Re: [PATCH v4 07/11] powerpc/pseries/iommu: Reorganize iommu_table_setparms*() with new helper

From: Alexey Kardashevskiy
Date: Mon May 10 2021 - 03:34:13 EST




On 5/1/21 02:31, Leonardo Bras wrote:
Add a new helper _iommu_table_setparms(), and use it in
iommu_table_setparms() and iommu_table_setparms_lpar() to avoid duplicated
code.

Also, setting tbl->it_ops was happening outsite iommu_table_setparms*(),
so move it to the new helper. Since we need the iommu_table_ops to be
declared before used, move iommu_table_lpar_multi_ops and
iommu_table_pseries_ops to before their respective iommu_table_setparms*().

Signed-off-by: Leonardo Bras <leobras.c@xxxxxxxxx>


This does not apply anymore as it conflicts with my 4be518d838809e2135.


---
arch/powerpc/platforms/pseries/iommu.c | 100 ++++++++++++-------------
1 file changed, 50 insertions(+), 50 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 5a70ecd579b8..89cb6e9e9f31 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -53,6 +53,11 @@ enum {
DDW_EXT_QUERY_OUT_SIZE = 2
};
+#ifdef CONFIG_IOMMU_API
+static int tce_exchange_pseries(struct iommu_table *tbl, long index, unsigned long *tce,
+ enum dma_data_direction *direction, bool realmode);
+#endif


Instead of declaring this so far from the the code which needs it, may be add

struct iommu_table_ops iommu_table_lpar_multi_ops;

right before iommu_table_setparms() (as the sctruct is what you actually want there), and you won't need to move iommu_table_pseries_ops as well.


+
static struct iommu_table *iommu_pseries_alloc_table(int node)
{
struct iommu_table *tbl;
@@ -501,6 +506,28 @@ static int tce_setrange_multi_pSeriesLP_walk(unsigned long start_pfn,
return tce_setrange_multi_pSeriesLP(start_pfn, num_pfn, arg);
}
+static inline void _iommu_table_setparms(struct iommu_table *tbl, unsigned long busno,


The underscore is confusing, may be iommu_table_do_setparms()? iommu_table_setparms_common()? Not sure. I cannot recall a single function with just one leading underscore, I suspect I was pushed back when I tried adding one ages ago :) "inline" seems excessive, the compiler will probably figure it out anyway.



+ unsigned long liobn, unsigned long win_addr,
+ unsigned long window_size, unsigned long page_shift,
+ unsigned long base, struct iommu_table_ops *table_ops)


Make "base" a pointer. Or, better, just keep setting it directly in iommu_table_setparms() rather than passing 0 around.

The same comment about "liobn" - set it in iommu_table_setparms_lpar(). The reviewer will see what field atters in what situation imho.



+{
+ tbl->it_busno = busno;
+ tbl->it_index = liobn;
+ tbl->it_offset = win_addr >> page_shift;
+ tbl->it_size = window_size >> page_shift;
+ tbl->it_page_shift = page_shift;
+ tbl->it_base = base;
+ tbl->it_blocksize = 16;
+ tbl->it_type = TCE_PCI;
+ tbl->it_ops = table_ops;
+}
+
+struct iommu_table_ops iommu_table_pseries_ops = {
+ .set = tce_build_pSeries,
+ .clear = tce_free_pSeries,
+ .get = tce_get_pseries
+};
+
static void iommu_table_setparms(struct pci_controller *phb,
struct device_node *dn,
struct iommu_table *tbl)
@@ -509,8 +536,13 @@ static void iommu_table_setparms(struct pci_controller *phb,
const unsigned long *basep;
const u32 *sizep;
- node = phb->dn;
+ /* Test if we are going over 2GB of DMA space */
+ if (phb->dma_window_base_cur + phb->dma_window_size > SZ_2G) {
+ udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
+ panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
+ }
+ node = phb->dn;
basep = of_get_property(node, "linux,tce-base", NULL);
sizep = of_get_property(node, "linux,tce-size", NULL);
if (basep == NULL || sizep == NULL) {
@@ -519,33 +551,25 @@ static void iommu_table_setparms(struct pci_controller *phb,
return;
}
- tbl->it_base = (unsigned long)__va(*basep);
+ _iommu_table_setparms(tbl, phb->bus->number, 0, phb->dma_window_base_cur,
+ phb->dma_window_size, IOMMU_PAGE_SHIFT_4K,
+ (unsigned long)__va(*basep), &iommu_table_pseries_ops);
if (!is_kdump_kernel())
memset((void *)tbl->it_base, 0, *sizep);
- tbl->it_busno = phb->bus->number;
- tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
-
- /* Units of tce entries */
- tbl->it_offset = phb->dma_window_base_cur >> tbl->it_page_shift;
-
- /* Test if we are going over 2GB of DMA space */
- if (phb->dma_window_base_cur + phb->dma_window_size > 0x80000000ul) {
- udbg_printf("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
- panic("PCI_DMA: Unexpected number of IOAs under this PHB.\n");
- }
-
phb->dma_window_base_cur += phb->dma_window_size;
-
- /* Set the tce table size - measured in entries */
- tbl->it_size = phb->dma_window_size >> tbl->it_page_shift;
-
- tbl->it_index = 0;
- tbl->it_blocksize = 16;
- tbl->it_type = TCE_PCI;
}
+struct iommu_table_ops iommu_table_lpar_multi_ops = {
+ .set = tce_buildmulti_pSeriesLP,
+#ifdef CONFIG_IOMMU_API
+ .xchg_no_kill = tce_exchange_pseries,
+#endif
+ .clear = tce_freemulti_pSeriesLP,
+ .get = tce_get_pSeriesLP
+};
+
/*
* iommu_table_setparms_lpar
*
@@ -557,28 +581,17 @@ static void iommu_table_setparms_lpar(struct pci_controller *phb,
struct iommu_table_group *table_group,
const __be32 *dma_window)
{
- unsigned long offset, size;
+ unsigned long offset, size, liobn;
- of_parse_dma_window(dn, dma_window, &tbl->it_index, &offset, &size);
+ of_parse_dma_window(dn, dma_window, &liobn, &offset, &size);
- tbl->it_busno = phb->bus->number;
- tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
- tbl->it_base = 0;
- tbl->it_blocksize = 16;
- tbl->it_type = TCE_PCI;
- tbl->it_offset = offset >> tbl->it_page_shift;
- tbl->it_size = size >> tbl->it_page_shift;
+ _iommu_table_setparms(tbl, phb->bus->number, liobn, offset, size, IOMMU_PAGE_SHIFT_4K, 0,
+ &iommu_table_lpar_multi_ops);
table_group->tce32_start = offset;
table_group->tce32_size = size;
}
-struct iommu_table_ops iommu_table_pseries_ops = {
- .set = tce_build_pSeries,
- .clear = tce_free_pSeries,
- .get = tce_get_pseries
-};
-
static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
{
struct device_node *dn;
@@ -647,7 +660,6 @@ static void pci_dma_bus_setup_pSeries(struct pci_bus *bus)
tbl = pci->table_group->tables[0];
iommu_table_setparms(pci->phb, dn, tbl);
- tbl->it_ops = &iommu_table_pseries_ops;
iommu_init_table(tbl, pci->phb->node, 0, 0);
/* Divide the rest (1.75GB) among the children */
@@ -664,7 +676,7 @@ static int tce_exchange_pseries(struct iommu_table *tbl, long index, unsigned
bool realmode)
{
long rc;
- unsigned long ioba = (unsigned long) index << tbl->it_page_shift;
+ unsigned long ioba = (unsigned long)index << tbl->it_page_shift;


Unrelated change, why, did checkpatch.pl complain?


unsigned long flags, oldtce = 0;
u64 proto_tce = iommu_direction_to_tce_perm(*direction);
unsigned long newtce = *tce | proto_tce;
@@ -686,15 +698,6 @@ static int tce_exchange_pseries(struct iommu_table *tbl, long index, unsigned
}
#endif
-struct iommu_table_ops iommu_table_lpar_multi_ops = {
- .set = tce_buildmulti_pSeriesLP,
-#ifdef CONFIG_IOMMU_API
- .xchg_no_kill = tce_exchange_pseries,
-#endif
- .clear = tce_freemulti_pSeriesLP,
- .get = tce_get_pSeriesLP
-};
-
static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
{
struct iommu_table *tbl;
@@ -729,7 +732,6 @@ static void pci_dma_bus_setup_pSeriesLP(struct pci_bus *bus)
tbl = ppci->table_group->tables[0];
iommu_table_setparms_lpar(ppci->phb, pdn, tbl,
ppci->table_group, dma_window);
- tbl->it_ops = &iommu_table_lpar_multi_ops;
iommu_init_table(tbl, ppci->phb->node, 0, 0);
iommu_register_group(ppci->table_group,
pci_domain_nr(bus), 0);
@@ -758,7 +760,6 @@ static void pci_dma_dev_setup_pSeries(struct pci_dev *dev)
PCI_DN(dn)->table_group = iommu_pseries_alloc_group(phb->node);
tbl = PCI_DN(dn)->table_group->tables[0];
iommu_table_setparms(phb, dn, tbl);
- tbl->it_ops = &iommu_table_pseries_ops;
iommu_init_table(tbl, phb->node, 0, 0);
set_iommu_table_base(&dev->dev, tbl);
return;
@@ -1436,7 +1437,6 @@ static void pci_dma_dev_setup_pSeriesLP(struct pci_dev *dev)
tbl = pci->table_group->tables[0];
iommu_table_setparms_lpar(pci->phb, pdn, tbl,
pci->table_group, dma_window);
- tbl->it_ops = &iommu_table_lpar_multi_ops;
iommu_init_table(tbl, pci->phb->node, 0, 0);
iommu_register_group(pci->table_group,
pci_domain_nr(pci->phb->bus), 0);


--
Alexey