2018-11-21 10:31:01

by Christophe Leroy

[permalink] [raw]
Subject: [PATCH v3] powerpc/mm: dump block address translation on book3s/32

This patch adds a debugfs file to dump block address translation:

~# cat /sys/kernel/debug/block_address_translation
---[ Instruction Block Address Translations ]---
0: -
1: -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel EXEC coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel EXEC coherent
4: -
5: -
6: -
7: -

---[ Data Block Address Translations ]---
0: -
1: -
2: 0xc0000000-0xcfffffff 0x00000000 Kernel RW coherent
3: 0xd0000000-0xdfffffff 0x10000000 Kernel RW coherent
4: -
5: -
6: -
7: -

Signed-off-by: Christophe Leroy <[email protected]>
---
v3: Fixed PHYS_BAT_ADDR() when !CONFIG_PHYS_64BIT
Cosmetic changes to have it look more like kernel_page_table with ---[ xxx ]---
Removed unnecessary includes
Using CPU feature to know if it is a 601 instead of SPRN_PVR

v2: Fixed phys address display for CONFIG_PHYS_64BIT

arch/powerpc/include/asm/book3s/32/mmu-hash.h | 4 +
arch/powerpc/mm/Makefile | 2 +-
arch/powerpc/mm/dump_bats.c | 173 ++++++++++++++++++++++++++
3 files changed, 178 insertions(+), 1 deletion(-)
create mode 100644 arch/powerpc/mm/dump_bats.c

diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index e38c91388c40..1a380cc5cfc3 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -34,8 +34,12 @@
#define BAT_PHYS_ADDR(x) ((u32)((x & 0x00000000fffe0000ULL) | \
((x & 0x0000000e00000000ULL) >> 24) | \
((x & 0x0000000100000000ULL) >> 30)))
+#define PHYS_BAT_ADDR(x) (((u64)(x) & 0x00000000fffe0000ULL) | \
+ (((u64)(x) << 24) & 0x0000000e00000000ULL) | \
+ (((u64)(x) << 30) & 0x0000000100000000ULL))
#else
#define BAT_PHYS_ADDR(x) (x)
+#define PHYS_BAT_ADDR(x) ((x) & 0xfffe0000)
#endif

struct ppc_bat {
diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
index 1adc3d8a89cc..20c537a5c436 100644
--- a/arch/powerpc/mm/Makefile
+++ b/arch/powerpc/mm/Makefile
@@ -47,7 +47,7 @@ ifdef CONFIG_PPC_PTDUMP
obj-$(CONFIG_4xx) += dump_linuxpagetables-generic.o
obj-$(CONFIG_PPC_8xx) += dump_linuxpagetables-8xx.o
obj-$(CONFIG_PPC_BOOK3E_MMU) += dump_linuxpagetables-generic.o
-obj-$(CONFIG_PPC_BOOK3S_32) += dump_linuxpagetables-generic.o
+obj-$(CONFIG_PPC_BOOK3S_32) += dump_linuxpagetables-generic.o dump_bats.o
obj-$(CONFIG_PPC_BOOK3S_64) += dump_linuxpagetables-book3s64.o
endif
obj-$(CONFIG_PPC_HTDUMP) += dump_hashpagetable.o
diff --git a/arch/powerpc/mm/dump_bats.c b/arch/powerpc/mm/dump_bats.c
new file mode 100644
index 000000000000..b7f13f95e908
--- /dev/null
+++ b/arch/powerpc/mm/dump_bats.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright 2018, Christophe Leroy CS S.I.
+ * <[email protected]>
+ *
+ * This dumps the content of BATS
+ */
+
+#include <linux/debugfs.h>
+#include <asm/pgtable.h>
+#include <asm/cpu_has_feature.h>
+
+static char *pp_601(int k, int pp)
+{
+ if (pp == 0)
+ return k ? "NA" : "RWX";
+ if (pp == 1)
+ return k ? "ROX" : "RWX";
+ if (pp == 2)
+ return k ? "RWX" : "RWX";
+ return k ? "ROX" : "ROX";
+}
+
+static void bat_show_601(struct seq_file *m, int idx, u32 lower, u32 upper)
+{
+ u32 blpi = upper & 0xfffe0000;
+ u32 k = (upper >> 2) & 3;
+ u32 pp = upper & 3;
+ phys_addr_t pbn = PHYS_BAT_ADDR(lower);
+ u32 bsm = lower & 0x3ff;
+ u32 size = (bsm + 1) << 17;
+
+ seq_printf(m, "%d: ", idx);
+ if (!(lower & 0x40)) {
+ seq_puts(m, " -\n");
+ return;
+ }
+
+ seq_printf(m, "0x%08x-0x%08x ", blpi, blpi + size - 1);
+#ifdef CONFIG_PHYS_64BIT
+ seq_printf(m, "0x%016llx ", pbn);
+#else
+ seq_printf(m, "0x%08x ", pbn);
+#endif
+
+ seq_printf(m, "Kernel %s User %s", pp_601(k & 2, pp), pp_601(k & 1, pp));
+
+ if (lower & _PAGE_WRITETHRU)
+ seq_puts(m, "write through ");
+ if (lower & _PAGE_NO_CACHE)
+ seq_puts(m, "no cache ");
+ if (lower & _PAGE_COHERENT)
+ seq_puts(m, "coherent ");
+ seq_puts(m, "\n");
+}
+
+#define BAT_SHOW_601(_m, _n, _l, _u) bat_show_601(_m, _n, mfspr(_l), mfspr(_u))
+
+static int bats_show_601(struct seq_file *m, void *v)
+{
+ seq_puts(m, "---[ Block Address Translation ]---\n");
+
+ BAT_SHOW_601(m, 0, SPRN_IBAT0L, SPRN_IBAT0U);
+ BAT_SHOW_601(m, 1, SPRN_IBAT1L, SPRN_IBAT1U);
+ BAT_SHOW_601(m, 2, SPRN_IBAT2L, SPRN_IBAT2U);
+ BAT_SHOW_601(m, 3, SPRN_IBAT3L, SPRN_IBAT3U);
+
+ return 0;
+}
+
+static void bat_show_603(struct seq_file *m, int idx, u32 lower, u32 upper, bool is_d)
+{
+ u32 bepi = upper & 0xfffe0000;
+ u32 bl = (upper >> 2) & 0x7ff;
+ u32 k = upper & 3;
+ phys_addr_t brpn = PHYS_BAT_ADDR(lower);
+ u32 size = (bl + 1) << 17;
+
+ seq_printf(m, "%d: ", idx);
+ if (k == 0) {
+ seq_puts(m, " -\n");
+ return;
+ }
+
+ seq_printf(m, "0x%08x-0x%08x ", bepi, bepi + size - 1);
+#ifdef CONFIG_PHYS_64BIT
+ seq_printf(m, "0x%016llx ", brpn);
+#else
+ seq_printf(m, "0x%08x ", brpn);
+#endif
+
+ if (k == 1)
+ seq_puts(m, "User ");
+ else if (k == 2)
+ seq_puts(m, "Kernel ");
+ else
+ seq_puts(m, "Kernel/User ");
+
+ if (lower & BPP_RX)
+ seq_puts(m, is_d ? "RO " : "EXEC ");
+ else if (lower & BPP_RW)
+ seq_puts(m, is_d ? "RW " : "EXEC ");
+ else
+ seq_puts(m, is_d ? "NA " : "NX ");
+
+ if (lower & _PAGE_WRITETHRU)
+ seq_puts(m, "write through ");
+ if (lower & _PAGE_NO_CACHE)
+ seq_puts(m, "no cache ");
+ if (lower & _PAGE_COHERENT)
+ seq_puts(m, "coherent ");
+ if (lower & _PAGE_GUARDED)
+ seq_puts(m, "guarded ");
+ seq_puts(m, "\n");
+}
+
+#define BAT_SHOW_603(_m, _n, _l, _u, _d) bat_show_603(_m, _n, mfspr(_l), mfspr(_u), _d)
+
+static int bats_show_603(struct seq_file *m, void *v)
+{
+ seq_puts(m, "---[ Instruction Block Address Translation ]---\n");
+
+ BAT_SHOW_603(m, 0, SPRN_IBAT0L, SPRN_IBAT0U, false);
+ BAT_SHOW_603(m, 1, SPRN_IBAT1L, SPRN_IBAT1U, false);
+ BAT_SHOW_603(m, 2, SPRN_IBAT2L, SPRN_IBAT2U, false);
+ BAT_SHOW_603(m, 3, SPRN_IBAT3L, SPRN_IBAT3U, false);
+ if (mmu_has_feature(MMU_FTR_USE_HIGH_BATS)) {
+ BAT_SHOW_603(m, 4, SPRN_IBAT4L, SPRN_IBAT4U, false);
+ BAT_SHOW_603(m, 5, SPRN_IBAT5L, SPRN_IBAT5U, false);
+ BAT_SHOW_603(m, 6, SPRN_IBAT6L, SPRN_IBAT6U, false);
+ BAT_SHOW_603(m, 7, SPRN_IBAT7L, SPRN_IBAT7U, false);
+ }
+
+ seq_puts(m, "\n---[ Data Block Address Translation ]---\n");
+
+ BAT_SHOW_603(m, 0, SPRN_DBAT0L, SPRN_DBAT0U, true);
+ BAT_SHOW_603(m, 1, SPRN_DBAT1L, SPRN_DBAT1U, true);
+ BAT_SHOW_603(m, 2, SPRN_DBAT2L, SPRN_DBAT2U, true);
+ BAT_SHOW_603(m, 3, SPRN_DBAT3L, SPRN_DBAT3U, true);
+ if (mmu_has_feature(MMU_FTR_USE_HIGH_BATS)) {
+ BAT_SHOW_603(m, 4, SPRN_DBAT4L, SPRN_DBAT4U, true);
+ BAT_SHOW_603(m, 5, SPRN_DBAT5L, SPRN_DBAT5U, true);
+ BAT_SHOW_603(m, 6, SPRN_DBAT6L, SPRN_DBAT6U, true);
+ BAT_SHOW_603(m, 7, SPRN_DBAT7L, SPRN_DBAT7U, true);
+ }
+
+ return 0;
+}
+
+static int bats_open(struct inode *inode, struct file *file)
+{
+ if (cpu_has_feature(CPU_FTR_601))
+ return single_open(file, bats_show_601, NULL);
+
+ return single_open(file, bats_show_603, NULL);
+}
+
+static const struct file_operations bats_fops = {
+ .open = bats_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static int bats_init(void)
+{
+ struct dentry *debugfs_file;
+
+ debugfs_file = debugfs_create_file("block_address_translation", 0400,
+ NULL, NULL, &bats_fops);
+ return debugfs_file ? 0 : -ENOMEM;
+}
+device_initcall(bats_init);
--
2.13.3