Merge tag 'loongarch-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Fix missing NULL checks for kstrdup(), workaround LS2K/LS7A GPU
  DMA hang bug, emit GNU_EH_FRAME for vDSO correctly, and fix some
  KVM-related bugs"

* tag 'loongarch-fixes-7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: KVM: Fix base address calculation in kvm_eiointc_regs_access()
  LoongArch: KVM: Handle the case that EIOINTC's coremap is empty
  LoongArch: KVM: Make kvm_get_vcpu_by_cpuid() more robust
  LoongArch: vDSO: Emit GNU_EH_FRAME correctly
  LoongArch: Workaround LS2K/LS7A GPU DMA hang bug
  LoongArch: Fix missing NULL checks for kstrdup()

arch/loongarch/include/asm/linkage.h

@@ -41,4 +41,40 @@
 	.cfi_endproc;					\
 	SYM_END(name, SYM_T_NONE)
 
+/*
+ * This is for the signal handler trampoline, which is used as the return
+ * address of the signal handlers in userspace instead of called normally.
+ * The long standing libgcc bug https://gcc.gnu.org/PR124050 requires a
+ * nop between .cfi_startproc and the actual address of the trampoline, so
+ * we cannot simply use SYM_FUNC_START.
+ *
+ * This wrapper also contains all the .cfi_* directives for recovering
+ * the content of the GPRs and the "return address" (where the rt_sigreturn
+ * syscall will jump to), assuming there is a struct rt_sigframe (where
+ * a struct sigcontext containing those information we need to recover) at
+ * $sp.  The "DWARF for the LoongArch(TM) Architecture" manual states
+ * column 0 is for $zero, but it does not make too much sense to
+ * save/restore the hardware zero register.  Repurpose this column here
+ * for the return address (here it's not the content of $ra we cannot use
+ * the default column 3).
+ */
+#define SYM_SIGFUNC_START(name)				\
+	.cfi_startproc;					\
+	.cfi_signal_frame;				\
+	.cfi_def_cfa 3, RT_SIGFRAME_SC;			\
+	.cfi_return_column 0;				\
+	.cfi_offset 0, SC_PC;				\
+							\
+	.irp num, 1,  2,  3,  4,  5,  6,  7,  8, 	\
+		  9,  10, 11, 12, 13, 14, 15, 16,	\
+		  17, 18, 19, 20, 21, 22, 23, 24,	\
+		  25, 26, 27, 28, 29, 30, 31;		\
+	.cfi_offset \num, SC_REGS + \num * SZREG;	\
+	.endr;						\
+							\
+	nop;						\
+	SYM_START(name, SYM_L_GLOBAL, SYM_A_ALIGN)
+
+#define SYM_SIGFUNC_END(name) SYM_FUNC_END(name)
+
 #endif

arch/loongarch/include/asm/sigframe.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <asm/siginfo.h>
+#include <asm/ucontext.h>
+
+struct rt_sigframe {
+	struct siginfo rs_info;
+	struct ucontext rs_uctx;
+};

arch/loongarch/kernel/asm-offsets.c

@@ -16,6 +16,7 @@
 #include <asm/ptrace.h>
 #include <asm/processor.h>
 #include <asm/ftrace.h>
+#include <asm/sigframe.h>
 #include <vdso/datapage.h>
 
 static void __used output_ptreg_defines(void)
@@ -220,6 +221,7 @@ static void __used output_sc_defines(void)
 	COMMENT("Linux sigcontext offsets.");
 	OFFSET(SC_REGS, sigcontext, sc_regs);
 	OFFSET(SC_PC, sigcontext, sc_pc);
+	OFFSET(RT_SIGFRAME_SC, rt_sigframe, rs_uctx.uc_mcontext);
 	BLANK();
 }
 

arch/loongarch/kernel/env.c

@@ -42,16 +42,15 @@ static int __init init_cpu_fullname(void)
 	int cpu, ret;
 	char *cpuname;
 	const char *model;
-	struct device_node *root;
 
 	/* Parsing cpuname from DTS model property */
-	root = of_find_node_by_path("/");
-	ret = of_property_read_string(root, "model", &model);
+	ret = of_property_read_string(of_root, "model", &model);
 	if (ret == 0) {
 		cpuname = kstrdup(model, GFP_KERNEL);
+		if (!cpuname)
+			return -ENOMEM;
 		loongson_sysconf.cpuname = strsep(&cpuname, " ");
 	}
-	of_node_put(root);
 
 	if (loongson_sysconf.cpuname && !strncmp(loongson_sysconf.cpuname, "Loongson", 8)) {
 		for (cpu = 0; cpu < NR_CPUS; cpu++)

arch/loongarch/kernel/signal.c

@@ -35,6 +35,7 @@
 #include <asm/cpu-features.h>
 #include <asm/fpu.h>
 #include <asm/lbt.h>
+#include <asm/sigframe.h>
 #include <asm/ucontext.h>
 #include <asm/vdso.h>
 
@@ -51,11 +52,6 @@
 #define lock_lbt_owner()	({ preempt_disable(); pagefault_disable(); })
 #define unlock_lbt_owner()	({ pagefault_enable(); preempt_enable(); })
 
-struct rt_sigframe {
-	struct siginfo rs_info;
-	struct ucontext rs_uctx;
-};
-
 struct _ctx_layout {
 	struct sctx_info *addr;
 	unsigned int size;

arch/loongarch/kvm/intc/eiointc.c

@@ -83,7 +83,7 @@ static inline void eiointc_update_sw_coremap(struct loongarch_eiointc *s,
 
 		if (!(s->status & BIT(EIOINTC_ENABLE_CPU_ENCODE))) {
 			cpuid = ffs(cpuid) - 1;
-			cpuid = (cpuid >= 4) ? 0 : cpuid;
+			cpuid = ((cpuid < 0) || (cpuid >= 4)) ? 0 : cpuid;
 		}
 
 		vcpu = kvm_get_vcpu_by_cpuid(s->kvm, cpuid);
@@ -472,34 +472,34 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev,
 	switch (addr) {
 	case EIOINTC_NODETYPE_START ... EIOINTC_NODETYPE_END:
 		offset = (addr - EIOINTC_NODETYPE_START) / 4;
-		p = s->nodetype + offset * 4;
+		p = (void *)s->nodetype + offset * 4;
 		break;
 	case EIOINTC_IPMAP_START ... EIOINTC_IPMAP_END:
 		offset = (addr - EIOINTC_IPMAP_START) / 4;
-		p = &s->ipmap + offset * 4;
+		p = (void *)&s->ipmap + offset * 4;
 		break;
 	case EIOINTC_ENABLE_START ... EIOINTC_ENABLE_END:
 		offset = (addr - EIOINTC_ENABLE_START) / 4;
-		p = s->enable + offset * 4;
+		p = (void *)s->enable + offset * 4;
 		break;
 	case EIOINTC_BOUNCE_START ... EIOINTC_BOUNCE_END:
 		offset = (addr - EIOINTC_BOUNCE_START) / 4;
-		p = s->bounce + offset * 4;
+		p = (void *)s->bounce + offset * 4;
 		break;
 	case EIOINTC_ISR_START ... EIOINTC_ISR_END:
 		offset = (addr - EIOINTC_ISR_START) / 4;
-		p = s->isr + offset * 4;
+		p = (void *)s->isr + offset * 4;
 		break;
 	case EIOINTC_COREISR_START ... EIOINTC_COREISR_END:
 		if (cpu >= s->num_cpu)
 			return -EINVAL;
 
 		offset = (addr - EIOINTC_COREISR_START) / 4;
-		p = s->coreisr[cpu] + offset * 4;
+		p = (void *)s->coreisr[cpu] + offset * 4;
 		break;
 	case EIOINTC_COREMAP_START ... EIOINTC_COREMAP_END:
 		offset = (addr - EIOINTC_COREMAP_START) / 4;
-		p = s->coremap + offset * 4;
+		p = (void *)s->coremap + offset * 4;
 		break;
 	default:
 		kvm_err("%s: unknown eiointc register, addr = %d\n", __func__, addr);

arch/loongarch/kvm/vcpu.c

@@ -588,6 +588,9 @@ struct kvm_vcpu *kvm_get_vcpu_by_cpuid(struct kvm *kvm, int cpuid)
 {
 	struct kvm_phyid_map *map;
 
+	if (cpuid < 0)
+		return NULL;
+
 	if (cpuid >= KVM_MAX_PHYID)
 		return NULL;
 

arch/loongarch/pci/pci.c

@@ -5,9 +5,11 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/acpi.h>
+#include <linux/delay.h>
 #include <linux/types.h>
 #include <linux/pci.h>
 #include <linux/vgaarb.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
 #include <asm/cacheflush.h>
 #include <asm/loongson.h>
 
@@ -15,6 +17,9 @@
 #define PCI_DEVICE_ID_LOONGSON_DC1      0x7a06
 #define PCI_DEVICE_ID_LOONGSON_DC2      0x7a36
 #define PCI_DEVICE_ID_LOONGSON_DC3      0x7a46
+#define PCI_DEVICE_ID_LOONGSON_GPU1     0x7a15
+#define PCI_DEVICE_ID_LOONGSON_GPU2     0x7a25
+#define PCI_DEVICE_ID_LOONGSON_GPU3     0x7a35
 
 int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 						int reg, int len, u32 *val)
@@ -99,3 +104,78 @@ static void pci_fixup_vgadev(struct pci_dev *pdev)
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC1, pci_fixup_vgadev);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC2, pci_fixup_vgadev);
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_DC3, pci_fixup_vgadev);
+
+#define CRTC_NUM_MAX		2
+#define CRTC_OUTPUT_ENABLE	0x100
+
+static void loongson_gpu_fixup_dma_hang(struct pci_dev *pdev, bool on)
+{
+	u32 i, val, count, crtc_offset, device;
+	void __iomem *crtc_reg, *base, *regbase;
+	static u32 crtc_status[CRTC_NUM_MAX] = { 0 };
+
+	base = pdev->bus->ops->map_bus(pdev->bus, pdev->devfn + 1, 0);
+	device = readw(base + PCI_DEVICE_ID);
+
+	regbase = ioremap(readq(base + PCI_BASE_ADDRESS_0) & ~0xffull, SZ_64K);
+	if (!regbase) {
+		pci_err(pdev, "Failed to ioremap()\n");
+		return;
+	}
+
+	switch (device) {
+	case PCI_DEVICE_ID_LOONGSON_DC2:
+		crtc_reg = regbase + 0x1240;
+		crtc_offset = 0x10;
+		break;
+	case PCI_DEVICE_ID_LOONGSON_DC3:
+		crtc_reg = regbase;
+		crtc_offset = 0x400;
+		break;
+	}
+
+	for (i = 0; i < CRTC_NUM_MAX; i++, crtc_reg += crtc_offset) {
+		val = readl(crtc_reg);
+
+		if (!on)
+			crtc_status[i] = val;
+
+		/* No need to fixup if the status is off at startup. */
+		if (!(crtc_status[i] & CRTC_OUTPUT_ENABLE))
+			continue;
+
+		if (on)
+			val |= CRTC_OUTPUT_ENABLE;
+		else
+			val &= ~CRTC_OUTPUT_ENABLE;
+
+		mb();
+		writel(val, crtc_reg);
+
+		for (count = 0; count < 40; count++) {
+			val = readl(crtc_reg) & CRTC_OUTPUT_ENABLE;
+			if ((on && val) || (!on && !val))
+				break;
+			udelay(1000);
+		}
+
+		pci_info(pdev, "DMA hang fixup at reg[0x%lx]: 0x%x\n",
+				(unsigned long)crtc_reg & 0xffff, readl(crtc_reg));
+	}
+
+	iounmap(regbase);
+}
+
+static void pci_fixup_dma_hang_early(struct pci_dev *pdev)
+{
+	loongson_gpu_fixup_dma_hang(pdev, false);
+}
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_GPU2, pci_fixup_dma_hang_early);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_GPU3, pci_fixup_dma_hang_early);
+
+static void pci_fixup_dma_hang_final(struct pci_dev *pdev)
+{
+	loongson_gpu_fixup_dma_hang(pdev, true);
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_GPU2, pci_fixup_dma_hang_final);
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_LOONGSON, PCI_DEVICE_ID_LOONGSON_GPU3, pci_fixup_dma_hang_final);

arch/loongarch/vdso/Makefile

@@ -26,7 +26,7 @@ cflags-vdso := $(ccflags-vdso) \
 	$(filter -W%,$(filter-out -Wa$(comma)%,$(KBUILD_CFLAGS))) \
 	-std=gnu11 -fms-extensions -O2 -g -fno-strict-aliasing -fno-common -fno-builtin \
 	-fno-stack-protector -fno-jump-tables -DDISABLE_BRANCH_PROFILING \
-	$(call cc-option, -fno-asynchronous-unwind-tables) \
+	$(call cc-option, -fasynchronous-unwind-tables) \
 	$(call cc-option, -fno-stack-protector)
 aflags-vdso := $(ccflags-vdso) \
 	-D__ASSEMBLY__ -Wa,-gdwarf-2
@@ -41,7 +41,7 @@ endif
 
 # VDSO linker flags.
 ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
-	$(filter -E%,$(KBUILD_CFLAGS)) -shared --build-id -T
+	$(filter -E%,$(KBUILD_CFLAGS)) -shared --build-id --eh-frame-hdr -T
 
 #
 # Shared build commands.

arch/loongarch/vdso/sigreturn.S

@@ -12,13 +12,13 @@
 
 #include <asm/regdef.h>
 #include <asm/asm.h>
+#include <asm/asm-offsets.h>
 
 	.section	.text
-	.cfi_sections	.debug_frame
 
-SYM_FUNC_START(__vdso_rt_sigreturn)
+SYM_SIGFUNC_START(__vdso_rt_sigreturn)
 
 	li.w	a7, __NR_rt_sigreturn
 	syscall	0
 
-SYM_FUNC_END(__vdso_rt_sigreturn)
+SYM_SIGFUNC_END(__vdso_rt_sigreturn)