Re: [PATCH v4 1/3] powerpc/book3s64/radix/tlb: tlbie primitives for process-scoped invalidations from guests

On Wed, Feb 17, 2021 at 11:24:48AM +1100, David Gibson wrote:

On Mon, Feb 15, 2021 at 12:05:40PM +0530, Bharata B Rao wrote:

quoted

H_RPT_INVALIDATE hcall needs to perform process scoped tlbie
invalidations of L1 and nested guests from L0. This needs RS register
for TLBIE instruction to contain both PID and LPID. Introduce
primitives that execute tlbie instruction with both PID
and LPID set in prepartion for H_RPT_INVALIDATE hcall.

While we are here, move RIC_FLUSH definitions to header file
and introduce helper rpti_pgsize_to_psize() that will be needed
by the upcoming hcall.

Signed-off-by: Bharata B Rao <redacted>
---
 .../include/asm/book3s/64/tlbflush-radix.h    |  18 +++
 arch/powerpc/mm/book3s64/radix_tlb.c          | 122 +++++++++++++++++-
 2 files changed, 136 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
index 94439e0cefc9..aace7e9b2397 100644
--- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h
+++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h

@@ -4,6 +4,10 @@
 
 #include <asm/hvcall.h>
 
+#define RIC_FLUSH_TLB 0
+#define RIC_FLUSH_PWC 1
+#define RIC_FLUSH_ALL 2
+
 struct vm_area_struct;
 struct mm_struct;
 struct mmu_gather;

@@ -21,6 +25,20 @@ static inline u64 psize_to_rpti_pgsize(unsigned long psize)
 	return H_RPTI_PAGE_ALL;
 }
 
+static inline int rpti_pgsize_to_psize(unsigned long page_size)
+{
+	if (page_size == H_RPTI_PAGE_4K)
+		return MMU_PAGE_4K;
+	if (page_size == H_RPTI_PAGE_64K)
+		return MMU_PAGE_64K;
+	if (page_size == H_RPTI_PAGE_2M)
+		return MMU_PAGE_2M;
+	if (page_size == H_RPTI_PAGE_1G)
+		return MMU_PAGE_1G;
+	else
+		return MMU_PAGE_64K; /* Default */
+}

Would it make sense to put the H_RPT_PAGE_ tags into the
mmu_psize_defs table and scan that here, rather than open coding the
conversion?

I will give this a try and see how it looks.

Otherwise the changes in the patch which are mainly about
introducing primitives that require to set both PID and LPID
for tlbie instruction - do they look right?

Regards,
Bharata.