On 08/12/2015 08:45 PM, Gavin Shan wrote:
On Tue, Aug 11, 2015 at 12:23:42PM +1000, Alexey Kardashevskiy wrote:
On 08/11/2015 10:03 AM, Gavin Shan wrote:
On Mon, Aug 10, 2015 at 05:16:40PM +1000, Alexey Kardashevskiy wrote:
On 08/06/2015 02:11 PM, Gavin Shan wrote:
The patch is adding 6 bitmaps, three to PE and three to PHB, to track
The patch is also removing 2 arrays (io_segmap and m32_segmap), what is that
all about? Also, there was no m64_segmap, now there is, needs an explanation
may be.
Originally, the bitmaps (io_segmap and m32_segmap) are allocated dynamically.
Now, they have fixed sizes - 512 bits.
The subject "powerpc/powernv: Track IO/M32/M64 segments from PE" indicates
why m64_segmap is added.
But before this patch, you somehow managed to keep it working without a map
for M64, by the same time you needed map for IO and M32. It seems you are
making things consistent in this patch but it also feels like you do not have
to do so as M64 did not need a map before and I cannot see why it needs one
now.
The M64 map is used by [PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
where the M64 segments consumed by one particular PE will be released.
Then add it where it is really started being used. It is really hard to
review a patch which is actually spread between patches. Do not count that
reviewers will just trust you.
the consumed by one particular PE, which can be released once the PE
is destroyed during PCI unplugging time. Also, we're using fixed
quantity of bits to trace the used IO, M32 and M64 segments by PEs
in one particular PHB.
Out of curiosity - have you considered having just 3 arrays, in PHB, storing
PE numbers, and ditching PE's arrays? Does PE itself need to know what PEs it
is using? Not sure about this master/slave PEs though.
I don't follow your suggestion. Can you rephrase and explain it a bit more?
Please explains in what situations you need same map in both PHB and PE and
how you are going to use them. For example, pe::m64_segmap and
phb::m64_segmap.
I believe you need to know what segment is used by what PE and that's it and
having 2 bitmaps is overcomplicated hard to follow. Is there anything else
what I am missing?
The situation is same to all (IO, M32 and M64) segment maps. Taking m64_segmap
as an example, it will be used when creating or destroying the PE who consumes
M64 segments. phb::m64_segmap is recording the M64 segment usage in PHB's domain.
It's used to check same M64 segment won't be used for towice. pe::m64_segmap tracks
the M64 segments consumed by the PE.
You could have a single map in PHB, key would be a segment number and value
would be PE number. No need to have a map in PE. At all. No need to
initialize bitmaps, etc.
It would be easier to read patches if this one was right before
[PATCH v6 23/42] powerpc/powernv: Release PEs dynamically
I'll try to reoder the patch, but not expect too much...
Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/platforms/powernv/pci-ioda.c | 29 +++++++++++++++--------------
arch/powerpc/platforms/powernv/pci.h | 18 ++++++++++++++----
2 files changed, 29 insertions(+), 18 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index e4ac703..78b49a1 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -388,6 +388,12 @@ static int pnv_ioda_pick_m64_pe(struct pci_bus *bus, bool all)
list_add_tail(&pe->list, &master_pe->slaves);
}
+ /* M64 segments consumed by slave PEs are tracked
+ * by master PE
+ */
+ set_bit(pe->pe_number, master_pe->m64_segmap);
+ set_bit(pe->pe_number, phb->ioda.m64_segmap);
+
/* P7IOC supports M64DT, which helps mapping M64 segment
* to one particular PE#. However, PHB3 has fixed mapping
* between M64 segment and PE#. In order to have same logic
@@ -2871,9 +2877,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
while (index < phb->ioda.total_pe &&
region.start <= region.end) {
- phb->ioda.io_segmap[index] = pe->pe_number;
+ set_bit(index, pe->io_segmap);
+ set_bit(index, phb->ioda.io_segmap);
rc = opal_pci_map_pe_mmio_window(phb->opal_id,
- pe->pe_number, OPAL_IO_WINDOW_TYPE, 0, index);
+ pe->pe_number, OPAL_IO_WINDOW_TYPE,
+ 0, index);
Unrelated change.
True, will drop. However, checkpatch.pl will complain wtih:
exceeding 80 characters.
It will not as you are not changing these lines, it only complains on changes.
if (rc != OPAL_SUCCESS) {
pr_err("%s: OPAL error %d when mapping IO "
"segment #%d to PE#%d\n",
@@ -2896,9 +2904,11 @@ static void pnv_ioda_setup_pe_seg(struct pci_controller *hose,
while (index < phb->ioda.total_pe &&
region.start <= region.end) {
- phb->ioda.m32_segmap[index] = pe->pe_number;
+ set_bit(index, pe->m32_segmap);
+ set_bit(index, phb->ioda.m32_segmap);
rc = opal_pci_map_pe_mmio_window(phb->opal_id,
- pe->pe_number, OPAL_M32_WINDOW_TYPE, 0, index);
+ pe->pe_number, OPAL_M32_WINDOW_TYPE,
+ 0, index);
Unrelated change.
same as above.
if (rc != OPAL_SUCCESS) {
pr_err("%s: OPAL error %d when mapping M32 "
"segment#%d to PE#%d",
@@ -3090,7 +3100,7 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
{
struct pci_controller *hose;
struct pnv_phb *phb;
- unsigned long size, m32map_off, pemap_off, iomap_off = 0;
+ unsigned long size, pemap_off;
const __be64 *prop64;
const __be32 *prop32;
int len;
@@ -3175,19 +3185,10 @@ static void __init pnv_pci_init_ioda_phb(struct device_node *np,
/* Allocate aux data & arrays. We don't have IO ports on PHB3 */
This comment came with if(IODA1) below, since you are removing the condition
below, makes sense to remove the comment as well or move it where people will
look for it (arch/powerpc/platforms/powernv/pci.h ?)
Yes, will do.
size = _ALIGN_UP(phb->ioda.total_pe / 8, sizeof(unsigned long));
- m32map_off = size;
- size += phb->ioda.total_pe * sizeof(phb->ioda.m32_segmap[0]);
- if (phb->type == PNV_PHB_IODA1) {
- iomap_off = size;
- size += phb->ioda.total_pe * sizeof(phb->ioda.io_segmap[0]);
- }
pemap_off = size;
size += phb->ioda.total_pe * sizeof(struct pnv_ioda_pe);
aux = memblock_virt_alloc(size, 0);
After adding static arrays to PE and PHB, do you still need this "aux"?
"aux" is still needed to tell the boundary of pe_alloc_bitmap and pe_array.
phb->ioda.pe_alloc = aux;
- phb->ioda.m32_segmap = aux + m32map_off;
- if (phb->type == PNV_PHB_IODA1)
- phb->ioda.io_segmap = aux + iomap_off;
phb->ioda.pe_array = aux + pemap_off;
set_bit(phb->ioda.reserved_pe, phb->ioda.pe_alloc);
diff --git a/arch/powerpc/platforms/powernv/pci.h b/arch/powerpc/platforms/powernv/pci.h
index 62239b1..08a4e57 100644
--- a/arch/powerpc/platforms/powernv/pci.h
+++ b/arch/powerpc/platforms/powernv/pci.h
@@ -49,6 +49,15 @@ struct pnv_ioda_pe {
/* PE number */
unsigned int pe_number;
+ /* IO/M32/M64 segments consumed by the PE. Each PE can
+ * have one M64 segment at most, but M64 segments consumed
+ * by slave PEs will be contributed to the master PE. One
+ * PE can own multiple IO and M32 segments.
A PE can have multiple IO and M32 segments but just one M64 segment? Is this
correct for IODA1 or IODA2 or both? Is this a limitation of this
implementation or it comes from P7IOC/PHB3 hardware?
It's correct for IO and M32. However, on IODA1 or IODA2, one PE can have
multiple M64 segments as well.
But the comment says "Each PE can have one M64 segment at most". Which
statement is correct?
The comment is correct regarding PHB's 15th M64 BAR: Each PE can have one
M64 segment at post. It's from hardware limitation. However, once one PE
consumes multiple M64 segments. all those M64 segments will be tracked in
"master" PE and it's determined by software implementation.
+ */
+ unsigned long io_segmap[8];
+ unsigned long m32_segmap[8];
+ unsigned long m64_segmap[8];
Magic constant "8", 64bit*8 = 512 PEs - where did this come from?
Anyway,
#define PNV_IODA_MAX_PE_NUM 512
unsigned long io_segmap[PNV_IODA_MAX_PE_NUM/BITS_PER_LONG]
I prefer "8", not macro for 3 reasons:
- The macro won't be used in the code.
You will use it 6 times in the header, if you give it a good name, people
won't have to guess if the meaning of all these "8"s is the same and you
won't have to comment every use of it in this header file (now you have).
Also, using BITS_PER_LONG tells the reader that this is a bitmask for sure.
- The total segment number of specific resource is variable
on IODA1 and IODA2. I just choosed the max value with margin.
- PNV_IODA_MAX_PE_NUM, indicating max PE number, isn't 512 on
IODA1 or IODA2.
Give it a better name.
Ok. It it has to be a macro, then it's as below:
#define PNV_IODA_MAX_SEG_NUM 512
Thanks mate :)
+
/* "Weight" assigned to the PE for the sake of DMA resource
* allocations
*/
@@ -145,15 +154,16 @@ struct pnv_phb {
unsigned int io_segsize;
unsigned int io_pci_base;
+ /* IO, M32, M64 segment maps */
+ unsigned long io_segmap[8];
+ unsigned long m32_segmap[8];
+ unsigned long m64_segmap[8];
+
/* PE allocation */
struct mutex pe_alloc_mutex;
unsigned long *pe_alloc;
struct pnv_ioda_pe *pe_array;
- /* M32 & IO segment maps */
- unsigned int *m32_segmap;
- unsigned int *io_segmap;
-
/* IRQ chip */
int irq_chip_init;
struct irq_chip irq_chip;
Thanks,
Gavin
--
Alexey
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