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From:   Matthew Rosato <mjrosato@linux.ibm.com>
To:     linux-s390@vger.kernel.org
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        schnelle@linux.ibm.com, farman@linux.ibm.com, pmorel@linux.ibm.com,
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Subject: [PATCH v4 13/32] s390/pci: return status from zpci_refresh_trans
Date:   Mon, 14 Mar 2022 15:44:32 -0400
Message-Id: <20220314194451.58266-14-mjrosato@linux.ibm.com>
In-Reply-To: <20220314194451.58266-1-mjrosato@linux.ibm.com>
References: <20220314194451.58266-1-mjrosato@linux.ibm.com>
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Current callers of zpci_refresh_trans don't need to interrogate the status
returned from the underlying instructions.  However, a subsequent patch
will add a KVM caller that needs this information.  Add a new argument to
zpci_refresh_trans to pass the address of a status byte and update
existing call sites to provide it.

Reviewed-by: Pierre Morel <pmorel@linux.ibm.com>
Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
---
 arch/s390/include/asm/pci_insn.h |  2 +-
 arch/s390/pci/pci_dma.c          |  6 ++++--
 arch/s390/pci/pci_insn.c         | 10 +++++-----
 drivers/iommu/s390-iommu.c       |  4 +++-
 4 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/s390/include/asm/pci_insn.h b/arch/s390/include/asm/pci_insn.h
index 5331082fa516..32759c407b8f 100644
--- a/arch/s390/include/asm/pci_insn.h
+++ b/arch/s390/include/asm/pci_insn.h
@@ -135,7 +135,7 @@ union zpci_sic_iib {
 DECLARE_STATIC_KEY_FALSE(have_mio);
 
 u8 zpci_mod_fc(u64 req, struct zpci_fib *fib, u8 *status);
-int zpci_refresh_trans(u64 fn, u64 addr, u64 range);
+int zpci_refresh_trans(u64 fn, u64 addr, u64 range, u8 *status);
 int __zpci_load(u64 *data, u64 req, u64 offset);
 int zpci_load(u64 *data, const volatile void __iomem *addr, unsigned long len);
 int __zpci_store(u64 data, u64 req, u64 offset);
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index a81de48d5ea7..b0a2380bcad8 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -23,8 +23,9 @@ static u32 s390_iommu_aperture_factor = 1;
 
 static int zpci_refresh_global(struct zpci_dev *zdev)
 {
+	u8 status;
 	return zpci_refresh_trans((u64) zdev->fh << 32, zdev->start_dma,
-				  zdev->iommu_pages * PAGE_SIZE);
+				  zdev->iommu_pages * PAGE_SIZE, &status);
 }
 
 unsigned long *dma_alloc_cpu_table(void)
@@ -183,6 +184,7 @@ static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
 			   size_t size, int flags)
 {
 	unsigned long irqflags;
+	u8 status;
 	int ret;
 
 	/*
@@ -201,7 +203,7 @@ static int __dma_purge_tlb(struct zpci_dev *zdev, dma_addr_t dma_addr,
 	}
 
 	ret = zpci_refresh_trans((u64) zdev->fh << 32, dma_addr,
-				 PAGE_ALIGN(size));
+				 PAGE_ALIGN(size), &status);
 	if (ret == -ENOMEM && !s390_iommu_strict) {
 		/* enable the hypervisor to free some resources */
 		if (zpci_refresh_global(zdev))
diff --git a/arch/s390/pci/pci_insn.c b/arch/s390/pci/pci_insn.c
index 0509554301c7..ca6399d52767 100644
--- a/arch/s390/pci/pci_insn.c
+++ b/arch/s390/pci/pci_insn.c
@@ -77,20 +77,20 @@ static inline u8 __rpcit(u64 fn, u64 addr, u64 range, u8 *status)
 	return cc;
 }
 
-int zpci_refresh_trans(u64 fn, u64 addr, u64 range)
+int zpci_refresh_trans(u64 fn, u64 addr, u64 range, u8 *status)
 {
-	u8 cc, status;
+	u8 cc;
 
 	do {
-		cc = __rpcit(fn, addr, range, &status);
+		cc = __rpcit(fn, addr, range, status);
 		if (cc == 2)
 			udelay(ZPCI_INSN_BUSY_DELAY);
 	} while (cc == 2);
 
 	if (cc)
-		zpci_err_insn(cc, status, addr, range);
+		zpci_err_insn(cc, *status, addr, range);
 
-	if (cc == 1 && (status == 4 || status == 16))
+	if (cc == 1 && (*status == 4 || *status == 16))
 		return -ENOMEM;
 
 	return (cc) ? -EIO : 0;
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 3833e86c6e7b..73a85c599dc2 100644
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -214,6 +214,7 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
 	unsigned long irq_flags, nr_pages, i;
 	unsigned long *entry;
 	int rc = 0;
+	u8 status;
 
 	if (dma_addr < s390_domain->domain.geometry.aperture_start ||
 	    dma_addr + size > s390_domain->domain.geometry.aperture_end)
@@ -238,7 +239,8 @@ static int s390_iommu_update_trans(struct s390_domain *s390_domain,
 	spin_lock(&s390_domain->list_lock);
 	list_for_each_entry(domain_device, &s390_domain->devices, list) {
 		rc = zpci_refresh_trans((u64) domain_device->zdev->fh << 32,
-					start_dma_addr, nr_pages * PAGE_SIZE);
+					start_dma_addr, nr_pages * PAGE_SIZE,
+					&status);
 		if (rc)
 			break;
 	}
-- 
2.27.0