[RFC PATCH 04/10] powerpc/fsl_booke/32: introduce create_tlb_entry() helper

From: Jason Yan
Date: Wed Jul 17 2019 - 03:50:15 EST


Add a new helper create_tlb_entry() to create a tlb entry by the virtual
and physical address. This is a preparation to support boot kernel at a
randomized address.

Signed-off-by: Jason Yan <yanaijie@xxxxxxxxxx>
Cc: Diana Craciun <diana.craciun@xxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Christophe Leroy <christophe.leroy@xxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Nicholas Piggin <npiggin@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
---
arch/powerpc/kernel/head_fsl_booke.S | 30 ++++++++++++++++++++++++++++
arch/powerpc/mm/mmu_decl.h | 1 +
2 files changed, 31 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index adf0505dbe02..a57d44638031 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1114,6 +1114,36 @@ __secondary_hold_acknowledge:
.long -1
#endif

+/*
+ * Create a 64M tlb by address and entry
+ * r3/r4 - physical address
+ * r5 - virtual address
+ * r6 - entry
+ */
+_GLOBAL(create_tlb_entry)
+ lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */
+ rlwimi r7,r6,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */
+ mtspr SPRN_MAS0,r7 /* Write MAS0 */
+
+ lis r6,(MAS1_VALID|MAS1_IPROT)@h
+ ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l
+ mtspr SPRN_MAS1,r6 /* Write MAS1 */
+
+ lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h
+ ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l
+ and r6,r6,r5
+ ori r6,r6,MAS2_M@l
+ mtspr SPRN_MAS2,r6 /* Write MAS2(EPN) */
+
+ mr r8,r4
+ ori r8,r8,(MAS3_SW|MAS3_SR|MAS3_SX)
+ mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */
+
+ tlbwe /* Write TLB */
+ isync
+ sync
+ blr
+
/*
* Create a tlb entry with the same effective and physical address as
* the tlb entry used by the current running code. But set the TS to 1.
diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h
index 32c1a191c28a..d7737cf97cee 100644
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -142,6 +142,7 @@ extern unsigned long calc_cam_sz(unsigned long ram, unsigned long virt,
extern void adjust_total_lowmem(void);
extern int switch_to_as1(void);
extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu);
+extern void create_tlb_entry(phys_addr_t phys, unsigned long virt, int entry);
#endif
extern void loadcam_entry(unsigned int index);
extern void loadcam_multi(int first_idx, int num, int tmp_idx);
--
2.17.2