[PATCH 2/6] powerpc/64e: Split out nohash Book3E 64-bit code
Michael Ellerman
mpe at ellerman.id.au
Fri May 24 17:31:37 AEST 2024
A reasonable chunk of nohash/tlb.c is 64-bit only code, split it out
into a separate file.
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
---
arch/powerpc/mm/nohash/Makefile | 2 +-
arch/powerpc/mm/nohash/tlb.c | 343 +----------------------------
arch/powerpc/mm/nohash/tlb_64e.c | 361 +++++++++++++++++++++++++++++++
3 files changed, 363 insertions(+), 343 deletions(-)
create mode 100644 arch/powerpc/mm/nohash/tlb_64e.c
diff --git a/arch/powerpc/mm/nohash/Makefile b/arch/powerpc/mm/nohash/Makefile
index f3894e79d5f7..24b445a5fcac 100644
--- a/arch/powerpc/mm/nohash/Makefile
+++ b/arch/powerpc/mm/nohash/Makefile
@@ -3,7 +3,7 @@
ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
obj-y += mmu_context.o tlb.o tlb_low.o kup.o
-obj-$(CONFIG_PPC_BOOK3E_64) += tlb_low_64e.o book3e_pgtable.o
+obj-$(CONFIG_PPC_BOOK3E_64) += tlb_64e.o tlb_low_64e.o book3e_pgtable.o
obj-$(CONFIG_40x) += 40x.o
obj-$(CONFIG_44x) += 44x.o
obj-$(CONFIG_PPC_8xx) += 8xx.o
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index a5bb87ec8578..f57dc721d063 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -110,28 +110,6 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
};
#endif
-/* The variables below are currently only used on 64-bit Book3E
- * though this will probably be made common with other nohash
- * implementations at some point
- */
-#ifdef CONFIG_PPC64
-
-int mmu_pte_psize; /* Page size used for PTE pages */
-int mmu_vmemmap_psize; /* Page size used for the virtual mem map */
-int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */
-unsigned long linear_map_top; /* Top of linear mapping */
-
-
-/*
- * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
- * exceptions. This is used for bolted and e6500 TLB miss handlers which
- * do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
- * this is set to zero.
- */
-int extlb_level_exc;
-
-#endif /* CONFIG_PPC64 */
-
#ifdef CONFIG_PPC_E500
/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
DEFINE_PER_CPU(int, next_tlbcam_idx);
@@ -358,326 +336,7 @@ void tlb_flush(struct mmu_gather *tlb)
flush_tlb_mm(tlb->mm);
}
-/*
- * Below are functions specific to the 64-bit variant of Book3E though that
- * may change in the future
- */
-
-#ifdef CONFIG_PPC64
-
-/*
- * Handling of virtual linear page tables or indirect TLB entries
- * flushing when PTE pages are freed
- */
-void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
-{
- int tsize = mmu_psize_defs[mmu_pte_psize].enc;
-
- if (book3e_htw_mode != PPC_HTW_NONE) {
- unsigned long start = address & PMD_MASK;
- unsigned long end = address + PMD_SIZE;
- unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
-
- /* This isn't the most optimal, ideally we would factor out the
- * while preempt & CPU mask mucking around, or even the IPI but
- * it will do for now
- */
- while (start < end) {
- __flush_tlb_page(tlb->mm, start, tsize, 1);
- start += size;
- }
- } else {
- unsigned long rmask = 0xf000000000000000ul;
- unsigned long rid = (address & rmask) | 0x1000000000000000ul;
- unsigned long vpte = address & ~rmask;
-
- vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
- vpte |= rid;
- __flush_tlb_page(tlb->mm, vpte, tsize, 0);
- }
-}
-
-static void __init setup_page_sizes(void)
-{
- unsigned int tlb0cfg;
- unsigned int eptcfg;
- int psize;
-
-#ifdef CONFIG_PPC_E500
- unsigned int mmucfg = mfspr(SPRN_MMUCFG);
- int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
-
- if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
- unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
- unsigned int min_pg, max_pg;
-
- min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
- max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
-
- for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
- struct mmu_psize_def *def;
- unsigned int shift;
-
- def = &mmu_psize_defs[psize];
- shift = def->shift;
-
- if (shift == 0 || shift & 1)
- continue;
-
- /* adjust to be in terms of 4^shift Kb */
- shift = (shift - 10) >> 1;
-
- if ((shift >= min_pg) && (shift <= max_pg))
- def->flags |= MMU_PAGE_SIZE_DIRECT;
- }
-
- goto out;
- }
-
- if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
- u32 tlb1cfg, tlb1ps;
-
- tlb0cfg = mfspr(SPRN_TLB0CFG);
- tlb1cfg = mfspr(SPRN_TLB1CFG);
- tlb1ps = mfspr(SPRN_TLB1PS);
- eptcfg = mfspr(SPRN_EPTCFG);
-
- if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
- book3e_htw_mode = PPC_HTW_E6500;
-
- /*
- * We expect 4K subpage size and unrestricted indirect size.
- * The lack of a restriction on indirect size is a Freescale
- * extension, indicated by PSn = 0 but SPSn != 0.
- */
- if (eptcfg != 2)
- book3e_htw_mode = PPC_HTW_NONE;
-
- for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
- struct mmu_psize_def *def = &mmu_psize_defs[psize];
-
- if (!def->shift)
- continue;
-
- if (tlb1ps & (1U << (def->shift - 10))) {
- def->flags |= MMU_PAGE_SIZE_DIRECT;
-
- if (book3e_htw_mode && psize == MMU_PAGE_2M)
- def->flags |= MMU_PAGE_SIZE_INDIRECT;
- }
- }
-
- goto out;
- }
-#endif
-out:
- /* Cleanup array and print summary */
- pr_info("MMU: Supported page sizes\n");
- for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
- struct mmu_psize_def *def = &mmu_psize_defs[psize];
- const char *__page_type_names[] = {
- "unsupported",
- "direct",
- "indirect",
- "direct & indirect"
- };
- if (def->flags == 0) {
- def->shift = 0;
- continue;
- }
- pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10),
- __page_type_names[def->flags & 0x3]);
- }
-}
-
-static void __init setup_mmu_htw(void)
-{
- /*
- * If we want to use HW tablewalk, enable it by patching the TLB miss
- * handlers to branch to the one dedicated to it.
- */
-
- switch (book3e_htw_mode) {
-#ifdef CONFIG_PPC_E500
- case PPC_HTW_E6500:
- extlb_level_exc = EX_TLB_SIZE;
- patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
- patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
- break;
-#endif
- }
- pr_info("MMU: Book3E HW tablewalk %s\n",
- book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
-}
-
-/*
- * Early initialization of the MMU TLB code
- */
-static void early_init_this_mmu(void)
-{
- unsigned int mas4;
-
- /* Set MAS4 based on page table setting */
-
- mas4 = 0x4 << MAS4_WIMGED_SHIFT;
- switch (book3e_htw_mode) {
- case PPC_HTW_E6500:
- mas4 |= MAS4_INDD;
- mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
- mas4 |= MAS4_TLBSELD(1);
- mmu_pte_psize = MMU_PAGE_2M;
- break;
-
- case PPC_HTW_NONE:
- mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
- mmu_pte_psize = mmu_virtual_psize;
- break;
- }
- mtspr(SPRN_MAS4, mas4);
-
-#ifdef CONFIG_PPC_E500
- if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
- unsigned int num_cams;
- bool map = true;
-
- /* use a quarter of the TLBCAM for bolted linear map */
- num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
-
- /*
- * Only do the mapping once per core, or else the
- * transient mapping would cause problems.
- */
-#ifdef CONFIG_SMP
- if (hweight32(get_tensr()) > 1)
- map = false;
-#endif
-
- if (map)
- linear_map_top = map_mem_in_cams(linear_map_top,
- num_cams, false, true);
- }
-#endif
-
- /* A sync won't hurt us after mucking around with
- * the MMU configuration
- */
- mb();
-}
-
-static void __init early_init_mmu_global(void)
-{
- /* XXX This should be decided at runtime based on supported
- * page sizes in the TLB, but for now let's assume 16M is
- * always there and a good fit (which it probably is)
- *
- * Freescale booke only supports 4K pages in TLB0, so use that.
- */
- if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
- mmu_vmemmap_psize = MMU_PAGE_4K;
- else
- mmu_vmemmap_psize = MMU_PAGE_16M;
-
- /* XXX This code only checks for TLB 0 capabilities and doesn't
- * check what page size combos are supported by the HW. It
- * also doesn't handle the case where a separate array holds
- * the IND entries from the array loaded by the PT.
- */
- /* Look for supported page sizes */
- setup_page_sizes();
-
- /* Look for HW tablewalk support */
- setup_mmu_htw();
-
-#ifdef CONFIG_PPC_E500
- if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
- if (book3e_htw_mode == PPC_HTW_NONE) {
- extlb_level_exc = EX_TLB_SIZE;
- patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
- patch_exception(0x1e0,
- exc_instruction_tlb_miss_bolted_book3e);
- }
- }
-#endif
-
- /* Set the global containing the top of the linear mapping
- * for use by the TLB miss code
- */
- linear_map_top = memblock_end_of_DRAM();
-
- ioremap_bot = IOREMAP_BASE;
-}
-
-static void __init early_mmu_set_memory_limit(void)
-{
-#ifdef CONFIG_PPC_E500
- if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
- /*
- * Limit memory so we dont have linear faults.
- * Unlike memblock_set_current_limit, which limits
- * memory available during early boot, this permanently
- * reduces the memory available to Linux. We need to
- * do this because highmem is not supported on 64-bit.
- */
- memblock_enforce_memory_limit(linear_map_top);
- }
-#endif
-
- memblock_set_current_limit(linear_map_top);
-}
-
-/* boot cpu only */
-void __init early_init_mmu(void)
-{
- early_init_mmu_global();
- early_init_this_mmu();
- early_mmu_set_memory_limit();
-}
-
-void early_init_mmu_secondary(void)
-{
- early_init_this_mmu();
-}
-
-void setup_initial_memory_limit(phys_addr_t first_memblock_base,
- phys_addr_t first_memblock_size)
-{
- /* On non-FSL Embedded 64-bit, we adjust the RMA size to match
- * the bolted TLB entry. We know for now that only 1G
- * entries are supported though that may eventually
- * change.
- *
- * on FSL Embedded 64-bit, usually all RAM is bolted, but with
- * unusual memory sizes it's possible for some RAM to not be mapped
- * (such RAM is not used at all by Linux, since we don't support
- * highmem on 64-bit). We limit ppc64_rma_size to what would be
- * mappable if this memblock is the only one. Additional memblocks
- * can only increase, not decrease, the amount that ends up getting
- * mapped. We still limit max to 1G even if we'll eventually map
- * more. This is due to what the early init code is set up to do.
- *
- * We crop it to the size of the first MEMBLOCK to
- * avoid going over total available memory just in case...
- */
-#ifdef CONFIG_PPC_E500
- if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
- unsigned long linear_sz;
- unsigned int num_cams;
-
- /* use a quarter of the TLBCAM for bolted linear map */
- num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
-
- linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
- true, true);
-
- ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
- } else
-#endif
- ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
-
- /* Finally limit subsequent allocations */
- memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
-}
-#else /* ! CONFIG_PPC64 */
+#ifndef CONFIG_PPC64
void __init early_init_mmu(void)
{
unsigned long root = of_get_flat_dt_root();
diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
new file mode 100644
index 000000000000..7d5506d23eab
--- /dev/null
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -0,0 +1,361 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2008,2009 Ben Herrenschmidt <benh at kernel.crashing.org>
+ * IBM Corp.
+ *
+ * Derived from arch/ppc/mm/init.c:
+ * Copyright (C) 1995-1996 Gary Thomas (gdt at linuxppc.org)
+ *
+ * Modifications by Paul Mackerras (PowerMac) (paulus at cs.anu.edu.au)
+ * and Cort Dougan (PReP) (cort at cs.nmt.edu)
+ * Copyright (C) 1996 Paul Mackerras
+ *
+ * Derived from "arch/i386/mm/init.c"
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+#include <linux/kernel.h>
+#include <linux/export.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/memblock.h>
+
+#include <asm/pgalloc.h>
+#include <asm/tlbflush.h>
+#include <asm/tlb.h>
+#include <asm/code-patching.h>
+#include <asm/cputhreads.h>
+
+#include <mm/mmu_decl.h>
+
+/* The variables below are currently only used on 64-bit Book3E
+ * though this will probably be made common with other nohash
+ * implementations at some point
+ */
+int mmu_pte_psize; /* Page size used for PTE pages */
+int mmu_vmemmap_psize; /* Page size used for the virtual mem map */
+int book3e_htw_mode; /* HW tablewalk? Value is PPC_HTW_* */
+unsigned long linear_map_top; /* Top of linear mapping */
+
+
+/*
+ * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
+ * exceptions. This is used for bolted and e6500 TLB miss handlers which
+ * do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
+ * this is set to zero.
+ */
+int extlb_level_exc;
+
+/*
+ * Handling of virtual linear page tables or indirect TLB entries
+ * flushing when PTE pages are freed
+ */
+void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
+{
+ int tsize = mmu_psize_defs[mmu_pte_psize].enc;
+
+ if (book3e_htw_mode != PPC_HTW_NONE) {
+ unsigned long start = address & PMD_MASK;
+ unsigned long end = address + PMD_SIZE;
+ unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
+
+ /* This isn't the most optimal, ideally we would factor out the
+ * while preempt & CPU mask mucking around, or even the IPI but
+ * it will do for now
+ */
+ while (start < end) {
+ __flush_tlb_page(tlb->mm, start, tsize, 1);
+ start += size;
+ }
+ } else {
+ unsigned long rmask = 0xf000000000000000ul;
+ unsigned long rid = (address & rmask) | 0x1000000000000000ul;
+ unsigned long vpte = address & ~rmask;
+
+ vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
+ vpte |= rid;
+ __flush_tlb_page(tlb->mm, vpte, tsize, 0);
+ }
+}
+
+static void __init setup_page_sizes(void)
+{
+ unsigned int tlb0cfg;
+ unsigned int eptcfg;
+ int psize;
+
+#ifdef CONFIG_PPC_E500
+ unsigned int mmucfg = mfspr(SPRN_MMUCFG);
+ int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
+
+ if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
+ unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
+ unsigned int min_pg, max_pg;
+
+ min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
+ max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
+
+ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+ struct mmu_psize_def *def;
+ unsigned int shift;
+
+ def = &mmu_psize_defs[psize];
+ shift = def->shift;
+
+ if (shift == 0 || shift & 1)
+ continue;
+
+ /* adjust to be in terms of 4^shift Kb */
+ shift = (shift - 10) >> 1;
+
+ if ((shift >= min_pg) && (shift <= max_pg))
+ def->flags |= MMU_PAGE_SIZE_DIRECT;
+ }
+
+ goto out;
+ }
+
+ if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
+ u32 tlb1cfg, tlb1ps;
+
+ tlb0cfg = mfspr(SPRN_TLB0CFG);
+ tlb1cfg = mfspr(SPRN_TLB1CFG);
+ tlb1ps = mfspr(SPRN_TLB1PS);
+ eptcfg = mfspr(SPRN_EPTCFG);
+
+ if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
+ book3e_htw_mode = PPC_HTW_E6500;
+
+ /*
+ * We expect 4K subpage size and unrestricted indirect size.
+ * The lack of a restriction on indirect size is a Freescale
+ * extension, indicated by PSn = 0 but SPSn != 0.
+ */
+ if (eptcfg != 2)
+ book3e_htw_mode = PPC_HTW_NONE;
+
+ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+ struct mmu_psize_def *def = &mmu_psize_defs[psize];
+
+ if (!def->shift)
+ continue;
+
+ if (tlb1ps & (1U << (def->shift - 10))) {
+ def->flags |= MMU_PAGE_SIZE_DIRECT;
+
+ if (book3e_htw_mode && psize == MMU_PAGE_2M)
+ def->flags |= MMU_PAGE_SIZE_INDIRECT;
+ }
+ }
+
+ goto out;
+ }
+#endif
+out:
+ /* Cleanup array and print summary */
+ pr_info("MMU: Supported page sizes\n");
+ for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
+ struct mmu_psize_def *def = &mmu_psize_defs[psize];
+ const char *__page_type_names[] = {
+ "unsupported",
+ "direct",
+ "indirect",
+ "direct & indirect"
+ };
+ if (def->flags == 0) {
+ def->shift = 0;
+ continue;
+ }
+ pr_info(" %8ld KB as %s\n", 1ul << (def->shift - 10),
+ __page_type_names[def->flags & 0x3]);
+ }
+}
+
+static void __init setup_mmu_htw(void)
+{
+ /*
+ * If we want to use HW tablewalk, enable it by patching the TLB miss
+ * handlers to branch to the one dedicated to it.
+ */
+
+ switch (book3e_htw_mode) {
+#ifdef CONFIG_PPC_E500
+ case PPC_HTW_E6500:
+ extlb_level_exc = EX_TLB_SIZE;
+ patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
+ patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
+ break;
+#endif
+ }
+ pr_info("MMU: Book3E HW tablewalk %s\n",
+ book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
+}
+
+/*
+ * Early initialization of the MMU TLB code
+ */
+static void early_init_this_mmu(void)
+{
+ unsigned int mas4;
+
+ /* Set MAS4 based on page table setting */
+
+ mas4 = 0x4 << MAS4_WIMGED_SHIFT;
+ switch (book3e_htw_mode) {
+ case PPC_HTW_E6500:
+ mas4 |= MAS4_INDD;
+ mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
+ mas4 |= MAS4_TLBSELD(1);
+ mmu_pte_psize = MMU_PAGE_2M;
+ break;
+
+ case PPC_HTW_NONE:
+ mas4 |= BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
+ mmu_pte_psize = mmu_virtual_psize;
+ break;
+ }
+ mtspr(SPRN_MAS4, mas4);
+
+#ifdef CONFIG_PPC_E500
+ if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+ unsigned int num_cams;
+ bool map = true;
+
+ /* use a quarter of the TLBCAM for bolted linear map */
+ num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+
+ /*
+ * Only do the mapping once per core, or else the
+ * transient mapping would cause problems.
+ */
+#ifdef CONFIG_SMP
+ if (hweight32(get_tensr()) > 1)
+ map = false;
+#endif
+
+ if (map)
+ linear_map_top = map_mem_in_cams(linear_map_top,
+ num_cams, false, true);
+ }
+#endif
+
+ /* A sync won't hurt us after mucking around with
+ * the MMU configuration
+ */
+ mb();
+}
+
+static void __init early_init_mmu_global(void)
+{
+ /* XXX This should be decided at runtime based on supported
+ * page sizes in the TLB, but for now let's assume 16M is
+ * always there and a good fit (which it probably is)
+ *
+ * Freescale booke only supports 4K pages in TLB0, so use that.
+ */
+ if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
+ mmu_vmemmap_psize = MMU_PAGE_4K;
+ else
+ mmu_vmemmap_psize = MMU_PAGE_16M;
+
+ /* XXX This code only checks for TLB 0 capabilities and doesn't
+ * check what page size combos are supported by the HW. It
+ * also doesn't handle the case where a separate array holds
+ * the IND entries from the array loaded by the PT.
+ */
+ /* Look for supported page sizes */
+ setup_page_sizes();
+
+ /* Look for HW tablewalk support */
+ setup_mmu_htw();
+
+#ifdef CONFIG_PPC_E500
+ if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+ if (book3e_htw_mode == PPC_HTW_NONE) {
+ extlb_level_exc = EX_TLB_SIZE;
+ patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
+ patch_exception(0x1e0,
+ exc_instruction_tlb_miss_bolted_book3e);
+ }
+ }
+#endif
+
+ /* Set the global containing the top of the linear mapping
+ * for use by the TLB miss code
+ */
+ linear_map_top = memblock_end_of_DRAM();
+
+ ioremap_bot = IOREMAP_BASE;
+}
+
+static void __init early_mmu_set_memory_limit(void)
+{
+#ifdef CONFIG_PPC_E500
+ if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+ /*
+ * Limit memory so we dont have linear faults.
+ * Unlike memblock_set_current_limit, which limits
+ * memory available during early boot, this permanently
+ * reduces the memory available to Linux. We need to
+ * do this because highmem is not supported on 64-bit.
+ */
+ memblock_enforce_memory_limit(linear_map_top);
+ }
+#endif
+
+ memblock_set_current_limit(linear_map_top);
+}
+
+/* boot cpu only */
+void __init early_init_mmu(void)
+{
+ early_init_mmu_global();
+ early_init_this_mmu();
+ early_mmu_set_memory_limit();
+}
+
+void early_init_mmu_secondary(void)
+{
+ early_init_this_mmu();
+}
+
+void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+ phys_addr_t first_memblock_size)
+{
+ /* On non-FSL Embedded 64-bit, we adjust the RMA size to match
+ * the bolted TLB entry. We know for now that only 1G
+ * entries are supported though that may eventually
+ * change.
+ *
+ * on FSL Embedded 64-bit, usually all RAM is bolted, but with
+ * unusual memory sizes it's possible for some RAM to not be mapped
+ * (such RAM is not used at all by Linux, since we don't support
+ * highmem on 64-bit). We limit ppc64_rma_size to what would be
+ * mappable if this memblock is the only one. Additional memblocks
+ * can only increase, not decrease, the amount that ends up getting
+ * mapped. We still limit max to 1G even if we'll eventually map
+ * more. This is due to what the early init code is set up to do.
+ *
+ * We crop it to the size of the first MEMBLOCK to
+ * avoid going over total available memory just in case...
+ */
+#ifdef CONFIG_PPC_E500
+ if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
+ unsigned long linear_sz;
+ unsigned int num_cams;
+
+ /* use a quarter of the TLBCAM for bolted linear map */
+ num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+
+ linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
+ true, true);
+
+ ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
+ } else
+#endif
+ ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
+
+ /* Finally limit subsequent allocations */
+ memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
+}
--
2.45.1
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