Blackfin: unify memory region checks between kgdb and traps

The kgdb (in multiple places) and traps code developed pretty much
identical checks for how to access different regions of the Blackfin
memory map, but each wasn't 100%, so unify them to avoid duplication,
bitrot, and bugs with edge cases.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 121 insertions, 30 deletions

diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index 3e1d86e456f..79cad0ac589 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -344,6 +344,87 @@ void finish_atomic_sections (struct pt_regs *regs)
 	}
 }
 
+static inline
+int in_mem(unsigned long addr, unsigned long size,
+           unsigned long start, unsigned long end)
+{
+	return addr >= start && addr + size <= end;
+}
+static inline
+int in_mem_const_off(unsigned long addr, unsigned long size, unsigned long off,
+                     unsigned long const_addr, unsigned long const_size)
+{
+	return const_size &&
+	       in_mem(addr, size, const_addr + off, const_addr + const_size);
+}
+static inline
+int in_mem_const(unsigned long addr, unsigned long size,
+                 unsigned long const_addr, unsigned long const_size)
+{
+	return in_mem_const_off(addr, 0, size, const_addr, const_size);
+}
+#define IN_ASYNC(bnum, bctlnum) \
+({ \
+	(bfin_read_EBIU_AMGCTL() & 0xe) < ((bnum + 1) << 1) ? -EFAULT : \
+	bfin_read_EBIU_AMBCTL##bctlnum() & B##bnum##RDYEN ? -EFAULT : \
+	BFIN_MEM_ACCESS_CORE; \
+})
+
+int bfin_mem_access_type(unsigned long addr, unsigned long size)
+{
+	int cpu = raw_smp_processor_id();
+
+	/* Check that things do not wrap around */
+	if (addr > ULONG_MAX - size)
+		return -EFAULT;
+
+	if (in_mem(addr, size, FIXED_CODE_START, physical_mem_end))
+		return BFIN_MEM_ACCESS_CORE;
+
+	if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
+		return cpu == 0 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
+	if (in_mem_const(addr, size, L1_SCRATCH_START, L1_SCRATCH_LENGTH))
+		return cpu == 0 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
+	if (in_mem_const(addr, size, L1_DATA_A_START, L1_DATA_A_LENGTH))
+		return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
+	if (in_mem_const(addr, size, L1_DATA_B_START, L1_DATA_B_LENGTH))
+		return cpu == 0 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
+#ifdef COREB_L1_CODE_START
+	if (in_mem_const(addr, size, COREB_L1_CODE_START, L1_CODE_LENGTH))
+		return cpu == 1 ? BFIN_MEM_ACCESS_ITEST : BFIN_MEM_ACCESS_IDMA;
+	if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
+		return cpu == 1 ? BFIN_MEM_ACCESS_CORE_ONLY : -EFAULT;
+	if (in_mem_const(addr, size, COREB_L1_DATA_A_START, L1_DATA_A_LENGTH))
+		return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
+	if (in_mem_const(addr, size, COREB_L1_DATA_B_START, L1_DATA_B_LENGTH))
+		return cpu == 1 ? BFIN_MEM_ACCESS_CORE : BFIN_MEM_ACCESS_IDMA;
+#endif
+	if (in_mem_const(addr, size, L2_START, L2_LENGTH))
+		return BFIN_MEM_ACCESS_CORE;
+
+	if (addr >= SYSMMR_BASE)
+		return BFIN_MEM_ACCESS_CORE_ONLY;
+
+	/* We can't read EBIU banks that aren't enabled or we end up hanging
+	 * on the access to the async space.
+	 */
+	if (in_mem_const(addr, size, ASYNC_BANK0_BASE, ASYNC_BANK0_SIZE))
+		return IN_ASYNC(0, 0);
+	if (in_mem_const(addr, size, ASYNC_BANK1_BASE, ASYNC_BANK1_SIZE))
+		return IN_ASYNC(1, 0);
+	if (in_mem_const(addr, size, ASYNC_BANK2_BASE, ASYNC_BANK2_SIZE))
+		return IN_ASYNC(2, 1);
+	if (in_mem_const(addr, size, ASYNC_BANK3_BASE, ASYNC_BANK3_SIZE))
+		return IN_ASYNC(3, 1);
+
+	if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
+		return BFIN_MEM_ACCESS_CORE;
+	if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
+		return BFIN_MEM_ACCESS_DMA;
+
+	return -EFAULT;
+}
+
 #if defined(CONFIG_ACCESS_CHECK)
 #ifdef CONFIG_ACCESS_OK_L1
 __attribute__((l1_text))
@@ -353,51 +434,61 @@ int _access_ok(unsigned long addr, unsigned long size)
 {
 	if (size == 0)
 		return 1;
-	if (addr > (addr + size))
+	/* Check that things do not wrap around */
+	if (addr > ULONG_MAX - size)
 		return 0;
 	if (segment_eq(get_fs(), KERNEL_DS))
 		return 1;
 #ifdef CONFIG_MTD_UCLINUX
-	if (addr >= memory_start && (addr + size) <= memory_end)
-		return 1;
-	if (addr >= memory_mtd_end && (addr + size) <= physical_mem_end)
+	if (1)
+#else
+	if (0)
+#endif
+	{
+		if (in_mem(addr, size, memory_start, memory_end))
+			return 1;
+		if (in_mem(addr, size, memory_mtd_end, physical_mem_end))
+			return 1;
+# ifndef CONFIG_ROMFS_ON_MTD
+		if (0)
+# endif
+			/* For XIP, allow user space to use pointers within the ROMFS.  */
+			if (in_mem(addr, size, memory_mtd_start, memory_mtd_end))
+				return 1;
+	} else {
+		if (in_mem(addr, size, memory_start, physical_mem_end))
+			return 1;
+	}
+
+	if (in_mem(addr, size, (unsigned long)__init_begin, (unsigned long)__init_end))
 		return 1;
 
-#ifdef CONFIG_ROMFS_ON_MTD
-	/* For XIP, allow user space to use pointers within the ROMFS.  */
-	if (addr >= memory_mtd_start && (addr + size) <= memory_mtd_end)
+	if (in_mem_const(addr, size, L1_CODE_START, L1_CODE_LENGTH))
 		return 1;
-#endif
-#else
-	if (addr >= memory_start && (addr + size) <= physical_mem_end)
+	if (in_mem_const_off(addr, size, _etext_l1 - _stext_l1, L1_CODE_START, L1_CODE_LENGTH))
 		return 1;
-#endif
-	if (addr >= (unsigned long)__init_begin &&
-	    addr + size <= (unsigned long)__init_end)
+	if (in_mem_const_off(addr, size, _ebss_l1 - _sdata_l1, L1_DATA_A_START, L1_DATA_A_LENGTH))
 		return 1;
-	if (addr >= get_l1_scratch_start()
-	    && addr + size <= get_l1_scratch_start() + L1_SCRATCH_LENGTH)
+	if (in_mem_const_off(addr, size, _ebss_b_l1 - _sdata_b_l1, L1_DATA_B_START, L1_DATA_B_LENGTH))
 		return 1;
-#if L1_CODE_LENGTH != 0
-	if (addr >= get_l1_code_start() + (_etext_l1 - _stext_l1)
-	    && addr + size <= get_l1_code_start() + L1_CODE_LENGTH)
+#ifdef COREB_L1_CODE_START
+	if (in_mem_const(addr, size, COREB_L1_CODE_START, L1_CODE_LENGTH))
 		return 1;
-#endif
-#if L1_DATA_A_LENGTH != 0
-	if (addr >= get_l1_data_a_start() + (_ebss_l1 - _sdata_l1)
-	    && addr + size <= get_l1_data_a_start() + L1_DATA_A_LENGTH)
+	if (in_mem_const(addr, size, COREB_L1_SCRATCH_START, L1_SCRATCH_LENGTH))
 		return 1;
-#endif
-#if L1_DATA_B_LENGTH != 0
-	if (addr >= get_l1_data_b_start() + (_ebss_b_l1 - _sdata_b_l1)
-	    && addr + size <= get_l1_data_b_start() + L1_DATA_B_LENGTH)
+	if (in_mem_const(addr, size, COREB_L1_DATA_A_START, L1_DATA_A_LENGTH))
 		return 1;
-#endif
-#if L2_LENGTH != 0
-	if (addr >= L2_START + (_ebss_l2 - _stext_l2)
-	    && addr + size <= L2_START + L2_LENGTH)
+	if (in_mem_const(addr, size, COREB_L1_DATA_B_START, L1_DATA_B_LENGTH))
 		return 1;
 #endif
+	if (in_mem_const_off(addr, size, _ebss_l2 - _stext_l2, L2_START, L2_LENGTH))
+		return 1;
+
+	if (in_mem_const(addr, size, BOOT_ROM_START, BOOT_ROM_LENGTH))
+		return 1;
+	if (in_mem_const(addr, size, L1_ROM_START, L1_ROM_LENGTH))
+		return 1;
+
 	return 0;
 }
 EXPORT_SYMBOL(_access_ok);