This implements os_vm_map, os_vm_unmap. OPAL uses EA regions that
is specifies in OPAL_FIND_VM_AREA for these mappings, so provided
the page tables are allocated at init-time and not freed, these
services can be provided without memory allocation / blocking.
Signed-off-by: Nicholas Piggin <npig...@gmail.com>
---
arch/powerpc/include/asm/opal-api.h | 2 +
arch/powerpc/platforms/powernv/opal.c | 57 +++++++++++++++++++++++++++
2 files changed, 59 insertions(+)
diff --git a/arch/powerpc/include/asm/opal-api.h
b/arch/powerpc/include/asm/opal-api.h
index 1b2f176677fc..97c5e5423827 100644
--- a/arch/powerpc/include/asm/opal-api.h
+++ b/arch/powerpc/include/asm/opal-api.h
@@ -1205,6 +1205,8 @@ struct opal_vm_area {
struct opal_os_ops {
__be64 os_printf; /* void printf(int32_t level, const char *str) */
+ __be64 os_vm_map; /* int64_t os_vm_map(uint64_t ea, uint64_t pa,
uint64_t flags) */
+ __be64 os_vm_unmap; /* void os_vm_unmap(uint64_t ea) */
};
#endif /* __ASSEMBLY__ */
diff --git a/arch/powerpc/platforms/powernv/opal.c
b/arch/powerpc/platforms/powernv/opal.c
index 0fbfcd088c58..93b9afaf33b3 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -1095,6 +1095,61 @@ static pgprot_t opal_vm_flags_to_prot(uint64_t flags)
return prot;
}
+static int64_t os_vm_map(uint64_t ea, uint64_t pa, uint64_t flags)
+{
+ struct mm_struct *mm = opal_mm;
+ spinlock_t *ptl;
+ pte_t pte, *ptep;
+ pgprot_t prot;
+
+ if (WARN_ON_ONCE(!opal_mm_enabled))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(!(mfmsr() & (MSR_IR|MSR_DR))))
+ return -EINVAL;
+
+ /* mm should be active_mm if MMU is on here */
+
+// printk("os_vm_map 0x%llx->0x%llx flags=0x%llx\n", ea, pa, flags);
+
+ prot = opal_vm_flags_to_prot(flags);
+
+ pte = pfn_pte(pa >> PAGE_SHIFT, PAGE_KERNEL_X);
+
+ ptep = get_locked_pte(mm, ea, &ptl);
+ set_pte_at(mm, ea, ptep, pte);
+ pte_unmap_unlock(ptep, ptl);
+
+ return 0;
+}
+
+static void os_vm_unmap(uint64_t ea)
+{
+ struct mm_struct *mm = opal_mm;
+ spinlock_t *ptl;
+ pte_t *ptep;
+
+ if (WARN_ON_ONCE(!opal_mm_enabled))
+ return;
+
+ if (WARN_ON_ONCE(!(mfmsr() & (MSR_IR|MSR_DR))))
+ return;
+
+// printk("os_vm_unmap 0x%llx\n", ea);
+
+ /* mm should be active_mm if MMU is on here */
+
+ ptep = get_locked_pte(mm, ea, &ptl);
+ pte_clear(mm, ea, ptep);
+ pte_unmap_unlock(ptep, ptl);
+
+ /*
+ * This leaves potential TLBs in other CPUs for this EA, but it is
+ * only used by this CPU. Can't do a broadcast flush here, no IPIs.
+ */
+ local_flush_tlb_mm(mm);
+}
+
static int __init opal_init_mm(void)
{
struct mm_struct *mm;
@@ -1174,6 +1229,8 @@ static int __init opal_init_early(void)
memset(&opal_os_ops, 0, sizeof(opal_os_ops));
opal_os_ops.os_printf = cpu_to_be64(&os_printf);
+ opal_os_ops.os_vm_map = cpu_to_be64(&os_vm_map);
+ opal_os_ops.os_vm_unmap = cpu_to_be64(&os_vm_unmap);
if (opal_register_os_ops(&opal_os_ops, sizeof(opal_os_ops))) {
pr_warn("OPAL register OS ops failed, firmware will run
in v3 mode.\n");
} else {
--
2.23.0
