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authorDavid Daney <ddaney@caviumnetworks.com>2010-12-27 18:07:57 -0800
committerRalf Baechle <ralf@linux-mips.org>2011-01-18 19:30:23 +0100
commit2c8c53e28f178577dfdf3a69731b998b7e3df8ae (patch)
tree0b65ff7fa0ac67795698be7a50559d77d3bc72db /arch/mips/mm/tlbex.c
parentbb3d68c30a00918d4c9fa02a5c17a5aacf597977 (diff)
MIPS: Optimize TLB handlers for Octeon CPUs
Octeon can use scratch registers in the TLB handlers. Octeon II can use LDX instructions. Signed-off-by: David Daney <ddaney@caviumnetworks.com> To: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/1904/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch/mips/mm/tlbex.c')
-rw-r--r--arch/mips/mm/tlbex.c361
1 files changed, 310 insertions, 51 deletions
diff --git a/arch/mips/mm/tlbex.c b/arch/mips/mm/tlbex.c
index 883cf76fb2b..083d3412d0b 100644
--- a/arch/mips/mm/tlbex.c
+++ b/arch/mips/mm/tlbex.c
@@ -77,6 +77,40 @@ static int use_bbit_insns(void)
}
}
+static int use_lwx_insns(void)
+{
+ switch (current_cpu_type()) {
+ case CPU_CAVIUM_OCTEON2:
+ return 1;
+ default:
+ return 0;
+ }
+}
+#if defined(CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE) && \
+ CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE > 0
+static bool scratchpad_available(void)
+{
+ return true;
+}
+static int scratchpad_offset(int i)
+{
+ /*
+ * CVMSEG starts at address -32768 and extends for
+ * CAVIUM_OCTEON_CVMSEG_SIZE 128 byte cache lines.
+ */
+ i += 1; /* Kernel use starts at the top and works down. */
+ return CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE * 128 - (8 * i) - 32768;
+}
+#else
+static bool scratchpad_available(void)
+{
+ return false;
+}
+static int scratchpad_offset(int i)
+{
+ BUG();
+}
+#endif
/*
* Found by experiment: At least some revisions of the 4kc throw under
* some circumstances a machine check exception, triggered by invalid
@@ -187,7 +221,7 @@ static struct uasm_reloc relocs[128] __cpuinitdata;
static int check_for_high_segbits __cpuinitdata;
#endif
-#ifdef CONFIG_MIPS_PGD_C0_CONTEXT
+static int check_for_high_segbits __cpuinitdata;
static unsigned int kscratch_used_mask __cpuinitdata;
@@ -208,9 +242,12 @@ static int __cpuinit allocate_kscratch(void)
return r;
}
+static int scratch_reg __cpuinitdata;
static int pgd_reg __cpuinitdata;
+enum vmalloc64_mode {not_refill, refill_scratch, refill_noscratch};
+
+#ifndef CONFIG_MIPS_PGD_C0_CONTEXT
-#else /* !CONFIG_MIPS_PGD_C0_CONTEXT*/
/*
* CONFIG_MIPS_PGD_C0_CONTEXT implies 64 bit and lack of pgd_current,
* we cannot do r3000 under these circumstances.
@@ -481,21 +518,43 @@ static __cpuinit __maybe_unused void build_convert_pte_to_entrylo(u32 **p,
static __cpuinit void build_restore_pagemask(u32 **p,
struct uasm_reloc **r,
unsigned int tmp,
- enum label_id lid)
+ enum label_id lid,
+ int restore_scratch)
{
- /* Reset default page size */
- if (PM_DEFAULT_MASK >> 16) {
- uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
- uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
- uasm_il_b(p, r, lid);
- uasm_i_mtc0(p, tmp, C0_PAGEMASK);
- } else if (PM_DEFAULT_MASK) {
- uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
- uasm_il_b(p, r, lid);
- uasm_i_mtc0(p, tmp, C0_PAGEMASK);
+ if (restore_scratch) {
+ /* Reset default page size */
+ if (PM_DEFAULT_MASK >> 16) {
+ uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
+ uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
+ uasm_i_mtc0(p, tmp, C0_PAGEMASK);
+ uasm_il_b(p, r, lid);
+ } else if (PM_DEFAULT_MASK) {
+ uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
+ uasm_i_mtc0(p, tmp, C0_PAGEMASK);
+ uasm_il_b(p, r, lid);
+ } else {
+ uasm_i_mtc0(p, 0, C0_PAGEMASK);
+ uasm_il_b(p, r, lid);
+ }
+ if (scratch_reg > 0)
+ UASM_i_MFC0(p, 1, 31, scratch_reg);
+ else
+ UASM_i_LW(p, 1, scratchpad_offset(0), 0);
} else {
- uasm_il_b(p, r, lid);
- uasm_i_mtc0(p, 0, C0_PAGEMASK);
+ /* Reset default page size */
+ if (PM_DEFAULT_MASK >> 16) {
+ uasm_i_lui(p, tmp, PM_DEFAULT_MASK >> 16);
+ uasm_i_ori(p, tmp, tmp, PM_DEFAULT_MASK & 0xffff);
+ uasm_il_b(p, r, lid);
+ uasm_i_mtc0(p, tmp, C0_PAGEMASK);
+ } else if (PM_DEFAULT_MASK) {
+ uasm_i_ori(p, tmp, 0, PM_DEFAULT_MASK);
+ uasm_il_b(p, r, lid);
+ uasm_i_mtc0(p, tmp, C0_PAGEMASK);
+ } else {
+ uasm_il_b(p, r, lid);
+ uasm_i_mtc0(p, 0, C0_PAGEMASK);
+ }
}
}
@@ -503,7 +562,8 @@ static __cpuinit void build_huge_tlb_write_entry(u32 **p,
struct uasm_label **l,
struct uasm_reloc **r,
unsigned int tmp,
- enum tlb_write_entry wmode)
+ enum tlb_write_entry wmode,
+ int restore_scratch)
{
/* Set huge page tlb entry size */
uasm_i_lui(p, tmp, PM_HUGE_MASK >> 16);
@@ -512,7 +572,7 @@ static __cpuinit void build_huge_tlb_write_entry(u32 **p,
build_tlb_write_entry(p, l, r, wmode);
- build_restore_pagemask(p, r, tmp, label_leave);
+ build_restore_pagemask(p, r, tmp, label_leave, restore_scratch);
}
/*
@@ -577,7 +637,7 @@ static __cpuinit void build_huge_handler_tail(u32 **p,
UASM_i_SW(p, pte, 0, ptr);
#endif
build_huge_update_entries(p, pte, ptr);
- build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed);
+ build_huge_tlb_write_entry(p, l, r, pte, tlb_indexed, 0);
}
#endif /* CONFIG_HUGETLB_PAGE */
@@ -674,7 +734,6 @@ build_get_pmde64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
#endif
}
-enum vmalloc64_mode {not_refill, refill};
/*
* BVADDR is the faulting address, PTR is scratch.
* PTR will hold the pgd for vmalloc.
@@ -692,7 +751,7 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
uasm_l_vmalloc(l, *p);
- if (mode == refill && check_for_high_segbits) {
+ if (mode != not_refill && check_for_high_segbits) {
if (single_insn_swpd) {
uasm_il_bltz(p, r, bvaddr, label_vmalloc_done);
uasm_i_lui(p, ptr, uasm_rel_hi(swpd));
@@ -715,7 +774,7 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
uasm_i_daddiu(p, ptr, ptr, uasm_rel_lo(swpd));
}
}
- if (mode == refill && check_for_high_segbits) {
+ if (mode != not_refill && check_for_high_segbits) {
uasm_l_large_segbits_fault(l, *p);
/*
* We get here if we are an xsseg address, or if we are
@@ -731,7 +790,15 @@ build_get_pgd_vmalloc64(u32 **p, struct uasm_label **l, struct uasm_reloc **r,
*/
UASM_i_LA(p, ptr, (unsigned long)tlb_do_page_fault_0);
uasm_i_jr(p, ptr);
- uasm_i_nop(p);
+
+ if (mode == refill_scratch) {
+ if (scratch_reg > 0)
+ UASM_i_MFC0(p, 1, 31, scratch_reg);
+ else
+ UASM_i_LW(p, 1, scratchpad_offset(0), 0);
+ } else {
+ uasm_i_nop(p);
+ }
}
}
@@ -888,6 +955,185 @@ static void __cpuinit build_update_entries(u32 **p, unsigned int tmp,
#endif
}
+struct mips_huge_tlb_info {
+ int huge_pte;
+ int restore_scratch;
+};
+
+static struct mips_huge_tlb_info __cpuinit
+build_fast_tlb_refill_handler (u32 **p, struct uasm_label **l,
+ struct uasm_reloc **r, unsigned int tmp,
+ unsigned int ptr, int c0_scratch)
+{
+ struct mips_huge_tlb_info rv;
+ unsigned int even, odd;
+ int vmalloc_branch_delay_filled = 0;
+ const int scratch = 1; /* Our extra working register */
+
+ rv.huge_pte = scratch;
+ rv.restore_scratch = 0;
+
+ if (check_for_high_segbits) {
+ UASM_i_MFC0(p, tmp, C0_BADVADDR);
+
+ if (pgd_reg != -1)
+ UASM_i_MFC0(p, ptr, 31, pgd_reg);
+ else
+ UASM_i_MFC0(p, ptr, C0_CONTEXT);
+
+ if (c0_scratch >= 0)
+ UASM_i_MTC0(p, scratch, 31, c0_scratch);
+ else
+ UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
+
+ uasm_i_dsrl_safe(p, scratch, tmp,
+ PGDIR_SHIFT + PGD_ORDER + PAGE_SHIFT - 3);
+ uasm_il_bnez(p, r, scratch, label_vmalloc);
+
+ if (pgd_reg == -1) {
+ vmalloc_branch_delay_filled = 1;
+ /* Clear lower 23 bits of context. */
+ uasm_i_dins(p, ptr, 0, 0, 23);
+ }
+ } else {
+ if (pgd_reg != -1)
+ UASM_i_MFC0(p, ptr, 31, pgd_reg);
+ else
+ UASM_i_MFC0(p, ptr, C0_CONTEXT);
+
+ UASM_i_MFC0(p, tmp, C0_BADVADDR);
+
+ if (c0_scratch >= 0)
+ UASM_i_MTC0(p, scratch, 31, c0_scratch);
+ else
+ UASM_i_SW(p, scratch, scratchpad_offset(0), 0);
+
+ if (pgd_reg == -1)
+ /* Clear lower 23 bits of context. */
+ uasm_i_dins(p, ptr, 0, 0, 23);
+
+ uasm_il_bltz(p, r, tmp, label_vmalloc);
+ }
+
+ if (pgd_reg == -1) {
+ vmalloc_branch_delay_filled = 1;
+ /* 1 0 1 0 1 << 6 xkphys cached */
+ uasm_i_ori(p, ptr, ptr, 0x540);
+ uasm_i_drotr(p, ptr, ptr, 11);
+ }
+
+#ifdef __PAGETABLE_PMD_FOLDED
+#define LOC_PTEP scratch
+#else
+#define LOC_PTEP ptr
+#endif
+
+ if (!vmalloc_branch_delay_filled)
+ /* get pgd offset in bytes */
+ uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
+
+ uasm_l_vmalloc_done(l, *p);
+
+ /*
+ * tmp ptr
+ * fall-through case = badvaddr *pgd_current
+ * vmalloc case = badvaddr swapper_pg_dir
+ */
+
+ if (vmalloc_branch_delay_filled)
+ /* get pgd offset in bytes */
+ uasm_i_dsrl_safe(p, scratch, tmp, PGDIR_SHIFT - 3);
+
+#ifdef __PAGETABLE_PMD_FOLDED
+ GET_CONTEXT(p, tmp); /* get context reg */
+#endif
+ uasm_i_andi(p, scratch, scratch, (PTRS_PER_PGD - 1) << 3);
+
+ if (use_lwx_insns()) {
+ UASM_i_LWX(p, LOC_PTEP, scratch, ptr);
+ } else {
+ uasm_i_daddu(p, ptr, ptr, scratch); /* add in pgd offset */
+ uasm_i_ld(p, LOC_PTEP, 0, ptr); /* get pmd pointer */
+ }
+
+#ifndef __PAGETABLE_PMD_FOLDED
+ /* get pmd offset in bytes */
+ uasm_i_dsrl_safe(p, scratch, tmp, PMD_SHIFT - 3);
+ uasm_i_andi(p, scratch, scratch, (PTRS_PER_PMD - 1) << 3);
+ GET_CONTEXT(p, tmp); /* get context reg */
+
+ if (use_lwx_insns()) {
+ UASM_i_LWX(p, scratch, scratch, ptr);
+ } else {
+ uasm_i_daddu(p, ptr, ptr, scratch); /* add in pmd offset */
+ UASM_i_LW(p, scratch, 0, ptr);
+ }
+#endif
+ /* Adjust the context during the load latency. */
+ build_adjust_context(p, tmp);
+
+#ifdef CONFIG_HUGETLB_PAGE
+ uasm_il_bbit1(p, r, scratch, ilog2(_PAGE_HUGE), label_tlb_huge_update);
+ /*
+ * The in the LWX case we don't want to do the load in the
+ * delay slot. It cannot issue in the same cycle and may be
+ * speculative and unneeded.
+ */
+ if (use_lwx_insns())
+ uasm_i_nop(p);
+#endif /* CONFIG_HUGETLB_PAGE */
+
+
+ /* build_update_entries */
+ if (use_lwx_insns()) {
+ even = ptr;
+ odd = tmp;
+ UASM_i_LWX(p, even, scratch, tmp);
+ UASM_i_ADDIU(p, tmp, tmp, sizeof(pte_t));
+ UASM_i_LWX(p, odd, scratch, tmp);
+ } else {
+ UASM_i_ADDU(p, ptr, scratch, tmp); /* add in offset */
+ even = tmp;
+ odd = ptr;
+ UASM_i_LW(p, even, 0, ptr); /* get even pte */
+ UASM_i_LW(p, odd, sizeof(pte_t), ptr); /* get odd pte */
+ }
+ if (kernel_uses_smartmips_rixi) {
+ uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_NO_EXEC));
+ uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_NO_EXEC));
+ uasm_i_drotr(p, even, even,
+ ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
+ UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
+ uasm_i_drotr(p, odd, odd,
+ ilog2(_PAGE_GLOBAL) - ilog2(_PAGE_NO_EXEC));
+ } else {
+ uasm_i_dsrl_safe(p, even, even, ilog2(_PAGE_GLOBAL));
+ UASM_i_MTC0(p, even, C0_ENTRYLO0); /* load it */
+ uasm_i_dsrl_safe(p, odd, odd, ilog2(_PAGE_GLOBAL));
+ }
+ UASM_i_MTC0(p, odd, C0_ENTRYLO1); /* load it */
+
+ if (c0_scratch >= 0) {
+ UASM_i_MFC0(p, scratch, 31, c0_scratch);
+ build_tlb_write_entry(p, l, r, tlb_random);
+ uasm_l_leave(l, *p);
+ rv.restore_scratch = 1;
+ } else if (PAGE_SHIFT == 14 || PAGE_SHIFT == 13) {
+ build_tlb_write_entry(p, l, r, tlb_random);
+ uasm_l_leave(l, *p);
+ UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
+ } else {
+ UASM_i_LW(p, scratch, scratchpad_offset(0), 0);
+ build_tlb_write_entry(p, l, r, tlb_random);
+ uasm_l_leave(l, *p);
+ rv.restore_scratch = 1;
+ }
+
+ uasm_i_eret(p); /* return from trap */
+
+ return rv;
+}
+
/*
* For a 64-bit kernel, we are using the 64-bit XTLB refill exception
* because EXL == 0. If we wrap, we can also use the 32 instruction
@@ -903,54 +1149,67 @@ static void __cpuinit build_r4000_tlb_refill_handler(void)
struct uasm_reloc *r = relocs;
u32 *f;
unsigned int final_len;
+ struct mips_huge_tlb_info htlb_info;
+ enum vmalloc64_mode vmalloc_mode;
memset(tlb_handler, 0, sizeof(tlb_handler));
memset(labels, 0, sizeof(labels));
memset(relocs, 0, sizeof(relocs));
memset(final_handler, 0, sizeof(final_handler));
- /*
- * create the plain linear handler
- */
- if (bcm1250_m3_war()) {
- unsigned int segbits = 44;
+ if (scratch_reg == 0)
+ scratch_reg = allocate_kscratch();
- uasm_i_dmfc0(&p, K0, C0_BADVADDR);
- uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
- uasm_i_xor(&p, K0, K0, K1);
- uasm_i_dsrl_safe(&p, K1, K0, 62);
- uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
- uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
- uasm_i_or(&p, K0, K0, K1);
- uasm_il_bnez(&p, &r, K0, label_leave);
- /* No need for uasm_i_nop */
- }
+ if ((scratch_reg > 0 || scratchpad_available()) && use_bbit_insns()) {
+ htlb_info = build_fast_tlb_refill_handler(&p, &l, &r, K0, K1,
+ scratch_reg);
+ vmalloc_mode = refill_scratch;
+ } else {
+ htlb_info.huge_pte = K0;
+ htlb_info.restore_scratch = 0;
+ vmalloc_mode = refill_noscratch;
+ /*
+ * create the plain linear handler
+ */
+ if (bcm1250_m3_war()) {
+ unsigned int segbits = 44;
+
+ uasm_i_dmfc0(&p, K0, C0_BADVADDR);
+ uasm_i_dmfc0(&p, K1, C0_ENTRYHI);
+ uasm_i_xor(&p, K0, K0, K1);
+ uasm_i_dsrl_safe(&p, K1, K0, 62);
+ uasm_i_dsrl_safe(&p, K0, K0, 12 + 1);
+ uasm_i_dsll_safe(&p, K0, K0, 64 + 12 + 1 - segbits);
+ uasm_i_or(&p, K0, K0, K1);
+ uasm_il_bnez(&p, &r, K0, label_leave);
+ /* No need for uasm_i_nop */
+ }
#ifdef CONFIG_64BIT
- build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
+ build_get_pmde64(&p, &l, &r, K0, K1); /* get pmd in K1 */
#else
- build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
+ build_get_pgde32(&p, K0, K1); /* get pgd in K1 */
#endif
#ifdef CONFIG_HUGETLB_PAGE
- build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
+ build_is_huge_pte(&p, &r, K0, K1, label_tlb_huge_update);
#endif
- build_get_ptep(&p, K0, K1);
- build_update_entries(&p, K0, K1);
- build_tlb_write_entry(&p, &l, &r, tlb_random);
- uasm_l_leave(&l, p);
- uasm_i_eret(&p); /* return from trap */
-
+ build_get_ptep(&p, K0, K1);
+ build_update_entries(&p, K0, K1);
+ build_tlb_write_entry(&p, &l, &r, tlb_random);
+ uasm_l_leave(&l, p);
+ uasm_i_eret(&p); /* return from trap */
+ }
#ifdef CONFIG_HUGETLB_PAGE
uasm_l_tlb_huge_update(&l, p);
- UASM_i_LW(&p, K0, 0, K1);
- build_huge_update_entries(&p, K0, K1);
- build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random);
+ build_huge_update_entries(&p, htlb_info.huge_pte, K1);
+ build_huge_tlb_write_entry(&p, &l, &r, K0, tlb_random,
+ htlb_info.restore_scratch);
#endif
#ifdef CONFIG_64BIT
- build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, refill);
+ build_get_pgd_vmalloc64(&p, &l, &r, K0, K1, vmalloc_mode);
#endif
/*
@@ -1616,7 +1875,7 @@ static void __cpuinit build_r4000_tlb_load_handler(void)
* We clobbered C0_PAGEMASK, restore it. On the other branch
* it is restored in build_huge_tlb_write_entry.
*/
- build_restore_pagemask(&p, &r, K0, label_nopage_tlbl);
+ build_restore_pagemask(&p, &r, K0, label_nopage_tlbl, 0);
uasm_l_tlbl_goaround2(&l, p);
}