Merge tag 'powerpc-5.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc...

Pull powerpc fixes from Michael Ellerman:
 "Two weeks worth of accumulated fixes:

   - A fix for a performance regression seen on PowerVM LPARs using
     dedicated CPUs, caused by our vcpu_is_preempted() returning true
     even for idle CPUs.

   - One of the ultravisor support patches broke KVM on big endian hosts
     in v5.4.

   - Our KUAP (Kernel User Access Prevention) code missed allowing
     access in __clear_user(), which could lead to an oops or erroneous
     SEGV when triggered via PTRACE_GETREGSET.

   - Two fixes for the ocxl driver, an open/remove race, and a memory
     leak in an error path.

   - A handful of other small fixes.

  Thanks to: Andrew Donnellan, Christian Zigotzky, Christophe Leroy,
  Christoph Hellwig, Daniel Axtens, David Hildenbrand, Frederic Barrat,
  Gautham R. Shenoy, Greg Kurz, Ihor Pasichnyk, Juri Lelli, Marcus
  Comstedt, Mike Rapoport, Parth Shah, Srikar Dronamraju, Vaidyanathan
  Srinivasan"

* tag 'powerpc-5.5-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  KVM: PPC: Book3S HV: Fix regression on big endian hosts
  powerpc: Fix __clear_user() with KUAP enabled
  powerpc/pseries/cmm: fix managed page counts when migrating pages between zones
  powerpc/8xx: fix bogus __init on mmu_mapin_ram_chunk()
  ocxl: Fix potential memory leak on context creation
  powerpc/irq: fix stack overflow verification
  powerpc: Ensure that swiotlb buffer is allocated from low memory
  powerpc/shared: Use static key to detect shared processor
  powerpc/vcpu: Assume dedicated processors as non-preempt
  ocxl: Fix concurrent AFU open and device removal

diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h
index e9a960e28f3c8468af557533ce3f9b71154d7cac..1b55fc08f8532c38b32c0349c5051e40e59be757 100644 (file)
--- a/arch/powerpc/include/asm/spinlock.h
+++ b/arch/powerpc/include/asm/spinlock.h
@@ -36,10 +36,12 @@
 #endif
 
 #ifdef CONFIG_PPC_PSERIES
+DECLARE_STATIC_KEY_FALSE(shared_processor);
+
 #define vcpu_is_preempted vcpu_is_preempted
 static inline bool vcpu_is_preempted(int cpu)
 {
-       if (!firmware_has_feature(FW_FEATURE_SPLPAR))
+       if (!static_branch_unlikely(&shared_processor))
                return false;
        return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1);
 }
@@ -110,13 +112,8 @@ static inline void splpar_rw_yield(arch_rwlock_t *lock) {};
 
 static inline bool is_shared_processor(void)
 {
-/*
- * LPPACA is only available on Pseries so guard anything LPPACA related to
- * allow other platforms (which include this common header) to compile.
- */
-#ifdef CONFIG_PPC_PSERIES
-       return (IS_ENABLED(CONFIG_PPC_SPLPAR) &&
-               lppaca_shared_proc(local_paca->lppaca_ptr));
+#ifdef CONFIG_PPC_SPLPAR
+       return static_branch_unlikely(&shared_processor);
 #else
        return false;
 #endif

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index 15002b51ff18df83d5d5a5c37c2c65462fffcdc3..c92fe7fe9692ceedcb98d2a88afdecea689bbaca 100644 (file)
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -401,7 +401,7 @@ copy_to_user_mcsafe(void __user *to, const void *from, unsigned long n)
        return n;
 }
 
-extern unsigned long __clear_user(void __user *addr, unsigned long size);
+unsigned long __arch_clear_user(void __user *addr, unsigned long size);
 
 static inline unsigned long clear_user(void __user *addr, unsigned long size)
 {
@@ -409,12 +409,17 @@ static inline unsigned long clear_user(void __user *addr, unsigned long size)
        might_fault();
        if (likely(access_ok(addr, size))) {
                allow_write_to_user(addr, size);
-               ret = __clear_user(addr, size);
+               ret = __arch_clear_user(addr, size);
                prevent_write_to_user(addr, size);
        }
        return ret;
 }
 
+static inline unsigned long __clear_user(void __user *addr, unsigned long size)
+{
+       return clear_user(addr, size);
+}
+
 extern long strncpy_from_user(char *dst, const char __user *src, long count);
 extern __must_check long strnlen_user(const char __user *str, long n);
 

diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 5645bc9cbc09a28c1fbc324743e4d568c3033dc6..add67498c126bffdc8050f804bed16fa97efd8e4 100644 (file)
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -619,8 +619,6 @@ void __do_irq(struct pt_regs *regs)
 
        trace_irq_entry(regs);
 
-       check_stack_overflow();
-
        /*
         * Query the platform PIC for the interrupt & ack it.
         *
@@ -652,6 +650,8 @@ void do_IRQ(struct pt_regs *regs)
        irqsp = hardirq_ctx[raw_smp_processor_id()];
        sirqsp = softirq_ctx[raw_smp_processor_id()];
 
+       check_stack_overflow();
+
        /* Already there ? */
        if (unlikely(cursp == irqsp || cursp == sirqsp)) {
                __do_irq(regs);

diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 0496e66aaa565fbe69f8fb238f503b0eccb6a27f..c6fbbd29bd8717a44bcac3cc5706269867d9d272 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -1117,7 +1117,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
        ld      r7, VCPU_GPR(R7)(r4)
        bne     ret_to_ultra
 
-       lwz     r0, VCPU_CR(r4)
+       ld      r0, VCPU_CR(r4)
        mtcr    r0
 
        ld      r0, VCPU_GPR(R0)(r4)
@@ -1137,7 +1137,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
  *   R3 = UV_RETURN
  */
 ret_to_ultra:
-       lwz     r0, VCPU_CR(r4)
+       ld      r0, VCPU_CR(r4)
        mtcr    r0
 
        ld      r0, VCPU_GPR(R3)(r4)

diff --git a/arch/powerpc/lib/string_32.S b/arch/powerpc/lib/string_32.S
index f69a6aab7bfbb5cb65fd082eaedb939d46c12149..1ddb26394e8ac5a1739b6f5aaf12512e5c3ed9f6 100644 (file)
--- a/arch/powerpc/lib/string_32.S
+++ b/arch/powerpc/lib/string_32.S
@@ -17,7 +17,7 @@ CACHELINE_BYTES = L1_CACHE_BYTES
 LG_CACHELINE_BYTES = L1_CACHE_SHIFT
 CACHELINE_MASK = (L1_CACHE_BYTES-1)
 
-_GLOBAL(__clear_user)
+_GLOBAL(__arch_clear_user)
 /*
  * Use dcbz on the complete cache lines in the destination
  * to set them to zero.  This requires that the destination
@@ -87,4 +87,4 @@ _GLOBAL(__clear_user)
        EX_TABLE(8b, 91b)
        EX_TABLE(9b, 91b)
 
-EXPORT_SYMBOL(__clear_user)
+EXPORT_SYMBOL(__arch_clear_user)

diff --git a/arch/powerpc/lib/string_64.S b/arch/powerpc/lib/string_64.S
index 507b18b1660e6e2221242b24d9b8e90055d42842..169872bc08928aa5fc566355ac0e5165985a1d00 100644 (file)
--- a/arch/powerpc/lib/string_64.S
+++ b/arch/powerpc/lib/string_64.S
@@ -17,7 +17,7 @@ PPC64_CACHES:
        .section        ".text"
 
 /**
- * __clear_user: - Zero a block of memory in user space, with less checking.
+ * __arch_clear_user: - Zero a block of memory in user space, with less checking.
  * @to:   Destination address, in user space.
  * @n:    Number of bytes to zero.
  *
@@ -58,7 +58,7 @@ err3; stb     r0,0(r3)
        mr      r3,r4
        blr
 
-_GLOBAL_TOC(__clear_user)
+_GLOBAL_TOC(__arch_clear_user)
        cmpdi   r4,32
        neg     r6,r3
        li      r0,0
@@ -181,4 +181,4 @@ err1;       dcbz    0,r3
        cmpdi   r4,32
        blt     .Lshort_clear
        b       .Lmedium_clear
-EXPORT_SYMBOL(__clear_user)
+EXPORT_SYMBOL(__arch_clear_user)

diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 9488b63dfc872d2bb7fc3350e1adf22251581f58..617c2777926fc15344937701d9d02f2bbc09c962 100644 (file)
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -289,6 +289,14 @@ void __init mem_init(void)
        BUILD_BUG_ON(MMU_PAGE_COUNT > 16);
 
 #ifdef CONFIG_SWIOTLB
+       /*
+        * Some platforms (e.g. 85xx) limit DMA-able memory way below
+        * 4G. We force memblock to bottom-up mode to ensure that the
+        * memory allocated in swiotlb_init() is DMA-able.
+        * As it's the last memblock allocation, no need to reset it
+        * back to to-down.
+        */
+       memblock_set_bottom_up(true);
        swiotlb_init(0);
 #endif
 

diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 090af2d2d3e4c512f4e04356d01bfe968869cc35..96eb8e43f39b5484db1f22192ff20740276b7a2b 100644 (file)
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -103,7 +103,7 @@ static void mmu_patch_addis(s32 *site, long simm)
        patch_instruction_site(site, instr);
 }
 
-void __init mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, pgprot_t prot)
+static void mmu_mapin_ram_chunk(unsigned long offset, unsigned long top, pgprot_t prot)
 {
        unsigned long s = offset;
        unsigned long v = PAGE_OFFSET + s;

diff --git a/arch/powerpc/platforms/pseries/cmm.c b/arch/powerpc/platforms/pseries/cmm.c
index 91571841df8a70d0ea2520dd9c3977e6f85ccc24..9dba7e88088530726862179d53ebc5f8ff986ce6 100644 (file)
--- a/arch/powerpc/platforms/pseries/cmm.c
+++ b/arch/powerpc/platforms/pseries/cmm.c
@@ -539,6 +539,16 @@ static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
        /* balloon page list reference */
        get_page(newpage);
 
+       /*
+        * When we migrate a page to a different zone, we have to fixup the
+        * count of both involved zones as we adjusted the managed page count
+        * when inflating.
+        */
+       if (page_zone(page) != page_zone(newpage)) {
+               adjust_managed_page_count(page, 1);
+               adjust_managed_page_count(newpage, -1);
+       }
+
        spin_lock_irqsave(&b_dev_info->pages_lock, flags);
        balloon_page_insert(b_dev_info, newpage);
        balloon_page_delete(page);

diff --git a/arch/powerpc/platforms/pseries/setup.c b/arch/powerpc/platforms/pseries/setup.c
index 0a40201f315ffd14dd39c9a7b71274c1d3db25a3..0c8421dd01ab5bc911e24f340dbe80407089c204 100644 (file)
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -74,6 +74,9 @@
 #include "pseries.h"
 #include "../../../../drivers/pci/pci.h"
 
+DEFINE_STATIC_KEY_FALSE(shared_processor);
+EXPORT_SYMBOL_GPL(shared_processor);
+
 int CMO_PrPSP = -1;
 int CMO_SecPSP = -1;
 unsigned long CMO_PageSize = (ASM_CONST(1) << IOMMU_PAGE_SHIFT_4K);
@@ -758,6 +761,10 @@ static void __init pSeries_setup_arch(void)
 
        if (firmware_has_feature(FW_FEATURE_LPAR)) {
                vpa_init(boot_cpuid);
+
+               if (lppaca_shared_proc(get_lppaca()))
+                       static_branch_enable(&shared_processor);
+
                ppc_md.power_save = pseries_lpar_idle;
                ppc_md.enable_pmcs = pseries_lpar_enable_pmcs;
 #ifdef CONFIG_PCI_IOV

diff --git a/drivers/misc/ocxl/context.c b/drivers/misc/ocxl/context.c
index 994563a078eb9f249b8576ddb0ab69abaa4de434..de8a66b9d76bbf93d0f1a85b1119c10b2ea2cc48 100644 (file)
--- a/drivers/misc/ocxl/context.c
+++ b/drivers/misc/ocxl/context.c
@@ -10,18 +10,17 @@ int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu,
        int pasid;
        struct ocxl_context *ctx;
 
-       *context = kzalloc(sizeof(struct ocxl_context), GFP_KERNEL);
-       if (!*context)
+       ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
                return -ENOMEM;
 
-       ctx = *context;
-
        ctx->afu = afu;
        mutex_lock(&afu->contexts_lock);
        pasid = idr_alloc(&afu->contexts_idr, ctx, afu->pasid_base,
                        afu->pasid_base + afu->pasid_max, GFP_KERNEL);
        if (pasid < 0) {
                mutex_unlock(&afu->contexts_lock);
+               kfree(ctx);
                return pasid;
        }
        afu->pasid_count++;
@@ -43,6 +42,7 @@ int ocxl_context_alloc(struct ocxl_context **context, struct ocxl_afu *afu,
         * duration of the life of the context
         */
        ocxl_afu_get(afu);
+       *context = ctx;
        return 0;
 }
 EXPORT_SYMBOL_GPL(ocxl_context_alloc);

diff --git a/drivers/misc/ocxl/file.c b/drivers/misc/ocxl/file.c
index 2870c25da166f7bc1576464f248940b8396d2699..4d1b44de14921d58e6c5f4c20e9a0dc01c20aec2 100644 (file)
--- a/drivers/misc/ocxl/file.c
+++ b/drivers/misc/ocxl/file.c
@@ -18,18 +18,15 @@ static struct class *ocxl_class;
 static struct mutex minors_idr_lock;
 static struct idr minors_idr;
 
-static struct ocxl_file_info *find_file_info(dev_t devno)
+static struct ocxl_file_info *find_and_get_file_info(dev_t devno)
 {
        struct ocxl_file_info *info;
 
-       /*
-        * We don't declare an RCU critical section here, as our AFU
-        * is protected by a reference counter on the device. By the time the
-        * info reference is removed from the idr, the ref count of
-        * the device is already at 0, so no user API will access that AFU and
-        * this function can't return it.
-        */
+       mutex_lock(&minors_idr_lock);
        info = idr_find(&minors_idr, MINOR(devno));
+       if (info)
+               get_device(&info->dev);
+       mutex_unlock(&minors_idr_lock);
        return info;
 }
 
@@ -58,14 +55,16 @@ static int afu_open(struct inode *inode, struct file *file)
 
        pr_debug("%s for device %x\n", __func__, inode->i_rdev);
 
-       info = find_file_info(inode->i_rdev);
+       info = find_and_get_file_info(inode->i_rdev);
        if (!info)
                return -ENODEV;
 
        rc = ocxl_context_alloc(&ctx, info->afu, inode->i_mapping);
-       if (rc)
+       if (rc) {
+               put_device(&info->dev);
                return rc;
-
+       }
+       put_device(&info->dev);
        file->private_data = ctx;
        return 0;
 }
@@ -487,7 +486,6 @@ static void info_release(struct device *dev)
 {
        struct ocxl_file_info *info = container_of(dev, struct ocxl_file_info, dev);
 
-       free_minor(info);
        ocxl_afu_put(info->afu);
        kfree(info);
 }
@@ -577,6 +575,7 @@ void ocxl_file_unregister_afu(struct ocxl_afu *afu)
 
        ocxl_file_make_invisible(info);
        ocxl_sysfs_unregister_afu(info);
+       free_minor(info);
        device_unregister(&info->dev);
 }