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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH 4/5] xen/swiotlb: Use the swiotlb_late_init_with_tbl to init Xen-SWIOTLB late when PV PCI is used.
On Fri, Aug 17, 2012 at 06:25:56PM +0100, Stefano Stabellini wrote:
> On Thu, 16 Aug 2012, Konrad Rzeszutek Wilk wrote:
> > With this patch we provide the functionality to initialize the
> > Xen-SWIOTLB late in the bootup cycle - specifically for
> > Xen PCI-frontend. We still will work if the user had
> > supplied 'iommu=soft' on the Linux command line.
> >
> > CC: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
> > [v1: Fix smatch warnings]
> > Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> > ---
> > arch/x86/include/asm/xen/swiotlb-xen.h | 2 +
> > arch/x86/xen/pci-swiotlb-xen.c | 17 +++++++++-
> > drivers/xen/swiotlb-xen.c | 54
> > ++++++++++++++++++++++++++-----
> > include/xen/swiotlb-xen.h | 1 +
> > 4 files changed, 64 insertions(+), 10 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h
> > b/arch/x86/include/asm/xen/swiotlb-xen.h
> > index 1be1ab7..ee52fca 100644
> > --- a/arch/x86/include/asm/xen/swiotlb-xen.h
> > +++ b/arch/x86/include/asm/xen/swiotlb-xen.h
> > @@ -5,10 +5,12 @@
> > extern int xen_swiotlb;
> > extern int __init pci_xen_swiotlb_detect(void);
> > extern void __init pci_xen_swiotlb_init(void);
> > +extern int pci_xen_swiotlb_init_late(void);
> > #else
> > #define xen_swiotlb (0)
> > static inline int __init pci_xen_swiotlb_detect(void) { return 0; }
> > static inline void __init pci_xen_swiotlb_init(void) { }
> > +static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; }
> > #endif
> >
> > #endif /* _ASM_X86_SWIOTLB_XEN_H */
> > diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
> > index 1c17227..031d8bc 100644
> > --- a/arch/x86/xen/pci-swiotlb-xen.c
> > +++ b/arch/x86/xen/pci-swiotlb-xen.c
> > @@ -12,7 +12,7 @@
> > #include <asm/iommu.h>
> > #include <asm/dma.h>
> > #endif
> > -
> > +#include <linux/export.h>
> > int xen_swiotlb __read_mostly;
> >
> > static struct dma_map_ops xen_swiotlb_dma_ops = {
> > @@ -76,6 +76,21 @@ void __init pci_xen_swiotlb_init(void)
> > pci_request_acs();
> > }
> > }
> > +
> > +int pci_xen_swiotlb_init_late(void)
> > +{
> > + int rc = xen_swiotlb_late_init(1);
> > + if (rc)
> > + return rc;
> > +
> > + dma_ops = &xen_swiotlb_dma_ops;
> > + /* Make sure ACS will be enabled */
> > + pci_request_acs();
> > +
> > + return 0;
> > +}
> > +EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
>
> shouldn't we be checking whether the xen_swiotlb has already been
> initialized?
Yes.
>
>
> > IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
> > 0,
> > pci_xen_swiotlb_init,
> > diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> > index 1afb4fb..1942a3e 100644
> > --- a/drivers/xen/swiotlb-xen.c
> > +++ b/drivers/xen/swiotlb-xen.c
> > @@ -145,13 +145,14 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned
> > long nslabs)
> > return 0;
> > }
> >
> > -void __init xen_swiotlb_init(int verbose)
> > +static int __ref __xen_swiotlb_init(int verbose, bool early)
> > {
> > unsigned long bytes;
> > int rc = -ENOMEM;
> > unsigned long nr_tbl;
> > char *m = NULL;
> > unsigned int repeat = 3;
> > + unsigned long order;
> >
> > nr_tbl = swiotlb_nr_tbl();
> > if (nr_tbl)
> > @@ -161,12 +162,31 @@ void __init xen_swiotlb_init(int verbose)
> > xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
> > }
> > retry:
> > + order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
> > bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
> >
> > /*
> > * Get IO TLB memory from any location.
> > */
> > - xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
> > + if (early)
> > + xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
> > + else {
> > +#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
> > +#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
>
>
> > + while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
> > + xen_io_tlb_start = (void
> > *)__get_free_pages(__GFP_NOWARN, order);
> > + if (xen_io_tlb_start)
> > + break;
> > + order--;
> > + }
> > + if (order != get_order(bytes)) {
> > + pr_warn("Warning: only able to allocate %ld MB "
> > + "for software IO TLB\n", (PAGE_SIZE << order)
> > >> 20);
> > + xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
> > + bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
> > + }
> > + }
> > if (!xen_io_tlb_start) {
> > m = "Cannot allocate Xen-SWIOTLB buffer!\n";
> > goto error;
> > @@ -179,17 +199,22 @@ retry:
> > bytes,
> > xen_io_tlb_nslabs);
> > if (rc) {
> > - free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
> > + if (early)
> > + free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
> > m = "Failed to get contiguous memory for DMA from Xen!\n"\
> > "You either: don't have the permissions, do not have"\
> > " enough free memory under 4GB, or the hypervisor memory"\
> > - "is too fragmented!";
> > + " is too fragmented!";
> > goto error;
> > }
> > start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
> > - swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
> >
> > - return;
> > + rc = 0;
> > + if (early)
> > + swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
> > verbose);
> > + else
> > + rc = swiotlb_late_init_with_tbl(xen_io_tlb_start,
> > xen_io_tlb_nslabs);
> > + return rc;
> > error:
> > if (repeat--) {
> > xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
> > @@ -198,10 +223,21 @@ error:
> > (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
> > goto retry;
> > }
> > - xen_raw_printk("%s (rc:%d)", m, rc);
> > - panic("%s (rc:%d)", m, rc);
> > + pr_err("%s (rc:%d)", m, rc);
> > + if (early)
> > + panic("%s (rc:%d)", m, rc);
> > + else
> > + free_pages((unsigned long)xen_io_tlb_start, order);
> > + return rc;
> > +}
>
> All these "if" make the code a harder to read. Would it be possible at
> least to unify the error paths and just check on after_bootmem whether
> we need to call free_pages or free_bootmem?
> In fact using after_bootmem you might get away without an early
> parameter.
Sure thing. Here is a stab at it.
>From 573db1dbc6adf3f5efc8c699714329caffa43daf Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Thu, 23 Aug 2012 13:55:26 -0400
Subject: [PATCH 1/3] xen/swiotlb: Move the nr_tbl determination in its own
function.
Moving the function out of the way to prepare for the late
SWIOTLB init.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
drivers/xen/swiotlb-xen.c | 21 +++++++++++----------
1 files changed, 11 insertions(+), 10 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 1afb4fb..a2aad6e 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -144,25 +144,26 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long
nslabs)
} while (i < nslabs);
return 0;
}
+static unsigned long xen_set_nslabs(unsigned long nr_tbl)
+{
+ if (!nr_tbl) {
+ xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
+ xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
+ } else
+ xen_io_tlb_nslabs = nr_tbl;
+ return xen_io_tlb_nslabs << IO_TLB_SHIFT;
+}
void __init xen_swiotlb_init(int verbose)
{
unsigned long bytes;
int rc = -ENOMEM;
- unsigned long nr_tbl;
char *m = NULL;
unsigned int repeat = 3;
- nr_tbl = swiotlb_nr_tbl();
- if (nr_tbl)
- xen_io_tlb_nslabs = nr_tbl;
- else {
- xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
- xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
- }
+ xen_io_tlb_nslabs = swiotlb_nr_tbl();
retry:
- bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
-
+ bytes = xen_set_nslabs(xen_io_tlb_nslabs);
/*
* Get IO TLB memory from any location.
*/
--
1.7.7.6
>From 1bee8a244d1fed47e307c5951a98f7922cab7993 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Thu, 23 Aug 2012 14:03:55 -0400
Subject: [PATCH 2/3] xen/swiotlb: Move the error strings to its own function.
That way we can more easily reuse those errors when using the
late SWIOTLB init.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
drivers/xen/swiotlb-xen.c | 35 +++++++++++++++++++++++++++--------
1 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index a2aad6e..701b103 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -154,11 +154,33 @@ static unsigned long xen_set_nslabs(unsigned long nr_tbl)
return xen_io_tlb_nslabs << IO_TLB_SHIFT;
}
+
+enum xen_swiotlb_err {
+ XEN_SWIOTLB_UNKNOWN = 0,
+ XEN_SWIOTLB_ENOMEM,
+ XEN_SWIOTLB_EFIXUP
+};
+
+static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
+{
+ switch (err) {
+ case XEN_SWIOTLB_ENOMEM:
+ return "Cannot allocate Xen-SWIOTLB buffer\n";
+ case XEN_SWIOTLB_EFIXUP:
+ return "Failed to get contiguous memory for DMA from Xen!\n"\
+ "You either: don't have the permissions, do not have"\
+ " enough free memory under 4GB, or the hypervisor memory"\
+ " is too fragmented!";
+ default:
+ break;
+ }
+ return "";
+}
void __init xen_swiotlb_init(int verbose)
{
unsigned long bytes;
int rc = -ENOMEM;
- char *m = NULL;
+ enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
unsigned int repeat = 3;
xen_io_tlb_nslabs = swiotlb_nr_tbl();
@@ -169,7 +191,7 @@ retry:
*/
xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
if (!xen_io_tlb_start) {
- m = "Cannot allocate Xen-SWIOTLB buffer!\n";
+ m_ret = XEN_SWIOTLB_ENOMEM;
goto error;
}
xen_io_tlb_end = xen_io_tlb_start + bytes;
@@ -181,10 +203,7 @@ retry:
xen_io_tlb_nslabs);
if (rc) {
free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
- m = "Failed to get contiguous memory for DMA from Xen!\n"\
- "You either: don't have the permissions, do not have"\
- " enough free memory under 4GB, or the hypervisor memory"\
- "is too fragmented!";
+ m_ret = XEN_SWIOTLB_EFIXUP;
goto error;
}
start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
@@ -199,8 +218,8 @@ error:
(xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
goto retry;
}
- xen_raw_printk("%s (rc:%d)", m, rc);
- panic("%s (rc:%d)", m, rc);
+ xen_raw_printk("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+ panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
}
void *
--
1.7.7.6
and the last one:
>From d815253cbf26a5273e77f829cc414e0808500263 Mon Sep 17 00:00:00 2001
From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Date: Thu, 23 Aug 2012 14:36:15 -0400
Subject: [PATCH 3/3] xen/swiotlb: Use the swiotlb_late_init_with_tbl to init
Xen-SWIOTLB late when PV PCI is used.
With this patch we provide the functionality to initialize the
Xen-SWIOTLB late in the bootup cycle - specifically for
Xen PCI-frontend. We still will work if the user had
supplied 'iommu=soft' on the Linux command line.
CC: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx>
[v1: Fix smatch warnings]
[v2: Added check for xen_swiotlb]
[v3: Rebased with new xen-swiotlb changes]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
---
arch/x86/include/asm/xen/swiotlb-xen.h | 2 +
arch/x86/xen/pci-swiotlb-xen.c | 22 ++++++++++++++-
drivers/xen/swiotlb-xen.c | 48 +++++++++++++++++++++++++------
include/xen/swiotlb-xen.h | 2 +-
4 files changed, 62 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/xen/swiotlb-xen.h
b/arch/x86/include/asm/xen/swiotlb-xen.h
index 1be1ab7..ee52fca 100644
--- a/arch/x86/include/asm/xen/swiotlb-xen.h
+++ b/arch/x86/include/asm/xen/swiotlb-xen.h
@@ -5,10 +5,12 @@
extern int xen_swiotlb;
extern int __init pci_xen_swiotlb_detect(void);
extern void __init pci_xen_swiotlb_init(void);
+extern int pci_xen_swiotlb_init_late(void);
#else
#define xen_swiotlb (0)
static inline int __init pci_xen_swiotlb_detect(void) { return 0; }
static inline void __init pci_xen_swiotlb_init(void) { }
+static inline int pci_xen_swiotlb_init_late(void) { return -ENXIO; }
#endif
#endif /* _ASM_X86_SWIOTLB_XEN_H */
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index 1c17227..406f9c4 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -12,7 +12,7 @@
#include <asm/iommu.h>
#include <asm/dma.h>
#endif
-
+#include <linux/export.h>
int xen_swiotlb __read_mostly;
static struct dma_map_ops xen_swiotlb_dma_ops = {
@@ -76,6 +76,26 @@ void __init pci_xen_swiotlb_init(void)
pci_request_acs();
}
}
+
+int pci_xen_swiotlb_init_late(void)
+{
+ int rc;
+
+ if (xen_swiotlb)
+ return 0;
+
+ rc = xen_swiotlb_init(1);
+ if (rc)
+ return rc;
+
+ dma_ops = &xen_swiotlb_dma_ops;
+ /* Make sure ACS will be enabled */
+ pci_request_acs();
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
+
IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
0,
pci_xen_swiotlb_init,
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 701b103..f0825cb 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -176,9 +176,9 @@ static const char *xen_swiotlb_error(enum xen_swiotlb_err
err)
}
return "";
}
-void __init xen_swiotlb_init(int verbose)
+int __ref xen_swiotlb_init(int verbose)
{
- unsigned long bytes;
+ unsigned long bytes, order;
int rc = -ENOMEM;
enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
unsigned int repeat = 3;
@@ -186,10 +186,28 @@ void __init xen_swiotlb_init(int verbose)
xen_io_tlb_nslabs = swiotlb_nr_tbl();
retry:
bytes = xen_set_nslabs(xen_io_tlb_nslabs);
+ order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
/*
* Get IO TLB memory from any location.
*/
- xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
+ if (!after_bootmem)
+ xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
+ else {
+#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
+#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
+ while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
+ xen_io_tlb_start = (void
*)__get_free_pages(__GFP_NOWARN, order);
+ if (xen_io_tlb_start)
+ break;
+ order--;
+ }
+ if (order != get_order(bytes)) {
+ pr_warn("Warning: only able to allocate %ld MB "
+ "for software IO TLB\n", (PAGE_SIZE << order)
>> 20);
+ xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
+ bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
+ }
+ }
if (!xen_io_tlb_start) {
m_ret = XEN_SWIOTLB_ENOMEM;
goto error;
@@ -202,14 +220,21 @@ retry:
bytes,
xen_io_tlb_nslabs);
if (rc) {
- free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
+ if (!after_bootmem)
+ free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
+ else {
+ free_pages((unsigned long)xen_io_tlb_start, order);
+ xen_io_tlb_start = NULL;
+ }
m_ret = XEN_SWIOTLB_EFIXUP;
goto error;
}
start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
- swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs, verbose);
-
- return;
+ if (!after_bootmem)
+ swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
verbose);
+ else
+ rc = swiotlb_late_init_with_tbl(xen_io_tlb_start,
xen_io_tlb_nslabs);
+ return rc;
error:
if (repeat--) {
xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
@@ -218,10 +243,13 @@ error:
(xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
goto retry;
}
- xen_raw_printk("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
- panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+ pr_err("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+ if (!after_bootmem)
+ panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
+ else
+ free_pages((unsigned long)xen_io_tlb_start, order);
+ return rc;
}
-
void *
xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index 4f4d449..f26f9f3 100644
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -3,7 +3,7 @@
#include <linux/swiotlb.h>
-extern void xen_swiotlb_init(int verbose);
+extern int xen_swiotlb_init(int verbose);
extern void
*xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
--
1.7.7.6
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