[PATCH v5 12/16] powerpc/mm/32s: add setibat() clearibat() and update_bats()

Christophe Leroy
2019-02-21T19:09:18Z

setibat() and clearibat() allows to manipulate IBATs independently
of DBATs.

update_bats() allows to update bats after init. This is done
with MMU off.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
---
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 2 ++
arch/powerpc/kernel/head_32.S | 35 +++++++++++++++++++++++++++
arch/powerpc/mm/ppc_mmu_32.c | 32 ++++++++++++++++++++++++
3 files changed, 69 insertions(+)

diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index 0c261ba2c826..5cb588395fdc 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -92,6 +92,8 @@ typedef struct {
unsigned long vdso_base;
} mm_context_t;

+void update_bats(void);
+
/* patch sites */
extern s32 patch__hash_page_A0, patch__hash_page_A1, patch__hash_page_A2;
extern s32 patch__hash_page_B, patch__hash_page_C;
diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index c2f564690778..91b302b0797f 100644
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -1104,6 +1104,41 @@ BEGIN_MMU_FTR_SECTION
END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
blr

+_ENTRY(update_bats)
+ lis r4, 1f@h
+ ori r4, r4, 1f@l
+ tophys(r4, r4)
+ mfmsr r6
+ mflr r7
+ li r3, MSR_KERNEL & ~(MSR_IR | MSR_DR)
+ rlwinm r0, r6, 0, ~MSR_RI
+ rlwinm r0, r0, 0, ~MSR_EE
+ mtmsr r0
+ mtspr SPRN_SRR0, r4
+ mtspr SPRN_SRR1, r3
+ SYNC
+ RFI
+1: bl clear_bats
+ lis r3, BATS@ha
+ addi r3, r3, BATS@l
+ tophys(r3, r3)
+ LOAD_BAT(0, r3, r4, r5)
+ LOAD_BAT(1, r3, r4, r5)
+ LOAD_BAT(2, r3, r4, r5)
+ LOAD_BAT(3, r3, r4, r5)
+BEGIN_MMU_FTR_SECTION
+ LOAD_BAT(4, r3, r4, r5)
+ LOAD_BAT(5, r3, r4, r5)
+ LOAD_BAT(6, r3, r4, r5)
+ LOAD_BAT(7, r3, r4, r5)
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
+ li r3, MSR_KERNEL & ~(MSR_IR | MSR_DR | MSR_RI)
+ mtmsr r3
+ mtspr SPRN_SRR0, r7
+ mtspr SPRN_SRR1, r6
+ SYNC
+ RFI
+
flush_tlbs:
lis r10, 0x40
1: addic. r10, r10, -0x1000
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
index ff8580c6ab11..66f1319e8e20 100644
--- a/arch/powerpc/mm/ppc_mmu_32.c
+++ b/arch/powerpc/mm/ppc_mmu_32.c
@@ -106,6 +106,38 @@ static unsigned int block_size(unsigned long base, unsigned long top)
return min3(max_size, 1U << base_shift, 1U << block_shift);
}

+/*
+ * Set up one of the IBAT (block address translation) register pairs.
+ * The parameters are not checked; in particular size must be a power
+ * of 2 between 128k and 256M.
+ * Only for 603+ ...
+ */
+static void setibat(int index, unsigned long virt, phys_addr_t phys,
+ unsigned int size, pgprot_t prot)
+{
+ unsigned int bl = (size >> 17) - 1;
+ int wimgxpp;
+ struct ppc_bat *bat = BATS[index];
+ unsigned long flags = pgprot_val(prot);
+
+ if (!cpu_has_feature(CPU_FTR_NEED_COHERENT))
+ flags &= ~_PAGE_COHERENT;
+
+ wimgxpp = (flags & _PAGE_COHERENT) | (_PAGE_EXEC ? BPP_RX : BPP_XX);
+ bat[0].batu = virt | (bl << 2) | 2; /* Vs=1, Vp=0 */
+ bat[0].batl = BAT_PHYS_ADDR(phys) | wimgxpp;
+ if (flags & _PAGE_USER)
+ bat[0].batu |= 1; /* Vp = 1 */
+}
+
+static void clearibat(int index)
+{
+ struct ppc_bat *bat = BATS[index];
+
+ bat[0].batu = 0;
+ bat[0].batl = 0;
+}
+
unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top)
{
int idx;
--
2.13.3