a535240c..3371ea05b7d3 100644
--- a/arch/powerpc/include/asm/book3s/64/mmu.h
+++ b/arch/powerpc/include/asm/book3s/64/mmu.h
@@ -209,6 +209,12 @@ extern int mmu_io_psize;
void mmu_early_init_devtree(void);
void hash__early_init_devtree(void);
void radix__early_init_devtree(void);
+#ifdef CONFIG_PPC_MEM_KEYS
+void pkey_early_init_devtree(void);
+#else
+static inline void pkey_early_init_devtree(void) {}
+#endif
+
extern void hash__early_init_mmu(void);
extern void radix__early_init_mmu(void);
static inline void __init early_init_mmu(void)
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index f4ac25d4df05..88aed01fad81 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -28,6 +28,10 @@
* 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
*/
@@ -177,6 +181,9 @@ enum {
MMU_FTR_RADIX_KUAP |
#endif /* CONFIG_PPC_KUAP */
#endif /* CONFIG_PPC_RADIX_MMU */
+#ifdef CONFIG_PPC_MEM_KEYS
+ MMU_FTR_PKEY |
+#endif
0,
};
@@ -356,6 +363,8 @@ extern void setup_initial_memory_limit(phys_addr_t first_memblock_base,
phys_addr_t first_memblock_size);
static inline void mmu_early_init_devtree(void) { }
+static inline void pkey_early_init_devtree(void) {}
+
extern void *abatron_pteptrs[2];
#endif /* __ASSEMBLY__ */
#endif
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 9cc49f265c86..4cb65fd5f532 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();
+
#ifdef CONFIG_PPC_PS3
/* Identify PS3 firmware */
if (of_flat_dt_is_compatible(of_get_flat_dt_root(), "sony,ps3"))
diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c
index ac272166e5b4..c795a28c1964 100644
--- a/arch/powerpc/mm/book3s64/pkeys.c
+++ b/arch/powerpc/mm/book3s64/pkeys.c
@@ -10,7 +10,8 @@
#include <asm/mmu.h>
#include <asm/setup.h>
#include <linux/pkeys.h>
-#include <linux/of_device.h>
+#include <linux/of_fdt.h>
+
DEFINE_STATIC_KEY_FALSE(pkey_disabled);
int num_pkey; /* Max number of pkeys supported */
@@ -46,31 +47,38 @@ 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 = (int *) data;
+
+ /* 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 1;
+}
+
static int scan_pkey_feature(void)
{
- u32 vals[2];
+ int ret;
int pkeys_total = 0;
- struct device_node *cpu;
/*
* Pkey is not supported with Radix translation.
*/
- if (radix_enabled())
- return 0;
-
- cpu = of_find_node_by_type(NULL, "cpu");
- if (!cpu)
+ if (early_radix_enabled())
return 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];
- } else {
-
+ 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
* tree. We make this exception since some version of skiboot forgot to
@@ -94,7 +102,7 @@ static int scan_pkey_feature(void)
return pkeys_total;
}
-static int pkey_initialize(void)
+void __init pkey_early_init_devtree(void)
{
int pkeys_total, i;
@@ -119,9 +127,11 @@ static int pkey_initialize(void)
if (!pkeys_total) {
/* No support for pkey. Mark it disabled */
static_branch_enable(&pkey_disabled);
- return 0;
+ return;
}
+ cur_cpu_spec->mmu_features |= MMU_FTR_PKEY;
+
/*
* The device tree cannot be relied to indicate support for
* execute_disable support. Instead we use a PVR check.
@@ -201,11 +211,9 @@ static int pkey_initialize(void)
*/
initial_allocation_mask |= reserved_allocation_mask;
- return 0;
+ return;
}
-arch_initcall(pkey_initialize);
-
void pkey_mm_init(struct mm_struct *mm)
{
if (static_branch_likely(&pkey_disabled))
--
2.26.2
More information about the Linuxppc-dev
mailing list