Re: [PATCH v1 6/8] crypto: ccp - Add vdata for platform device

From: Tom Lendacky
Date: Mon Feb 06 2023 - 14:14:09 EST


On 2/1/23 13:24, Jeremi Piotrowski wrote:
On Tue, Jan 31, 2023 at 02:36:01PM -0600, Tom Lendacky wrote:
On 1/23/23 09:22, Jeremi Piotrowski wrote:
When matching the "psp" platform_device, determine the register offsets
at runtime from the ASP ACPI table. Pass the parsed register offsets
>from the ASPT through platdata.

To support this scenario, mark the members of 'struct sev_vdata' and
'struct psp_vdata' non-const so that the probe function can write the
values. This does not affect the other users of sev_vdata/psp_vdata as
they define the whole struct const and the pointer in struct
sp_dev_vdata stays const too.

Signed-off-by: Jeremi Piotrowski <jpiotrowski@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/kernel/psp.c | 3 ++
drivers/crypto/ccp/sp-dev.h | 12 +++----
drivers/crypto/ccp/sp-platform.c | 57 +++++++++++++++++++++++++++++++-
3 files changed, 65 insertions(+), 7 deletions(-)

diff --git a/arch/x86/kernel/psp.c b/arch/x86/kernel/psp.c
index 24181d132bae..68511a14df63 100644
--- a/arch/x86/kernel/psp.c
+++ b/arch/x86/kernel/psp.c
@@ -199,6 +199,9 @@ static int __init psp_init_platform_device(void)
if (err)
return err;
err = platform_device_add_resources(&psp_device, res, 2);
+ if (err)
+ return err;
+ err = platform_device_add_data(&psp_device, &pdata, sizeof(pdata));
if (err)
return err;
diff --git a/drivers/crypto/ccp/sp-dev.h b/drivers/crypto/ccp/sp-dev.h
index 20377e67f65d..aaa651364425 100644
--- a/drivers/crypto/ccp/sp-dev.h
+++ b/drivers/crypto/ccp/sp-dev.h
@@ -40,9 +40,9 @@ struct ccp_vdata {
};
struct sev_vdata {
- const unsigned int cmdresp_reg;
- const unsigned int cmdbuff_addr_lo_reg;
- const unsigned int cmdbuff_addr_hi_reg;
+ unsigned int cmdresp_reg;
+ unsigned int cmdbuff_addr_lo_reg;
+ unsigned int cmdbuff_addr_hi_reg;
};
struct tee_vdata {
@@ -56,9 +56,9 @@ struct tee_vdata {
struct psp_vdata {
const struct sev_vdata *sev;
const struct tee_vdata *tee;
- const unsigned int feature_reg;
- const unsigned int inten_reg;
- const unsigned int intsts_reg;
+ unsigned int feature_reg;
+ unsigned int inten_reg;
+ unsigned int intsts_reg;
};
/* Structure to hold SP device data */
diff --git a/drivers/crypto/ccp/sp-platform.c b/drivers/crypto/ccp/sp-platform.c
index ea8926e87981..281dbf6b150c 100644
--- a/drivers/crypto/ccp/sp-platform.c
+++ b/drivers/crypto/ccp/sp-platform.c
@@ -22,6 +22,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/acpi.h>
+#include <linux/platform_data/psp.h>
#include "ccp-dev.h"
@@ -30,11 +31,31 @@ struct sp_platform {
unsigned int irq_count;
};
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
+static struct sev_vdata sev_platform = {
+ .cmdresp_reg = -1,
+ .cmdbuff_addr_lo_reg = -1,
+ .cmdbuff_addr_hi_reg = -1,
+};
+static struct psp_vdata psp_platform = {
+ .sev = &sev_platform,
+ .feature_reg = -1,
+ .inten_reg = -1,
+ .intsts_reg = -1,
+};
+#endif
+
static const struct sp_dev_vdata dev_vdata[] = {
{
.bar = 0,
#ifdef CONFIG_CRYPTO_DEV_SP_CCP
.ccp_vdata = &ccpv3_platform,
+#endif
+ },
+ {
+ .bar = 0,
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP
+ .psp_vdata = &psp_platform,
#endif
},
};
@@ -57,7 +78,7 @@ MODULE_DEVICE_TABLE(of, sp_of_match);
#endif
static const struct platform_device_id sp_plat_match[] = {
- { "psp" },
+ { "psp", (kernel_ulong_t)&dev_vdata[1] },
{ },
};
MODULE_DEVICE_TABLE(platform, sp_plat_match);
@@ -86,6 +107,38 @@ static struct sp_dev_vdata *sp_get_acpi_version(struct platform_device *pdev)
return NULL;
}
+static struct sp_dev_vdata *sp_get_plat_version(struct platform_device *pdev)
+{
+ struct sp_dev_vdata *drvdata = (struct sp_dev_vdata *)pdev->id_entry->driver_data;

s/drvdata/vdata/


ok

+ struct device *dev = &pdev->dev;
+

Should check for null vdata and return NULL, e.g.:

if (!vdata)
return NULL;


ok

+ if (drvdata == &dev_vdata[1]) {

This should be a check for vdata->psp_vdata being non-NULL and
vdata->psp_vdata->sev being non-NULL, e.g.:

if (vdata->psp_vdata && vdata->psp_vdata->sev) {

+ struct psp_platform_data *pdata = dev_get_platdata(dev);
+
+ if (!pdata) {
+ dev_err(dev, "missing platform data\n");
+ return NULL;
+ }
+#ifdef CONFIG_CRYPTO_DEV_SP_PSP

No need for this with the above checks

+ psp_platform.feature_reg = pdata->feature_reg;

These should then be:

vdata->psp_vdata->inten_reg = pdata->feature_reg;
...

I see where you're going with this and the above suggestions, but
the psp_vdata pointer is const in struct sp_dev_vdata and so is the
sev pointer in struct psp_vdata. I find these consts to be important
and doing it this way would require casting away the const. I don't
think that's worth doing.

Ok, then maybe it would be better to kmalloc a vdata structure that you fill in and then assign that to dev_vdata field for use. That could eliminate the removal of the "const" notations in one of the previous patches. I just don't think you should be changing the underlying module data that isn't expected to be changed.



+ psp_platform.inten_reg = pdata->irq_en_reg;
+ psp_platform.intsts_reg = pdata->irq_st_reg;
+ sev_platform.cmdresp_reg = pdata->sev_cmd_resp_reg;

And this should be:

vdata->psp_vdata->sev->cmdbuff_addr_lo = ...

+ sev_platform.cmdbuff_addr_lo_reg = pdata->sev_cmd_buf_lo_reg;
+ sev_platform.cmdbuff_addr_hi_reg = pdata->sev_cmd_buf_hi_reg;
+ dev_dbg(dev, "GLBL feature:\t%x\n", pdata->feature_reg);

s/GLBL feature/PSP feature register/

+ dev_dbg(dev, "GLBL irq en:\t%x\n", pdata->irq_en_reg);

s/GLBL irq en/PSP IRQ enable register/

+ dev_dbg(dev, "GLBL irq st:\t%x\n", pdata->irq_st_reg);

s/GLBL irq st/PSP IRQ status register/

+ dev_dbg(dev, "SEV cmdresp:\t%x\n", pdata->sev_cmd_resp_reg);

s/SEV cmdresp/SEV cmdresp register/

+ dev_dbg(dev, "SEV cmdbuf lo:\t%x\n", pdata->sev_cmd_buf_lo_reg);

s/SEV cmdbuf lo/SEV cmdbuf lo register/

+ dev_dbg(dev, "SEV cmdbuf hi:\t%x\n", pdata->sev_cmd_buf_hi_reg);

s/SEV cmdbuf hi/SEV cmdbuf hi register/

+ dev_dbg(dev, "SEV mbox:\t%x\n", pdata->mbox_irq_id);

s/SEV mbox/SEV cmdresp IRQ/


ok to all the above rewordings


+ dev_dbg(dev, "ACPI cmdresp:\t%x\n", pdata->acpi_cmd_resp_reg);

Duplicate entry

I don't see it. This is the ACPI register (the one used for the IRQ config).
Here's how these prints look when the module is loaded with dyndbg=+p:

My bad, misread it as SEV cmdresp.

Thanks,
Tom


ccp psp: GLBL feature: 0
ccp psp: GLBL irq en: 4
ccp psp: GLBL irq st: 8
ccp psp: SEV cmdresp: 10
ccp psp: SEV cmdbuf lo: 14
ccp psp: SEV cmdbuf hi: 18
ccp psp: SEV mbox: 1
ccp psp: ACPI cmdresp: 20


+#endif
+ }
+ return drvdata;
+}
+
static int sp_get_irqs(struct sp_device *sp)
{
struct sp_platform *sp_platform = sp->dev_specific;
@@ -137,6 +190,8 @@ static int sp_platform_probe(struct platform_device *pdev)
sp->dev_specific = sp_platform;
sp->dev_vdata = pdev->dev.of_node ? sp_get_of_version(pdev)
: sp_get_acpi_version(pdev);
+ if (!sp->dev_vdata && pdev->id_entry)

Move this pdev->id_entry check into sp_get_plat_version(), returning
NULL if not set.


ok

Thanks,
Tom

+ sp->dev_vdata = sp_get_plat_version(pdev);
if (!sp->dev_vdata) {
ret = -ENODEV;
dev_err(dev, "missing driver data\n");