Re: [PATCH v2 04/10] powerpc/fsl_booke/32: introduce create_tlb_entry() helper

[Christophe Leroy]

Le 30/07/2019 à 09:42, Jason Yan a écrit :

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 <yanai...@huawei.com>
Cc: Diana Craciun <diana.crac...@nxp.com>
Cc: Michael Ellerman <m...@ellerman.id.au>
Cc: Christophe Leroy <christophe.le...@c-s.fr>
Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Nicholas Piggin <npig...@gmail.com>
Cc: Kees Cook <keesc...@chromium.org>

Reviewed-by: Christophe Leroy <christophe.le...@c-s.fr>

---
  arch/powerpc/kernel/head_fsl_booke.S | 29 ++++++++++++++++++++++++++++
  arch/powerpc/mm/mmu_decl.h           |  1 +
  2 files changed, 30 insertions(+)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S 
b/arch/powerpc/kernel/head_fsl_booke.S
index adf0505dbe02..04d124fee17d 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1114,6 +1114,35 @@ __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) */
+
+       ori     r8,r4,(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..a09f89d3aa0f 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);
+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);