22 files changed, 1028 insertions, 8 deletions

diff --git a/Documentation/sparc/adi.txt b/Documentation/sparc/adi.txt
new file mode 100644
index 000000000000..e1aed155fb89
--- /dev/null
+++ b/Documentation/sparc/adi.txt
@@ -0,0 +1,278 @@
+Application Data Integrity (ADI)
+================================
+
+SPARC M7 processor adds the Application Data Integrity (ADI) feature.
+ADI allows a task to set version tags on any subset of its address
+space. Once ADI is enabled and version tags are set for ranges of
+address space of a task, the processor will compare the tag in pointers
+to memory in these ranges to the version set by the application
+previously. Access to memory is granted only if the tag in given pointer
+matches the tag set by the application. In case of mismatch, processor
+raises an exception.
+
+Following steps must be taken by a task to enable ADI fully:
+
+1. Set the user mode PSTATE.mcde bit. This acts as master switch for
+   the task's entire address space to enable/disable ADI for the task.
+
+2. Set TTE.mcd bit on any TLB entries that correspond to the range of
+   addresses ADI is being enabled on. MMU checks the version tag only
+   on the pages that have TTE.mcd bit set.
+
+3. Set the version tag for virtual addresses using stxa instruction
+   and one of the MCD specific ASIs. Each stxa instruction sets the
+   given tag for one ADI block size number of bytes. This step must
+   be repeated for entire page to set tags for entire page.
+
+ADI block size for the platform is provided by the hypervisor to kernel
+in machine description tables. Hypervisor also provides the number of
+top bits in the virtual address that specify the version tag.  Once
+version tag has been set for a memory location, the tag is stored in the
+physical memory and the same tag must be present in the ADI version tag
+bits of the virtual address being presented to the MMU. For example on
+SPARC M7 processor, MMU uses bits 63-60 for version tags and ADI block
+size is same as cacheline size which is 64 bytes. A task that sets ADI
+version to, say 10, on a range of memory, must access that memory using
+virtual addresses that contain 0xa in bits 63-60.
+
+ADI is enabled on a set of pages using mprotect() with PROT_ADI flag.
+When ADI is enabled on a set of pages by a task for the first time,
+kernel sets the PSTATE.mcde bit fot the task. Version tags for memory
+addresses are set with an stxa instruction on the addresses using
+ASI_MCD_PRIMARY or ASI_MCD_ST_BLKINIT_PRIMARY. ADI block size is
+provided by the hypervisor to the kernel.  Kernel returns the value of
+ADI block size to userspace using auxiliary vector along with other ADI
+info. Following auxiliary vectors are provided by the kernel:
+
+	AT_ADI_BLKSZ	ADI block size. This is the granularity and
+			alignment, in bytes, of ADI versioning.
+	AT_ADI_NBITS	Number of ADI version bits in the VA
+
+
+IMPORTANT NOTES:
+
+- Version tag values of 0x0 and 0xf are reserved. These values match any
+  tag in virtual address and never generate a mismatch exception.
+
+- Version tags are set on virtual addresses from userspace even though
+  tags are stored in physical memory. Tags are set on a physical page
+  after it has been allocated to a task and a pte has been created for
+  it.
+
+- When a task frees a memory page it had set version tags on, the page
+  goes back to free page pool. When this page is re-allocated to a task,
+  kernel clears the page using block initialization ASI which clears the
+  version tags as well for the page. If a page allocated to a task is
+  freed and allocated back to the same task, old version tags set by the
+  task on that page will no longer be present.
+
+- ADI tag mismatches are not detected for non-faulting loads.
+
+- Kernel does not set any tags for user pages and it is entirely a
+  task's responsibility to set any version tags. Kernel does ensure the
+  version tags are preserved if a page is swapped out to the disk and
+  swapped back in. It also preserves that version tags if a page is
+  migrated.
+
+- ADI works for any size pages. A userspace task need not be aware of
+  page size when using ADI. It can simply select a virtual address
+  range, enable ADI on the range using mprotect() and set version tags
+  for the entire range. mprotect() ensures range is aligned to page size
+  and is a multiple of page size.
+
+- ADI tags can only be set on writable memory. For example, ADI tags can
+  not be set on read-only mappings.
+
+
+
+ADI related traps
+-----------------
+
+With ADI enabled, following new traps may occur:
+
+Disrupting memory corruption
+
+	When a store accesses a memory localtion that has TTE.mcd=1,
+	the task is running with ADI enabled (PSTATE.mcde=1), and the ADI
+	tag in the address used (bits 63:60) does not match the tag set on
+	the corresponding cacheline, a memory corruption trap occurs. By
+	default, it is a disrupting trap and is sent to the hypervisor
+	first. Hypervisor creates a sun4v error report and sends a
+	resumable error (TT=0x7e) trap to the kernel. The kernel sends
+	a SIGSEGV to the task that resulted in this trap with the following
+	info:
+
+		siginfo.si_signo = SIGSEGV;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ADIDERR;
+		siginfo.si_addr = addr; /* PC where first mismatch occurred */
+		siginfo.si_trapno = 0;
+
+
+Precise memory corruption
+
+	When a store accesses a memory location that has TTE.mcd=1,
+	the task is running with ADI enabled (PSTATE.mcde=1), and the ADI
+	tag in the address used (bits 63:60) does not match the tag set on
+	the corresponding cacheline, a memory corruption trap occurs. If
+	MCD precise exception is enabled (MCDPERR=1), a precise
+	exception is sent to the kernel with TT=0x1a. The kernel sends
+	a SIGSEGV to the task that resulted in this trap with the following
+	info:
+
+		siginfo.si_signo = SIGSEGV;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ADIPERR;
+		siginfo.si_addr = addr;	/* address that caused trap */
+		siginfo.si_trapno = 0;
+
+	NOTE: ADI tag mismatch on a load always results in precise trap.
+
+
+MCD disabled
+
+	When a task has not enabled ADI and attempts to set ADI version
+	on a memory address, processor sends an MCD disabled trap. This
+	trap is handled by hypervisor first and the hypervisor vectors this
+	trap through to the kernel as Data Access Exception trap with
+	fault type set to 0xa (invalid ASI). When this occurs, the kernel
+	sends the task SIGSEGV signal with following info:
+
+		siginfo.si_signo = SIGSEGV;
+		siginfo.errno = 0;
+		siginfo.si_code = SEGV_ACCADI;
+		siginfo.si_addr = addr;	/* address that caused trap */
+		siginfo.si_trapno = 0;
+
+
+Sample program to use ADI
+-------------------------
+
+Following sample program is meant to illustrate how to use the ADI
+functionality.
+
+#include <unistd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <elf.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+#include <sys/mman.h>
+#include <asm/asi.h>
+
+#ifndef AT_ADI_BLKSZ
+#define AT_ADI_BLKSZ	48
+#endif
+#ifndef AT_ADI_NBITS
+#define AT_ADI_NBITS	49
+#endif
+
+#ifndef PROT_ADI
+#define PROT_ADI	0x10
+#endif
+
+#define BUFFER_SIZE     32*1024*1024UL
+
+main(int argc, char* argv[], char* envp[])
+{
+        unsigned long i, mcde, adi_blksz, adi_nbits;
+        char *shmaddr, *tmp_addr, *end, *veraddr, *clraddr;
+        int shmid, version;
+	Elf64_auxv_t *auxv;
+
+	adi_blksz = 0;
+
+	while(*envp++ != NULL);
+	for (auxv = (Elf64_auxv_t *)envp; auxv->a_type != AT_NULL; auxv++) {
+		switch (auxv->a_type) {
+		case AT_ADI_BLKSZ:
+			adi_blksz = auxv->a_un.a_val;
+			break;
+		case AT_ADI_NBITS:
+			adi_nbits = auxv->a_un.a_val;
+			break;
+		}
+	}
+	if (adi_blksz == 0) {
+		fprintf(stderr, "Oops! ADI is not supported\n");
+		exit(1);
+	}
+
+	printf("ADI capabilities:\n");
+	printf("\tBlock size = %ld\n", adi_blksz);
+	printf("\tNumber of bits = %ld\n", adi_nbits);
+
+        if ((shmid = shmget(2, BUFFER_SIZE,
+                                IPC_CREAT | SHM_R | SHM_W)) < 0) {
+                perror("shmget failed");
+                exit(1);
+        }
+
+        shmaddr = shmat(shmid, NULL, 0);
+        if (shmaddr == (char *)-1) {
+                perror("shm attach failed");
+                shmctl(shmid, IPC_RMID, NULL);
+                exit(1);
+        }
+
+	if (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE|PROT_ADI)) {
+		perror("mprotect failed");
+		goto err_out;
+	}
+
+        /* Set the ADI version tag on the shm segment
+         */
+        version = 10;
+        tmp_addr = shmaddr;
+        end = shmaddr + BUFFER_SIZE;
+        while (tmp_addr < end) {
+                asm volatile(
+                        "stxa %1, [%0]0x90\n\t"
+                        :
+                        : "r" (tmp_addr), "r" (version));
+                tmp_addr += adi_blksz;
+        }
+	asm volatile("membar #Sync\n\t");
+
+        /* Create a versioned address from the normal address by placing
+	 * version tag in the upper adi_nbits bits
+         */
+        tmp_addr = (void *) ((unsigned long)shmaddr << adi_nbits);
+        tmp_addr = (void *) ((unsigned long)tmp_addr >> adi_nbits);
+        veraddr = (void *) (((unsigned long)version << (64-adi_nbits))
+                        | (unsigned long)tmp_addr);
+
+        printf("Starting the writes:\n");
+        for (i = 0; i < BUFFER_SIZE; i++) {
+                veraddr[i] = (char)(i);
+                if (!(i % (1024 * 1024)))
+                        printf(".");
+        }
+        printf("\n");
+
+        printf("Verifying data...");
+	fflush(stdout);
+        for (i = 0; i < BUFFER_SIZE; i++)
+                if (veraddr[i] != (char)i)
+                        printf("\nIndex %lu mismatched\n", i);
+        printf("Done.\n");
+
+        /* Disable ADI and clean up
+         */
+	if (mprotect(shmaddr, BUFFER_SIZE, PROT_READ|PROT_WRITE)) {
+		perror("mprotect failed");
+		goto err_out;
+	}
+
+        if (shmdt((const void *)shmaddr) != 0)
+                perror("Detach failure");
+        shmctl(shmid, IPC_RMID, NULL);
+
+        exit(0);
+
+err_out:
+        if (shmdt((const void *)shmaddr) != 0)
+                perror("Detach failure");
+        shmctl(shmid, IPC_RMID, NULL);
+        exit(1);
+}
diff --git a/arch/sparc/include/asm/mman.h b/arch/sparc/include/asm/mman.h
index 7e9472143f9b..f94532f25db1 100644
--- a/arch/sparc/include/asm/mman.h
+++ b/arch/sparc/include/asm/mman.h
@@ -7,5 +7,87 @@
 #ifndef __ASSEMBLY__
 #define arch_mmap_check(addr,len,flags)	sparc_mmap_check(addr,len)
 int sparc_mmap_check(unsigned long addr, unsigned long len);
-#endif
+
+#ifdef CONFIG_SPARC64
+#include <asm/adi_64.h>
+
+static inline void ipi_set_tstate_mcde(void *arg)
+{
+	struct mm_struct *mm = arg;
+
+	/* Set TSTATE_MCDE for the task using address map that ADI has been
+	 * enabled on if the task is running. If not, it will be set
+	 * automatically at the next context switch
+	 */
+	if (current->mm == mm) {
+		struct pt_regs *regs;
+
+		regs = task_pt_regs(current);
+		regs->tstate |= TSTATE_MCDE;
+	}
+}
+
+#define arch_calc_vm_prot_bits(prot, pkey) sparc_calc_vm_prot_bits(prot)
+static inline unsigned long sparc_calc_vm_prot_bits(unsigned long prot)
+{
+	if (adi_capable() && (prot & PROT_ADI)) {
+		struct pt_regs *regs;
+
+		if (!current->mm->context.adi) {
+			regs = task_pt_regs(current);
+			regs->tstate |= TSTATE_MCDE;
+			current->mm->context.adi = true;
+			on_each_cpu_mask(mm_cpumask(current->mm),
+					 ipi_set_tstate_mcde, current->mm, 0);
+		}
+		return VM_SPARC_ADI;
+	} else {
+		return 0;
+	}
+}
+
+#define arch_vm_get_page_prot(vm_flags) sparc_vm_get_page_prot(vm_flags)
+static inline pgprot_t sparc_vm_get_page_prot(unsigned long vm_flags)
+{
+	return (vm_flags & VM_SPARC_ADI) ? __pgprot(_PAGE_MCD_4V) : __pgprot(0);
+}
+
+#define arch_validate_prot(prot, addr) sparc_validate_prot(prot, addr)
+static inline int sparc_validate_prot(unsigned long prot, unsigned long addr)
+{
+	if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_ADI))
+		return 0;
+	if (prot & PROT_ADI) {
+		if (!adi_capable())
+			return 0;
+
+		if (addr) {
+			struct vm_area_struct *vma;
+
+			vma = find_vma(current->mm, addr);
+			if (vma) {
+				/* ADI can not be enabled on PFN
+				 * mapped pages
+				 */
+				if (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP))
+					return 0;
+
+				/* Mergeable pages can become unmergeable
+				 * if ADI is enabled on them even if they
+				 * have identical data on them. This can be
+				 * because ADI enabled pages with identical
+				 * data may still not have identical ADI
+				 * tags on them. Disallow ADI on mergeable
+				 * pages.
+				 */
+				if (vma->vm_flags & VM_MERGEABLE)
+					return 0;
+			}
+		}
+	}
+	return 1;
+}
+#endif /* CONFIG_SPARC64 */
+
+#endif /* __ASSEMBLY__ */
 #endif /* __SPARC_MMAN_H__ */
diff --git a/arch/sparc/include/asm/mmu_64.h b/arch/sparc/include/asm/mmu_64.h
index ad4fb93508ba..7e2704c770e9 100644
--- a/arch/sparc/include/asm/mmu_64.h
+++ b/arch/sparc/include/asm/mmu_64.h
@@ -90,6 +90,20 @@ struct tsb_config {
 #define MM_NUM_TSBS	1
 #endif
 
+/* ADI tags are stored when a page is swapped out and the storage for
+ * tags is allocated dynamically. There is a tag storage descriptor
+ * associated with each set of tag storage pages. Tag storage descriptors
+ * are allocated dynamically. Since kernel will allocate a full page for
+ * each tag storage descriptor, we can store up to
+ * PAGE_SIZE/sizeof(tag storage descriptor) descriptors on that page.
+ */
+typedef struct {
+	unsigned long	start;		/* Start address for this tag storage */
+	unsigned long	end;		/* Last address for tag storage */
+	unsigned char	*tags;		/* Where the tags are */
+	unsigned long	tag_users;	/* number of references to descriptor */
+} tag_storage_desc_t;
+
 typedef struct {
 	spinlock_t		lock;
 	unsigned long		sparc64_ctx_val;
@@ -98,6 +112,9 @@ typedef struct {
 	struct tsb_config	tsb_block[MM_NUM_TSBS];
 	struct hv_tsb_descr	tsb_descr[MM_NUM_TSBS];
 	void			*vdso;
+	bool			adi;
+	tag_storage_desc_t	*tag_store;
+	spinlock_t		tag_lock;
 } mm_context_t;
 
 #endif /* !__ASSEMBLY__ */
diff --git a/arch/sparc/include/asm/mmu_context_64.h b/arch/sparc/include/asm/mmu_context_64.h
index b361702ef52a..312fcee8df2b 100644
--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h
@@ -9,8 +9,10 @@
 #include <linux/spinlock.h>
 #include <linux/mm_types.h>
 #include <linux/smp.h>
+#include <linux/sched.h>
 
 #include <asm/spitfire.h>
+#include <asm/adi_64.h>
 #include <asm-generic/mm_hooks.h>
 #include <asm/percpu.h>
 
@@ -136,6 +138,55 @@ static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, str
 
 #define deactivate_mm(tsk,mm)	do { } while (0)
 #define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL)
+
+#define  __HAVE_ARCH_START_CONTEXT_SWITCH
+static inline void arch_start_context_switch(struct task_struct *prev)
+{
+	/* Save the current state of MCDPER register for the process
+	 * we are switching from
+	 */
+	if (adi_capable()) {
+		register unsigned long tmp_mcdper;
+
+		__asm__ __volatile__(
+			".word 0x83438000\n\t"	/* rd  %mcdper, %g1 */
+			"mov %%g1, %0\n\t"
+			: "=r" (tmp_mcdper)
+			:
+			: "g1");
+		if (tmp_mcdper)
+			set_tsk_thread_flag(prev, TIF_MCDPER);
+		else
+			clear_tsk_thread_flag(prev, TIF_MCDPER);
+	}
+}
+
+#define finish_arch_post_lock_switch	finish_arch_post_lock_switch
+static inline void finish_arch_post_lock_switch(void)
+{
+	/* Restore the state of MCDPER register for the new process
+	 * just switched to.
+	 */
+	if (adi_capable()) {
+		register unsigned long tmp_mcdper;
+
+		tmp_mcdper = test_thread_flag(TIF_MCDPER);
+		__asm__ __volatile__(
+			"mov %0, %%g1\n\t"
+			".word 0x9d800001\n\t"	/* wr %g0, %g1, %mcdper" */
+			".word 0xaf902001\n\t"	/* wrpr %g0, 1, %pmcdper */
+			:
+			: "ir" (tmp_mcdper)
+			: "g1");
+		if (current && current->mm && current->mm->context.adi) {
+			struct pt_regs *regs;
+
+			regs = task_pt_regs(current);
+			regs->tstate |= TSTATE_MCDE;
+		}
+	}
+}
+
 #endif /* !(__ASSEMBLY__) */
 
 #endif /* !(__SPARC64_MMU_CONTEXT_H) */
diff --git a/arch/sparc/include/asm/page_64.h b/arch/sparc/include/asm/page_64.h
index c28379b1b0fc..e80f2d5bf62f 100644
--- a/arch/sparc/include/asm/page_64.h
+++ b/arch/sparc/include/asm/page_64.h
@@ -48,6 +48,12 @@ struct page;
 void clear_user_page(void *addr, unsigned long vaddr, struct page *page);
 #define copy_page(X,Y)	memcpy((void *)(X), (void *)(Y), PAGE_SIZE)
 void copy_user_page(void *to, void *from, unsigned long vaddr, struct page *topage);
+#define __HAVE_ARCH_COPY_USER_HIGHPAGE
+struct vm_area_struct;
+void copy_user_highpage(struct page *to, struct page *from,
+			unsigned long vaddr, struct vm_area_struct *vma);
+#define __HAVE_ARCH_COPY_HIGHPAGE
+void copy_highpage(struct page *to, struct page *from);
 
 /* Unlike sparc32, sparc64's parameter passing API is more
  * sane in that structures which as small enough are passed
diff --git a/arch/sparc/include/asm/pgtable_64.h b/arch/sparc/include/asm/pgtable_64.h
index 619332a44402..44d6ac47e035 100644
--- a/arch/sparc/include/asm/pgtable_64.h
+++ b/arch/sparc/include/asm/pgtable_64.h
@@ -19,6 +19,7 @@
 #include <asm/types.h>
 #include <asm/spitfire.h>
 #include <asm/asi.h>
+#include <asm/adi.h>
 #include <asm/page.h>
 #include <asm/processor.h>
 
@@ -606,6 +607,18 @@ static inline pte_t pte_mkspecial(pte_t pte)
 	return pte;
 }
 
+static inline pte_t pte_mkmcd(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_MCD_4V;
+	return pte;
+}
+
+static inline pte_t pte_mknotmcd(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_MCD_4V;
+	return pte;
+}
+
 static inline unsigned long pte_young(pte_t pte)
 {
 	unsigned long mask;
@@ -1048,6 +1061,39 @@ int page_in_phys_avail(unsigned long paddr);
 int remap_pfn_range(struct vm_area_struct *, unsigned long, unsigned long,
 		    unsigned long, pgprot_t);
 
+void adi_restore_tags(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long addr, pte_t pte);
+
+int adi_save_tags(struct mm_struct *mm, struct vm_area_struct *vma,
+		  unsigned long addr, pte_t oldpte);
+
+#define __HAVE_ARCH_DO_SWAP_PAGE
+static inline void arch_do_swap_page(struct mm_struct *mm,
+				     struct vm_area_struct *vma,
+				     unsigned long addr,
+				     pte_t pte, pte_t oldpte)
+{
+	/* If this is a new page being mapped in, there can be no
+	 * ADI tags stored away for this page. Skip looking for
+	 * stored tags
+	 */
+	if (pte_none(oldpte))
+		return;
+
+	if (adi_state.enabled && (pte_val(pte) & _PAGE_MCD_4V))
+		adi_restore_tags(mm, vma, addr, pte);
+}
+
+#define __HAVE_ARCH_UNMAP_ONE
+static inline int arch_unmap_one(struct mm_struct *mm,
+				 struct vm_area_struct *vma,
+				 unsigned long addr, pte_t oldpte)
+{
+	if (adi_state.enabled && (pte_val(oldpte) & _PAGE_MCD_4V))
+		return adi_save_tags(mm, vma, addr, oldpte);
+	return 0;
+}
+
 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
 				     unsigned long from, unsigned long pfn,
 				     unsigned long size, pgprot_t prot)
diff --git a/arch/sparc/include/asm/thread_info_64.h b/arch/sparc/include/asm/thread_info_64.h
index f7e7b0baec9f..7fb676360928 100644
--- a/arch/sparc/include/asm/thread_info_64.h
+++ b/arch/sparc/include/asm/thread_info_64.h
@@ -188,7 +188,7 @@ register struct thread_info *current_thread_info_reg asm("g6");
  *       in using in assembly, else we can't use the mask as
  *       an immediate value in instructions such as andcc.
  */
-/* flag bit 12 is available */
+#define TIF_MCDPER		12	/* Precise MCD exception */
 #define TIF_MEMDIE		13	/* is terminating due to OOM killer */
 #define TIF_POLLING_NRFLAG	14
 
diff --git a/arch/sparc/include/asm/trap_block.h b/arch/sparc/include/asm/trap_block.h
index 6a4c8652ad67..0f6d0c4f6683 100644
--- a/arch/sparc/include/asm/trap_block.h
+++ b/arch/sparc/include/asm/trap_block.h
@@ -76,6 +76,8 @@ extern struct sun4v_1insn_patch_entry __sun4v_1insn_patch,
 	__sun4v_1insn_patch_end;
 extern struct sun4v_1insn_patch_entry __fast_win_ctrl_1insn_patch,
 	__fast_win_ctrl_1insn_patch_end;
+extern struct sun4v_1insn_patch_entry __sun_m7_1insn_patch,
+	__sun_m7_1insn_patch_end;
 
 struct sun4v_2insn_patch_entry {
 	unsigned int	addr;
diff --git a/arch/sparc/include/uapi/asm/mman.h b/arch/sparc/include/uapi/asm/mman.h
index 715a2c927e79..f6f99ec65bb3 100644
--- a/arch/sparc/include/uapi/asm/mman.h
+++ b/arch/sparc/include/uapi/asm/mman.h
@@ -6,6 +6,8 @@
 
 /* SunOS'ified... */
 
+#define PROT_ADI	0x10		/* ADI enabled */
+
 #define MAP_RENAME      MAP_ANONYMOUS   /* In SunOS terminology */
 #define MAP_NORESERVE   0x40            /* don't reserve swap pages */
 #define MAP_INHERIT     0x80            /* SunOS doesn't do this, but... */
diff --git a/arch/sparc/kernel/adi_64.c b/arch/sparc/kernel/adi_64.c
index 8fb72585d9f1..d0a2ac975b42 100644
--- a/arch/sparc/kernel/adi_64.c
+++ b/arch/sparc/kernel/adi_64.c
@@ -8,10 +8,24 @@
  * This work is licensed under the terms of the GNU GPL, version 2.
  */
 #include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/mm_types.h>
 #include <asm/mdesc.h>
 #include <asm/adi_64.h>
+#include <asm/mmu_64.h>
+#include <asm/pgtable_64.h>
+
+/* Each page of storage for ADI tags can accommodate tags for 128
+ * pages. When ADI enabled pages are being swapped out, it would be
+ * prudent to allocate at least enough tag storage space to accommodate
+ * SWAPFILE_CLUSTER number of pages. Allocate enough tag storage to
+ * store tags for four SWAPFILE_CLUSTER pages to reduce need for
+ * further allocations for same vma.
+ */
+#define TAG_STORAGE_PAGES	8
 
 struct adi_config adi_state;
+EXPORT_SYMBOL(adi_state);
 
 /* mdesc_adi_init() : Parse machine description provided by the
  *	hypervisor to detect ADI capabilities
@@ -84,6 +98,19 @@ void __init mdesc_adi_init(void)
 		goto adi_not_found;
 	adi_state.caps.ue_on_adi = *val;
 
+	/* Some of the code to support swapping ADI tags is written
+	 * assumption that two ADI tags can fit inside one byte. If
+	 * this assumption is broken by a future architecture change,
+	 * that code will have to be revisited. If that were to happen,
+	 * disable ADI support so we do not get unpredictable results
+	 * with programs trying to use ADI and their pages getting
+	 * swapped out
+	 */
+	if (adi_state.caps.nbits > 4) {
+		pr_warn("WARNING: ADI tag size >4 on this platform. Disabling AADI support\n");
+		adi_state.enabled = false;
+	}
+
 	mdesc_release(hp);
 	return;
 
@@ -94,3 +121,277 @@ adi_not_found:
 	if (hp)
 		mdesc_release(hp);
 }
+
+tag_storage_desc_t *find_tag_store(struct mm_struct *mm,
+				   struct vm_area_struct *vma,
+				   unsigned long addr)
+{
+	tag_storage_desc_t *tag_desc = NULL;
+	unsigned long i, max_desc, flags;
+
+	/* Check if this vma already has tag storage descriptor
+	 * allocated for it.
+	 */
+	max_desc = PAGE_SIZE/sizeof(tag_storage_desc_t);
+	if (mm->context.tag_store) {
+		tag_desc = mm->context.tag_store;
+		spin_lock_irqsave(&mm->context.tag_lock, flags);
+		for (i = 0; i < max_desc; i++) {
+			if ((addr >= tag_desc->start) &&
+			    ((addr + PAGE_SIZE - 1) <= tag_desc->end))
+				break;
+			tag_desc++;
+		}
+		spin_unlock_irqrestore(&mm->context.tag_lock, flags);
+
+		/* If no matching entries were found, this must be a
+		 * freshly allocated page
+		 */
+		if (i >= max_desc)
+			tag_desc = NULL;
+	}
+
+	return tag_desc;
+}
+
+tag_storage_desc_t *alloc_tag_store(struct mm_struct *mm,
+				    struct vm_area_struct *vma,
+				    unsigned long addr)
+{
+	unsigned char *tags;
+	unsigned long i, size, max_desc, flags;
+	tag_storage_desc_t *tag_desc, *open_desc;
+	unsigned long end_addr, hole_start, hole_end;
+
+	max_desc = PAGE_SIZE/sizeof(tag_storage_desc_t);
+	open_desc = NULL;
+	hole_start = 0;
+	hole_end = ULONG_MAX;
+	end_addr = addr + PAGE_SIZE - 1;
+
+	/* Check if this vma already has tag storage descriptor
+	 * allocated for it.
+	 */
+	spin_lock_irqsave(&mm->context.tag_lock, flags);
+	if (mm->context.tag_store) {
+		tag_desc = mm->context.tag_store;
+
+		/* Look for a matching entry for this address. While doing
+		 * that, look for the first open slot as well and find
+		 * the hole in already allocated range where this request
+		 * will fit in.
+		 */
+		for (i = 0; i < max_desc; i++) {
+			if (tag_desc->tag_users == 0) {
+				if (open_desc == NULL)
+					open_desc = tag_desc;
+			} else {
+				if ((addr >= tag_desc->start) &&
+				    (tag_desc->end >= (addr + PAGE_SIZE - 1))) {
+					tag_desc->tag_users++;
+					goto out;
+				}
+			}
+			if ((tag_desc->start > end_addr) &&
+			    (tag_desc->start < hole_end))
+				hole_end = tag_desc->start;
+			if ((tag_desc->end < addr) &&
+			    (tag_desc->end > hole_start))
+				hole_start = tag_desc->end;
+			tag_desc++;
+		}
+
+	} else {
+		size = sizeof(tag_storage_desc_t)*max_desc;
+		mm->context.tag_store = kzalloc(size, GFP_NOWAIT|__GFP_NOWARN);
+		if (mm->context.tag_store == NULL) {
+			tag_desc = NULL;
+			goto out;
+		}
+		tag_desc = mm->context.tag_store;
+		for (i = 0; i < max_desc; i++, tag_desc++)
+			tag_desc->tag_users = 0;
+		open_desc = mm->context.tag_store;
+		i = 0;
+	}
+
+	/* Check if we ran out of tag storage descriptors */
+	if (open_desc == NULL) {
+		tag_desc = NULL;
+		goto out;
+	}
+
+	/* Mark this tag descriptor slot in use and then initialize it */
+	tag_desc = open_desc;
+	tag_desc->tag_users = 1;
+
+	/* Tag storage has not been allocated for this vma and space
+	 * is available in tag storage descriptor. Since this page is
+	 * being swapped out, there is high probability subsequent pages
+	 * in the VMA will be swapped out as well. Allocate pages to
+	 * store tags for as many pages in this vma as possible but not
+	 * more than TAG_STORAGE_PAGES. Each byte in tag space holds
+	 * two ADI tags since each ADI tag is 4 bits. Each ADI tag
+	 * covers adi_blksize() worth of addresses. Check if the hole is
+	 * big enough to accommodate full address range for using
+	 * TAG_STORAGE_PAGES number of tag pages.
+	 */
+	size = TAG_STORAGE_PAGES * PAGE_SIZE;
+	end_addr = addr + (size*2*adi_blksize()) - 1;
+	/* Check for overflow. If overflow occurs, allocate only one page */
+	if (end_addr < addr) {
+		size = PAGE_SIZE;
+		end_addr = addr + (size*2*adi_blksize()) - 1;
+		/* If overflow happens with the minimum tag storage
+		 * allocation as well, adjust ending address for this
+		 * tag storage.
+		 */
+		if (end_addr < addr)
+			end_addr = ULONG_MAX;
+	}
+	if (hole_end < end_addr) {
+		/* Available hole is too small on the upper end of
+		 * address. Can we expand the range towards the lower
+		 * address and maximize use of this slot?
+		 */
+		unsigned long tmp_addr;
+
+		end_addr = hole_end - 1;
+		tmp_addr = end_addr - (size*2*adi_blksize()) + 1;
+		/* Check for underflow. If underflow occurs, allocate
+		 * only one page for storing ADI tags
+		 */
+		if (tmp_addr > addr) {
+			size = PAGE_SIZE;
+			tmp_addr = end_addr - (size*2*adi_blksize()) - 1;
+			/* If underflow happens with the minimum tag storage
+			 * allocation as well, adjust starting address for
+			 * this tag storage.
+			 */
+			if (tmp_addr > addr)
+				tmp_addr = 0;
+		}
+		if (tmp_addr < hole_start) {
+			/* Available hole is restricted on lower address
+			 * end as well
+			 */
+			tmp_addr = hole_start + 1;
+		}
+		addr = tmp_addr;
+		size = (end_addr + 1 - addr)/(2*adi_blksize());
+		size = (size + (PAGE_SIZE-adi_blksize()))/PAGE_SIZE;
+		size = size * PAGE_SIZE;
+	}
+	tags = kzalloc(size, GFP_NOWAIT|__GFP_NOWARN);
+	if (tags == NULL) {
+		tag_desc->tag_users = 0;
+		tag_desc = NULL;
+		goto out;
+	}
+	tag_desc->start = addr;
+	tag_desc->tags = tags;
+	tag_desc->end = end_addr;
+
+out:
+	spin_unlock_irqrestore(&mm->context.tag_lock, flags);
+	return tag_desc;
+}
+
+void del_tag_store(tag_storage_desc_t *tag_desc, struct mm_struct *mm)
+{
+	unsigned long flags;
+	unsigned char *tags = NULL;
+
+	spin_lock_irqsave(&mm->context.tag_lock, flags);
+	tag_desc->tag_users--;
+	if (tag_desc->tag_users == 0) {
+		tag_desc->start = tag_desc->end = 0;
+		/* Do not free up the tag storage space allocated
+		 * by the first descriptor. This is persistent
+		 * emergency tag storage space for the task.
+		 */
+		if (tag_desc != mm->context.tag_store) {
+			tags = tag_desc->tags;
+			tag_desc->tags = NULL;
+		}
+	}
+	spin_unlock_irqrestore(&mm->context.tag_lock, flags);
+	kfree(tags);
+}
+
+#define tag_start(addr, tag_desc)		\
+	((tag_desc)->tags + ((addr - (tag_desc)->start)/(2*adi_blksize())))
+
+/* Retrieve any saved ADI tags for the page being swapped back in and
+ * restore these tags to the newly allocated physical page.
+ */
+void adi_restore_tags(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long addr, pte_t pte)
+{
+	unsigned char *tag;
+	tag_storage_desc_t *tag_desc;
+	unsigned long paddr, tmp, version1, version2;
+
+	/* Check if the swapped out page has an ADI version
+	 * saved. If yes, restore version tag to the newly
+	 * allocated page.
+	 */
+	tag_desc = find_tag_store(mm, vma, addr);
+	if (tag_desc == NULL)
+		return;
+
+	tag = tag_start(addr, tag_desc);
+	paddr = pte_val(pte) & _PAGE_PADDR_4V;
+	for (tmp = paddr; tmp < (paddr+PAGE_SIZE); tmp += adi_blksize()) {
+		version1 = (*tag) >> 4;